/mod/forum/lib.php

<?php  // $Id$



require_once($CFG->libdir.'/filelib.php');



/// CONSTANTS ///////////////////////////////////////////////////////////



define('FORUM_MODE_FLATOLDEST', 1);

define('FORUM_MODE_FLATNEWEST', -1);

define('FORUM_MODE_THREADED', 2);

define('FORUM_MODE_NESTED', 3);



define('FORUM_FORCESUBSCRIBE', 1);

define('FORUM_INITIALSUBSCRIBE', 2);

define('FORUM_DISALLOWSUBSCRIBE',3);



define('FORUM_TRACKING_OFF', 0);

define('FORUM_TRACKING_OPTIONAL', 1);

define('FORUM_TRACKING_ON', 2);



define('FORUM_UNSET_POST_RATING', -999);



define ('FORUM_AGGREGATE_NONE', 0); //no ratings

define ('FORUM_AGGREGATE_AVG', 1);

define ('FORUM_AGGREGATE_COUNT', 2);

define ('FORUM_AGGREGATE_MAX', 3);

define ('FORUM_AGGREGATE_MIN', 4);

define ('FORUM_AGGREGATE_SUM', 5);



/// STANDARD FUNCTIONS ///////////////////////////////////////////////////////////



/**

 * Given an object containing all the necessary data,

 * (defined by the form in mod.html) this function

 * will create a new instance and return the id number

 * of the new instance.

 * @param object $forum add forum instance (with magic quotes)

 * @return int intance id

 */

function forum_add_instance($forum) {

    global $CFG;



    $forum->timemodified = time();



    if (empty($forum->assessed)) {

        $forum->assessed = 0;

    }



    if (empty($forum->ratingtime) or empty($forum->assessed)) {

        $forum->assesstimestart  = 0;

        $forum->assesstimefinish = 0;

    }



    if (!$forum->id = insert_record('forum', $forum)) {

        return false;

    }



    if ($forum->type == 'single') {  // Create related discussion.

        $discussion = new object();

        $discussion->course   = $forum->course;

        $discussion->forum    = $forum->id;

        $discussion->name     = $forum->name;

        $discussion->intro    = $forum->intro;

        $discussion->assessed = $forum->assessed;

        $discussion->format   = $forum->type;

        $discussion->mailnow  = false;

        $discussion->groupid  = -1;



        if (! forum_add_discussion($discussion, $discussion->intro)) {

            error('Could not add the discussion for this forum');

        }

    }



    if ($forum->forcesubscribe == FORUM_INITIALSUBSCRIBE) {

    /// all users should be subscribed initially

    /// Note: forum_get_potential_subscribers should take the forum context,

    /// but that does not exist yet, becuase the forum is only half build at this

    /// stage. However, because the forum is brand new, we know that there are

    /// no role assignments or overrides in the forum context, so using the

    /// course context gives the same list of users.

        $users = forum_get_potential_subscribers(get_context_instance(CONTEXT_COURSE, $forum->course), 0, 'u.id, u.email', '');

        foreach ($users as $user) {

            forum_subscribe($user->id, $forum->id);

        }

    }



    $forum = stripslashes_recursive($forum);

    forum_grade_item_update($forum);



    return $forum->id;

}





/**

 * Given an object containing all the necessary data,

 * (defined by the form in mod.html) this function

 * will update an existing instance with new data.

 * @param object $forum forum instance (with magic quotes)

 * @return bool success

 */

function forum_update_instance($forum) {

    global $USER;



    $forum->timemodified = time();

    $forum->id           = $forum->instance;



    if (empty($forum->assessed)) {

        $forum->assessed = 0;

    }



    if (empty($forum->ratingtime) or empty($forum->assessed)) {

        $forum->assesstimestart  = 0;

        $forum->assesstimefinish = 0;

    }



    $oldforum = get_record('forum', 'id', $forum->id);



    // MDL-3942 - if the aggregation type or scale (i.e. max grade) changes then recalculate the grades for the entire forum

    // if  scale changes - do we need to recheck the ratings, if ratings higher than scale how do we want to respond?

    // for count and sum aggregation types the grade we check to make sure they do not exceed the scale (i.e. max score) when calculating the grade

    if (($oldforum->assessed<>$forum->assessed) or ($oldforum->scale<>$forum->scale)) {

        forum_update_grades($forum); // recalculate grades for the forum

    }



    if ($forum->type == 'single') {  // Update related discussion and post.

        if (! $discussion = get_record('forum_discussions', 'forum', $forum->id)) {

            if ($discussions = get_records('forum_discussions', 'forum', $forum->id, 'timemodified ASC')) {

                notify('Warning! There is more than one discussion in this forum - using the most recent');

                $discussion = array_pop($discussions);

            } else {

                // try to recover by creating initial discussion - MDL-16262

                $discussion = new object();

                $discussion->course   = $forum->course;

                $discussion->forum    = $forum->id;

                $discussion->name     = $forum->name;

                $discussion->intro    = $forum->intro;

                $discussion->assessed = $forum->assessed;

                $discussion->format   = $forum->type;

                $discussion->mailnow  = false;

                $discussion->groupid  = -1;



                forum_add_discussion($discussion, $discussion->intro);



                if (! $discussion = get_record('forum_discussions', 'forum', $forum->id)) {

                    error('Could not add the discussion for this forum');

                }



            }

        }

        if (! $post = get_record('forum_posts', 'id', $discussion->firstpost)) {

            error('Could not find the first post in this forum discussion');

        }



        $post->subject  = $forum->name;

        $post->message  = $forum->intro;

        $post->modified = $forum->timemodified;

        $post->userid   = $USER->id;    // MDL-18599, so that current teacher can take ownership of activities



        if (! update_record('forum_posts', ($post))) {

            error('Could not update the first post');

        }



        $discussion->name = $forum->name;



        if (! update_record('forum_discussions', ($discussion))) {

            error('Could not update the discussion');

        }

    }



    if (!update_record('forum', $forum)) {

        error('Can not update forum');

    }



    $forum = stripslashes_recursive($forum);

    forum_grade_item_update($forum);



    return true;

}





/**

 * Given an ID of an instance of this module,

 * this function will permanently delete the instance

 * and any data that depends on it.

 * @param int forum instance id

 * @return bool success

 */

function forum_delete_instance($id) {



    if (!$forum = get_record('forum', 'id', $id)) {

        return false;

    }



    $result = true;



    if ($discussions = get_records('forum_discussions', 'forum', $forum->id)) {

        foreach ($discussions as $discussion) {

            if (!forum_delete_discussion($discussion, true)) {

                $result = false;

            }

        }

    }



    if (!delete_records('forum_subscriptions', 'forum', $forum->id)) {

        $result = false;

    }



    forum_tp_delete_read_records(-1, -1, -1, $forum->id);



    if (!delete_records('forum', 'id', $forum->id)) {

        $result = false;

    }



    forum_grade_item_delete($forum);



    return $result;

}





/**

 * Function to be run periodically according to the moodle cron

 * Finds all posts that have yet to be mailed out, and mails them

 * out to all subscribers

 * @return void

 */

function forum_cron() {

    global $CFG, $USER;



    $cronuser = clone($USER);

    $site = get_site();



    // all users that are subscribed to any post that needs sending

    $users = array();



    // status arrays

    $mailcount  = array();

    $errorcount = array();



    // caches

    $discussions     = array();

    $forums          = array();

    $courses         = array();

    $coursemodules   = array();

    $subscribedusers = array();





    // Posts older than 2 days will not be mailed.  This is to avoid the problem where

    // cron has not been running for a long time, and then suddenly people are flooded

    // with mail from the past few weeks or months

    $timenow   = time();

    $endtime   = $timenow - $CFG->maxeditingtime;

    $starttime = $endtime - 48 * 3600;   // Two days earlier



    if ($posts = forum_get_unmailed_posts($starttime, $endtime, $timenow)) {

        // Mark them all now as being mailed.  It's unlikely but possible there

        // might be an error later so that a post is NOT actually mailed out,

        // but since mail isn't crucial, we can accept this risk.  Doing it now

        // prevents the risk of duplicated mails, which is a worse problem.



        if (!forum_mark_old_posts_as_mailed($endtime)) {

            mtrace('Errors occurred while trying to mark some posts as being mailed.');

            return false;  // Don't continue trying to mail them, in case we are in a cron loop

        }



        // checking post validity, and adding users to loop through later

        foreach ($posts as $pid => $post) {



            $discussionid = $post->discussion;

            if (!isset($discussions[$discussionid])) {

                if ($discussion = get_record('forum_discussions', 'id', $post->discussion)) {

                    $discussions[$discussionid] = $discussion;

                } else {

                    mtrace('Could not find discussion '.$discussionid);

                    unset($posts[$pid]);

                    continue;

                }

            }

            $forumid = $discussions[$discussionid]->forum;

            if (!isset($forums[$forumid])) {

                if ($forum = get_record('forum', 'id', $forumid)) {

                    $forums[$forumid] = $forum;

                } else {

                    mtrace('Could not find forum '.$forumid);

                    unset($posts[$pid]);

                    continue;

                }

            }

            $courseid = $forums[$forumid]->course;

            if (!isset($courses[$courseid])) {

                if ($course = get_record('course', 'id', $courseid)) {

                    $courses[$courseid] = $course;

                } else {

                    mtrace('Could not find course '.$courseid);

                    unset($posts[$pid]);

                    continue;

                }

            }

            if (!isset($coursemodules[$forumid])) {

                if ($cm = get_coursemodule_from_instance('forum', $forumid, $courseid)) {

                    $coursemodules[$forumid] = $cm;

                } else {

                    mtrace('Could not course module for forum '.$forumid);

                    unset($posts[$pid]);

                    continue;

                }

            }





            // caching subscribed users of each forum

            if (!isset($subscribedusers[$forumid])) {

                $modcontext = get_context_instance(CONTEXT_MODULE, $coursemodules[$forumid]->id);

                if ($subusers = forum_subscribed_users($courses[$courseid], $forums[$forumid], 0, $modcontext)) {

                    foreach ($subusers as $postuser) {

                        // do not try to mail users with stopped email

                        if ($postuser->emailstop) {

                            if (!empty($CFG->forum_logblocked)) {

                                add_to_log(SITEID, 'forum', 'mail blocked', '', '', 0, $postuser->id);

                            }

                            continue;

                        }

                        // this user is subscribed to this forum

                        $subscribedusers[$forumid][$postuser->id] = $postuser->id;

                        // this user is a user we have to process later

                        $users[$postuser->id] = $postuser;

                    }

                    unset($subusers); // release memory

                }

            }



            $mailcount[$pid] = 0;

            $errorcount[$pid] = 0;

        }

    }



    if ($users && $posts) {



        $urlinfo = parse_url($CFG->wwwroot);

        $hostname = $urlinfo['host'];



        foreach ($users as $userto) {



            @set_time_limit(120); // terminate if processing of any account takes longer than 2 minutes



            // set this so that the capabilities are cached, and environment matches receiving user

            $USER = $userto;



            mtrace('Processing user '.$userto->id);



            // init caches

            $userto->viewfullnames = array();

            $userto->canpost       = array();

            $userto->markposts     = array();

            $userto->enrolledin    = array();



            // reset the caches

            foreach ($coursemodules as $forumid=>$unused) {

                $coursemodules[$forumid]->cache       = new object();

                $coursemodules[$forumid]->cache->caps = array();

                unset($coursemodules[$forumid]->uservisible);

            }



            foreach ($posts as $pid => $post) {



                // Set up the environment for the post, discussion, forum, course

                $discussion = $discussions[$post->discussion];

                $forum      = $forums[$discussion->forum];

                $course     = $courses[$forum->course];

                $cm         =& $coursemodules[$forum->id];



                // Do some checks  to see if we can bail out now

                if (!isset($subscribedusers[$forum->id][$userto->id])) {

                    continue; // user does not subscribe to this forum

                }



                // Verify user is enrollend in course - if not do not send any email

                if (!isset($userto->enrolledin[$course->id])) {

                    $userto->enrolledin[$course->id] = has_capability('moodle/course:view', get_context_instance(CONTEXT_COURSE, $course->id));

                }

                if (!$userto->enrolledin[$course->id]) {

                    // oops - this user should not receive anything from this course

                    continue;

                }



                // Don't send email if the forum is Q&A and the user has not posted

                if ($forum->type == 'qanda' && !forum_get_user_posted_time($discussion->id, $userto->id)) {

                    mtrace('Did not email '.$userto->id.' because user has not posted in discussion');

                    continue;

                }



                // Get info about the sending user

                if (array_key_exists($post->userid, $users)) { // we might know him/her already

                    $userfrom = $users[$post->userid];

                } else if ($userfrom = get_record('user', 'id', $post->userid)) {

                    $users[$userfrom->id] = $userfrom; // fetch only once, we can add it to user list, it will be skipped anyway

                } else {

                    mtrace('Could not find user '.$post->userid);

                    continue;

                }



                // setup global $COURSE properly - needed for roles and languages

                course_setup($course);   // More environment



                // Fill caches

                if (!isset($userto->viewfullnames[$forum->id])) {

                    $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

                    $userto->viewfullnames[$forum->id] = has_capability('moodle/site:viewfullnames', $modcontext);

                }

                if (!isset($userto->canpost[$discussion->id])) {

                    $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

                    $userto->canpost[$discussion->id] = forum_user_can_post($forum, $discussion, $userto, $cm, $course, $modcontext);

                }

                if (!isset($userfrom->groups[$forum->id])) {

                    if (!isset($userfrom->groups)) {

                        $userfrom->groups = array();

                        $users[$userfrom->id]->groups = array();

                    }

                    $userfrom->groups[$forum->id] = groups_get_all_groups($course->id, $userfrom->id, $cm->groupingid);

                    $users[$userfrom->id]->groups[$forum->id] = $userfrom->groups[$forum->id];

                }



                // Make sure groups allow this user to see this email

                if ($discussion->groupid > 0 and $groupmode = groups_get_activity_groupmode($cm, $course)) {   // Groups are being used

                    if (!groups_group_exists($discussion->groupid)) { // Can't find group

                        continue;                           // Be safe and don't send it to anyone

                    }



                    if (!groups_is_member($discussion->groupid) and !has_capability('moodle/site:accessallgroups', $modcontext)) {

                        // do not send posts from other groups when in SEPARATEGROUPS or VISIBLEGROUPS

                        continue;

                    }

                }



                // Make sure we're allowed to see it...

                if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {

                    mtrace('user '.$userto->id. ' can not see '.$post->id);

                    continue;

                }



                // OK so we need to send the email.



                // Does the user want this post in a digest?  If so postpone it for now.

                if ($userto->maildigest > 0) {

                    // This user wants the mails to be in digest form

                    $queue = new object();

                    $queue->userid       = $userto->id;

                    $queue->discussionid = $discussion->id;

                    $queue->postid       = $post->id;

                    $queue->timemodified = $post->created;

                    if (!insert_record('forum_queue', $queue)) {

                        mtrace("Error: mod/forum/cron.php: Could not queue for digest mail for id $post->id to user $userto->id ($userto->email) .. not trying again.");

                    }

                    continue;

                }





                // Prepare to actually send the post now, and build up the content



                $cleanforumname = str_replace('"', "'", strip_tags(format_string($forum->name)));



                $userfrom->customheaders = array (  // Headers to make emails easier to track

                           'Precedence: Bulk',

                           'List-Id: "'.$cleanforumname.'" <moodleforum'.$forum->id.'@'.$hostname.'>',

                           'List-Help: '.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id,

                           'Message-ID: <moodlepost'.$post->id.'@'.$hostname.'>',

                           'X-Course-Id: '.$course->id,

                           'X-Course-Name: '.format_string($course->fullname, true)

                );



                if ($post->parent) {  // This post is a reply, so add headers for threading (see MDL-22551)

                    $userfrom->customheaders[] = 'In-Reply-To: <moodlepost'.$post->parent.'@'.$hostname.'>';

                    $userfrom->customheaders[] = 'References: <moodlepost'.$post->parent.'@'.$hostname.'>';

                }



                $postsubject = "$course->shortname: ".format_string($post->subject,true);

                $posttext = forum_make_mail_text($course, $forum, $discussion, $post, $userfrom, $userto);

                $posthtml = forum_make_mail_html($course, $forum, $discussion, $post, $userfrom, $userto);



                // Send the post now!



                mtrace('Sending ', '');



                if (!$mailresult = email_to_user($userto, $userfrom, $postsubject, $posttext,

                                                 $posthtml, '', '', $CFG->forum_replytouser)) {

                    mtrace("Error: mod/forum/cron.php: Could not send out mail for id $post->id to user $userto->id".

                         " ($userto->email) .. not trying again.");

                    add_to_log($course->id, 'forum', 'mail error', "discuss.php?d=$discussion->id#p$post->id",

                               substr(format_string($post->subject,true),0,30), $cm->id, $userto->id);

                    $errorcount[$post->id]++;

                } else if ($mailresult === 'emailstop') {

                    // should not be reached anymore - see check above

                } else {

                    $mailcount[$post->id]++;



                // Mark post as read if forum_usermarksread is set off

                    if (!$CFG->forum_usermarksread) {

                        $userto->markposts[$post->id] = $post->id;

                    }

                }



                mtrace('post '.$post->id. ': '.$post->subject);

            }



            // mark processed posts as read

            forum_tp_mark_posts_read($userto, $userto->markposts);

        }

    }



    if ($posts) {

        foreach ($posts as $post) {

            mtrace($mailcount[$post->id]." users were sent post $post->id, '$post->subject'");

            if ($errorcount[$post->id]) {

                set_field("forum_posts", "mailed", "2", "id", "$post->id");

            }

        }

    }



    // release some memory

    unset($subscribedusers);

    unset($mailcount);

    unset($errorcount);



    $USER = clone($cronuser);

    course_setup(SITEID);



    $sitetimezone = $CFG->timezone;



    // Now see if there are any digest mails waiting to be sent, and if we should send them



    mtrace('Starting digest processing...');



    @set_time_limit(300); // terminate if not able to fetch all digests in 5 minutes



    if (!isset($CFG->digestmailtimelast)) {    // To catch the first time

        set_config('digestmailtimelast', 0);

    }



    $timenow = time();

    $digesttime = usergetmidnight($timenow, $sitetimezone) + ($CFG->digestmailtime * 3600);



    // Delete any really old ones (normally there shouldn't be any)

    $weekago = $timenow - (7 * 24 * 3600);

    delete_records_select('forum_queue', "timemodified < $weekago");

    mtrace ('Cleaned old digest records');



    if ($CFG->digestmailtimelast < $digesttime and $timenow > $digesttime) {



        mtrace('Sending forum digests: '.userdate($timenow, '', $sitetimezone));



        $digestposts_rs = get_recordset_select('forum_queue', "timemodified < $digesttime");



        if (!rs_EOF($digestposts_rs)) {



            // We have work to do

            $usermailcount = 0;



            //caches - reuse the those filled before too

            $discussionposts = array();

            $userdiscussions = array();



            while ($digestpost = rs_fetch_next_record($digestposts_rs)) {

                if (!isset($users[$digestpost->userid])) {

                    if ($user = get_record('user', 'id', $digestpost->userid)) {

                        $users[$digestpost->userid] = $user;

                    } else {

                        continue;

                    }

                }

                $postuser = $users[$digestpost->userid];

                if ($postuser->emailstop) {

                    if (!empty($CFG->forum_logblocked)) {

                        add_to_log(SITEID, 'forum', 'mail blocked', '', '', 0, $postuser->id);

                    }

                    continue;

                }



                if (!isset($posts[$digestpost->postid])) {

                    if ($post = get_record('forum_posts', 'id', $digestpost->postid)) {

                        $posts[$digestpost->postid] = $post;

                    } else {

                        continue;

                    }

                }

                $discussionid = $digestpost->discussionid;

                if (!isset($discussions[$discussionid])) {

                    if ($discussion = get_record('forum_discussions', 'id', $discussionid)) {

                        $discussions[$discussionid] = $discussion;

                    } else {

                        continue;

                    }

                }

                $forumid = $discussions[$discussionid]->forum;

                if (!isset($forums[$forumid])) {

                    if ($forum = get_record('forum', 'id', $forumid)) {

                        $forums[$forumid] = $forum;

                    } else {

                        continue;

                    }

                }



                $courseid = $forums[$forumid]->course;

                if (!isset($courses[$courseid])) {

                    if ($course = get_record('course', 'id', $courseid)) {

                        $courses[$courseid] = $course;

                    } else {

                        continue;

                    }

                }



                if (!isset($coursemodules[$forumid])) {

                    if ($cm = get_coursemodule_from_instance('forum', $forumid, $courseid)) {

                        $coursemodules[$forumid] = $cm;

                    } else {

                        continue;

                    }

                }

                $userdiscussions[$digestpost->userid][$digestpost->discussionid] = $digestpost->discussionid;

                $discussionposts[$digestpost->discussionid][$digestpost->postid] = $digestpost->postid;

            }

            rs_close($digestposts_rs); /// Finished iteration, let's close the resultset



            // Data collected, start sending out emails to each user

            foreach ($userdiscussions as $userid => $thesediscussions) {



                @set_time_limit(120); // terminate if processing of any account takes longer than 2 minutes



                $USER = $cronuser;

                course_setup(SITEID); // reset cron user language, theme and timezone settings



                mtrace(get_string('processingdigest', 'forum', $userid), '... ');



                // First of all delete all the queue entries for this user

                delete_records_select('forum_queue', "userid = $userid AND timemodified < $digesttime");

                $userto = $users[$userid];



                // Override the language and timezone of the "current" user, so that

                // mail is customised for the receiver.

                $USER = $userto;

                course_setup(SITEID);



                // init caches

                $userto->viewfullnames = array();

                $userto->canpost       = array();

                $userto->markposts     = array();



                $postsubject = get_string('digestmailsubject', 'forum', format_string($site->shortname, true));



                $headerdata = new object();

                $headerdata->sitename = format_string($site->fullname, true);

                $headerdata->userprefs = $CFG->wwwroot.'/user/edit.php?id='.$userid.'&amp;course='.$site->id;



                $posttext = get_string('digestmailheader', 'forum', $headerdata)."\n\n";

                $headerdata->userprefs = '<a target="_blank" href="'.$headerdata->userprefs.'">'.get_string('digestmailprefs', 'forum').'</a>';



                $posthtml = "<head>";

                foreach ($CFG->stylesheets as $stylesheet) {

                    $posthtml .= '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'" />'."\n";

                }

                $posthtml .= "</head>\n<body id=\"email\">\n";

                $posthtml .= '<p>'.get_string('digestmailheader', 'forum', $headerdata).'</p><br /><hr size="1" noshade="noshade" />';



                foreach ($thesediscussions as $discussionid) {



                    @set_time_limit(120);   // to be reset for each post



                    $discussion = $discussions[$discussionid];

                    $forum      = $forums[$discussion->forum];

                    $course     = $courses[$forum->course];

                    $cm         = $coursemodules[$forum->id];



                    //override language

                    course_setup($course);



                    // Fill caches

                    if (!isset($userto->viewfullnames[$forum->id])) {

                        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

                        $userto->viewfullnames[$forum->id] = has_capability('moodle/site:viewfullnames', $modcontext);

                    }

                    if (!isset($userto->canpost[$discussion->id])) {

                        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

                        $userto->canpost[$discussion->id] = forum_user_can_post($forum, $discussion, $userto, $cm, $course, $modcontext);

                    }



                    $strforums      = get_string('forums', 'forum');

                    $canunsubscribe = ! forum_is_forcesubscribed($forum);

                    $canreply       = $userto->canpost[$discussion->id];



                    $posttext .= "\n \n";

                    $posttext .= '=====================================================================';

                    $posttext .= "\n \n";

                    $posttext .= "$course->shortname -> $strforums -> ".format_string($forum->name,true);

                    if ($discussion->name != $forum->name) {

                        $posttext  .= " -> ".format_string($discussion->name,true);

                    }

                    $posttext .= "\n";



                    $posthtml .= "<p><font face=\"sans-serif\">".

                    "<a target=\"_blank\" href=\"$CFG->wwwroot/course/view.php?id=$course->id\">$course->shortname</a> -> ".

                    "<a target=\"_blank\" href=\"$CFG->wwwroot/mod/forum/index.php?id=$course->id\">$strforums</a> -> ".

                    "<a target=\"_blank\" href=\"$CFG->wwwroot/mod/forum/view.php?f=$forum->id\">".format_string($forum->name,true)."</a>";

                    if ($discussion->name == $forum->name) {

                        $posthtml .= "</font></p>";

                    } else {

                        $posthtml .= " -> <a target=\"_blank\" href=\"$CFG->wwwroot/mod/forum/discuss.php?d=$discussion->id\">".format_string($discussion->name,true)."</a></font></p>";

                    }

                    $posthtml .= '<p>';



                    $postsarray = $discussionposts[$discussionid];

                    sort($postsarray);



                    foreach ($postsarray as $postid) {

                        $post = $posts[$postid];



                        if (array_key_exists($post->userid, $users)) { // we might know him/her already

                            $userfrom = $users[$post->userid];

                        } else if ($userfrom = get_record('user', 'id', $post->userid)) {

                            $users[$userfrom->id] = $userfrom; // fetch only once, we can add it to user list, it will be skipped anyway

                        } else {

                            mtrace('Could not find user '.$post->userid);

                            continue;

                        }



                        if (!isset($userfrom->groups[$forum->id])) {

                            if (!isset($userfrom->groups)) {

                                $userfrom->groups = array();

                                $users[$userfrom->id]->groups = array();

                            }

                            $userfrom->groups[$forum->id] = groups_get_all_groups($course->id, $userfrom->id, $cm->groupingid);

                            $users[$userfrom->id]->groups[$forum->id] = $userfrom->groups[$forum->id];

                        }



                        $userfrom->customheaders = array ("Precedence: Bulk");



                        if ($userto->maildigest == 2) {

                            // Subjects only

                            $by = new object();

                            $by->name = fullname($userfrom);

                            $by->date = userdate($post->modified);

                            $posttext .= "\n".format_string($post->subject,true).' '.get_string("bynameondate", "forum", $by);

                            $posttext .= "\n---------------------------------------------------------------------";



                            $by->name = "<a target=\"_blank\" href=\"$CFG->wwwroot/user/view.php?id=$userfrom->id&amp;course=$course->id\">$by->name</a>";

                            $posthtml .= '<div><a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$discussion->id.'#p'.$post->id.'">'.format_string($post->subject,true).'</a> '.get_string("bynameondate", "forum", $by).'</div>';



                        } else {

                            // The full treatment

                            $posttext .= forum_make_mail_text($course, $forum, $discussion, $post, $userfrom, $userto, true);

                            $posthtml .= forum_make_mail_post($course, $forum, $discussion, $post, $userfrom, $userto, false, $canreply, true, false);



                        // Create an array of postid's for this user to mark as read.

                            if (!$CFG->forum_usermarksread) {

                                $userto->markposts[$post->id] = $post->id;

                            }

                        }

                    }

                    if ($canunsubscribe) {

                        $posthtml .= "\n<div class='mdl-right'><font size=\"1\"><a href=\"$CFG->wwwroot/mod/forum/subscribe.php?id=$forum->id\">".get_string("unsubscribe", "forum")."</a></font></div>";

                    } else {

                        $posthtml .= "\n<div class='mdl-right'><font size=\"1\">".get_string("everyoneissubscribed", "forum")."</font></div>";

                    }

                    $posthtml .= '<hr size="1" noshade="noshade" /></p>';

                }

                $posthtml .= '</body>';



                if ($userto->mailformat != 1) {

                    // This user DOESN'T want to receive HTML

                    $posthtml = '';

                }



                if (!$mailresult =  email_to_user($userto, $site->shortname, $postsubject, $posttext, $posthtml,

                                                  '', '', $CFG->forum_replytouser)) {

                    mtrace("ERROR!");

                    echo "Error: mod/forum/cron.php: Could not send out digest mail to user $userto->id ($userto->email)... not trying again.\n";

                    add_to_log($course->id, 'forum', 'mail digest error', '', '', $cm->id, $userto->id);

                } else if ($mailresult === 'emailstop') {

                    // should not happen anymore - see check above

                } else {

                    mtrace("success.");

                    $usermailcount++;



                    // Mark post as read if forum_usermarksread is set off

                    forum_tp_mark_posts_read($userto, $userto->markposts);

                }

            }

        }

    /// We have finishied all digest emails, update $CFG->digestmailtimelast

        set_config('digestmailtimelast', $timenow);

    }



    $USER = $cronuser;

    course_setup(SITEID); // reset cron user language, theme and timezone settings



    if (!empty($usermailcount)) {

        mtrace(get_string('digestsentusers', 'forum', $usermailcount));

    }



    if (!empty($CFG->forum_lastreadclean)) {

        $timenow = time();

        if ($CFG->forum_lastreadclean + (24*3600) < $timenow) {

            set_config('forum_lastreadclean', $timenow);

            mtrace('Removing old forum read tracking info...');

            forum_tp_clean_read_records();

        }

    } else {

        set_config('forum_lastreadclean', time());

    }





    return true;

}



/**

 * Builds and returns the body of the email notification in plain text.

 *

 * @param object $course

 * @param object $forum

 * @param object $discussion

 * @param object $post

 * @param object $userfrom

 * @param object $userto

 * @param boolean $bare

 * @return string The email body in plain text format.

 */

function forum_make_mail_text($course, $forum, $discussion, $post, $userfrom, $userto, $bare = false) {

    global $CFG, $USER;



    if (!isset($userto->viewfullnames[$forum->id])) {

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {

            error('Course Module ID was incorrect');

        }

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        $viewfullnames = has_capability('moodle/site:viewfullnames', $modcontext, $userto->id);

    } else {

        $viewfullnames = $userto->viewfullnames[$forum->id];

    }



    if (!isset($userto->canpost[$discussion->id])) {

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        $canreply = forum_user_can_post($forum, $discussion, $userto, $cm, $course, $modcontext);

    } else {

        $canreply = $userto->canpost[$discussion->id];

    }



    $by = New stdClass;

    $by->name = fullname($userfrom, $viewfullnames);

    $by->date = userdate($post->modified, "", $userto->timezone);



    $strbynameondate = get_string('bynameondate', 'forum', $by);



    $strforums = get_string('forums', 'forum');



    $canunsubscribe = ! forum_is_forcesubscribed($forum);



    $posttext = '';



    if (!$bare) {

        $posttext  = "$course->shortname -> $strforums -> ".format_string($forum->name,true);



        if ($discussion->name != $forum->name) {

            $posttext  .= " -> ".format_string($discussion->name,true);

        }

    }



    $posttext .= "\n---------------------------------------------------------------------\n";

    $posttext .= format_string($post->subject,true);

    if ($bare) {

        $posttext .= " ($CFG->wwwroot/mod/forum/discuss.php?d=$discussion->id#p$post->id)";

    }

    $posttext .= "\n".$strbynameondate."\n";

    $posttext .= "---------------------------------------------------------------------\n";

    $posttext .= format_text_email(trusttext_strip($post->message), $post->format);

    $posttext .= "\n\n";

    if ($post->attachment) {

        $post->course = $course->id;

        $post->forum = $forum->id;

        $posttext .= forum_print_attachments($post, "text");

    }

    if (!$bare && $canreply) {

        $posttext .= "---------------------------------------------------------------------\n";

        $posttext .= get_string("postmailinfo", "forum", $course->shortname)."\n";

        $posttext .= "$CFG->wwwroot/mod/forum/post.php?reply=$post->id\n";

    }

    if (!$bare && $canunsubscribe) {

        $posttext .= "\n---------------------------------------------------------------------\n";

        $posttext .= get_string("unsubscribe", "forum");

        $posttext .= ": $CFG->wwwroot/mod/forum/subscribe.php?id=$forum->id\n";

    }



    return $posttext;

}



/**

 * Builds and returns the body of the email notification in html format.

 *

 * @param object $course

 * @param object $forum

 * @param object $discussion

 * @param object $post

 * @param object $userfrom

 * @param object $userto

 * @return string The email text in HTML format

 */

function forum_make_mail_html($course, $forum, $discussion, $post, $userfrom, $userto) {

    global $CFG;



    if ($userto->mailformat != 1) {  // Needs to be HTML

        return '';

    }



    if (!isset($userto->canpost[$discussion->id])) {

        $canreply = forum_user_can_post($forum, $discussion, $userto);

    } else {

        $canreply = $userto->canpost[$discussion->id];

    }



    $strforums = get_string('forums', 'forum');

    $canunsubscribe = ! forum_is_forcesubscribed($forum);



    $posthtml = '<head>';

    foreach ($CFG->stylesheets as $stylesheet) {

        $posthtml .= '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'" />'."\n";

    }

    $posthtml .= '</head>';

    $posthtml .= "\n<body id=\"email\">\n\n";



    $posthtml .= '<div class="navbar">'.

    '<a target="_blank" href="'.$CFG->wwwroot.'/course/view.php?id='.$course->id.'">'.$course->shortname.'</a> &raquo; '.

    '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/index.php?id='.$course->id.'">'.$strforums.'</a> &raquo; '.

    '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id.'">'.format_string($forum->name,true).'</a>';

    if ($discussion->name == $forum->name) {

        $posthtml .= '</div>';

    } else {

        $posthtml .= ' &raquo; <a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$discussion->id.'">'.

                     format_string($discussion->name,true).'</a></div>';

    }

    $posthtml .= forum_make_mail_post($course, $forum, $discussion, $post, $userfrom, $userto, false, $canreply, true, false);



    if ($canunsubscribe) {

        $posthtml .= '<hr /><div class="mdl-align unsubscribelink">

                      <a href="'.$CFG->wwwroot.'/mod/forum/subscribe.php?id='.$forum->id.'">'.get_string('unsubscribe', 'forum').'</a>&nbsp;

                      <a href="'.$CFG->wwwroot.'/mod/forum/unsubscribeall.php">'.get_string('unsubscribeall', 'forum').'</a></div>';

    }



    $posthtml .= '</body>';



    return $posthtml;

}





/**

 *

 * @param object $course

 * @param object $user

 * @param object $mod TODO this is not used in this function, refactor

 * @param object $forum

 * @return object A standard object with 2 variables: info (number of posts for this user) and time (last modified)

 */

function forum_user_outline($course, $user, $mod, $forum) {

    global $CFG;

    require_once("$CFG->libdir/gradelib.php");

    $grades = grade_get_grades($course->id, 'mod', 'forum', $forum->id, $user->id);

    if (empty($grades->items[0]->grades)) {

        $grade = false;

    } else {

        $grade = reset($grades->items[0]->grades);

    }



    $count = forum_count_user_posts($forum->id, $user->id);



    if ($count && $count->postcount > 0) {

        $result = new object();

        $result->info = get_string("numposts", "forum", $count->postcount);

        $result->time = $count->lastpost;

        if ($grade) {

            $result->info .= ', ' . get_string('grade') . ': ' . $grade->str_long_grade;

        }

        return $result;

    } else if ($grade) {

        $result = new object();

        $result->info = get_string('grade') . ': ' . $grade->str_long_grade;



        //datesubmitted == time created. dategraded == time modified or time overridden

        //if grade was last modified by the user themselves use date graded. Otherwise use date submitted

        if ($grade->usermodified == $user->id || empty($grade->datesubmitted)) {

            $result->time = $grade->dategraded;

        } else {

            $result->time = $grade->datesubmitted;

        }



        return $result;

    }

    return NULL;

}





/**

 *

 */

function forum_user_complete($course, $user, $mod, $forum) {

    global $CFG,$USER;

    require_once("$CFG->libdir/gradelib.php");



    $grades = grade_get_grades($course->id, 'mod', 'forum', $forum->id, $user->id);

    if (!empty($grades->items[0]->grades)) {

        $grade = reset($grades->items[0]->grades);

        echo '<p>'.get_string('grade').': '.$grade->str_long_grade.'</p>';

        if ($grade->str_feedback) {

            echo '<p>'.get_string('feedback').': '.$grade->str_feedback.'</p>';

        }

    }



    if ($posts = forum_get_user_posts($forum->id, $user->id)) {



        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {

            error('Course Module ID was incorrect');

        }

        $discussions = forum_get_user_involved_discussions($forum->id, $user->id);



        // preload all user ratings for these discussions - one query only and minimal memory

        $cm->cache->ratings = array();

        $cm->cache->myratings = array();

        if ($postratings = forum_get_all_user_ratings($user->id, $discussions)) {

            foreach ($postratings as $pr) {

                if (!isset($cm->cache->ratings[$pr->postid])) {

                    $cm->cache->ratings[$pr->postid] = array();

                }

                $cm->cache->ratings[$pr->postid][$pr->id] = $pr->rating;



                if ($pr->userid == $USER->id) {

                    $cm->cache->myratings[$pr->postid] = $pr->rating;

                }

            }

            unset($postratings);

        }



        foreach ($posts as $post) {

            if (!isset($discussions[$post->discussion])) {

                continue;

            }

            $discussion = $discussions[$post->discussion];

            

            $ratings = null;



            if ($forum->assessed) {

                if ($scale = make_grades_menu($forum->scale)) {

                    $ratings =new object();

                    $ratings->scale = $scale;

                    $ratings->assesstimestart = $forum->assesstimestart;

                    $ratings->assesstimefinish = $forum->assesstimefinish;

                    $ratings->allow = false;

                }

            }



            forum_print_post($post, $discussion, $forum, $cm, $course, false, false, false, $ratings);



        }

    } else {

        echo "<p>".get_string("noposts", "forum")."</p>";

    }

}





/**

 *

 */

function forum_print_overview($courses,&$htmlarray) {

    global $USER, $CFG;

    //$LIKE = sql_ilike();//no longer using like in queries. MDL-20578



    if (empty($courses) || !is_array($courses) || count($courses) == 0) {

        return array();

    }



    if (!$forums = get_all_instances_in_courses('forum',$courses)) {

        return;

    }





    // get all forum logs in ONE query (much better!)

    $sql = "SELECT instance,cmid,l.course,COUNT(l.id) as count FROM {$CFG->prefix}log l "

        ." JOIN {$CFG->prefix}course_modules cm ON cm.id = cmid "

        ." WHERE (";

    foreach ($courses as $course) {

        $sql .= '(l.course = '.$course->id.' AND l.time > '.$course->lastaccess.') OR ';

    }

    $sql = substr($sql,0,-3); // take off the last OR



    $sql .= ") AND l.module = 'forum' AND action = 'add post' "

        ." AND userid != ".$USER->id." GROUP BY cmid,l.course,instance";



    if (!$new = get_records_sql($sql)) {

        $new = array(); // avoid warnings

    }



    // also get all forum tracking stuff ONCE.

    $trackingforums = array();

    foreach ($forums as $forum) {

        if (forum_tp_can_track_forums($forum)) {

            $trackingforums[$forum->id] = $forum;

        }

    }



    if (count($trackingforums) > 0) {

        $cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;

        $sql = 'SELECT d.forum,d.course,COUNT(p.id) AS count '.

            ' FROM '.$CFG->prefix.'forum_posts p '.

            ' JOIN '.$CFG->prefix.'forum_discussions d ON p.discussion = d.id '.

            ' LEFT JOIN '.$CFG->prefix.'forum_read r ON r.postid = p.id AND r.userid = '.$USER->id.' WHERE (';

        foreach ($trackingforums as $track) {

            $sql .= '(d.forum = '.$track->id.' AND (d.groupid = -1 OR d.groupid = 0 OR d.groupid = '.get_current_group($track->course).')) OR ';

        }

        $sql = substr($sql,0,-3); // take off the last OR

        $sql .= ') AND p.modified >= '.$cutoffdate.' AND r.id is NULL GROUP BY d.forum,d.course';



        if (!$unread = get_records_sql($sql)) {

            $unread = array();

        }

    } else {

        $unread = array();

    }



    if (empty($unread) and empty($new)) {

        return;

    }



    $strforum = get_string('modulename','forum');

    $strnumunread = get_string('overviewnumunread','forum');

    $strnumpostssince = get_string('overviewnumpostssince','forum');



    foreach ($forums as $forum) {

        $str = '';

        $count = 0;

        $thisunread = 0;

        $showunread = false;

        // either we have something from logs, or trackposts, or nothing.

        if (array_key_exists($forum->id, $new) && !empty($new[$forum->id])) {

            $count = $new[$forum->id]->count;

        }

        if (array_key_exists($forum->id,$unread)) {

            $thisunread = $unread[$forum->id]->count;

            $showunread = true;

        }

        if ($count > 0 || $thisunread > 0) {

            $str .= '<div class="overview forum"><div class="name">'.$strforum.': <a title="'.$strforum.'" href="'.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id.'">'.

                $forum->name.'</a></div>';

            $str .= '<div class="info">';

            $str .= $count.' '.$strnumpostssince;

            if (!empty($showunread)) {

                $str .= '<br />'.$thisunread .' '.$strnumunread;

            }

            $str .= '</div></div>';

        }

        if (!empty($str)) {

            if (!array_key_exists($forum->course,$htmlarray)) {

                $htmlarray[$forum->course] = array();

            }

            if (!array_key_exists('forum',$htmlarray[$forum->course])) {

                $htmlarray[$forum->course]['forum'] = ''; // initialize, avoid warnings

            }

            $htmlarray[$forum->course]['forum'] .= $str;

        }

    }

}



/**

 * Given a course and a date, prints a summary of all the new

 * messages posted in the course since that date

 * @param object $course

 * @param bool $viewfullnames capability

 * @param int $timestart

 * @return bool success

 */

function forum_print_recent_activity($course, $viewfullnames, $timestart) {

    global $CFG, $USER;



    // do not use log table if possible, it may be huge and is expensive to join with other tables



    if (!$posts = get_records_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,

                                          d.timestart, d.timeend, d.userid AS duserid,

                                          u.firstname, u.lastname, u.email, u.picture

                                     FROM {$CFG->prefix}forum_posts p

                                          JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                                          JOIN {$CFG->prefix}forum f             ON f.id = d.forum

                                          JOIN {$CFG->prefix}user u              ON u.id = p.userid

                                    WHERE p.created > $timestart AND f.course = {$course->id}

                                 ORDER BY p.id ASC")) { // order by initial posting date

         return false;

    }



    $modinfo =& get_fast_modinfo($course);



    $groupmodes = array();

    $cms    = array();



    $strftimerecent = get_string('strftimerecent');



    $printposts = array();

    foreach ($posts as $post) {

        if (!isset($modinfo->instances['forum'][$post->forum])) {

            // not visible

            continue;

        }

        $cm = $modinfo->instances['forum'][$post->forum];

        if (!$cm->uservisible) {

            continue;

        }

        $context = get_context_instance(CONTEXT_MODULE, $cm->id);



        if (!has_capability('mod/forum:viewdiscussion', $context)) {

            continue;

        }



        if (!empty($CFG->forum_enabletimedposts) and $USER->id != $post->duserid

          and (($post->timestart > 0 and $post->timestart > time()) or ($post->timeend > 0 and $post->timeend < time()))) {

            if (!has_capability('mod/forum:viewhiddentimedposts', $context)) {

                continue;

            }

        }



        $groupmode = groups_get_activity_groupmode($cm, $course);



        if ($groupmode) {

            if ($post->groupid == -1 or $groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $context)) {

                // oki (Open discussions have groupid -1)

            } else {

                // separate mode

                if (isguestuser()) {

                    // shortcut

                    continue;

                }



                if (is_null($modinfo->groups)) {

                    $modinfo->groups = groups_get_user_groups($course->id); // load all my groups and cache it in modinfo

                }



                if (!array_key_exists($post->groupid, $modinfo->groups[0])) {

                    continue;

                }

            }

        }



        $printposts[] = $post;

    }

    unset($posts);



    if (!$printposts) {

        return false;

    }



    print_headline(get_string('newforumposts', 'forum').':', 3);

    echo "\n<ul class='unlist'>\n";



    foreach ($printposts as $post) {

        $subjectclass = empty($post->parent) ? ' bold' : '';



        echo '<li><div class="head">'.

               '<div class="date">'.userdate($post->modified, $strftimerecent).'</div>'.

               '<div class="name">'.fullname($post, $viewfullnames).'</div>'.

             '</div>';

        echo '<div class="info'.$subjectclass.'">';

        if (empty($post->parent)) {

            echo '"<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';

        } else {

            echo '"<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'&amp;parent='.$post->parent.'#p'.$post->id.'">';

        }

        $post->subject = break_up_long_words(format_string($post->subject, true));

        echo $post->subject;

        echo "</a>\"</div></li>\n";

    }



    echo "</ul>\n";



    return true;

}



/**

 * Return grade for given user or all users.

 *

 * @param int $forumid id of forum

 * @param int $userid optional user id, 0 means all users

 * @return array array of grades, false if none

 */

function forum_get_user_grades($forum, $userid=0) {

    global $CFG;



    $user = $userid ? "AND u.id = $userid" : "";



    $aggtype = $forum->assessed;

    switch ($aggtype) {

        case FORUM_AGGREGATE_COUNT :

            $sql = "SELECT u.id, u.id AS userid, COUNT(fr.rating) AS rawgrade

                      FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,

                           {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd

                     WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id

                           AND fr.userid != u.id AND fd.forum = $forum->id

                           $user

                  GROUP BY u.id";

            break;

        case FORUM_AGGREGATE_MAX :

            $sql = "SELECT u.id, u.id AS userid, MAX(fr.rating) AS rawgrade

                      FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,

                           {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd

                     WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id

                           AND fr.userid != u.id AND fd.forum = $forum->id

                           $user

                  GROUP BY u.id";

            break;

        case FORUM_AGGREGATE_MIN :

            $sql = "SELECT u.id, u.id AS userid, MIN(fr.rating) AS rawgrade

                      FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,

                           {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd

                     WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id

                           AND fr.userid != u.id AND fd.forum = $forum->id

                           $user

                  GROUP BY u.id";

            break;

        case FORUM_AGGREGATE_SUM :

            $sql = "SELECT u.id, u.id AS userid, SUM(fr.rating) AS rawgrade

                     FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,

                          {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd

                    WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id

                          AND fr.userid != u.id AND fd.forum = $forum->id

                          $user

                 GROUP BY u.id";

            break;

        default : //avg

            $sql = "SELECT u.id, u.id AS userid, AVG(fr.rating) AS rawgrade

                      FROM {$CFG->prefix}user u, {$CFG->prefix}forum_posts fp,

                           {$CFG->prefix}forum_ratings fr, {$CFG->prefix}forum_discussions fd

                     WHERE u.id = fp.userid AND fp.discussion = fd.id AND fr.post = fp.id

                           AND fr.userid != u.id AND fd.forum = $forum->id

                           $user

                  GROUP BY u.id";

            break;

    }



    if ($results = get_records_sql($sql)) {

        // it could throw off the grading if count and sum returned a rawgrade higher than scale

        // so to prevent it we review the results and ensure that rawgrade does not exceed the scale, if it does we set rawgrade = scale (i.e. full credit)

        foreach ($results as $rid=>$result) {

            if ($forum->scale >= 0) {

                //numeric

                if ($result->rawgrade > $forum->scale) {

                    $results[$rid]->rawgrade = $forum->scale;

                }

            } else {

                //scales

                if ($scale = get_record('scale', 'id', -$forum->scale)) {

                    $scale = explode(',', $scale->scale);

                    $max = count($scale);

                    if ($result->rawgrade > $max) {

                        $results[$rid]->rawgrade = $max;

                    }

                }

            }

        }

    }



    return $results;

}



/**

 * Update grades by firing grade_updated event

 *

 * @param object $forum null means all forums

 * @param int $userid specific user only, 0 mean all

 * @param boolean $nullifnone return null if grade does not exist

 * @return void

 */

function forum_update_grades($forum=null, $userid=0, $nullifnone=true) {

    global $CFG;



    if ($forum != null) {

        require_once($CFG->libdir.'/gradelib.php');

        if ($grades = forum_get_user_grades($forum, $userid)) {

            forum_grade_item_update($forum, $grades);



        } else if ($userid and $nullifnone) {

            $grade = new object();

            $grade->userid   = $userid;

            $grade->rawgrade = NULL;

            forum_grade_item_update($forum, $grade);



        } else {

            forum_grade_item_update($forum);

        }



    } else {

        $sql = "SELECT f.*, cm.idnumber as cmidnumber

                  FROM {$CFG->prefix}forum f, {$CFG->prefix}course_modules cm, {$CFG->prefix}modules m

                 WHERE m.name='forum' AND m.id=cm.module AND cm.instance=f.id";

        if ($rs = get_recordset_sql($sql)) {

            while ($forum = rs_fetch_next_record($rs)) {

                if ($forum->assessed) {

                    forum_update_grades($forum, 0, false);

                } else {

                    forum_grade_item_update($forum);

                }

            }

            rs_close($rs);

        }

    }

}



/**

 * Create/update grade item for given forum

 *

 * @param object $forum object with extra cmidnumber

 * @param mixed optional array/object of grade(s); 'reset' means reset grades in gradebook

 * @return int 0 if ok

 */

function forum_grade_item_update($forum, $grades=NULL) {

    global $CFG;

    if (!function_exists('grade_update')) { //workaround for buggy PHP versions

        require_once($CFG->libdir.'/gradelib.php');

    }



    $params = array('itemname'=>$forum->name, 'idnumber'=>$forum->cmidnumber);



    if (!$forum->assessed or $forum->scale == 0) {

        $params['gradetype'] = GRADE_TYPE_NONE;



    } else if ($forum->scale > 0) {

        $params['gradetype'] = GRADE_TYPE_VALUE;

        $params['grademax']  = $forum->scale;

        $params['grademin']  = 0;



    } else if ($forum->scale < 0) {

        $params['gradetype'] = GRADE_TYPE_SCALE;

        $params['scaleid']   = -$forum->scale;

    }



    if ($grades  === 'reset') {

        $params['reset'] = true;

        $grades = NULL;

    }



    return grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 0, $grades, $params);

}



/**

 * Delete grade item for given forum

 *

 * @param object $forum object

 * @return object grade_item

 */

function forum_grade_item_delete($forum) {

    global $CFG;

    require_once($CFG->libdir.'/gradelib.php');



    return grade_update('mod/forum', $forum->course, 'mod', 'forum', $forum->id, 0, NULL, array('deleted'=>1));

}





/**

 * Returns the users with data in one forum

 * (users with records in forum_subscriptions, forum_posts and forum_ratings, students)

 * @param int $forumid

 * @return mixed array or false if none

 */

function forum_get_participants($forumid) {



    global $CFG;



    //Get students from forum_subscriptions

    $st_subscriptions = get_records_sql("SELECT DISTINCT u.id, u.id

                                         FROM {$CFG->prefix}user u,

                                              {$CFG->prefix}forum_subscriptions s

                                         WHERE s.forum = '$forumid' and

                                               u.id = s.userid");

    //Get students from forum_posts

    $st_posts = get_records_sql("SELECT DISTINCT u.id, u.id

                                 FROM {$CFG->prefix}user u,

                                      {$CFG->prefix}forum_discussions d,

                                      {$CFG->prefix}forum_posts p

                                 WHERE d.forum = '$forumid' and

                                       p.discussion = d.id and

                                       u.id = p.userid");



    //Get students from forum_ratings

    $st_ratings = get_records_sql("SELECT DISTINCT u.id, u.id

                                   FROM {$CFG->prefix}user u,

                                        {$CFG->prefix}forum_discussions d,

                                        {$CFG->prefix}forum_posts p,

                                        {$CFG->prefix}forum_ratings r

                                   WHERE d.forum = '$forumid' and

                                         p.discussion = d.id and

                                         r.post = p.id and

                                         u.id = r.userid");



    //Add st_posts to st_subscriptions

    if ($st_posts) {

        foreach ($st_posts as $st_post) {

            $st_subscriptions[$st_post->id] = $st_post;

        }

    }

    //Add st_ratings to st_subscriptions

    if ($st_ratings) {

        foreach ($st_ratings as $st_rating) {

            $st_subscriptions[$st_rating->id] = $st_rating;

        }

    }

    //Return st_subscriptions array (it contains an array of unique users)

    return ($st_subscriptions);

}



/**

 * This function returns if a scale is being used by one forum

 * @param int $forumid

 * @param int $scaleid negative number

 * @return bool

 */

function forum_scale_used ($forumid,$scaleid) {



    $return = false;



    $rec = get_record("forum","id","$forumid","scale","-$scaleid");



    if (!empty($rec) && !empty($scaleid)) {

        $return = true;

    }



    return $return;

}



/**

 * Checks if scale is being used by any instance of forum

 *

 * This is used to find out if scale used anywhere

 * @param $scaleid int

 * @return boolean True if the scale is used by any forum

 */

function forum_scale_used_anywhere($scaleid) {

    if ($scaleid and record_exists('forum', 'scale', -$scaleid)) {

        return true;

    } else {

        return false;

    }

}



// SQL FUNCTIONS ///////////////////////////////////////////////////////////



/**

 * Gets a post with all info ready for forum_print_post

 * Most of these joins are just to get the forum id

 * @param int $postid

 * @return mixed array of posts or false

 */

function forum_get_post_full($postid) {

    global $CFG;



    return get_record_sql("SELECT p.*, d.forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt

                             FROM {$CFG->prefix}forum_posts p

                                  JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id

                                  LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id

                            WHERE p.id = '$postid'");

}



/**

 * Gets posts with all info ready for forum_print_post

 * We pass forumid in because we always know it so no need to make a

 * complicated join to find it out.

 * @return mixed array of posts or false

 */

function forum_get_discussion_posts($discussion, $sort, $forumid) {

    global $CFG;



    return get_records_sql("SELECT p.*, $forumid AS forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt

                              FROM {$CFG->prefix}forum_posts p

                         LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id

                             WHERE p.discussion = $discussion

                               AND p.parent > 0 $sort");

}



/**

 * Gets all posts in discussion including top parent.

 * @param int $discussionid

 * @param string $sort

 * @param bool $tracking does user track the forum?

 * @return array of posts

 */

function forum_get_all_discussion_posts($discussionid, $sort, $tracking=false) {

    global $CFG, $USER;



    $tr_sel  = "";

    $tr_join = "";



    if ($tracking) {

        $now = time();

        $cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 3600);

        $tr_sel  = ", fr.id AS postread";

        $tr_join = "LEFT JOIN {$CFG->prefix}forum_read fr ON (fr.postid = p.id AND fr.userid = $USER->id)";

    }



    if (!$posts = get_records_sql("SELECT p.*, u.firstname, u.lastname, u.email, u.picture, u.imagealt $tr_sel

                                     FROM {$CFG->prefix}forum_posts p

                                          LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id

                                          $tr_join

                                    WHERE p.discussion = $discussionid

                                 ORDER BY $sort")) {

        return array();

    }



    foreach ($posts as $pid=>$p) {

        if ($tracking) {

            if (forum_tp_is_post_old($p)) {

                 $posts[$pid]->postread = true;

            }

        }

        if (!$p->parent) {

            continue;

        }

        if (!isset($posts[$p->parent])) {

            continue; // parent does not exist??

        }

        if (!isset($posts[$p->parent]->children)) {

            $posts[$p->parent]->children = array();

        }

        $posts[$p->parent]->children[$pid] =& $posts[$pid];

    }



    return $posts;

}



/**

 * Gets posts with all info ready for forum_print_post

 * We pass forumid in because we always know it so no need to make a

 * complicated join to find it out.

 */

function forum_get_child_posts($parent, $forumid) {

    global $CFG;



    return get_records_sql("SELECT p.*, $forumid AS forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt

                              FROM {$CFG->prefix}forum_posts p

                         LEFT JOIN {$CFG->prefix}user u ON p.userid = u.id

                             WHERE p.parent = '$parent'

                          ORDER BY p.created ASC");

}



/**

 * An array of forum objects that the user is allowed to read/search through.

 * @param $userid

 * @param $courseid - if 0, we look for forums throughout the whole site.

 * @return array of forum objects, or false if no matches

 *         Forum objects have the following attributes:

 *         id, type, course, cmid, cmvisible, cmgroupmode, accessallgroups,

 *         viewhiddentimedposts

 */

function forum_get_readable_forums($userid, $courseid=0) {



    global $CFG, $USER;

    require_once($CFG->dirroot.'/course/lib.php');



    if (!$forummod = get_record('modules', 'name', 'forum')) {

        error('The forum module is not installed');

    }



    if ($courseid) {

        $courses = get_records('course', 'id', $courseid);

    } else {

        // If no course is specified, then the user can see SITE + his courses.

        // And admins can see all courses, so pass the $doanything flag enabled

        $courses1 = get_records('course', 'id', SITEID);

        $courses2 = get_my_courses($userid, null, null, true);

        $courses = array_merge($courses1, $courses2);

    }

    if (!$courses) {

        return array();

    }



    $readableforums = array();



    foreach ($courses as $course) {



        $modinfo =& get_fast_modinfo($course);

        if (is_null($modinfo->groups)) {

            $modinfo->groups = groups_get_user_groups($course->id, $userid);

        }



        if (empty($modinfo->instances['forum'])) {

            // hmm, no forums?

            continue;

        }



        $courseforums = get_records('forum', 'course', $course->id);



        foreach ($modinfo->instances['forum'] as $forumid => $cm) {

            if (!$cm->uservisible or !isset($courseforums[$forumid])) {

                continue;

            }

            $context = get_context_instance(CONTEXT_MODULE, $cm->id);

            $forum = $courseforums[$forumid];

            $forum->context = $context;

            $forum->cm = $cm;



            if (!has_capability('mod/forum:viewdiscussion', $context)) {

                continue;

            }



         /// group access

            if (groups_get_activity_groupmode($cm, $course) == SEPARATEGROUPS and !has_capability('moodle/site:accessallgroups', $context)) {

                if (is_null($modinfo->groups)) {

                    $modinfo->groups = groups_get_user_groups($course->id, $USER->id);

                }

                if (empty($CFG->enablegroupings)) {

                    $forum->onlygroups = $modinfo->groups[0];

                    $forum->onlygroups[] = -1;

                } else if (isset($modinfo->groups[$cm->groupingid])) {

                    $forum->onlygroups = $modinfo->groups[$cm->groupingid];

                    $forum->onlygroups[] = -1;

                } else {

                    $forum->onlygroups = array(-1);

                }

            }



        /// hidden timed discussions

            $forum->viewhiddentimedposts = true;

            if (!empty($CFG->forum_enabletimedposts)) {

                if (!has_capability('mod/forum:viewhiddentimedposts', $context)) {

                    $forum->viewhiddentimedposts = false;

                }

            }



        /// qanda access

            if ($forum->type == 'qanda'

                    && !has_capability('mod/forum:viewqandawithoutposting', $context)) {



                // We need to check whether the user has posted in the qanda forum.

                $forum->onlydiscussions = array();  // Holds discussion ids for the discussions

                                                    // the user is allowed to see in this forum.

                if ($discussionspostedin = forum_discussions_user_has_posted_in($forum->id, $USER->id)) {

                    foreach ($discussionspostedin as $d) {

                        $forum->onlydiscussions[] = $d->id;

                    }

                }

            }



            $readableforums[$forum->id] = $forum;

        }



        unset($modinfo);



    } // End foreach $courses



    //print_object($courses);

    //print_object($readableforums);



    return $readableforums;

}



/**

 * Returns a list of posts found using an array of search terms.

 * @param $searchterms - array of search terms, e.g. word +word -word

 * @param $courseid - if 0, we search through the whole site

 * @param $page

 * @param $recordsperpage=50

 * @param &$totalcount

 * @param $extrasql

 * @return array of posts found

 */

function forum_search_posts($searchterms, $courseid=0, $limitfrom=0, $limitnum=50,

                            &$totalcount, $extrasql='') {

    global $CFG, $USER;

    require_once($CFG->libdir.'/searchlib.php');



    $forums = forum_get_readable_forums($USER->id, $courseid);



    if (count($forums) == 0) {

        $totalcount = 0;

        return false;

    }



    $now = round(time(), -2); // db friendly



    $fullaccess = array();

    $where = array();



    foreach ($forums as $forumid => $forum) {

        $select = array();



        if (!$forum->viewhiddentimedposts) {

            $select[] = "(d.userid = {$USER->id} OR (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)))";

        }



        $cm = $forum->cm;

        $context = $forum->context;



        if ($forum->type == 'qanda'

            && !has_capability('mod/forum:viewqandawithoutposting', $context)) {

            if (!empty($forum->onlydiscussions)) {

                $discussionsids = implode(',', $forum->onlydiscussions);

                $select[] = "(d.id IN ($discussionsids) OR p.parent = 0)";

            } else {

                $select[] = "p.parent = 0";

            }

        }



        if (!empty($forum->onlygroups)) {

            $groupids = implode(',', $forum->onlygroups);

            $select[] = "d.groupid IN ($groupids)";

        }



        if ($select) {

            $selects = implode(" AND ", $select);

            $where[] = "(d.forum = $forumid AND $selects)";

        } else {

            $fullaccess[] = $forumid;

        }

    }



    if ($fullaccess) {

        $fullids = implode(',', $fullaccess);

        $where[] = "(d.forum IN ($fullids))";

    }



    $selectdiscussion = "(".implode(" OR ", $where).")";



    // Some differences SQL

    $LIKE = sql_ilike();

    $NOTLIKE = 'NOT ' . $LIKE;

    if ($CFG->dbfamily == 'postgres') {

        $REGEXP = '~*';

        $NOTREGEXP = '!~*';

    } else {

        $REGEXP = 'REGEXP';

        $NOTREGEXP = 'NOT REGEXP';

    }



    $messagesearch = '';

    $searchstring = '';



    // Need to concat these back together for parser to work.

    foreach($searchterms as $searchterm){

        if ($searchstring != '') {

            $searchstring .= ' ';

        }

        $searchstring .= $searchterm;

    }



    // We need to allow quoted strings for the search. The quotes *should* be stripped

    // by the parser, but this should be examined carefully for security implications.

    $searchstring = str_replace("\\\"","\"",$searchstring);

    $parser = new search_parser();

    $lexer = new search_lexer($parser);



    if ($lexer->parse($searchstring)) {

        $parsearray = $parser->get_parsed_array();

    // Experimental feature under 1.8! MDL-8830

    // Use alternative text searches if defined

    // This feature only works under mysql until properly implemented for other DBs

    // Requires manual creation of text index for forum_posts before enabling it:

    // CREATE FULLTEXT INDEX foru_post_tix ON [prefix]forum_posts (subject, message)

    // Experimental feature under 1.8! MDL-8830

        if (!empty($CFG->forum_usetextsearches)) {

            $messagesearch = search_generate_text_SQL($parsearray, 'p.message', 'p.subject',

                                                 'p.userid', 'u.id', 'u.firstname',

                                                 'u.lastname', 'p.modified', 'd.forum');

        } else {

            $messagesearch = search_generate_SQL($parsearray, 'p.message', 'p.subject',

                                                 'p.userid', 'u.id', 'u.firstname',

                                                 'u.lastname', 'p.modified', 'd.forum');

        }

    }



    $fromsql = "{$CFG->prefix}forum_posts p,

                  {$CFG->prefix}forum_discussions d,

                  {$CFG->prefix}user u";



    $selectsql = " $messagesearch

               AND p.discussion = d.id

               AND p.userid = u.id

               AND $selectdiscussion

                   $extrasql";



    $countsql = "SELECT COUNT(*)

                   FROM $fromsql

                  WHERE $selectsql";



    $searchsql = "SELECT p.*,

                         d.forum,

                         u.firstname,

                         u.lastname,

                         u.email,

                         u.picture,

                         u.imagealt

                    FROM $fromsql

                   WHERE $selectsql

                ORDER BY p.modified DESC";



    $totalcount = count_records_sql($countsql);



    return get_records_sql($searchsql, $limitfrom, $limitnum);

}



/**

 * Returns a list of ratings for all posts in discussion

 * @param object $discussion

 * @return array of ratings or false

 */

function forum_get_all_discussion_ratings($discussion) {

    global $CFG;

    return get_records_sql("SELECT r.id, r.userid, p.id AS postid, r.rating

                              FROM {$CFG->prefix}forum_ratings r,

                                   {$CFG->prefix}forum_posts p

                             WHERE r.post = p.id AND p.discussion = $discussion->id

                             ORDER BY p.id ASC");

}



/**

 * Returns a list of ratings for one specific user for all posts in discussion

 * @global object $CFG

 * @param object $discussions the discussions for which we return all ratings

 * @param int $userid the user for who we return all ratings

 * @return object

 */

function forum_get_all_user_ratings($userid, $discussions) {

    global $CFG;





    foreach ($discussions as $discussion) {

     if (!isset($discussionsid)){

         $discussionsid = $discussion->id;

     }

     else {

         $discussionsid .= ",".$discussion->id;

     }

    }



    $sql = "SELECT r.id, r.userid, p.id AS postid, r.rating

                              FROM {$CFG->prefix}forum_ratings r,

                                   {$CFG->prefix}forum_posts p

                             WHERE r.post = p.id AND p.userid = $userid";

    //postgres compability

    if (!isset($discussionsid)) {

       $sql .=" AND p.discussion IN (".$discussionsid.")";

    }

    $sql .=" ORDER BY p.id ASC";



    return get_records_sql($sql);

    



}



/**

 * Returns a list of ratings for a particular post - sorted.

 * @param int $postid

 * @param string $sort

 * @return array of ratings or false

 */

function forum_get_ratings($postid, $sort="u.firstname ASC") {

    global $CFG;

    return get_records_sql("SELECT u.*, r.rating, r.time

                              FROM {$CFG->prefix}forum_ratings r,

                                   {$CFG->prefix}user u

                             WHERE r.post = '$postid'

                               AND r.userid = u.id

                             ORDER BY $sort");

}



/**

 * Returns a list of all new posts that have not been mailed yet

 * @param int $starttime - posts created after this time

 * @param int $endtime - posts created before this

 * @param int $now - used for timed discussions only

 */

function forum_get_unmailed_posts($starttime, $endtime, $now=null) {

    global $CFG;



    if (!empty($CFG->forum_enabletimedposts)) {

        if (empty($now)) {

            $now = time();

        }

        $timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";

    } else {

        $timedsql = "";

    }



    return get_records_sql("SELECT p.*, d.course, d.forum

                              FROM {$CFG->prefix}forum_posts p

                                   JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                             WHERE p.mailed = 0

                                   AND p.created >= $starttime

                                   AND (p.created < $endtime OR p.mailnow = 1)

                                   $timedsql

                          ORDER BY p.modified ASC");

}



/**

 * Marks posts before a certain time as being mailed already

 */

function forum_mark_old_posts_as_mailed($endtime, $now=null) {

    global $CFG;

    if (empty($now)) {

        $now = time();

    }



    if (empty($CFG->forum_enabletimedposts)) {

        return execute_sql("UPDATE {$CFG->prefix}forum_posts

                               SET mailed = '1'

                             WHERE (created < $endtime OR mailnow = 1)

                                   AND mailed = 0", false);



    } else {

        return execute_sql("UPDATE {$CFG->prefix}forum_posts

                               SET mailed = '1'

                             WHERE discussion NOT IN (SELECT d.id

                                                        FROM {$CFG->prefix}forum_discussions d

                                                       WHERE d.timestart > $now)

                                   AND (created < $endtime OR mailnow = 1)

                                   AND mailed = 0", false);

    }

}



/**

 * Get all the posts for a user in a forum suitable for forum_print_post

 */

function forum_get_user_posts($forumid, $userid) {

    global $CFG;



    $timedsql = "";

    if (!empty($CFG->forum_enabletimedposts)) {

        $cm = get_coursemodule_from_instance('forum', $forumid);

        if (!has_capability('mod/forum:viewhiddentimedposts' , get_context_instance(CONTEXT_MODULE, $cm->id))) {

            $now = time();

            $timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";

        }

    }



    return get_records_sql("SELECT p.*, d.forum, u.firstname, u.lastname, u.email, u.picture, u.imagealt

                              FROM {$CFG->prefix}forum f

                                   JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id

                                   JOIN {$CFG->prefix}forum_posts p       ON p.discussion = d.id

                                   JOIN {$CFG->prefix}user u              ON u.id = p.userid

                             WHERE f.id = $forumid

                                   AND p.userid = $userid

                                   $timedsql

                          ORDER BY p.modified ASC");

}



/**

 * Get all the discussions user participated in

 * @param int $forumid

 * @param int $userid

 * @return array or false

 */

function forum_get_user_involved_discussions($forumid, $userid) {

    global $CFG;



    $timedsql = "";

    if (!empty($CFG->forum_enabletimedposts)) {

        $cm = get_coursemodule_from_instance('forum', $forumid);

        if (!has_capability('mod/forum:viewhiddentimedposts' , get_context_instance(CONTEXT_MODULE, $cm->id))) {

            $now = time();

            $timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";

        }

    }



    return get_records_sql("SELECT DISTINCT d.*

                              FROM {$CFG->prefix}forum f

                                   JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id

                                   JOIN {$CFG->prefix}forum_posts p       ON p.discussion = d.id

                             WHERE f.id = $forumid

                                   AND p.userid = $userid

                                   $timedsql");

}



/**

 * Get all the posts for a user in a forum suitable for forum_print_post

 * @param int $forumid

 * @param int $userid

 * @return array of counts or false

 */

function forum_count_user_posts($forumid, $userid) {

    global $CFG;



    $timedsql = "";

    if (!empty($CFG->forum_enabletimedposts)) {

        $cm = get_coursemodule_from_instance('forum', $forumid);

        if (!has_capability('mod/forum:viewhiddentimedposts' , get_context_instance(CONTEXT_MODULE, $cm->id))) {

            $now = time();

            $timedsql = "AND (d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now))";

        }

    }



    return get_record_sql("SELECT COUNT(p.id) AS postcount, MAX(p.modified) AS lastpost

                             FROM {$CFG->prefix}forum f

                                  JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id

                                  JOIN {$CFG->prefix}forum_posts p       ON p.discussion = d.id

                                  JOIN {$CFG->prefix}user u              ON u.id = p.userid

                            WHERE f.id = $forumid

                                  AND p.userid = $userid

                                  $timedsql");

}



/**

 * Given a log entry, return the forum post details for it.

 */

function forum_get_post_from_log($log) {

    global $CFG;



    if ($log->action == "add post") {



        return get_record_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,

                                           u.firstname, u.lastname, u.email, u.picture

                                 FROM {$CFG->prefix}forum_discussions d,

                                      {$CFG->prefix}forum_posts p,

                                      {$CFG->prefix}forum f,

                                      {$CFG->prefix}user u

                                WHERE p.id = '$log->info'

                                  AND d.id = p.discussion

                                  AND p.userid = u.id

                                  AND u.deleted <> '1'

                                  AND f.id = d.forum");





    } else if ($log->action == "add discussion") {



        return get_record_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,

                                           u.firstname, u.lastname, u.email, u.picture

                                 FROM {$CFG->prefix}forum_discussions d,

                                      {$CFG->prefix}forum_posts p,

                                      {$CFG->prefix}forum f,

                                      {$CFG->prefix}user u

                                WHERE d.id = '$log->info'

                                  AND d.firstpost = p.id

                                  AND p.userid = u.id

                                  AND u.deleted <> '1'

                                  AND f.id = d.forum");

    }

    return NULL;

}



/**

 * Given a discussion id, return the first post from the discussion

 */

function forum_get_firstpost_from_discussion($discussionid) {

    global $CFG;



    return get_record_sql("SELECT p.*

                             FROM {$CFG->prefix}forum_discussions d,

                                  {$CFG->prefix}forum_posts p

                            WHERE d.id = '$discussionid'

                              AND d.firstpost = p.id ");

}



/**

 * Returns an array of counts of replies to each discussion

 */

function forum_count_discussion_replies($forumid, $forumsort="", $limit=-1, $page=-1, $perpage=0) {

    global $CFG;



    if ($limit > 0) {

        $limitfrom = 0;

        $limitnum  = $limit;

    } else if ($page != -1) {

        $limitfrom = $page*$perpage;

        $limitnum  = $perpage;

    } else {

        $limitfrom = 0;

        $limitnum  = 0;

    }



    if ($forumsort == "") {

        $orderby = "";

        $groupby = "";



    } else {

        $orderby = "ORDER BY $forumsort";

        $groupby = ", ".strtolower($forumsort);

        $groupby = str_replace('desc', '', $groupby);

        $groupby = str_replace('asc', '', $groupby);

    }



    if (($limitfrom == 0 and $limitnum == 0) or $forumsort == "") {

        $sql = "SELECT p.discussion, COUNT(p.id) AS replies, MAX(p.id) AS lastpostid

                  FROM {$CFG->prefix}forum_posts p

                       JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id

                 WHERE p.parent > 0 AND d.forum = $forumid

              GROUP BY p.discussion";

        return get_records_sql($sql);



    } else {

        $sql = "SELECT p.discussion, (COUNT(p.id) - 1) AS replies, MAX(p.id) AS lastpostid

                  FROM {$CFG->prefix}forum_posts p

                       JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id

                 WHERE d.forum = $forumid

              GROUP BY p.discussion $groupby

              $orderby";

        return get_records_sql("SELECT * FROM ($sql) sq", $limitfrom, $limitnum);

    }

}



function forum_count_discussions($forum, $cm, $course) {

    global $CFG, $USER;



    static $cache = array();



    $now = round(time(), -2); // db cache friendliness



    if (!isset($cache[$course->id])) {

        if (!empty($CFG->forum_enabletimedposts)) {

            $timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";

        } else {

            $timedsql = "";

        }



        $sql = "SELECT f.id, COUNT(d.id) as dcount

                  FROM {$CFG->prefix}forum f

                       JOIN {$CFG->prefix}forum_discussions d ON d.forum = f.id

                 WHERE f.course = $course->id

                       $timedsql

              GROUP BY f.id";



        if ($counts = get_records_sql($sql)) {

            foreach ($counts as $count) {

                $counts[$count->id] = $count->dcount;

            }

            $cache[$course->id] = $counts;

        } else {

            $cache[$course->id] = array();

        }

    }



    if (empty($cache[$course->id][$forum->id])) {

        return 0;

    }



    $groupmode = groups_get_activity_groupmode($cm, $course);



    if ($groupmode != SEPARATEGROUPS) {

        return $cache[$course->id][$forum->id];

    }



    if (has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {

        return $cache[$course->id][$forum->id];

    }



    require_once($CFG->dirroot.'/course/lib.php');



    $modinfo =& get_fast_modinfo($course);

    if (is_null($modinfo->groups)) {

        $modinfo->groups = groups_get_user_groups($course->id, $USER->id);

    }



    if (empty($CFG->enablegroupings)) {

        $mygroups = $modinfo->groups[0];

    } else {

        $mygroups = $modinfo->groups[$cm->groupingid];

    }



    // add all groups posts

    if (empty($mygroups)) {

        $mygroups = array(-1=>-1);

    } else {

        $mygroups[-1] = -1;

    }

    $mygroups = implode(',', $mygroups);



    if (!empty($CFG->forum_enabletimedposts)) {

        $timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";

    } else {

        $timedsql = "";

    }



    $sql = "SELECT COUNT(d.id)

              FROM {$CFG->prefix}forum_discussions d

             WHERE d.forum = $forum->id AND d.groupid IN ($mygroups)

                   $timedsql";



    return get_field_sql($sql);

}



/**

 * How many unrated posts are in the given discussion for a given user?

 */

function forum_count_unrated_posts($discussionid, $userid) {

    global $CFG;

    if ($posts = get_record_sql("SELECT count(*) as num

                                   FROM {$CFG->prefix}forum_posts

                                  WHERE parent > 0

                                    AND discussion = '$discussionid'

                                    AND userid <> '$userid' ")) {



        if ($rated = get_record_sql("SELECT count(*) as num

                                       FROM {$CFG->prefix}forum_posts p,

                                            {$CFG->prefix}forum_ratings r

                                      WHERE p.discussion = '$discussionid'

                                        AND p.id = r.post

                                        AND r.userid = '$userid'")) {

            $difference = $posts->num - $rated->num;

            if ($difference > 0) {

                return $difference;

            } else {

                return 0;    // Just in case there was a counting error

            }

        } else {

            return $posts->num;

        }

    } else {

        return 0;

    }

}



/**

 * Get all discussions in a forum

 */

function forum_get_discussions($cm, $forumsort="d.timemodified DESC", $fullpost=true, $unused=-1, $limit=-1, $userlastmodified=false, $page=-1, $perpage=0) {

    global $CFG, $USER;



    $timelimit = '';



    $modcontext = null;



    $now = round(time(), -2);



    $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);



    if (!has_capability('mod/forum:viewdiscussion', $modcontext)) { /// User must have perms to view discussions

        return array();

    }



    if (!empty($CFG->forum_enabletimedposts)) { /// Users must fulfill timed posts



        if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {

            $timelimit = " AND ((d.timestart <= $now AND (d.timeend = 0 OR d.timeend > $now))";

            if (isloggedin()) {

                $timelimit .= " OR d.userid = $USER->id";

            }

            $timelimit .= ")";

        }

    }



    if ($limit > 0) {

        $limitfrom = 0;

        $limitnum  = $limit;

    } else if ($page != -1) {

        $limitfrom = $page*$perpage;

        $limitnum  = $perpage;

    } else {

        $limitfrom = 0;

        $limitnum  = 0;

    }



    $groupmode    = groups_get_activity_groupmode($cm);

    $currentgroup = groups_get_activity_group($cm);



    if ($groupmode) {

        if (empty($modcontext)) {

            $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        }



        if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {

            if ($currentgroup) {

                $groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";

            } else {

                $groupselect = "";

            }



        } else {

            //seprate groups without access all

            if ($currentgroup) {

                $groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";

            } else {

                $groupselect = "AND d.groupid = -1";

            }

        }

    } else {

        $groupselect = "";

    }





    if (empty($forumsort)) {

        $forumsort = "d.timemodified DESC";

    }

    if (empty($fullpost)) {

        $postdata = "p.id,p.subject,p.modified,p.discussion,p.userid";

    } else {

        $postdata = "p.*";

    }



    if (empty($userlastmodified)) {  // We don't need to know this

        $umfields = "";

        $umtable  = "";

    } else {

        $umfields = ", um.firstname AS umfirstname, um.lastname AS umlastname";

        $umtable  = " LEFT JOIN {$CFG->prefix}user um ON (d.usermodified = um.id)";

    }



    $sql = "SELECT $postdata, d.name, d.timemodified, d.usermodified, d.groupid, d.timestart, d.timeend,

                   u.firstname, u.lastname, u.email, u.picture, u.imagealt $umfields

              FROM {$CFG->prefix}forum_discussions d

                   JOIN {$CFG->prefix}forum_posts p ON p.discussion = d.id

                   JOIN {$CFG->prefix}user u ON p.userid = u.id

                   $umtable

             WHERE d.forum = {$cm->instance} AND p.parent = 0

                   $timelimit $groupselect

          ORDER BY $forumsort";

    return get_records_sql($sql, $limitfrom, $limitnum);

}



function forum_get_discussions_unread($cm) {

    global $CFG, $USER;



    $now = round(time(), -2);



    $groupmode    = groups_get_activity_groupmode($cm);

    $currentgroup = groups_get_activity_group($cm);



    if ($groupmode) {

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);



        if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {

            if ($currentgroup) {

                $groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";

            } else {

                $groupselect = "";

            }



        } else {

            //seprate groups without access all

            if ($currentgroup) {

                $groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";

            } else {

                $groupselect = "AND d.groupid = -1";

            }

        }

    } else {

        $groupselect = "";

    }



    $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);



    if (!empty($CFG->forum_enabletimedposts)) {

        $timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";

    } else {

        $timedsql = "";

    }



    $sql = "SELECT d.id, COUNT(p.id) AS unread

              FROM {$CFG->prefix}forum_discussions d

                   JOIN {$CFG->prefix}forum_posts p     ON p.discussion = d.id

                   LEFT JOIN {$CFG->prefix}forum_read r ON (r.postid = p.id AND r.userid = $USER->id)

             WHERE d.forum = {$cm->instance}

                   AND p.modified >= $cutoffdate AND r.id is NULL

                   $timedsql

                   $groupselect

          GROUP BY d.id";

    if ($unreads = get_records_sql($sql)) {

        foreach ($unreads as $unread) {

            $unreads[$unread->id] = $unread->unread;

        }

        return $unreads;

    } else {

        return array();

    }

}



function forum_get_discussions_count($cm) {

    global $CFG, $USER;



    $now = round(time(), -2);



    $groupmode    = groups_get_activity_groupmode($cm);

    $currentgroup = groups_get_activity_group($cm);



    if ($groupmode) {

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);



        if ($groupmode == VISIBLEGROUPS or has_capability('moodle/site:accessallgroups', $modcontext)) {

            if ($currentgroup) {

                $groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";

            } else {

                $groupselect = "";

            }



        } else {

            //seprate groups without access all

            if ($currentgroup) {

                $groupselect = "AND (d.groupid = $currentgroup OR d.groupid = -1)";

            } else {

                $groupselect = "AND d.groupid = -1";

            }

        }

    } else {

        $groupselect = "";

    }



    $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);



    $timelimit = "";



    if (!empty($CFG->forum_enabletimedposts)) {



        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);



        if (!has_capability('mod/forum:viewhiddentimedposts', $modcontext)) {

            $timelimit = " AND ((d.timestart <= $now AND (d.timeend = 0 OR d.timeend > $now))";

            if (isloggedin()) {

                $timelimit .= " OR d.userid = $USER->id";

            }

            $timelimit .= ")";

        }

    }



    $sql = "SELECT COUNT(d.id)

              FROM {$CFG->prefix}forum_discussions d

                   JOIN {$CFG->prefix}forum_posts p ON p.discussion = d.id

             WHERE d.forum = {$cm->instance} AND p.parent = 0

                   $timelimit $groupselect";



    return get_field_sql($sql);

}





/**

 * Get all discussions started by a particular user in a course (or group)

 * This function no longer used ...

 */

function forum_get_user_discussions($courseid, $userid, $groupid=0) {

    global $CFG;



    if ($groupid) {

        $groupselect = " AND d.groupid = '$groupid' ";

    } else  {

        $groupselect = "";

    }



    return get_records_sql("SELECT p.*, d.groupid, u.firstname, u.lastname, u.email, u.picture, u.imagealt,

                                   f.type as forumtype, f.name as forumname, f.id as forumid

                              FROM {$CFG->prefix}forum_discussions d,

                                   {$CFG->prefix}forum_posts p,

                                   {$CFG->prefix}user u,

                                   {$CFG->prefix}forum f

                             WHERE d.course = '$courseid'

                               AND p.discussion = d.id

                               AND p.parent = 0

                               AND p.userid = u.id

                               AND u.id = '$userid'

                               AND d.forum = f.id $groupselect

                          ORDER BY p.created DESC");

}



/**

 * Get the list of potential subscribers to a forum. 

 *

 * @param object $forumcontext the forum context.

 * @param integer $groupid the id of a group, or 0 for all groups.

 * @param string $fields the list of fields to return for each user. As for get_users_by_capability.

 * @param string $sort sort order. As for get_users_by_capability.

 * @return array list of users.

 */

function forum_get_potential_subscribers($forumcontext, $groupid, $fields, $sort) {

    return get_users_by_capability($forumcontext, 'mod/forum:initialsubscriptions', $fields, $sort, '', '', $groupid, '', false, true);

}



/**

 * Returns list of user objects that are subscribed to this forum

 *

 * @param object $course the course

 * @param forum $forum the forum

 * @param integer $groupid group id, or 0 for all.

 * @param object $context the forum context, to save re-fetching it where possible.

 * @return array list of users.

 */

function forum_subscribed_users($course, $forum, $groupid=0, $context = NULL) {

    global $CFG;



    if ($groupid) {

        $grouptables = ", {$CFG->prefix}groups_members gm ";

        $groupselect = "AND gm.groupid = $groupid AND u.id = gm.userid";



    } else  {

        $grouptables = '';

        $groupselect = '';

    }



    if (forum_is_forcesubscribed($forum)) {

        if (empty($context)) {

            $cm = get_coursemodule_from_instance('forum', $forum->id, $course->id);

            $context = get_context_instance(CONTEXT_MODULE, $cm->id);

        }

        $sort = "u.email ASC";

        $fields ="u.id, u.username, u.firstname, u.lastname, u.maildisplay, u.mailformat, u.maildigest, u.emailstop, u.imagealt,

                  u.email, u.city, u.country, u.lastaccess, u.lastlogin, u.picture, u.timezone, u.theme, u.lang, u.trackforums, u.mnethostid";

        $results = forum_get_potential_subscribers($context, $groupid, $fields, $sort);

    } else {

        $results = get_records_sql("SELECT u.id, u.username, u.firstname, u.lastname, u.maildisplay, u.mailformat, u.maildigest, u.emailstop, u.imagealt,

                                   u.email, u.city, u.country, u.lastaccess, u.lastlogin, u.picture, u.timezone, u.theme, u.lang, u.trackforums, u.mnethostid

                              FROM {$CFG->prefix}user u,

                                   {$CFG->prefix}forum_subscriptions s $grouptables

                             WHERE s.forum = '$forum->id'

                               AND s.userid = u.id

                               AND u.deleted = 0  $groupselect

                          ORDER BY u.email ASC");

    }



    static $guestid = null;



    if (is_null($guestid)) {

        if ($guest = guest_user()) {

            $guestid = $guest->id;

        } else {

            $guestid = 0;

        }

    }



    // Guest user should never be subscribed to a forum.

    unset($results[$guestid]);



    return $results;

}







// OTHER FUNCTIONS ///////////////////////////////////////////////////////////





function forum_get_course_forum($courseid, $type) {

// How to set up special 1-per-course forums

    global $CFG;



    if ($forums = get_records_select("forum", "course = '$courseid' AND type = '$type'", "id ASC")) {

        // There should always only be ONE, but with the right combination of

        // errors there might be more.  In this case, just return the oldest one (lowest ID).

        foreach ($forums as $forum) {

            return $forum;   // ie the first one

        }

    }



    // Doesn't exist, so create one now.

    $forum->course = $courseid;

    $forum->type = "$type";

    switch ($forum->type) {

        case "news":

            $forum->name  = addslashes(get_string("namenews", "forum"));

            $forum->intro = addslashes(get_string("intronews", "forum"));

            $forum->forcesubscribe = FORUM_FORCESUBSCRIBE;

            $forum->assessed = 0;

            if ($courseid == SITEID) {

                $forum->name  = get_string("sitenews");

                $forum->forcesubscribe = 0;

            }

            break;

        case "social":

            $forum->name  = addslashes(get_string("namesocial", "forum"));

            $forum->intro = addslashes(get_string("introsocial", "forum"));

            $forum->assessed = 0;

            $forum->forcesubscribe = 0;

            break;

        default:

            notify("That forum type doesn't exist!");

            return false;

            break;

    }



    $forum->timemodified = time();

    $forum->id = insert_record("forum", $forum);



    if (! $module = get_record("modules", "name", "forum")) {

        notify("Could not find forum module!!");

        return false;

    }

    $mod = new object();

    $mod->course = $courseid;

    $mod->module = $module->id;

    $mod->instance = $forum->id;

    $mod->section = 0;

    if (! $mod->coursemodule = add_course_module($mod) ) {   // assumes course/lib.php is loaded

        notify("Could not add a new course module to the course '" . format_string($course->fullname) . "'");

        return false;

    }

    if (! $sectionid = add_mod_to_section($mod) ) {   // assumes course/lib.php is loaded

        notify("Could not add the new course module to that section");

        return false;

    }

    if (! set_field("course_modules", "section", $sectionid, "id", $mod->coursemodule)) {

        notify("Could not update the course module with the correct section");

        return false;

    }

    include_once("$CFG->dirroot/course/lib.php");

    rebuild_course_cache($courseid);



    return get_record("forum", "id", "$forum->id");

}





/**

* Given the data about a posting, builds up the HTML to display it and

* returns the HTML in a string.  This is designed for sending via HTML email.

*/

function forum_make_mail_post($course, $forum, $discussion, $post, $userfrom, $userto,

                              $ownpost=false, $reply=false, $link=false, $rate=false, $footer="") {



    global $CFG;



    if (!isset($userto->viewfullnames[$forum->id])) {

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {

            error('Course Module ID was incorrect');

        }

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        $viewfullnames = has_capability('moodle/site:viewfullnames', $modcontext, $userto->id);

    } else {

        $viewfullnames = $userto->viewfullnames[$forum->id];

    }



    // format the post body

    $options = new object();

    $options->para = true;

    $formattedtext = format_text(trusttext_strip($post->message), $post->format, $options, $course->id);



    $output = '<table border="0" cellpadding="3" cellspacing="0" class="forumpost">';



    $output .= '<tr class="header"><td width="35" valign="top" class="picture left">';

    $output .= print_user_picture($userfrom, $course->id, $userfrom->picture, false, true);

    $output .= '</td>';



    if ($post->parent) {

        $output .= '<td class="topic">';

    } else {

        $output .= '<td class="topic starter">';

    }

    $output .= '<div class="subject">'.format_string($post->subject).'</div>';



    $fullname = fullname($userfrom, $viewfullnames);

    $by = new object();

    $by->name = '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$userfrom->id.'&amp;course='.$course->id.'">'.$fullname.'</a>';

    $by->date = userdate($post->modified, '', $userto->timezone);

    $output .= '<div class="author">'.get_string('bynameondate', 'forum', $by).'</div>';



    $output .= '</td></tr>';



    $output .= '<tr><td class="left side" valign="top">';



    if (isset($userfrom->groups)) {

        $groups = $userfrom->groups[$forum->id];

    } else {

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $course->id)) {

            error('Course Module ID was incorrect');

        }

        $group = groups_get_all_groups($course->id, $userfrom->id, $cm->groupingid);

    }



    if ($groups) {

        $output .= print_group_picture($groups, $course->id, false, true, true);

    } else {

        $output .= '&nbsp;';

    }



    $output .= '</td><td class="content">';



    if ($post->attachment) {

        $post->course = $course->id;

        $output .= '<div class="attachments">';

        $output .= forum_print_attachments($post, 'html');

        $output .= "</div>";

    }



    $output .= $formattedtext;



// Commands

    $commands = array();



    if ($post->parent) {

        $commands[] = '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.

                      $post->discussion.'&amp;parent='.$post->parent.'">'.get_string('parent', 'forum').'</a>';

    }



    if ($reply) {

        $commands[] = '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/post.php?reply='.$post->id.'">'.

                      get_string('reply', 'forum').'</a>';

    }



    $output .= '<div class="commands">';

    $output .= implode(' | ', $commands);

    $output .= '</div>';



// Context link to post if required

    if ($link) {

        $output .= '<div class="link">';

        $output .= '<a target="_blank" href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'#p'.$post->id.'">'.

                     get_string('postincontext', 'forum').'</a>';

        $output .= '</div>';

    }



    if ($footer) {

        $output .= '<div class="footer">'.$footer.'</div>';

    }

    $output .= '</td></tr></table>'."\n\n";



    return $output;

}



/**

 * Print a forum post

 *

 * @param object $post The post to print.

 * @param integer $courseid The course this post belongs to.

 * @param boolean $ownpost Whether this post belongs to the current user.

 * @param boolean $reply Whether to print a 'reply' link at the bottom of the message.

 * @param boolean $link Just print a shortened version of the post as a link to the full post.

 * @param object $ratings -- I don't really know --

 * @param string $footer Extra stuff to print after the message.

 * @param string $highlight Space-separated list of terms to highlight.

 * @param int $post_read true, false or -99. If we already know whether this user

 *          has read this post, pass that in, otherwise, pass in -99, and this

 *          function will work it out.

 * @param boolean $dummyifcantsee When forum_user_can_see_post says that

 *          the current user can't see this post, if this argument is true

 *          (the default) then print a dummy 'you can't see this post' post.

 *          If false, don't output anything at all.

 */

function forum_print_post($post, $discussion, $forum, &$cm, $course, $ownpost=false, $reply=false, $link=false,

                          $ratings=NULL, $footer="", $highlight="", $post_read=null, $dummyifcantsee=true, $istracked=null) {



    global $USER, $CFG;



    static $stredit, $strdelete, $strreply, $strparent, $strprune;

    static $strpruneheading, $displaymode;

    static $strmarkread, $strmarkunread;



    $post->course = $course->id;

    $post->forum  = $forum->id;



    // caching

    if (!isset($cm->cache)) {

        $cm->cache = new object();

    }



    if (!isset($cm->cache->caps)) {

        $cm->cache->caps = array();

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        $cm->cache->caps['mod/forum:viewdiscussion']   = has_capability('mod/forum:viewdiscussion', $modcontext);

        $cm->cache->caps['moodle/site:viewfullnames']  = has_capability('moodle/site:viewfullnames', $modcontext);

        $cm->cache->caps['mod/forum:editanypost']      = has_capability('mod/forum:editanypost', $modcontext);

        $cm->cache->caps['mod/forum:splitdiscussions'] = has_capability('mod/forum:splitdiscussions', $modcontext);

        $cm->cache->caps['mod/forum:deleteownpost']    = has_capability('mod/forum:deleteownpost', $modcontext);

        $cm->cache->caps['mod/forum:deleteanypost']    = has_capability('mod/forum:deleteanypost', $modcontext);

        $cm->cache->caps['mod/forum:viewanyrating']    = has_capability('mod/forum:viewanyrating', $modcontext);

    }



    if (!isset($cm->uservisible)) {

        $cm->uservisible = coursemodule_visible_for_user($cm);

    }



    if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {

        if (!$dummyifcantsee) {

            return;

        }

        echo '<a id="p'.$post->id.'"></a>';

        echo '<table cellspacing="0" class="forumpost">';

        echo '<tr class="header"><td class="picture left">';

        //        print_user_picture($post->userid, $courseid, $post->picture);

        echo '</td>';

        if ($post->parent) {

            echo '<td class="topic">';

        } else {

            echo '<td class="topic starter">';

        }

        echo '<div class="subject">'.get_string('forumsubjecthidden','forum').'</div>';

        echo '<div class="author">';

        print_string('forumauthorhidden','forum');

        echo '</div></td></tr>';



        echo '<tr><td class="left side">';

        echo '&nbsp;';



        // Actual content



        echo '</td><td class="content">'."\n";

        echo get_string('forumbodyhidden','forum');

        echo '</td></tr></table>';

        return;

    }



    if (empty($stredit)) {

        $stredit         = get_string('edit', 'forum');

        $strdelete       = get_string('delete', 'forum');

        $strreply        = get_string('reply', 'forum');

        $strparent       = get_string('parent', 'forum');

        $strpruneheading = get_string('pruneheading', 'forum');

        $strprune        = get_string('prune', 'forum');

        $displaymode     = get_user_preferences('forum_displaymode', $CFG->forum_displaymode);

        $strmarkread     = get_string('markread', 'forum');

        $strmarkunread   = get_string('markunread', 'forum');



    }



    $read_style = '';

    // ignore trackign status if not tracked or tracked param missing

    if ($istracked) {

        if (is_null($post_read)) {

            debugging('fetching post_read info');

            $post_read = forum_tp_is_post_read($USER->id, $post);

        }



        if ($post_read) {

            $read_style = ' read';

        } else {

            $read_style = ' unread';

            echo '<a name="unread"></a>';

        }

    }



    echo '<a id="p'.$post->id.'"></a>';

    echo '<table cellspacing="0" class="forumpost'.$read_style.'">';



    // Picture

    $postuser = new object();

    $postuser->id        = $post->userid;

    $postuser->firstname = $post->firstname;

    $postuser->lastname  = $post->lastname;

    $postuser->imagealt  = $post->imagealt;

    $postuser->picture   = $post->picture;



    echo '<tr class="header"><td class="picture left">';

    print_user_picture($postuser, $course->id);

    echo '</td>';



    if ($post->parent) {

        echo '<td class="topic">';

    } else {

        echo '<td class="topic starter">';

    }



    if (!empty($post->subjectnoformat)) {

        echo '<div class="subject">'.$post->subject.'</div>';

    } else {

        echo '<div class="subject">'.format_string($post->subject).'</div>';

    }



    echo '<div class="author">';

    $fullname = fullname($postuser, $cm->cache->caps['moodle/site:viewfullnames']);

    $by = new object();

    $by->name = '<a href="'.$CFG->wwwroot.'/user/view.php?id='.

                $post->userid.'&amp;course='.$course->id.'">'.$fullname.'</a>';

    $by->date = userdate($post->modified);

    print_string('bynameondate', 'forum', $by);

    echo '</div></td></tr>';



    echo '<tr><td class="left side">';

    if (isset($cm->cache->usersgroups)) {

        $groups = array();

        if (isset($cm->cache->usersgroups[$post->userid])) {

            foreach ($cm->cache->usersgroups[$post->userid] as $gid) {

                $groups[$gid] = $cm->cache->groups[$gid];

            }

        }

    } else {

        $groups = groups_get_all_groups($course->id, $post->userid, $cm->groupingid);

    }



    if ($groups) {

        print_group_picture($groups, $course->id, false, false, true);

    } else {

        echo '&nbsp;';

    }



// Actual content



    echo '</td><td class="content">'."\n";



    if ($post->attachment) {

        echo '<div class="attachments">';

        $attachedimages = forum_print_attachments($post);

        echo '</div>';

    } else {

        $attachedimages = '';

    }





    $options = new object();

    $options->para      = false;

    $options->trusttext = true;

    if ($link and (strlen(strip_tags($post->message)) > $CFG->forum_longpost)) {

        // Print shortened version

        echo format_text(forum_shorten_post($post->message), $post->format, $options, $course->id);

        $numwords = count_words(strip_tags($post->message));

        echo '<div class="posting"><a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';

        echo get_string('readtherest', 'forum');

        echo '</a> ('.get_string('numwords', '', $numwords).')...</div>';

    } else {

        // Print whole message

        echo '<div class="posting">';

        if ($highlight) {

            echo highlight($highlight, format_text($post->message, $post->format, $options, $course->id));

        } else {

            echo format_text($post->message, $post->format, $options, $course->id);

        }

        echo '</div>';

        echo $attachedimages;

    }





// Commands



    $commands = array();



    if ($istracked) {

        // SPECIAL CASE: The front page can display a news item post to non-logged in users.

        // Don't display the mark read / unread controls in this case.

        if ($CFG->forum_usermarksread and isloggedin()) {

            if ($post_read) {

                $mcmd = '&amp;mark=unread&amp;postid='.$post->id;

                $mtxt = $strmarkunread;

            } else {

                $mcmd = '&amp;mark=read&amp;postid='.$post->id;

                $mtxt = $strmarkread;

            }

            if ($displaymode == FORUM_MODE_THREADED) {

                $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.

                              $post->discussion.'&amp;parent='.$post->id.$mcmd.'">'.$mtxt.'</a>';

            } else {

                $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.

                              $post->discussion.$mcmd.'#p'.$post->id.'">'.$mtxt.'</a>';

            }

        }

    }



    if ($post->parent) {  // Zoom in to the parent specifically

        if ($displaymode == FORUM_MODE_THREADED) {

            $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.

                      $post->discussion.'&amp;parent='.$post->parent.'">'.$strparent.'</a>';

        } else {

            $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.

                      $post->discussion.'#p'.$post->parent.'">'.$strparent.'</a>';

        }

    }



    $age = time() - $post->created;

    // Hack for allow to edit news posts those are not displayed yet until they are displayed

    if (!$post->parent and $forum->type == 'news' and $discussion->timestart > time()) {

        $age = 0;

    }

    $editanypost = $cm->cache->caps['mod/forum:editanypost'];



    if ($ownpost or $editanypost) {

        if (($age < $CFG->maxeditingtime) or $editanypost) {

            $commands[] =  '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?edit='.$post->id.'">'.$stredit.'</a>';

        }

    }



    if ($cm->cache->caps['mod/forum:splitdiscussions']

                && $post->parent && $forum->type != 'single') {



        $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?prune='.$post->id.

                      '" title="'.$strpruneheading.'">'.$strprune.'</a>';

    }



    if (($ownpost and $age < $CFG->maxeditingtime

                and $cm->cache->caps['mod/forum:deleteownpost'])

                or $cm->cache->caps['mod/forum:deleteanypost']) {

        $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?delete='.$post->id.'">'.$strdelete.'</a>';

    }



    if ($reply) {

        $commands[] = '<a href="'.$CFG->wwwroot.'/mod/forum/post.php?reply='.$post->id.'">'.$strreply.'</a>';

    }



    echo '<div class="commands">';

    echo implode(' | ', $commands);

    echo '</div>';





// Ratings



    $ratingsmenuused = false;

    if (!empty($ratings) and isloggedin()) {

        echo '<div class="ratings">';

        $useratings = true;

        if ($ratings->assesstimestart and $ratings->assesstimefinish) {

            if ($post->created < $ratings->assesstimestart or $post->created > $ratings->assesstimefinish) {

                $useratings = false;

            }

        }

        if ($useratings) {

            $mypost = ($USER->id == $post->userid);



            $canviewallratings = $cm->cache->caps['mod/forum:viewanyrating'];



            if (isset($cm->cache->ratings)) {

                if (isset($cm->cache->ratings[$post->id])) {

                    $allratings = $cm->cache->ratings[$post->id];

                } else {

                    $allratings = array(); // no reatings present yet

                }

            } else {

                $allratings = NULL; // not preloaded

            }



            if (isset($cm->cache->myratings)) {

                if (isset($cm->cache->myratings[$post->id])) {

                    $myrating = $cm->cache->myratings[$post->id];

                } else {

                    $myrating = FORUM_UNSET_POST_RATING; // no reatings present yet

                }

            } else {

                $myrating = NULL; // not preloaded

            }



            if ($canviewallratings and !$mypost) {

                echo '<span class="forumpostratingtext">' .

                     forum_print_ratings($post->id, $ratings->scale, $forum->assessed, $canviewallratings, $allratings, true) .

                     '</span>';

                if (!empty($ratings->allow)) {

                    echo '&nbsp;';

                    forum_print_rating_menu($post->id, $USER->id, $ratings->scale, $myrating);

                    $ratingsmenuused = true;

                }



            } else if ($mypost) {

                echo '<span class="forumpostratingtext">' .

                     forum_print_ratings($post->id, $ratings->scale, $forum->assessed, true, $allratings, true) .

                     '</span>';



            } else if (!empty($ratings->allow) ) {

                forum_print_rating_menu($post->id, $USER->id, $ratings->scale, $myrating);

                $ratingsmenuused = true;

            }

        }

        echo '</div>';

    }



// Link to post if required



    if ($link) {

        echo '<div class="link">';

        if ($post->replies == 1) {

            $replystring = get_string('repliesone', 'forum', $post->replies);

        } else {

            $replystring = get_string('repliesmany', 'forum', $post->replies);

        }

        echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">'.

             get_string('discussthistopic', 'forum').'</a>&nbsp;('.$replystring.')';

        echo '</div>';

    }



    if ($footer) {

        echo '<div class="footer">'.$footer.'</div>';

    }

    echo '</td></tr></table>'."\n\n";



    if ($istracked && !$CFG->forum_usermarksread && !$post_read) {

        forum_tp_mark_post_read($USER->id, $post, $forum->id);

    }



    return $ratingsmenuused;

}





/**

 * This function prints the overview of a discussion in the forum listing.

 * It needs some discussion information and some post information, these

 * happen to be combined for efficiency in the $post parameter by the function

 * that calls this one: forum_print_latest_discussions()

 *

 * @param object $post The post object (passed by reference for speed).

 * @param object $forum The forum object.

 * @param int $group Current group.

 * @param string $datestring Format to use for the dates.

 * @param boolean $cantrack Is tracking enabled for this forum.

 * @param boolean $forumtracked Is the user tracking this forum.

 * @param boolean $canviewparticipants True if user has the viewparticipants permission for this course

 */

function forum_print_discussion_header(&$post, $forum, $group=-1, $datestring="",

                                        $cantrack=true, $forumtracked=true, $canviewparticipants=true, $modcontext=NULL) {



    global $USER, $CFG;



    static $rowcount;

    static $strmarkalldread;



    if (empty($modcontext)) {

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {

            error('Course Module ID was incorrect');

        }

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

    }



    if (!isset($rowcount)) {

        $rowcount = 0;

        $strmarkalldread = get_string('markalldread', 'forum');

    } else {

        $rowcount = ($rowcount + 1) % 2;

    }



    $post->subject = format_string($post->subject,true);



    echo "\n\n";

    echo '<tr class="discussion r'.$rowcount.'">';



    // Topic

    echo '<td class="topic starter">';

    echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">'.$post->subject.'</a>';

    echo "</td>\n";



    // Picture

    $postuser = new object;

    $postuser->id = $post->userid;

    $postuser->firstname = $post->firstname;

    $postuser->lastname = $post->lastname;

    $postuser->imagealt = $post->imagealt;

    $postuser->picture = $post->picture;



    echo '<td class="picture">';

    print_user_picture($postuser, $forum->course);

    echo "</td>\n";



    // User name

    $fullname = fullname($post, has_capability('moodle/site:viewfullnames', $modcontext));

    echo '<td class="author">';

    echo '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$post->userid.'&amp;course='.$forum->course.'">'.$fullname.'</a>';

    echo "</td>\n";



    // Group picture

    if ($group !== -1) {  // Groups are active - group is a group data object or NULL

        echo '<td class="picture group">';

        if (!empty($group->picture) and empty($group->hidepicture)) {

            print_group_picture($group, $forum->course, false, false, true);

        } else if (isset($group->id)) {

            if($canviewparticipants) {

                echo '<a href="'.$CFG->wwwroot.'/user/index.php?id='.$forum->course.'&amp;group='.$group->id.'">'.$group->name.'</a>';

            } else {

                echo $group->name;

            }

        }

        echo "</td>\n";

    }



    if (has_capability('mod/forum:viewdiscussion', $modcontext)) {   // Show the column with replies

        echo '<td class="replies">';

        echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'">';

        echo $post->replies.'</a>';

        echo "</td>\n";



        if ($cantrack) {

            echo '<td class="replies">';

            if ($forumtracked) {

                if ($post->unread > 0) {

                    echo '<span class="unread">';

                    echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.'#unread">';

                    echo $post->unread;

                    echo '</a>';

                    echo '<a title="'.$strmarkalldread.'" href="'.$CFG->wwwroot.'/mod/forum/markposts.php?f='.

                         $forum->id.'&amp;d='.$post->discussion.'&amp;mark=read&amp;returnpage=view.php">' .

                         '<img src="'.$CFG->pixpath.'/t/clear.gif" class="iconsmall" alt="'.$strmarkalldread.'" /></a>';

                    echo '</span>';

                } else {

                    echo '<span class="read">';

                    echo $post->unread;

                    echo '</span>';

                }

            } else {

                echo '<span class="read">';

                echo '-';

                echo '</span>';

            }

            echo "</td>\n";

        }

    }



    echo '<td class="lastpost">';

    $usedate = (empty($post->timemodified)) ? $post->modified : $post->timemodified;  // Just in case

    $parenturl = (empty($post->lastpostid)) ? '' : '&amp;parent='.$post->lastpostid;

    $usermodified = new object();

    $usermodified->id        = $post->usermodified;

    $usermodified->firstname = $post->umfirstname;

    $usermodified->lastname  = $post->umlastname;

    echo '<a href="'.$CFG->wwwroot.'/user/view.php?id='.$post->usermodified.'&amp;course='.$forum->course.'">'.

         fullname($usermodified).'</a><br />';

    echo '<a href="'.$CFG->wwwroot.'/mod/forum/discuss.php?d='.$post->discussion.$parenturl.'">'.

          userdate($usedate, $datestring).'</a>';

    echo "</td>\n";



    echo "</tr>\n\n";



}





/**

 * Given a post object that we already know has a long message

 * this function truncates the message nicely to the first

 * sane place between $CFG->forum_longpost and $CFG->forum_shortpost

 */

function forum_shorten_post($message) {



   global $CFG;



   $i = 0;

   $tag = false;

   $length = strlen($message);

   $count = 0;

   $stopzone = false;

   $truncate = 0;



   for ($i=0; $i<$length; $i++) {

       $char = $message[$i];



       switch ($char) {

           case "<":

               $tag = true;

               break;

           case ">":

               $tag = false;

               break;

           default:

               if (!$tag) {

                   if ($stopzone) {

                       if ($char == ".") {

                           $truncate = $i+1;

                           break 2;

                       }

                   }

                   $count++;

               }

               break;

       }

       if (!$stopzone) {

           if ($count > $CFG->forum_shortpost) {

               $stopzone = true;

           }

       }

   }



   if (!$truncate) {

       $truncate = $i;

   }



   return substr($message, 0, $truncate);

}





/**

 * Print the multiple ratings on a post given to the current user by others.

 * Forumid prevents the double lookup of the forumid in discussion to determine the aggregate type

 * Scale is an array of ratings

 */

function forum_print_ratings($postid, $scale, $aggregatetype, $link=true, $ratings=null, $return=false) {



    $strratings = '';



    switch ($aggregatetype) {

        case FORUM_AGGREGATE_AVG :

            $agg        = forum_get_ratings_mean($postid, $scale, $ratings);

            $strratings = get_string("aggregateavg", "forum");

            break;

        case FORUM_AGGREGATE_COUNT :

            $agg        = forum_get_ratings_count($postid, $scale, $ratings);

            $strratings = get_string("aggregatecount", "forum");

            break;

        case FORUM_AGGREGATE_MAX :

            $agg        = forum_get_ratings_max($postid, $scale, $ratings);

            $strratings = get_string("aggregatemax", "forum");

            break;

        case FORUM_AGGREGATE_MIN :

            $agg        = forum_get_ratings_min($postid, $scale, $ratings);

            $strratings = get_string("aggregatemin", "forum");

            break;

        case FORUM_AGGREGATE_SUM :

            $agg        = forum_get_ratings_sum($postid, $scale, $ratings);

            $strratings = get_string("aggregatesum", "forum");

            break;

    }



    if ($agg !== "") {



        if (empty($strratings)) {

            $strratings = get_string("ratings", "forum");

        }



        $strratings .= ': ';



        if ($link) {

            $strratings .= link_to_popup_window ("/mod/forum/report.php?id=$postid", "ratings", $agg, 400, 600, null, null, true);

        } else {

            $strratings .= "$agg ";

        }



        if ($return) {

            return $strratings;

        } else {

            echo $strratings;

        }

    }

}





/**

 * Return the mean rating of a post given to the current user by others.

 * Scale is an array of possible ratings in the scale

 * Ratings is an optional simple array of actual ratings (just integers)

 * Forumid is the forum id field needed - passing it avoids a double query of lookup up the discusion and then the forum id to get the aggregate type

 */

function forum_get_ratings_mean($postid, $scale, $ratings=NULL) {



    if (is_null($ratings)) {

        $ratings = array();

        if ($rates = get_records("forum_ratings", "post", $postid)) {

            foreach ($rates as $rate) {

                $ratings[] = $rate->rating;

            }

        }

    }



    $count = count($ratings);



    if ($count == 0 ) {

        return "";



    } else if ($count == 1) {

        $rating = reset($ratings);

        return $scale[$rating];



    } else {

        $total = 0;

        foreach ($ratings as $rating) {

            $total += $rating;

        }

        $mean = round( ((float)$total/(float)$count) + 0.001);  // Little fudge factor so that 0.5 goes UP



        if (isset($scale[$mean])) {

            return $scale[$mean]." ($count)";

        } else {

            return "$mean ($count)";    // Should never happen, hopefully

        }

    }

}



/**

 * Return the count of the ratings of a post given to the current user by others.

 *

 * For numerical grades, the scale index is the same as the real grade value from interval {0..n}

 * and $scale looks like Array( 0 => '0/n', 1 => '1/n', ..., n => 'n/n' )

 *

 * For scales, the index is the order of the scale item {1..n}

 * and $scale looks like Array( 1 => 'poor', 2 => 'weak', 3 => 'good' )

 * In case of no ratings done yet, we have nothing to display.

 *

 * @param int $postid

 * @param array $scale Possible ratings in the scale - the end of the scale is the highest or max grade

 * @param array $ratings An optional simple array of actual ratings (just integers)

 */

function forum_get_ratings_count($postid, $scale, $ratings=NULL) {



    if (is_null($ratings)) {

        $ratings = array();

        if ($rates = get_records("forum_ratings", "post", $postid)) {

            foreach ($rates as $rate) {

                $ratings[] = $rate->rating;

            }

        }

    }



    $count = count($ratings);

    if (! array_key_exists(0, $scale)) {

        $scaleused = true;

    } else {

        $scaleused = false;

    }



    if ($count == 0) {

        if ($scaleused) {    // If no rating given yet and we use a scale

            return get_string('noratinggiven', 'forum');

        } else {

            return '';

        }

    }



    $maxgradeidx = max(array_keys($scale)); // For numerical grades, the index is the same as the real grade value {0..n}

                                            // and $scale looks like Array( 0 => '0/n', 1 => '1/n', ..., n => 'n/n' )

                                            // For scales, the index is the order of the scale item {1..n}

                                            // and $scale looks like Array( 1 => 'poor', 2 => 'weak', 3 => 'good' )



    if ($count > $maxgradeidx) {      // The count exceeds the max grade

        $a = new stdClass();

        $a->count = $count;

        $a->grade = $scale[$maxgradeidx];

        return get_string('aggregatecountformat', 'forum', $a);

    } else {                                // Display the count and the aggregated grade for this post

        $a = new stdClass();

        $a->count = $count;

        $a->grade = $scale[$count];

        return get_string('aggregatecountformat', 'forum', $a);

    }

}



/**

 * Return the max rating of a post given to the current user by others.

 * Scale is an array of possible ratings in the scale

 * Ratings is an optional simple array of actual ratings (just integers)

 */

function forum_get_ratings_max($postid, $scale, $ratings=NULL) {



    if (is_null($ratings)) {

        $ratings = array();

        if ($rates = get_records("forum_ratings", "post", $postid)) {

            foreach ($rates as $rate) {

                $ratings[] = $rate->rating;

            }

        }

    }



    $count = count($ratings);



    if ($count == 0 ) {

        return "";



    } else if ($count == 1) { //this works for max

        $rating = reset($ratings);

        return $scale[$rating];



    } else {

        $max = max($ratings);



        if (isset($scale[$max])) {

            return $scale[$max]." ($count)";

        } else {

            return "$max ($count)";    // Should never happen, hopefully

        }

    }

}



/**

 * Return the min rating of a post given to the current user by others.

 * Scale is an array of possible ratings in the scale

 * Ratings is an optional simple array of actual ratings (just integers)

 */

function forum_get_ratings_min($postid, $scale,  $ratings=NULL) {



    if (is_null($ratings)) {

        $ratings = array();

        if ($rates = get_records("forum_ratings", "post", $postid)) {

            foreach ($rates as $rate) {

                $ratings[] = $rate->rating;

            }

        }

    }



    $count = count($ratings);



    if ($count == 0 ) {

        return "";



    } else if ($count == 1) {

        $rating = reset($ratings);

        return $scale[$rating]; //this works for min



    } else {

        $min = min($ratings);



        if (isset($scale[$min])) {

            return $scale[$min]." ($count)";

        } else {

            return "$min ($count)";    // Should never happen, hopefully

        }

    }

}





/**

 * Return the sum or total of ratings of a post given to the current user by others.

 * Scale is an array of possible ratings in the scale

 * Ratings is an optional simple array of actual ratings (just integers)

 */

function forum_get_ratings_sum($postid, $scale, $ratings=NULL) {



    if (is_null($ratings)) {

        $ratings = array();

        if ($rates = get_records("forum_ratings", "post", $postid)) {

            foreach ($rates as $rate) {

                $ratings[] = $rate->rating;

            }

        }

    }



    $count = count($ratings);

    $scalecount = count($scale)-1; //this should give us the last element of the scale aka the max grade with  $scale[$scalecount]



    if ($count == 0 ) {

        return "";



    } else if ($count == 1) { //this works for max.

        $rating = reset($ratings);

        return $scale[$rating];



    } else {

        $total = 0;

        foreach ($ratings as $rating) {

            $total += $rating;

        }

        if ($total > $scale[$scalecount]) { //if the total exceeds the max grade then set it to the max grade

            $total = $scale[$scalecount];

        }

        if (isset($scale[$total])) {

            return $scale[$total]." ($count)";

        } else {

            return "$total ($count)";    // Should never happen, hopefully

        }

    }

}



/**

 * Return a summary of post ratings given to the current user by others.

 * Scale is an array of possible ratings in the scale

 * Ratings is an optional simple array of actual ratings (just integers)

 */

function forum_get_ratings_summary($postid, $scale, $ratings=NULL) {



    if (is_null($ratings)) {

        $ratings = array();

        if ($rates = get_records("forum_ratings", "post", $postid)) {

            foreach ($rates as $rate) {

                $rating[] = $rate->rating;

            }

        }

    }





    if (!$count = count($ratings)) {

        return "";

    }





    foreach ($scale as $key => $scaleitem) {

        $sumrating[$key] = 0;

    }



    foreach ($ratings as $rating) {

        $sumrating[$rating]++;

    }



    $summary = "";

    foreach ($scale as $key => $scaleitem) {

        $summary = $sumrating[$key].$summary;

        if ($key > 1) {

            $summary = "/$summary";

        }

    }

    return $summary;

}



/**

 * Print the menu of ratings as part of a larger form.

 * If the post has already been - set that value.

 * Scale is an array of ratings

 */

function forum_print_rating_menu($postid, $userid, $scale, $myrating=NULL) {



    static $strrate;



    if (is_null($myrating)) {

        if (!$rating = get_record("forum_ratings", "userid", $userid, "post", $postid)) {

            $myrating = FORUM_UNSET_POST_RATING;

        } else {

            $myrating = $rating->rating;

        }

    }



    if (empty($strrate)) {

        $strrate = get_string("rate", "forum");

    }

    $scale = array(FORUM_UNSET_POST_RATING => $strrate.'...') + $scale;

    choose_from_menu($scale, $postid, $myrating, '', '', '0', false, false, 0, '', false, false, 'forumpostratingmenu');

}



/**

 * Print the drop down that allows the user to select how they want to have

 * the discussion displayed.

 * @param $id - forum id if $forumtype is 'single',

 *              discussion id for any other forum type

 * @param $mode - forum layout mode

 * @param $forumtype - optional

 */

function forum_print_mode_form($id, $mode, $forumtype='') {

    if ($forumtype == 'single') {

        echo '<div class="forummode">';

        popup_form("view.php?f=$id&amp;mode=", forum_get_layout_modes(), "mode", $mode, "");

        echo '</div>';

    } else {

        popup_form("discuss.php?d=$id&amp;mode=", forum_get_layout_modes(), "mode", $mode, "");

    }

}



/**

 *

 */

function forum_search_form($course, $search='') {

    global $CFG;



    $output  = '<div class="forumsearch">';

    $output .= '<form action="'.$CFG->wwwroot.'/mod/forum/search.php" style="display:inline">';

    $output .= '<fieldset class="invisiblefieldset">';

    $output .= helpbutton('search', get_string('search'), 'moodle', true, false, '', true);

    $output .= '<input name="search" type="text" size="18" value="'.s($search, true).'" alt="search" />';

    $output .= '<input value="'.get_string('searchforums', 'forum').'" type="submit" />';

    $output .= '<input name="id" type="hidden" value="'.$course->id.'" />';

    $output .= '</fieldset>';

    $output .= '</form>';

    $output .= '</div>';



    return $output;

}





/**

 *

 */

function forum_set_return() {

    global $CFG, $SESSION;



    if (! isset($SESSION->fromdiscussion)) {

        if (!empty($_SERVER['HTTP_REFERER'])) {

            $referer = $_SERVER['HTTP_REFERER'];

        } else {

            $referer = "";

        }

        // If the referer is NOT a login screen then save it.

        if (! strncasecmp("$CFG->wwwroot/login", $referer, 300)) {

            $SESSION->fromdiscussion = $_SERVER["HTTP_REFERER"];

        }

    }

}





/**

 *

 */

function forum_go_back_to($default) {

    global $SESSION;



    if (!empty($SESSION->fromdiscussion)) {

        $returnto = $SESSION->fromdiscussion;

        unset($SESSION->fromdiscussion);

        return $returnto;

    } else {

        return $default;

    }

}



/**

 * Creates a directory file name, suitable for make_upload_directory()

 */

function forum_file_area_name($post) {

    global $CFG;



    if (!isset($post->forum) or !isset($post->course)) {

        debugging('missing forum or course', DEBUG_DEVELOPER);

        if (!$discussion = get_record('forum_discussions', 'id', $post->discussion)) {

            return false;

        }

        if (!$forum = get_record('forum', 'id', $discussion->forum)) {

            return false;

        }

        $forumid  = $forum->id;

        $courseid = $forum->course;

    } else {

        $forumid  = $post->forum;

        $courseid = $post->course;

    }



    return "$courseid/$CFG->moddata/forum/$forumid/$post->id";

}



/**

 *

 */

function forum_file_area($post) {

    $path = forum_file_area_name($post);

    if ($path) {

        return make_upload_directory($path);

    } else {

        return false;

    }

}



/**

 *

 */

function forum_delete_old_attachments($post, $exception="") {



/**

 * Deletes all the user files in the attachments area for a post

 * EXCEPT for any file named $exception

 */

    if ($basedir = forum_file_area($post)) {

        if ($files = get_directory_list($basedir)) {

            foreach ($files as $file) {

                if ($file != $exception) {

                    unlink("$basedir/$file");

                    notify("Existing file '$file' has been deleted!");

                }

            }

        }

        if (!$exception) {  // Delete directory as well, if empty

            rmdir("$basedir");

        }

    }

}



/**

 * Given a discussion object that is being moved to forumid,

 * this function checks all posts in that discussion

 * for attachments, and if any are found, these are

 * moved to the new forum directory.

 */

function forum_move_attachments($discussion, $forumid) {



    global $CFG;



    require_once($CFG->dirroot.'/lib/uploadlib.php');



    $return = true;



    if ($posts = get_records_select("forum_posts", "discussion = '$discussion->id' AND attachment <> ''")) {

        foreach ($posts as $oldpost) {

            $oldpost->course = $discussion->course;

            $oldpost->forum = $discussion->forum;

            $oldpostdir = "$CFG->dataroot/".forum_file_area_name($oldpost);

            if (is_dir($oldpostdir)) {

                $newpost = $oldpost;

                $newpost->forum = $forumid;

                $newpostdir = forum_file_area_name($newpost);

                // take off the last directory because otherwise we're renaming to a directory that already exists

                // and this is unhappy in certain situations, eg over an nfs mount and potentially on windows too.

                make_upload_directory(substr($newpostdir,0,strrpos($newpostdir,'/')));

                $newpostdir = $CFG->dataroot.'/'.forum_file_area_name($newpost);

                $files = get_directory_list($oldpostdir); // get it before we rename it.

                if (! @rename($oldpostdir, $newpostdir)) {

                    $return = false;

                }

                foreach ($files as $file) {

                    clam_change_log($oldpostdir.'/'.$file,$newpostdir.'/'.$file);

                }

            }

        }

    }

    return $return;

}



/**

 * if return=html, then return a html string.

 * if return=text, then return a text-only string.

 * otherwise, print HTML for non-images, and return image HTML

 */

function forum_print_attachments($post, $return=NULL) {



    global $CFG;



    $filearea = forum_file_area_name($post);



    $imagereturn = "";

    $output = "";



    if ($basedir = forum_file_area($post)) {

        if ($files = get_directory_list($basedir)) {

            $strattachment = get_string("attachment", "forum");

            foreach ($files as $file) {

                $icon = mimeinfo("icon", $file);

                $type = mimeinfo("type", $file);

                $ffurl = get_file_url("$filearea/$file");

                $image = "<img src=\"$CFG->pixpath/f/$icon\" class=\"icon\" alt=\"\" />";



                if ($return == "html") {

                    $output .= "<a href=\"$ffurl\">$image</a> ";

                    $output .= "<a href=\"$ffurl\">$file</a><br />";



                } else if ($return == "text") {

                    $output .= "$strattachment $file:\n$ffurl\n";



                } else {

                    if (in_array($type, array('image/gif', 'image/jpeg', 'image/png'))) {    // Image attachments don't get printed as links

                        $imagereturn .= "<br /><img src=\"$ffurl\" alt=\"\" />";

                    } else {

                        echo "<a href=\"$ffurl\">$image</a> ";

                        echo filter_text("<a href=\"$ffurl\">$file</a><br />");

                    }

                }

            }

        }

    }



    if ($return) {

        return $output;

    }



    return $imagereturn;

}

/**

 * If successful, this function returns the name of the file

 * @param $post is a full post record, including course and forum

 * @param $newfile is a full upload array from $_FILES

 * @param $message is a string to hold the messages.

 */



/**

 *

 */

function forum_add_attachment($post, $inputname,&$message) {



    global $CFG;



    if (!$forum = get_record("forum", "id", $post->forum)) {

        return "";

    }



    if (!$course = get_record("course", "id", $forum->course)) {

        return "";

    }



    require_once($CFG->dirroot.'/lib/uploadlib.php');

    $um = new upload_manager($inputname,true,false,$course,false,$forum->maxbytes,true,true);

    $dir = forum_file_area_name($post);

    if ($um->process_file_uploads($dir)) {

        $message .= $um->get_errors();

        return $um->get_new_filename();

    }

    $message .= $um->get_errors();

    return null;

}



/**

 *

 */

function forum_add_new_post($post,&$message) {



    global $USER, $CFG;



    $discussion = get_record('forum_discussions', 'id', $post->discussion);

    $forum      = get_record('forum', 'id', $discussion->forum);



    $post->created    = $post->modified = time();

    $post->mailed     = "0";

    $post->userid     = $USER->id;

    $post->attachment = "";

    $post->forum      = $forum->id;     // speedup

    $post->course     = $forum->course; // speedup



    if (! $post->id = insert_record("forum_posts", $post)) {

        return false;

    }



    if ($post->attachment = forum_add_attachment($post, 'attachment',$message)) {

        set_field("forum_posts", "attachment", $post->attachment, "id", $post->id);

    }



    // Update discussion modified date

    set_field("forum_discussions", "timemodified", $post->modified, "id", $post->discussion);

    set_field("forum_discussions", "usermodified", $post->userid, "id", $post->discussion);



    if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {

        forum_tp_mark_post_read($post->userid, $post, $post->forum);

    }



    return $post->id;

}



/**

 *

 */

function forum_update_post($post,&$message) {



    global $USER, $CFG;



    $forum = get_record('forum', 'id', $post->forum);



    $post->modified = time();



    $updatediscussion = new object();

    $updatediscussion->id           = $post->discussion;

    $updatediscussion->timemodified = $post->modified; // last modified tracking

    $updatediscussion->usermodified = $post->userid;   // last modified tracking



    if (!$post->parent) {   // Post is a discussion starter - update discussion title and times too

        $updatediscussion->name      = $post->subject;

        $updatediscussion->timestart = $post->timestart;

        $updatediscussion->timeend   = $post->timeend;

    }



    if (!update_record('forum_discussions', $updatediscussion)) {

        return false;

    }



    if ($newfilename = forum_add_attachment($post, 'attachment',$message)) {

        $post->attachment = $newfilename;

    } else {

        unset($post->attachment);

    }



    if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {

        forum_tp_mark_post_read($post->userid, $post, $post->forum);

    }



    return update_record('forum_posts', $post);

}



/**

 * Given an object containing all the necessary data,

 * create a new discussion and return the id

 */

function forum_add_discussion($discussion,&$message) {



    global $USER, $CFG;



    $timenow = time();



    // The first post is stored as a real post, and linked

    // to from the discuss entry.



    $forum = get_record('forum', 'id', $discussion->forum);



    $post = new object();

    $post->discussion  = 0;

    $post->parent      = 0;

    $post->userid      = $USER->id;

    $post->created     = $timenow;

    $post->modified    = $timenow;

    $post->mailed      = 0;

    $post->subject     = $discussion->name;

    $post->message     = $discussion->intro;

    $post->attachment  = "";

    $post->forum       = $forum->id;     // speedup

    $post->course      = $forum->course; // speedup

    $post->format      = $discussion->format;

    $post->mailnow     = $discussion->mailnow;



    if (! $post->id = insert_record("forum_posts", $post) ) {

        return 0;

    }



    if ($post->attachment = forum_add_attachment($post, 'attachment',$message)) {

        set_field("forum_posts", "attachment", $post->attachment, "id", $post->id); //ignore errors

    }



    // Now do the main entry for the discussion,

    // linking to this first post



    $discussion->firstpost    = $post->id;

    $discussion->timemodified = $timenow;

    $discussion->usermodified = $post->userid;

    $discussion->userid = $USER->id;



    if (! $post->discussion = insert_record("forum_discussions", $discussion) ) {

        delete_records("forum_posts", "id", $post->id);

        return 0;

    }



    // Finally, set the pointer on the post.

    if (! set_field("forum_posts", "discussion", $post->discussion, "id", $post->id)) {

        delete_records("forum_posts", "id", $post->id);

        delete_records("forum_discussions", "id", $post->discussion);

        return 0;

    }



    if (forum_tp_can_track_forums($forum) && forum_tp_is_tracked($forum)) {

        forum_tp_mark_post_read($post->userid, $post, $post->forum);

    }



    return $post->discussion;

}





/**

 *

 */

function forum_delete_discussion($discussion, $fulldelete=false) {

// $discussion is a discussion record object



    $result = true;



    if ($posts = get_records("forum_posts", "discussion", $discussion->id)) {

        foreach ($posts as $post) {

            $post->course = $discussion->course;

            $post->forum  = $discussion->forum;

            if (! delete_records("forum_ratings", "post", "$post->id")) {

                $result = false;

            }

            if (! forum_delete_post($post, $fulldelete)) {

                $result = false;

            }

        }

    }



    forum_tp_delete_read_records(-1, -1, $discussion->id);



    if (! delete_records("forum_discussions", "id", "$discussion->id")) {

        $result = false;

    }



    return $result;

}





/**

 *

 */

function forum_delete_post($post, $children=false) {

   if ($childposts = get_records('forum_posts', 'parent', $post->id)) {

       if ($children) {

           foreach ($childposts as $childpost) {

               forum_delete_post($childpost, true);

           }

       } else {

           return false;

       }

   }

   if (delete_records("forum_posts", "id", $post->id)) {

       delete_records("forum_ratings", "post", $post->id);  // Just in case



       forum_tp_delete_read_records(-1, $post->id);



       if ($post->attachment) {

           $discussion = get_record("forum_discussions", "id", $post->discussion);

           $post->course = $discussion->course;

           $post->forum  = $discussion->forum;

           forum_delete_old_attachments($post);

       }



   // Just in case we are deleting the last post

       forum_discussion_update_last_post($post->discussion);



       return true;

   }

   return false;

}



/**

 *

 */

function forum_count_replies($post, $children=true) {

    $count = 0;



    if ($children) {

        if ($childposts = get_records('forum_posts', 'parent', $post->id)) {

           foreach ($childposts as $childpost) {

               $count ++;                   // For this child

               $count += forum_count_replies($childpost, true);

           }

        }

    } else {

        $count += count_records('forum_posts', 'parent', $post->id);

    }



    return $count;

}





/**

 *

 */

function forum_forcesubscribe($forumid, $value=1) {

    return set_field("forum", "forcesubscribe", $value, "id", $forumid);

}



/**

 *

 */

function forum_is_forcesubscribed($forum) {

    if (isset($forum->forcesubscribe)) {    // then we use that

        return ($forum->forcesubscribe == FORUM_FORCESUBSCRIBE);

    } else {   // Check the database

       return (get_field('forum', 'forcesubscribe', 'id', $forum) == FORUM_FORCESUBSCRIBE);

    }

}



/**

 *

 */

function forum_is_subscribed($userid, $forum) {

    if (is_numeric($forum)) {

        $forum = get_record('forum', 'id', $forum);

    }

    if (forum_is_forcesubscribed($forum)) {

        return true;

    }

    return record_exists("forum_subscriptions", "userid", $userid, "forum", $forum->id);

}



function forum_get_subscribed_forums($course) {

    global $USER, $CFG;

    $sql = "SELECT f.id

              FROM {$CFG->prefix}forum f

                   LEFT JOIN {$CFG->prefix}forum_subscriptions fs ON (fs.forum = f.id AND fs.userid = $USER->id)

             WHERE f.forcesubscribe <> ".FORUM_DISALLOWSUBSCRIBE."

                   AND (f.forcesubscribe = ".FORUM_FORCESUBSCRIBE." OR fs.id IS NOT NULL)";

    if ($subscribed = get_records_sql($sql)) {

        foreach ($subscribed as $s) {

            $subscribed[$s->id] = $s->id;

        }

        return $subscribed;

    } else {

        return array();

    }

}



/**

 * Adds user to the subscriber list

 */

function forum_subscribe($userid, $forumid) {



    if (record_exists("forum_subscriptions", "userid", $userid, "forum", $forumid)) {

        return true;

    }



    $sub = new object();

    $sub->userid  = $userid;

    $sub->forum = $forumid;



    return insert_record("forum_subscriptions", $sub);

}



/**

 * Removes user from the subscriber list

 */

function forum_unsubscribe($userid, $forumid) {

    return delete_records("forum_subscriptions", "userid", $userid, "forum", $forumid);

}



/**

 * Given a new post, subscribes or unsubscribes as appropriate.

 * Returns some text which describes what happened.

 */

function forum_post_subscription($post, $forum) {



    global $USER;

    

    $action = '';

    $subscribed = forum_is_subscribed($USER->id, $forum);

    

    if ($forum->forcesubscribe == FORUM_FORCESUBSCRIBE) { // database ignored

        return "";



    } elseif (($forum->forcesubscribe == FORUM_DISALLOWSUBSCRIBE)

        && !has_capability('moodle/course:manageactivities', get_context_instance(CONTEXT_COURSE, $forum->course), $USER->id)) {

        if ($subscribed) {

            $action = 'unsubscribe'; // sanity check, following MDL-14558

        } else {

            return "";

        }



    } else { // go with the user's choice

        if (isset($post->subscribe)) {

            // no change

            if ((!empty($post->subscribe) && $subscribed)

                || (empty($post->subscribe) && !$subscribed)) {

                return "";



            } elseif (!empty($post->subscribe) && !$subscribed) {

                $action = 'subscribe';



            } elseif (empty($post->subscribe) && $subscribed) {

                $action = 'unsubscribe';

            }

        }

    }



    $info = new object();

    $info->name  = fullname($USER);

    $info->forum = format_string($forum->name);



    switch ($action) {

        case 'subscribe':

            forum_subscribe($USER->id, $post->forum);

            return "<p>".get_string("nowsubscribed", "forum", $info)."</p>";

        case 'unsubscribe':

            forum_unsubscribe($USER->id, $post->forum);

            return "<p>".get_string("nownotsubscribed", "forum", $info)."</p>";

    }

}



/**

 * Generate and return the subscribe or unsubscribe link for a forum.

 * @param object $forum the forum. Fields used are $forum->id and $forum->forcesubscribe.

 * @param object $context the context object for this forum.

 * @param array $messages text used for the link in its various states

 *      (subscribed, unsubscribed, forcesubscribed or cantsubscribe).

 *      Any strings not passed in are taken from the $defaultmessages array

 *      at the top of the function.

 * @param

 */

function forum_get_subscribe_link($forum, $context, $messages = array(), $cantaccessagroup = false, $fakelink=true, $backtoindex=false, $subscribed_forums=null) {

    global $CFG, $USER;

    $defaultmessages = array(

        'subscribed' => get_string('unsubscribe', 'forum'),

        'unsubscribed' => get_string('subscribe', 'forum'),

        'cantaccessgroup' => get_string('no'),

        'forcesubscribed' => get_string('everyoneissubscribed', 'forum'),

        'cantsubscribe' => get_string('disallowsubscribe','forum')

    );

    $messages = $messages + $defaultmessages;



    if (forum_is_forcesubscribed($forum)) {

        return $messages['forcesubscribed'];

    } else if ($forum->forcesubscribe == FORUM_DISALLOWSUBSCRIBE && !has_capability('mod/forum:managesubscriptions', $context)) {

        return $messages['cantsubscribe'];

    } else if ($cantaccessagroup) {

        return $messages['cantaccessgroup'];

    } else {

        if (is_null($subscribed_forums)) {

            $subscribed = forum_is_subscribed($USER->id, $forum);

        } else {

            $subscribed = !empty($subscribed_forums[$forum->id]);

        }

        if ($subscribed) {

            $linktext = $messages['subscribed'];

            $linktitle = get_string('subscribestop', 'forum');

        } else {

            $linktext = $messages['unsubscribed'];

            $linktitle = get_string('subscribestart', 'forum');

        }



        $options = array();

        if ($backtoindex) {

            $backtoindexlink = '&amp;backtoindex=1';

            $options['backtoindex'] = 1;

        } else {

            $backtoindexlink = '';

        }

        $link = '';

        $sesskeylink = '&amp;sesskey='.sesskey();



        if ($fakelink) {

            $link .= <<<EOD

<script type="text/javascript">

//<![CDATA[

var subs_link = document.getElementById("subscriptionlink");

if(subs_link){

    subs_link.innerHTML = "<a title=\"$linktitle\" href='$CFG->wwwroot/mod/forum/subscribe.php?id={$forum->id}{$backtoindexlink}{$sesskeylink}'>$linktext<\/a>";

}

//]]>

</script>

<noscript>

EOD;

        }

        $options['id'] = $forum->id;

        $options['sesskey'] = sesskey();

        $link .= print_single_button($CFG->wwwroot . '/mod/forum/subscribe.php',

                $options, $linktext, 'post', '_self', true, $linktitle);

        if ($fakelink) {

            $link .= '</noscript>';

        }



        return $link;

    }

}





/**

 * Generate and return the track or no track link for a forum.

 * @param object $forum the forum. Fields used are $forum->id and $forum->forcesubscribe.

 */

function forum_get_tracking_link($forum, $messages=array(), $fakelink=true) {

    global $CFG, $USER;



    static $strnotrackforum, $strtrackforum;



    if (isset($messages['trackforum'])) {

         $strtrackforum = $messages['trackforum'];

    }

    if (isset($messages['notrackforum'])) {

         $strnotrackforum = $messages['notrackforum'];

    }

    if (empty($strtrackforum)) {

        $strtrackforum = get_string('trackforum', 'forum');

    }

    if (empty($strnotrackforum)) {

        $strnotrackforum = get_string('notrackforum', 'forum');

    }



    if (forum_tp_is_tracked($forum)) {

        $linktitle = $strnotrackforum;

        $linktext = $strnotrackforum;

    } else {

        $linktitle = $strtrackforum;

        $linktext = $strtrackforum;

    } 



    $link = '';

    if ($fakelink) {

        $link .= '<script type="text/javascript">';

        $link .= '//<![CDATA['."\n";

        $link .= 'document.getElementById("trackinglink").innerHTML = "<a title=\"' . $linktitle . '\" href=\"' . $CFG->wwwroot .

           '/mod/forum/settracking.php?id=' . $forum->id . '\">' . $linktext . '<\/a>";'."\n";

        $link .= '//]]>'."\n";

        $link .= '</script>';

        // use <noscript> to print button in case javascript is not enabled

        $link .= '<noscript>';

    }

    $link .= print_single_button($CFG->wwwroot . '/mod/forum/settracking.php?id=' . $forum->id,

            '', $linktext, 'post', '_self', true, $linktitle);

    if ($fakelink) {

        $link .= '</noscript>';

    }



    return $link;

}







/**

 * Returns true if user created new discussion already

 * @param int $forumid

 * @param int $userid

 * @return bool

 */

function forum_user_has_posted_discussion($forumid, $userid) {

    global $CFG;



    $sql = "SELECT 'x'

              FROM {$CFG->prefix}forum_discussions d, {$CFG->prefix}forum_posts p

             WHERE d.forum = $forumid AND p.discussion = d.id AND p.parent = 0 and p.userid = $userid";



    return record_exists_sql($sql);

}



/**

 *

 */

function forum_discussions_user_has_posted_in($forumid, $userid) {

    global $CFG;



    $haspostedsql = "SELECT d.id AS id,

                            d.*

                       FROM {$CFG->prefix}forum_posts p,

                            {$CFG->prefix}forum_discussions d

                      WHERE p.discussion = d.id

                        AND d.forum = $forumid

                        AND p.userid = $userid";



    return get_records_sql($haspostedsql);

}



/**

 *

 */

function forum_user_has_posted($forumid, $did, $userid) {

    global $CFG;



    if (empty($did)) {

        // posted in any forum discussion?

        $sql = "SELECT 'x'

                  FROM {$CFG->prefix}forum_posts p

                  JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                 WHERE p.userid = $userid AND d.forum = $forumid";

        return record_exists_sql($sql);

    } else {

        // started discussion?

        return record_exists('forum_posts','discussion',$did,'userid',$userid);

    }

}



/**

 *

 */

function forum_user_can_post_discussion($forum, $currentgroup=null, $unused=-1, $cm=NULL, $context=NULL) {

// $forum is an object

    global $USER;



    // shortcut - guest and not-logged-in users can not post

    if (isguestuser() or !isloggedin()) {

        return false;

    }



    if (!$cm) {

        debugging('missing cm', DEBUG_DEVELOPER);

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {

            error('Course Module ID was incorrect');

        }

    }



    if (!$context) {

        $context = get_context_instance(CONTEXT_MODULE, $cm->id);

    }



    if ($currentgroup === null) {

        $currentgroup = groups_get_activity_group($cm);

    }



    $groupmode = groups_get_activity_groupmode($cm);



    if ($forum->type == 'news') {

        $capname = 'mod/forum:addnews';

    } else {

        $capname = 'mod/forum:startdiscussion';

    }



    if (!has_capability($capname, $context)) {

        return false;

    }



    if ($forum->type == 'single') {

        return false;

    }



    if ($forum->type == 'eachuser') {

        if (forum_user_has_posted_discussion($forum->id, $USER->id)) {

            return false;

        }

    }



    if (!$groupmode or has_capability('moodle/site:accessallgroups', $context)) {

        return true;

    }



    if ($currentgroup) {

        return groups_is_member($currentgroup);

    } else {

        // no group membership and no accessallgroups means no new discussions

        // reverted to 1.7 behaviour in 1.9+,  buggy in 1.8.0-1.9.0

        return false;

    }

}



/**

 * This function checks whether the user can reply to posts in a forum

 * discussion. Use forum_user_can_post_discussion() to check whether the user

 * can start dicussions.

 * @param $forum - forum object

 * @param $user - user object

 */

function forum_user_can_post($forum, $discussion, $user=NULL, $cm=NULL, $course=NULL, $context=NULL) {

    global $USER;

    if (empty($user)) {

        $user = $USER;

    }



    // shortcut - guest and not-logged-in users can not post

    if (isguestuser($user) or empty($user->id)) {

        return false;

    }



    if (!isset($discussion->groupid)) {

        debugging('incorrect discussion parameter', DEBUG_DEVELOPER);

        return false;

    }



    if (!$cm) {

        debugging('missing cm', DEBUG_DEVELOPER);

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {

            error('Course Module ID was incorrect');

        }

    }



    if (!$course) {

        debugging('missing course', DEBUG_DEVELOPER);

        if (!$course = get_record('course', 'id', $forum->course)) {

            error('Incorrect course id');

        }

    }



    if (!$context) {

        $context = get_context_instance(CONTEXT_MODULE, $cm->id);

    }



    // normal users with temporary guest access can not post

    if (has_capability('moodle/legacy:guest', $context, $user->id, false)) {

        return false;

    }



    if ($forum->type == 'news') {

        $capname = 'mod/forum:replynews';

    } else {

        $capname = 'mod/forum:replypost';

    }



    if (!has_capability($capname, $context, $user->id, false)) {

        return false;

    }



    if (!$groupmode = groups_get_activity_groupmode($cm, $course)) {

        return true;

    }



    if (has_capability('moodle/site:accessallgroups', $context)) {

        return true;

    }



    if ($groupmode == VISIBLEGROUPS) {

        if ($discussion->groupid == -1) {

            // allow students to reply to all participants discussions - this was not possible in Moodle <1.8

            return true;

        }

        return groups_is_member($discussion->groupid);



    } else {

        //separate groups

        if ($discussion->groupid == -1) {

            return false;

        }

        return groups_is_member($discussion->groupid);

    }

}





//checks to see if a user can view a particular post

function forum_user_can_view_post($post, $course, $cm, $forum, $discussion, $user=NULL){



    global $CFG, $USER;



    if (!$user){

        $user = $USER;

    }



    $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

    if (!has_capability('mod/forum:viewdiscussion', $modcontext)) {

        return false;

    }



// If it's a grouped discussion, make sure the user is a member

    if ($discussion->groupid > 0) {

        $groupmode = groups_get_activity_groupmode($cm);

        if ($groupmode == SEPARATEGROUPS) {

            return groups_is_member($discussion->groupid) || has_capability('moodle/site:accessallgroups', $modcontext);

        }

    }

    return true;

}





/**

 *

 */

function forum_user_can_see_discussion($forum, $discussion, $context, $user=NULL) {

    global $USER;



    if (empty($user) || empty($user->id)) {

        $user = $USER;

    }



    // retrieve objects (yuk)

    if (is_numeric($forum)) {

        debugging('missing full forum', DEBUG_DEVELOPER);

        if (!$forum = get_record('forum','id',$forum)) {

            return false;

        }

    }

    if (is_numeric($discussion)) {

        debugging('missing full discussion', DEBUG_DEVELOPER);

        if (!$discussion = get_record('forum_discussions','id',$discussion)) {

            return false;

        }

    }



    if (!has_capability('mod/forum:viewdiscussion', $context)) {

        return false;

    }



    if ($forum->type == 'qanda' &&

            !forum_user_has_posted($forum->id, $discussion->id, $user->id) &&

            !has_capability('mod/forum:viewqandawithoutposting', $context)) {

        return false;

    }

    return true;

}





/**

 *

 */

function forum_user_can_see_post($forum, $discussion, $post, $user=NULL, $cm=NULL) {

    global $CFG, $USER;



    // retrieve objects (yuk)

    if (is_numeric($forum)) {

        debugging('missing full forum', DEBUG_DEVELOPER);

        if (!$forum = get_record('forum','id',$forum)) {

            return false;

        }

    }



    if (is_numeric($discussion)) {

        debugging('missing full discussion', DEBUG_DEVELOPER);

        if (!$discussion = get_record('forum_discussions','id',$discussion)) {

            return false;

        }

    }

    if (is_numeric($post)) {

        debugging('missing full post', DEBUG_DEVELOPER);

        if (!$post = get_record('forum_posts','id',$post)) {

            return false;

        }

    }

    if (!isset($post->id) && isset($post->parent)) {

        $post->id = $post->parent;

    }



    if (!$cm) {

        debugging('missing cm', DEBUG_DEVELOPER);

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {

            error('Course Module ID was incorrect');

        }

    }



    if (empty($user) || empty($user->id)) {

        $user = $USER;

    }



    if (isset($cm->cache->caps['mod/forum:viewdiscussion'])) {

        if (!$cm->cache->caps['mod/forum:viewdiscussion']) {

            return false;

        }

    } else {

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        if (!has_capability('mod/forum:viewdiscussion', $modcontext, $user->id)) {

            return false;

        }

    }



    if (isset($cm->uservisible)) {

        if (!$cm->uservisible) {

            return false;

        }

    } else {

        if (!coursemodule_visible_for_user($cm, $user->id)) {

            return false;

        }

    }



    if ($forum->type == 'qanda') {

        $firstpost = forum_get_firstpost_from_discussion($discussion->id);

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        $userfirstpost = forum_get_user_posted_time($discussion->id, $user->id);



        return (($userfirstpost !== false && (time() - $userfirstpost >= $CFG->maxeditingtime)) ||

                $firstpost->id == $post->id || $post->userid == $user->id || $firstpost->userid == $user->id ||

                has_capability('mod/forum:viewqandawithoutposting', $modcontext, $user->id, false));

    }

    return true;

}





/**

 * Prints the discussion view screen for a forum.

 *

 * @param object $course The current course object.

 * @param object $forum Forum to be printed.

 * @param int $maxdiscussions .

 * @param string $displayformat The display format to use (optional).

 * @param string $sort Sort arguments for database query (optional).

 * @param int $groupmode Group mode of the forum (optional).

 * @param void $unused (originally current group)

 * @param int $page Page mode, page to display (optional).

 * @param int perpage The maximum number of discussions per page(optional)

 *

 */

function forum_print_latest_discussions($course, $forum, $maxdiscussions=-1, $displayformat='plain', $sort='',

                                        $currentgroup=-1, $groupmode=-1, $page=-1, $perpage=100, $cm=NULL) {

    global $CFG, $USER;



    if (!$cm) {

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {

            error('Course Module ID was incorrect');

        }

    }

    $context = get_context_instance(CONTEXT_MODULE, $cm->id);



    if (empty($sort)) {

        $sort = "d.timemodified DESC";

    }



    $olddiscussionlink = false;



 // Sort out some defaults

    if ($perpage <= 0) {

        $perpage = 0;

        $page    = -1;

    }



    if ($maxdiscussions == 0) {

        // all discussions - backwards compatibility

        $page    = -1;

        $perpage = 0;

        if ($displayformat == 'plain') {

            $displayformat = 'header';  // Abbreviate display by default

        }



    } else if ($maxdiscussions > 0) {

        $page    = -1;

        $perpage = $maxdiscussions;

    }



    $fullpost = false;

    if ($displayformat == 'plain') {

        $fullpost = true;

    }





// Decide if current user is allowed to see ALL the current discussions or not



// First check the group stuff

    if ($currentgroup == -1 or $groupmode == -1) {

        $groupmode    = groups_get_activity_groupmode($cm, $course);

        $currentgroup = groups_get_activity_group($cm);

    }



// If the user can post discussions, then this is a good place to put the

// button for it. We do not show the button if we are showing site news

// and the current user is a guest.



    if (forum_user_can_post_discussion($forum, $currentgroup, $groupmode, $cm, $context) ||

        ($forum->type != 'news'

         and (isguestuser() or !isloggedin() or has_capability('moodle/legacy:guest', $context, NULL, false))) ) {



        echo '<div class="singlebutton forumaddnew">';

        echo "<form id=\"newdiscussionform\" method=\"get\" action=\"$CFG->wwwroot/mod/forum/post.php\">";

        echo '<div>';

        echo "<input type=\"hidden\" name=\"forum\" value=\"$forum->id\" />";

        echo '<input type="submit" value="';

        echo ($forum->type == 'news') ? get_string('addanewtopic', 'forum')

            : (($forum->type == 'qanda')

               ? get_string('addanewquestion','forum')

               : get_string('addanewdiscussion', 'forum'));

        echo '" />';

        echo '</div>';

        echo '</form>';

        echo "</div>\n";



    } else if (isguestuser() or !isloggedin() or $forum->type == 'news') {

        // no button and no info



    } else if ($groupmode and has_capability('mod/forum:startdiscussion', $context)) {

        // inform users why they can not post new discussion

        if ($currentgroup) {

            notify(get_string('cannotadddiscussion', 'forum'));

        } else {

            notify(get_string('cannotadddiscussionall', 'forum'));

        }

    }



// Get all the recent discussions we're allowed to see



    $getuserlastmodified = ($displayformat == 'header');



    if (! $discussions = forum_get_discussions($cm, $sort, $fullpost, null, $maxdiscussions, $getuserlastmodified, $page, $perpage) ) {

        echo '<div class="forumnodiscuss">';

        if ($forum->type == 'news') {

            echo '('.get_string('nonews', 'forum').')';

        } else if ($forum->type == 'qanda') {

            echo '('.get_string('noquestions','forum').')';

        } else {

            echo '('.get_string('nodiscussions', 'forum').')';

        }

        echo "</div>\n";

        return;

    }



// If we want paging

    if ($page != -1) {

        ///Get the number of discussions found

        $numdiscussions = forum_get_discussions_count($cm);



        ///Show the paging bar

        print_paging_bar($numdiscussions, $page, $perpage, "view.php?f=$forum->id&amp;");

        if ($numdiscussions > 1000) {

            // saves some memory on sites with very large forums

            $replies = forum_count_discussion_replies($forum->id, $sort, $maxdiscussions, $page, $perpage);

        } else {

            $replies = forum_count_discussion_replies($forum->id);

        }



    } else {

        $replies = forum_count_discussion_replies($forum->id);



        if ($maxdiscussions > 0 and $maxdiscussions <= count($discussions)) {

            $olddiscussionlink = true;

        }

    }



    $canviewparticipants = has_capability('moodle/course:viewparticipants',$context);



    $strdatestring = get_string('strftimerecentfull');



    // Check if the forum is tracked.

    if ($cantrack = forum_tp_can_track_forums($forum)) {

        $forumtracked = forum_tp_is_tracked($forum);

    } else {

        $forumtracked = false;

    }



    if ($forumtracked) {

        $unreads = forum_get_discussions_unread($cm);

    } else {

        $unreads = array();

    }



    if ($displayformat == 'header') {

        echo '<table cellspacing="0" class="forumheaderlist">';

        echo '<thead>';

        echo '<tr>';

        echo '<th class="header topic" scope="col">'.get_string('discussion', 'forum').'</th>';

        echo '<th class="header author" colspan="2" scope="col">'.get_string('startedby', 'forum').'</th>';

        if ($groupmode > 0) {

            echo '<th class="header group" scope="col">'.get_string('group').'</th>';

        }

        if (has_capability('mod/forum:viewdiscussion', $context)) {

            echo '<th class="header replies" scope="col">'.get_string('replies', 'forum').'</th>';

            // If the forum can be tracked, display the unread column.

            if ($cantrack) {

                echo '<th class="header replies" scope="col">'.get_string('unread', 'forum');

                if ($forumtracked) {

                    echo '&nbsp;<a title="'.get_string('markallread', 'forum').

                         '" href="'.$CFG->wwwroot.'/mod/forum/markposts.php?f='.

                         $forum->id.'&amp;mark=read&amp;returnpage=view.php">'.

                         '<img src="'.$CFG->pixpath.'/t/clear.gif" class="iconsmall" alt="'.get_string('markallread', 'forum').'" /></a>';

                }

                echo '</th>';

            }

        }

        echo '<th class="header lastpost" scope="col">'.get_string('lastpost', 'forum').'</th>';

        echo '</tr>';

        echo '</thead>';

        echo '<tbody>';

    }



    foreach ($discussions as $discussion) {

        if (!empty($replies[$discussion->discussion])) {

            $discussion->replies = $replies[$discussion->discussion]->replies;

            $discussion->lastpostid = $replies[$discussion->discussion]->lastpostid;

        } else {

            $discussion->replies = 0;

        }



        // SPECIAL CASE: The front page can display a news item post to non-logged in users.

        // All posts are read in this case.

        if (!$forumtracked) {

            $discussion->unread = '-';

        } else if (empty($USER)) {

            $discussion->unread = 0;

        } else {

            if (empty($unreads[$discussion->discussion])) {

                $discussion->unread = 0;

            } else {

                $discussion->unread = $unreads[$discussion->discussion];

            }

        }



        if (!empty($USER->id)) {

            $ownpost = ($discussion->userid == $USER->id);

        } else {

            $ownpost=false;

        }

        // Use discussion name instead of subject of first post

        $discussion->subject = $discussion->name;



        switch ($displayformat) {

            case 'header':

                if ($groupmode > 0) {

                    if (isset($groups[$discussion->groupid])) {

                        $group = $groups[$discussion->groupid];

                    } else {

                        $group = $groups[$discussion->groupid] = groups_get_group($discussion->groupid);

                    }

                } else {

                    $group = -1;

                }

                forum_print_discussion_header($discussion, $forum, $group, $strdatestring, $cantrack, $forumtracked,

                    $canviewparticipants, $context);

            break;

            default:

                $link = false;



                if ($discussion->replies) {

                    $link = true;

                } else {

                    $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

                    $link = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);

                }



                $discussion->forum = $forum->id;



                forum_print_post($discussion, $discussion, $forum, $cm, $course, $ownpost, 0, $link, false);

            break;

        }

    }



    if ($displayformat == "header") {

        echo '</tbody>';

        echo '</table>';

    }



    if ($olddiscussionlink) {

        if ($forum->type == 'news') {

            $strolder = get_string('oldertopics', 'forum');

        } else {

            $strolder = get_string('olderdiscussions', 'forum');

        }

        echo '<div class="forumolddiscuss">';

        echo '<a href="'.$CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id.'&amp;showall=1">';

        echo $strolder.'</a> ...</div>';

    }



    if ($page != -1) { ///Show the paging bar

        print_paging_bar($numdiscussions, $page, $perpage, "view.php?f=$forum->id&amp;");

    }

}





/**

 *

 */

function forum_print_discussion($course, $cm, $forum, $discussion, $post, $mode, $canreply=NULL, $canrate=false) {



    global $USER, $CFG;



    if (!empty($USER->id)) {

        $ownpost = ($USER->id == $post->userid);

    } else {

        $ownpost = false;

    }

    if ($canreply === NULL) {

        $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

        $reply = forum_user_can_post($forum, $discussion, $USER, $cm, $course, $modcontext);

    } else {

        $reply = $canreply;

    }



    // $cm holds general cache for forum functions

    $cm->cache = new object();

    $cm->cache->groups      = groups_get_all_groups($course->id, 0, $cm->groupingid);

    $cm->cache->usersgroups = array();



    $posters = array();



    // preload all posts - TODO: improve...

    if ($mode == FORUM_MODE_FLATNEWEST) {

        $sort = "p.created DESC";

    } else {

        $sort = "p.created ASC";

    }



    $forumtracked = forum_tp_is_tracked($forum);

    $posts = forum_get_all_discussion_posts($discussion->id, $sort, $forumtracked);

    $post = $posts[$post->id];



    foreach ($posts as $pid=>$p) {

        $posters[$p->userid] = $p->userid;

    }



    // preload all groups of ppl that posted in this discussion

    if ($postersgroups = groups_get_all_groups($course->id, $posters, $cm->groupingid, 'gm.id, gm.groupid, gm.userid')) {

        foreach($postersgroups as $pg) {

            if (!isset($cm->cache->usersgroups[$pg->userid])) {

                $cm->cache->usersgroups[$pg->userid] = array();

            }

            $cm->cache->usersgroups[$pg->userid][$pg->groupid] = $pg->groupid;

        }

        unset($postersgroups);

    }



    $ratings = NULL;

    $ratingsmenuused = false;

    $ratingsformused = false;

    if ($forum->assessed and isloggedin()) {

        if ($scale = make_grades_menu($forum->scale)) {

            $ratings =new object();

            $ratings->scale = $scale;

            $ratings->assesstimestart = $forum->assesstimestart;

            $ratings->assesstimefinish = $forum->assesstimefinish;

            $ratings->allow = $canrate;



            if ($ratings->allow) {

                echo '<form id="form" method="post" action="rate.php">';

                echo '<div class="ratingform">';

                echo '<input type="hidden" name="forumid" value="'.$forum->id.'" />';

                echo '<input type="hidden" name="sesskey" value="'.sesskey().'" />';

                $ratingsformused = true;

            }



            // preload all ratings - one query only and minimal memory

            $cm->cache->ratings = array();

            $cm->cache->myratings = array();

            if ($postratings = forum_get_all_discussion_ratings($discussion)) {

                foreach ($postratings as $pr) {

                    if (!isset($cm->cache->ratings[$pr->postid])) {

                        $cm->cache->ratings[$pr->postid] = array();

                    }

                    $cm->cache->ratings[$pr->postid][$pr->id] = $pr->rating;

                    if ($pr->userid == $USER->id) {

                        $cm->cache->myratings[$pr->postid] = $pr->rating;

                    }

                }

                unset($postratings);

            }

        }



    }



    $post->forum = $forum->id;   // Add the forum id to the post object, later used by forum_print_post

    $post->forumtype = $forum->type;



    $post->subject = format_string($post->subject);



    $postread = !empty($post->postread);



    if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, false, $ratings,

                         '', '', $postread, true, $forumtracked)) {

        $ratingsmenuused = true;

    }



    switch ($mode) {

        case FORUM_MODE_FLATOLDEST :

        case FORUM_MODE_FLATNEWEST :

        default:

            if (forum_print_posts_flat($course, $cm, $forum, $discussion, $post, $mode, $ratings, $reply, $forumtracked, $posts)) {

                $ratingsmenuused = true;

            }

            break;



        case FORUM_MODE_THREADED :

            if (forum_print_posts_threaded($course, $cm, $forum, $discussion, $post, 0, $ratings, $reply, $forumtracked, $posts)) {

                $ratingsmenuused = true;

            }

            break;



        case FORUM_MODE_NESTED :

            if (forum_print_posts_nested($course, $cm, $forum, $discussion, $post, $ratings, $reply, $forumtracked, $posts)) {

                $ratingsmenuused = true;

            }

            break;

    }



    if ($ratingsformused) {

        if ($ratingsmenuused) {

            echo '<div class="ratingsubmit">';

            echo '<input type="submit" id="forumpostratingsubmit" value="'.get_string('sendinratings', 'forum').'" />';

            if (ajaxenabled() && !empty($CFG->forum_ajaxrating)) { /// AJAX enabled, standard submission form

                $rate_ajax_config_settings = array("pixpath"=>$CFG->pixpath, "wwwroot"=>$CFG->wwwroot, "sesskey"=>sesskey());

                echo "<script type=\"text/javascript\">//<![CDATA[\n".

                     "var rate_ajax_config = " . json_encode($rate_ajax_config_settings) . ";\n".

                     "init_rate_ajax();\n".

                     "//]]></script>\n";

            }

            if ($forum->scale < 0) {

                if ($scale = get_record("scale", "id", abs($forum->scale))) {

                    print_scale_menu_helpbutton($course->id, $scale );

                }

            }

            echo '</div>';

        }



        echo '</div>';

        echo '</form>';

    }

}





/**

 *

 */

function forum_print_posts_flat($course, &$cm, $forum, $discussion, $post, $mode, $ratings, $reply, $forumtracked, $posts) {

    global $USER, $CFG;



    $link  = false;

    $ratingsmenuused = false;



    if ($mode == FORUM_MODE_FLATNEWEST) {

        $sort = "ORDER BY created DESC";

    } else {

        $sort = "ORDER BY created ASC";

    }



    foreach ($posts as $post) {

        if (!$post->parent) {

            continue;

        }

        $post->subject = format_string($post->subject);

        $ownpost = ($USER->id == $post->userid);



        $postread = !empty($post->postread);



        if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link, $ratings,

                             '', '', $postread, true, $forumtracked)) {

            $ratingsmenuused = true;

        }

    }



    return $ratingsmenuused;

}





/**

 * TODO document

 */

function forum_print_posts_threaded($course, &$cm, $forum, $discussion, $parent, $depth, $ratings, $reply, $forumtracked, $posts) {

    global $USER, $CFG;



    $link  = false;

    $ratingsmenuused = false;



    if (!empty($posts[$parent->id]->children)) {

        $posts = $posts[$parent->id]->children;



        $modcontext       = get_context_instance(CONTEXT_MODULE, $cm->id);

        $canviewfullnames = has_capability('moodle/site:viewfullnames', $modcontext);



        foreach ($posts as $post) {



            echo '<div class="indent">';

            if ($depth > 0) {

                $ownpost = ($USER->id == $post->userid);

                $post->subject = format_string($post->subject);



                $postread = !empty($post->postread);



                if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link, $ratings,

                                     '', '', $postread, true, $forumtracked)) {

                    $ratingsmenuused = true;

                }

            } else {

                if (!forum_user_can_see_post($forum, $discussion, $post, NULL, $cm)) {

                    echo "</div>\n";

                    continue;

                }

                $by = new object();

                $by->name = fullname($post, $canviewfullnames);

                $by->date = userdate($post->modified);



                if ($forumtracked) {

                    if (!empty($post->postread)) {

                        $style = '<span class="forumthread read">';

                    } else {

                        $style = '<span class="forumthread unread">';

                    }

                } else {

                    $style = '<span class="forumthread">';

                }

                echo $style."<a name=\"$post->id\"></a>".

                     "<a href=\"discuss.php?d=$post->discussion&amp;parent=$post->id\">".format_string($post->subject,true)."</a> ";

                print_string("bynameondate", "forum", $by);

                echo "</span>";

            }



            if (forum_print_posts_threaded($course, $cm, $forum, $discussion, $post, $depth-1, $ratings, $reply, $forumtracked, $posts)) {

                $ratingsmenuused = true;

            }

            echo "</div>\n";

        }

    }

    return $ratingsmenuused;

}



/**

 *

 */

function forum_print_posts_nested($course, &$cm, $forum, $discussion, $parent, $ratings, $reply, $forumtracked, $posts) {

    global $USER, $CFG;



    $link  = false;

    $ratingsmenuused = false;



    if (!empty($posts[$parent->id]->children)) {

        $posts = $posts[$parent->id]->children;



        foreach ($posts as $post) {



            echo '<div class="indent">';

            if (empty($USER->id)) {

                $ownpost = false;

            } else {

                $ownpost = ($USER->id == $post->userid);

            }



            $post->subject = format_string($post->subject);

            $postread = !empty($post->postread);



            if (forum_print_post($post, $discussion, $forum, $cm, $course, $ownpost, $reply, $link, $ratings,

                                 '', '', $postread, true, $forumtracked)) {

                $ratingsmenuused = true;

            }

            if (forum_print_posts_nested($course, $cm, $forum, $discussion, $post, $ratings, $reply, $forumtracked, $posts)) {

                $ratingsmenuused = true;

            }

            echo "</div>\n";

        }

    }

    return $ratingsmenuused;

}



/**

 * Returns all forum posts since a given time in specified forum.

 */

function forum_get_recent_mod_activity(&$activities, &$index, $timestart, $courseid, $cmid, $userid=0, $groupid=0)  {

    global $CFG, $COURSE, $USER;



    if ($COURSE->id == $courseid) {

        $course = $COURSE;

    } else {

        $course = get_record('course', 'id', $courseid);

    }



    $modinfo =& get_fast_modinfo($course);



    $cm = $modinfo->cms[$cmid];



    if ($userid) {

        $userselect = "AND u.id = $userid";

    } else {

        $userselect = "";

    }



    if ($groupid) {

        $groupselect = "AND gm.groupid = $groupid";

        $groupjoin   = "JOIN {$CFG->prefix}groups_members gm ON  gm.userid=u.id";

    } else {

        $groupselect = "";

        $groupjoin   = "";

    }



    if (!$posts = get_records_sql("SELECT p.*, f.type AS forumtype, d.forum, d.groupid,

                                          d.timestart, d.timeend, d.userid AS duserid,

                                          u.firstname, u.lastname, u.email, u.picture, u.imagealt

                                     FROM {$CFG->prefix}forum_posts p

                                          JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                                          JOIN {$CFG->prefix}forum f             ON f.id = d.forum

                                          JOIN {$CFG->prefix}user u              ON u.id = p.userid

                                          $groupjoin

                                    WHERE p.created > $timestart AND f.id = $cm->instance

                                          $userselect $groupselect

                                 ORDER BY p.id ASC")) { // order by initial posting date

         return;

    }



    $groupmode       = groups_get_activity_groupmode($cm, $course);

    $cm_context      = get_context_instance(CONTEXT_MODULE, $cm->id);

    $viewhiddentimed = has_capability('mod/forum:viewhiddentimedposts', $cm_context);

    $accessallgroups = has_capability('moodle/site:accessallgroups', $cm_context);



    if (is_null($modinfo->groups)) {

        $modinfo->groups = groups_get_user_groups($course->id); // load all my groups and cache it in modinfo

    }



    $printposts = array();

    foreach ($posts as $post) {



        if (!empty($CFG->forum_enabletimedposts) and $USER->id != $post->duserid

          and (($post->timestart > 0 and $post->timestart > time()) or ($post->timeend > 0 and $post->timeend < time()))) {

            if (!$viewhiddentimed) {

                continue;

            }

        }



        if ($groupmode) {

            if ($post->groupid == -1 or $groupmode == VISIBLEGROUPS or $accessallgroups) {

                // oki (Open discussions have groupid -1)

            } else {

                // separate mode

                if (isguestuser()) {

                    // shortcut

                    continue;

                }



                if (!array_key_exists($post->groupid, $modinfo->groups[0])) {

                    continue;

                }

            }

        }



        $printposts[] = $post;

    }



    if (!$printposts) {

        return;

    }



    $aname = format_string($cm->name,true);



    foreach ($printposts as $post) {

        $tmpactivity = new object();



        $tmpactivity->type         = 'forum';

        $tmpactivity->cmid         = $cm->id;

        $tmpactivity->name         = $aname;

        $tmpactivity->sectionnum   = $cm->sectionnum;

        $tmpactivity->timestamp    = $post->modified;



        $tmpactivity->content = new object();

        $tmpactivity->content->id         = $post->id;

        $tmpactivity->content->discussion = $post->discussion;

        $tmpactivity->content->subject    = format_string($post->subject);

        $tmpactivity->content->parent     = $post->parent;



        $tmpactivity->user = new object();

        $tmpactivity->user->id        = $post->userid;

        $tmpactivity->user->firstname = $post->firstname;

        $tmpactivity->user->lastname  = $post->lastname;

        $tmpactivity->user->picture   = $post->picture;

        $tmpactivity->user->imagealt  = $post->imagealt;

        $tmpactivity->user->email     = $post->email;



        $activities[$index++] = $tmpactivity;

    }



    return;

}



/**

 *

 */

function forum_print_recent_mod_activity($activity, $courseid, $detail, $modnames, $viewfullnames) {

    global $CFG;



    if ($activity->content->parent) {

        $class = 'reply';

    } else {

        $class = 'discussion';

    }



    echo '<table border="0" cellpadding="3" cellspacing="0" class="forum-recent">';



    echo "<tr><td class=\"userpicture\" valign=\"top\">";

    print_user_picture($activity->user, $courseid);

    echo "</td><td class=\"$class\">";



    echo '<div class="title">';

    if ($detail) {

        $aname = s($activity->name);

        echo "<img src=\"$CFG->modpixpath/$activity->type/icon.gif\" ".

             "class=\"icon\" alt=\"{$aname}\" />";

    }

    echo "<a href=\"$CFG->wwwroot/mod/forum/discuss.php?d={$activity->content->discussion}"

         ."#p{$activity->content->id}\">{$activity->content->subject}</a>";

    echo '</div>';



    echo '<div class="user">';

    $fullname = fullname($activity->user, $viewfullnames);

    echo "<a href=\"$CFG->wwwroot/user/view.php?id={$activity->user->id}&amp;course=$courseid\">"

         ."{$fullname}</a> - ".userdate($activity->timestamp);

    echo '</div>';

      echo "</td></tr></table>";



    return;

}



/**

 * recursively sets the discussion field to $discussionid on $postid and all its children

 * used when pruning a post

 */

function forum_change_discussionid($postid, $discussionid) {

    set_field('forum_posts', 'discussion', $discussionid, 'id', $postid);

    if ($posts = get_records('forum_posts', 'parent', $postid)) {

        foreach ($posts as $post) {

            forum_change_discussionid($post->id, $discussionid);

        }

    }

    return true;

}



/**

 * Prints the editing button on subscribers page

 */

function forum_update_subscriptions_button($courseid, $forumid) {

    global $CFG, $USER;



    if (!empty($USER->subscriptionsediting)) {

        $string = get_string('turneditingoff');

        $edit = "off";

    } else {

        $string = get_string('turneditingon');

        $edit = "on";

    }



    return "<form $CFG->frametarget method=\"get\" action=\"$CFG->wwwroot/mod/forum/subscribers.php\">".

           "<input type=\"hidden\" name=\"id\" value=\"$forumid\" />".

           "<input type=\"hidden\" name=\"edit\" value=\"$edit\" />".

           "<input type=\"submit\" value=\"$string\" /></form>";

}



/*

 * This function gets run whenever a role is assigned to a user in a context

 *

 * @param integer $userid

 * @param object $context

 * @return bool

 */

function forum_role_assign($userid, $context, $roleid) {

    // check to see if this role comes with mod/forum:initialsubscriptions

    $cap = role_context_capabilities($roleid, $context, 'mod/forum:initialsubscriptions');

    $cap1 = role_context_capabilities($roleid, $context, 'moodle/course:view');

    // we are checking the role because has_capability() will pull this capability out

    // from other roles this user might have and resolve them, which is no good

    // the role needs course view to

    if (isset($cap['mod/forum:initialsubscriptions']) && $cap['mod/forum:initialsubscriptions'] == CAP_ALLOW &&

        isset($cap1['moodle/course:view']) && $cap1['moodle/course:view'] == CAP_ALLOW) {

        return forum_add_user_default_subscriptions($userid, $context);

    } else {

        // MDL-8981, do not subscribe to forum

        return true;

    }

}





/**

 * This function gets run whenever a role is assigned to a user in a context

 *

 * @param integer $userid

 * @param object $context

 * @return bool

 */

function forum_role_unassign($userid, $context) {

    if (empty($context->contextlevel)) {

        return false;

    }



    forum_remove_user_subscriptions($userid, $context);

    forum_remove_user_tracking($userid, $context);



    return true;

}





/**

 * Add subscriptions for new users

 */

function forum_add_user_default_subscriptions($userid, $context) {



    if (empty($context->contextlevel)) {

        return false;

    }



    switch ($context->contextlevel) {



        case CONTEXT_SYSTEM:   // For the whole site

             $rs = get_recordset('course', '', '', '', 'id');

             while ($course = rs_fetch_next_record($rs)) {

                 $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);

                 forum_add_user_default_subscriptions($userid, $subcontext);

             }

             rs_close($rs);

             break;



        case CONTEXT_COURSECAT:   // For a whole category

            $rs = get_recordset('course', 'category', $context->instanceid, '', 'id');

            while ($course = rs_fetch_next_record($rs)) {

                $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);

                forum_add_user_default_subscriptions($userid, $subcontext);

            }

            rs_close($rs);

             if ($categories = get_records('course_categories', 'parent', $context->instanceid)) {

                 foreach ($categories as $category) {

                     $subcontext = get_context_instance(CONTEXT_COURSECAT, $category->id);

                     forum_add_user_default_subscriptions($userid, $subcontext);

                 }

             }

             break;





        case CONTEXT_COURSE:   // For a whole course

             if ($course = get_record('course', 'id', $context->instanceid)) {

                 if ($forums = get_all_instances_in_course('forum', $course, $userid, false)) {

                     foreach ($forums as $forum) {

                         if ($forum->forcesubscribe != FORUM_INITIALSUBSCRIBE) {

                             continue;

                         }

                         if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {

                             if (has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {

                                 forum_subscribe($userid, $forum->id);

                             }

                         }

                     }

                 }

             }

             break;



        case CONTEXT_MODULE:   // Just one forum

             if ($cm = get_coursemodule_from_id('forum', $context->instanceid)) {

                 if ($forum = get_record('forum', 'id', $cm->instance)) {

                     if ($forum->forcesubscribe != FORUM_INITIALSUBSCRIBE) {

                         continue;

                     }

                     if (has_capability('mod/forum:viewdiscussion', $context, $userid)) {

                         forum_subscribe($userid, $forum->id);

                     }

                 }

             }

             break;

    }



    return true;

}





/**

 * Remove subscriptions for a user in a context

 */

function forum_remove_user_subscriptions($userid, $context) {



    global $CFG;



    if (empty($context->contextlevel)) {

        return false;

    }



    switch ($context->contextlevel) {



        case CONTEXT_SYSTEM:   // For the whole site

            //if ($courses = get_my_courses($userid)) {

            // find all courses in which this user has a forum subscription

            if ($courses = get_records_sql("SELECT c.id

                                              FROM {$CFG->prefix}course c,

                                                   {$CFG->prefix}forum_subscriptions fs,

                                                   {$CFG->prefix}forum f

                                                   WHERE c.id = f.course AND f.id = fs.forum AND fs.userid = $userid

                                                   GROUP BY c.id")) {



                foreach ($courses as $course) {

                    $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);

                    forum_remove_user_subscriptions($userid, $subcontext);

                }

            }

            break;



        case CONTEXT_COURSECAT:   // For a whole category

             if ($courses = get_records('course', 'category', $context->instanceid, '', 'id')) {

                 foreach ($courses as $course) {

                     $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);

                     forum_remove_user_subscriptions($userid, $subcontext);

                 }

             }

             if ($categories = get_records('course_categories', 'parent', $context->instanceid, '', 'id')) {

                 foreach ($categories as $category) {

                     $subcontext = get_context_instance(CONTEXT_COURSECAT, $category->id);

                     forum_remove_user_subscriptions($userid, $subcontext);

                 }

             }

             break;



        case CONTEXT_COURSE:   // For a whole course

             if ($course = get_record('course', 'id', $context->instanceid, '', '', '', '', 'id')) {

                // find all forums in which this user has a subscription, and its coursemodule id

                if ($forums = get_records_sql("SELECT f.id, cm.id as coursemodule

                                                 FROM {$CFG->prefix}forum f,

                                                      {$CFG->prefix}modules m,

                                                      {$CFG->prefix}course_modules cm,

                                                      {$CFG->prefix}forum_subscriptions fs

                                                WHERE fs.userid = $userid AND f.course = $context->instanceid

                                                      AND fs.forum = f.id AND cm.instance = f.id

                                                      AND cm.module = m.id AND m.name = 'forum'")) {



                     foreach ($forums as $forum) {

                         if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {

                             if (!has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {

                                 forum_unsubscribe($userid, $forum->id);

                             }

                         }

                     }

                 }

             }

             break;



        case CONTEXT_MODULE:   // Just one forum

             if ($cm = get_coursemodule_from_id('forum', $context->instanceid)) {

                 if ($forum = get_record('forum', 'id', $cm->instance)) {

                     if (!has_capability('mod/forum:viewdiscussion', $context, $userid)) {

                         forum_unsubscribe($userid, $forum->id);

                     }

                 }

             }

             break;

    }



    return true;

}



// Functions to do with read tracking.



/**

 * Remove post tracking for a user in a context

 */

function forum_remove_user_tracking($userid, $context) {



    global $CFG;



    if (empty($context->contextlevel)) {

        return false;

    }



    switch ($context->contextlevel) {



        case CONTEXT_SYSTEM:   // For the whole site

            // find all courses in which this user has tracking info

            $allcourses = array();

            if ($courses = get_records_sql("SELECT c.id

                                              FROM {$CFG->prefix}course c,

                                                   {$CFG->prefix}forum_read fr,

                                                   {$CFG->prefix}forum f

                                                   WHERE c.id = f.course AND f.id = fr.forumid AND fr.userid = $userid

                                                   GROUP BY c.id")) {



                $allcourses = $allcourses + $courses;

            }

            if ($courses = get_records_sql("SELECT c.id

                                              FROM {$CFG->prefix}course c,

                                                   {$CFG->prefix}forum_track_prefs ft,

                                                   {$CFG->prefix}forum f

                                             WHERE c.id = f.course AND f.id = ft.forumid AND ft.userid = $userid")) {



                $allcourses = $allcourses + $courses;

            }

            foreach ($allcourses as $course) {

                $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);

                forum_remove_user_tracking($userid, $subcontext);

            }

            break;



        case CONTEXT_COURSECAT:   // For a whole category

             if ($courses = get_records('course', 'category', $context->instanceid, '', 'id')) {

                 foreach ($courses as $course) {

                     $subcontext = get_context_instance(CONTEXT_COURSE, $course->id);

                     forum_remove_user_tracking($userid, $subcontext);

                 }

             }

             if ($categories = get_records('course_categories', 'parent', $context->instanceid, '', 'id')) {

                 foreach ($categories as $category) {

                     $subcontext = get_context_instance(CONTEXT_COURSECAT, $category->id);

                     forum_remove_user_tracking($userid, $subcontext);

                 }

             }

             break;



        case CONTEXT_COURSE:   // For a whole course

             if ($course = get_record('course', 'id', $context->instanceid, '', '', '', '', 'id')) {

                // find all forums in which this user has reading tracked

                if ($forums = get_records_sql("SELECT f.id, cm.id as coursemodule

                                                 FROM {$CFG->prefix}forum f,

                                                      {$CFG->prefix}modules m,

                                                      {$CFG->prefix}course_modules cm,

                                                      {$CFG->prefix}forum_read fr

                                                WHERE fr.userid = $userid AND f.course = $context->instanceid

                                                      AND fr.forumid = f.id AND cm.instance = f.id

                                                      AND cm.module = m.id AND m.name = 'forum'")) {



                     foreach ($forums as $forum) {

                         if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {

                             if (!has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {

                                forum_tp_delete_read_records($userid, -1, -1, $forum->id);

                             }

                         }

                     }

                 }



                // find all forums in which this user has a disabled tracking

                if ($forums = get_records_sql("SELECT f.id, cm.id as coursemodule

                                                 FROM {$CFG->prefix}forum f,

                                                      {$CFG->prefix}modules m,

                                                      {$CFG->prefix}course_modules cm,

                                                      {$CFG->prefix}forum_track_prefs ft

                                                WHERE ft.userid = $userid AND f.course = $context->instanceid

                                                      AND ft.forumid = f.id AND cm.instance = f.id

                                                      AND cm.module = m.id AND m.name = 'forum'")) {



                     foreach ($forums as $forum) {

                         if ($modcontext = get_context_instance(CONTEXT_MODULE, $forum->coursemodule)) {

                             if (!has_capability('mod/forum:viewdiscussion', $modcontext, $userid)) {

                                delete_records('forum_track_prefs', 'userid', $userid, 'forumid', $forum->id);

                             }

                         }

                     }

                 }

             }

             break;



        case CONTEXT_MODULE:   // Just one forum

             if ($cm = get_coursemodule_from_id('forum', $context->instanceid)) {

                 if ($forum = get_record('forum', 'id', $cm->instance)) {

                     if (!has_capability('mod/forum:viewdiscussion', $context, $userid)) {

                        delete_records('forum_track_prefs', 'userid', $userid, 'forumid', $forum->id);

                        forum_tp_delete_read_records($userid, -1, -1, $forum->id);

                     }

                 }

             }

             break;

    }



    return true;

}



/**

 * Mark posts as read.

 * @param object $user object

 * @param array $postids array of post ids

 * @return boolean success

 */

function forum_tp_mark_posts_read($user, $postids) {

    global $CFG;



    if (!forum_tp_can_track_forums(false, $user)) {

        return true;

    }



    $status = true;



    $now = time();

    $cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 3600);



    if (empty($postids)) {

        return true;



    } else if (count($postids) > 200) {

        while ($part = array_splice($postids, 0, 200)) {

            $status = forum_tp_mark_posts_read($user, $part) && $status;

        }

        return $status;

    }



    $sql = "SELECT id

              FROM {$CFG->prefix}forum_read

             WHERE userid = $user->id AND postid IN (".implode(',', $postids).")";

    if ($existing = get_records_sql($sql)) {

        $existing = array_keys($existing);

    } else {

        $existing = array();

    }



    $new = array_diff($postids, $existing);



    if ($new) {

        $sql = "INSERT INTO {$CFG->prefix}forum_read (userid, postid, discussionid, forumid, firstread, lastread)



                SELECT $user->id, p.id, p.discussion, d.forum, $now, $now

                  FROM {$CFG->prefix}forum_posts p

                       JOIN {$CFG->prefix}forum_discussions d       ON d.id = p.discussion

                       JOIN {$CFG->prefix}forum f                   ON f.id = d.forum

                       LEFT JOIN {$CFG->prefix}forum_track_prefs tf ON (tf.userid = $user->id AND tf.forumid = f.id)

                 WHERE p.id IN (".implode(',', $new).")

                       AND p.modified >= $cutoffdate

                       AND (f.trackingtype = ".FORUM_TRACKING_ON."

                            OR (f.trackingtype = ".FORUM_TRACKING_OPTIONAL." AND tf.id IS NULL))";

        $status = execute_sql($sql, false) && $status;

    }



    if ($existing) {

        $sql = "UPDATE {$CFG->prefix}forum_read

                   SET lastread = $now

                 WHERE userid = $user->id AND postid IN (".implode(',', $existing).")";

        $status = execute_sql($sql, false) && $status;

    }



    return $status;

}



/**

 * Mark post as read.

 */

function forum_tp_add_read_record($userid, $postid) {

    global $CFG;



    $now = time();

    $cutoffdate = $now - ($CFG->forum_oldpostdays * 24 * 3600);



    if (!record_exists('forum_read', 'userid', $userid, 'postid', $postid)) {

        $sql = "INSERT INTO {$CFG->prefix}forum_read (userid, postid, discussionid, forumid, firstread, lastread)



                SELECT $userid, p.id, p.discussion, d.forum, $now, $now

                  FROM {$CFG->prefix}forum_posts p

                       JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                 WHERE p.id = $postid AND p.modified >= $cutoffdate";

        return execute_sql($sql, false);



    } else {

        $sql = "UPDATE {$CFG->prefix}forum_read

                   SET lastread = $now

                 WHERE userid = $userid AND postid = $userid";

        return execute_sql($sql, false);

    }

}



/**

 * Returns all records in the 'forum_read' table matching the passed keys, indexed

 * by userid.

 */

function forum_tp_get_read_records($userid=-1, $postid=-1, $discussionid=-1, $forumid=-1) {

    $select = '';

    if ($userid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'userid = \''.$userid.'\'';

    }

    if ($postid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'postid = \''.$postid.'\'';

    }

    if ($discussionid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'discussionid = \''.$discussionid.'\'';

    }

    if ($forumid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'forumid = \''.$forumid.'\'';

    }



    return get_records_select('forum_read', $select);

}



/**

 * Returns all read records for the provided user and discussion, indexed by postid.

 */

function forum_tp_get_discussion_read_records($userid, $discussionid) {

    $select = 'userid = \''.$userid.'\' AND discussionid = \''.$discussionid.'\'';

    $fields = 'postid, firstread, lastread';

    return get_records_select('forum_read', $select, '', $fields);

}



/**

 * If its an old post, do nothing. If the record exists, the maintenance will clear it up later.

 */

function forum_tp_mark_post_read($userid, $post, $forumid) {

    if (!forum_tp_is_post_old($post)) {

        return forum_tp_add_read_record($userid, $post->id);

    } else {

        return true;

    }

}



/**

 * Marks a whole forum as read, for a given user

 */

function forum_tp_mark_forum_read($user, $forumid, $groupid=false) {

    global $CFG;



    $cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);



    $groupsel = "";

    if ($groupid !== false) {

        $groupsel = " AND (d.groupid = $groupid OR d.groupid = -1)";

    }



    $sql = "SELECT p.id

              FROM {$CFG->prefix}forum_posts p

                   LEFT JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                   LEFT JOIN {$CFG->prefix}forum_read r        ON (r.postid = p.id AND r.userid = $user->id)

             WHERE d.forum = $forumid

                   AND p.modified >= $cutoffdate AND r.id is NULL

                   $groupsel";



    if ($posts = get_records_sql($sql)) {

        $postids = array_keys($posts);

        return forum_tp_mark_posts_read($user, $postids);

    }



    return true;

}



/**

 * Marks a whole discussion as read, for a given user

 */

function forum_tp_mark_discussion_read($user, $discussionid) {

    global $CFG;



    $cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);



    $sql = "SELECT p.id

              FROM {$CFG->prefix}forum_posts p

                   LEFT JOIN {$CFG->prefix}forum_read r ON (r.postid = p.id AND r.userid = $user->id)

             WHERE p.discussion = $discussionid

                   AND p.modified >= $cutoffdate AND r.id is NULL";



    if ($posts = get_records_sql($sql)) {

        $postids = array_keys($posts);

        return forum_tp_mark_posts_read($user, $postids);

    }



    return true;

}



/**

 *

 */

function forum_tp_is_post_read($userid, $post) {

    return (forum_tp_is_post_old($post) ||

            record_exists('forum_read', 'userid', $userid, 'postid', $post->id));

}



/**

 *

 */

function forum_tp_is_post_old($post, $time=null) {

    global $CFG;



    if (is_null($time)) {

        $time = time();

    }

    return ($post->modified < ($time - ($CFG->forum_oldpostdays * 24 * 3600)));

}



/**

 * Returns the count of records for the provided user and discussion.

 */

function forum_tp_count_discussion_read_records($userid, $discussionid) {

    global $CFG;



    $cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;



    $sql = 'SELECT COUNT(DISTINCT p.id) '.

           'FROM '.$CFG->prefix.'forum_discussions d '.

           'LEFT JOIN '.$CFG->prefix.'forum_read r ON d.id = r.discussionid AND r.userid = '.$userid.' '.

           'LEFT JOIN '.$CFG->prefix.'forum_posts p ON p.discussion = d.id '.

                'AND (p.modified < '.$cutoffdate.' OR p.id = r.postid) '.

           'WHERE d.id = '.$discussionid;



    return (count_records_sql($sql));

}



/**

 * Returns the count of records for the provided user and discussion.

 */

function forum_tp_count_discussion_unread_posts($userid, $discussionid) {

    global $CFG;



    $cutoffdate = isset($CFG->forum_oldpostdays) ? (time() - ($CFG->forum_oldpostdays*24*60*60)) : 0;



    $sql = 'SELECT COUNT(p.id) '.

           'FROM '.$CFG->prefix.'forum_posts p '.

           'LEFT JOIN '.$CFG->prefix.'forum_read r ON r.postid = p.id AND r.userid = '.$userid.' '.

           'WHERE p.discussion = '.$discussionid.' '.

                'AND p.modified >= '.$cutoffdate.' AND r.id is NULL';



    return (count_records_sql($sql));

}



/**

 * Returns the count of posts for the provided forum and [optionally] group.

 */

function forum_tp_count_forum_posts($forumid, $groupid=false) {

    global $CFG;



    $sql = 'SELECT COUNT(*) '.

           'FROM '.$CFG->prefix.'forum_posts fp,'.$CFG->prefix.'forum_discussions fd '.

           'WHERE fd.forum = '.$forumid.' AND fp.discussion = fd.id';

    if ($groupid !== false) {

        $sql .= ' AND (fd.groupid = '.$groupid.' OR fd.groupid = -1)';

    }

    $count = count_records_sql($sql);





    return $count;

}



/**

 * Returns the count of records for the provided user and forum and [optionally] group.

 */

function forum_tp_count_forum_read_records($userid, $forumid, $groupid=false) {

    global $CFG;



    $cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);



    $groupsel = '';

    if ($groupid !== false) {

        $groupsel = "AND (d.groupid = $groupid OR d.groupid = -1)";

    }



    $sql = "SELECT COUNT(p.id)

              FROM  {$CFG->prefix}forum_posts p

                    JOIN {$CFG->prefix}forum_discussions d ON d.id = p.discussion

                    LEFT JOIN {$CFG->prefix}forum_read r   ON (r.postid = p.id AND r.userid= $userid)

              WHERE d.forum = $forumid

                    AND (p.modified < $cutoffdate OR (p.modified >= $cutoffdate AND r.id IS NOT NULL))

                    $groupsel";



    return get_field_sql($sql);

}



/**

 * Returns the count of records for the provided user and course.

 * Please note that group access is ignored!

 */

function forum_tp_get_course_unread_posts($userid, $courseid) {

    global $CFG;



    $now = round(time(), -2); // db cache friendliness

    $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);



    if (!empty($CFG->forum_enabletimedposts)) {

        $timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";

    } else {

        $timedsql = "";

    }



    $sql = "SELECT f.id, COUNT(p.id) AS unread

              FROM {$CFG->prefix}forum_posts p

                   JOIN {$CFG->prefix}forum_discussions d       ON d.id = p.discussion

                   JOIN {$CFG->prefix}forum f                   ON f.id = d.forum

                   JOIN {$CFG->prefix}course c                  ON c.id = f.course

                   LEFT JOIN {$CFG->prefix}forum_read r         ON (r.postid = p.id AND r.userid = $userid)

                   LEFT JOIN {$CFG->prefix}forum_track_prefs tf ON (tf.userid = $userid AND tf.forumid = f.id)

             WHERE f.course = $courseid

                   AND p.modified >= $cutoffdate AND r.id is NULL

                   AND (f.trackingtype = ".FORUM_TRACKING_ON."

                        OR (f.trackingtype = ".FORUM_TRACKING_OPTIONAL." AND tf.id IS NULL))

                   $timedsql

          GROUP BY f.id";



    if ($return = get_records_sql($sql)) {

        return $return;

    }



    return array();

}



/**

 * Returns the count of records for the provided user and forum and [optionally] group.

 */

function forum_tp_count_forum_unread_posts($cm, $course) {

    global $CFG, $USER;



    static $readcache = array();



    $forumid = $cm->instance;



    if (!isset($readcache[$course->id])) {

        $readcache[$course->id] = array();

        if ($counts = forum_tp_get_course_unread_posts($USER->id, $course->id)) {

            foreach ($counts as $count) {

                $readcache[$course->id][$count->id] = $count->unread;

            }

        }

    }



    if (empty($readcache[$course->id][$forumid])) {

        // no need to check group mode ;-)

        return 0;

    }



    $groupmode = groups_get_activity_groupmode($cm, $course);



    if ($groupmode != SEPARATEGROUPS) {

        return $readcache[$course->id][$forumid];

    }



    if (has_capability('moodle/site:accessallgroups', get_context_instance(CONTEXT_MODULE, $cm->id))) {

        return $readcache[$course->id][$forumid];

    }



    require_once($CFG->dirroot.'/course/lib.php');



    $modinfo =& get_fast_modinfo($course);

    if (is_null($modinfo->groups)) {

        $modinfo->groups = groups_get_user_groups($course->id, $USER->id);

    }



    if (empty($CFG->enablegroupings)) {

        $mygroups = $modinfo->groups[0];

    } else {

        if (array_key_exists($cm->groupingid, $modinfo->groups)) {

            $mygroups = $modinfo->groups[$cm->groupingid];

        } else {

            $mygroups = false; // Will be set below

        }

    }



    // add all groups posts

    if (empty($mygroups)) {

        $mygroups = array(-1=>-1);

    } else {

        $mygroups[-1] = -1;

    }

    $mygroups = implode(',', $mygroups);





    $now = round(time(), -2); // db cache friendliness

    $cutoffdate = $now - ($CFG->forum_oldpostdays*24*60*60);



    if (!empty($CFG->forum_enabletimedposts)) {

        $timedsql = "AND d.timestart < $now AND (d.timeend = 0 OR d.timeend > $now)";

    } else {

        $timedsql = "";

    }



    $sql = "SELECT COUNT(p.id)

              FROM {$CFG->prefix}forum_posts p

                   JOIN {$CFG->prefix}forum_discussions d ON p.discussion = d.id

                   LEFT JOIN {$CFG->prefix}forum_read r   ON (r.postid = p.id AND r.userid = $USER->id)

             WHERE d.forum = $forumid

                   AND p.modified >= $cutoffdate AND r.id is NULL

                   $timedsql

                   AND d.groupid IN ($mygroups)";



    return get_field_sql($sql);

}



/**

 * Deletes read records for the specified index. At least one parameter must be specified.

 */

function forum_tp_delete_read_records($userid=-1, $postid=-1, $discussionid=-1, $forumid=-1) {

    $select = '';

    if ($userid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'userid = \''.$userid.'\'';

    }

    if ($postid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'postid = \''.$postid.'\'';

    }

    if ($discussionid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'discussionid = \''.$discussionid.'\'';

    }

    if ($forumid > -1) {

        if ($select != '') $select .= ' AND ';

        $select .= 'forumid = \''.$forumid.'\'';

    }

    if ($select == '') {

        return false;

    }

    else {

        return delete_records_select('forum_read', $select);

    }

}

/**

 * Get a list of forums not tracked by the user.

 *

 * @param int $userid The id of the user to use.

 * @param int $courseid The id of the course being checked.

 * @return mixed An array indexed by forum id, or false.

 */

function forum_tp_get_untracked_forums($userid, $courseid) {

    global $CFG;



    $sql = "SELECT f.id

              FROM {$CFG->prefix}forum f

                   LEFT JOIN {$CFG->prefix}forum_track_prefs ft ON (ft.forumid = f.id AND ft.userid = $userid)

             WHERE f.course = $courseid

                   AND (f.trackingtype = ".FORUM_TRACKING_OFF."

                        OR (f.trackingtype = ".FORUM_TRACKING_OPTIONAL." AND ft.id IS NOT NULL))";



    if ($forums = get_records_sql($sql)) {

        foreach ($forums as $forum) {

            $forums[$forum->id] = $forum;

        }

        return $forums;



    } else {

        return array();

    }

}



/**

 * Determine if a user can track forums and optionally a particular forum.

 * Checks the site settings, the user settings and the forum settings (if

 * requested).

 *

 * @param mixed $forum The forum object to test, or the int id (optional).

 * @param mixed $userid The user object to check for (optional).

 * @return boolean

 */

function forum_tp_can_track_forums($forum=false, $user=false) {

    global $USER, $CFG;



    // if possible, avoid expensive

    // queries

    if (empty($CFG->forum_trackreadposts)) {

        return false;

    }



    if ($user === false) {

        $user = $USER;

    }



    if (isguestuser($user) or empty($user->id)) {

        return false;

    }



    if ($forum === false) {

        // general abitily to track forums

        return (bool)$user->trackforums;

    }





    // Work toward always passing an object...

    if (is_numeric($forum)) {

        debugging('Better use proper forum object.', DEBUG_DEVELOPER);

        $forum = get_record('forum', 'id', $forum, '','','','', 'id,trackingtype');

    }



    $forumallows = ($forum->trackingtype == FORUM_TRACKING_OPTIONAL);

    $forumforced = ($forum->trackingtype == FORUM_TRACKING_ON);



    return ($forumforced || $forumallows)  && !empty($user->trackforums);

}



/**

 * Tells whether a specific forum is tracked by the user. A user can optionally

 * be specified. If not specified, the current user is assumed.

 *

 * @param mixed $forum If int, the id of the forum being checked; if object, the forum object

 * @param int $userid The id of the user being checked (optional).

 * @return boolean

 */

function forum_tp_is_tracked($forum, $user=false) {

    global $USER, $CFG;



    if ($user === false) {

        $user = $USER;

    }



    if (isguestuser($user) or empty($user->id)) {

        return false;

    }



    // Work toward always passing an object...

    if (is_numeric($forum)) {

        debugging('Better use proper forum object.', DEBUG_DEVELOPER);

        $forum = get_record('forum', 'id', $forum);

    }



    if (!forum_tp_can_track_forums($forum, $user)) {

        return false;

    }



    $forumallows = ($forum->trackingtype == FORUM_TRACKING_OPTIONAL);

    $forumforced = ($forum->trackingtype == FORUM_TRACKING_ON);



    return $forumforced ||

           ($forumallows && get_record('forum_track_prefs', 'userid', $user->id, 'forumid', $forum->id) === false);

}



/**

 *

 */

function forum_tp_start_tracking($forumid, $userid=false) {

    global $USER;



    if ($userid === false) {

        $userid = $USER->id;

    }



    return delete_records('forum_track_prefs', 'userid', $userid, 'forumid', $forumid);

}



/**

 *

 */

function forum_tp_stop_tracking($forumid, $userid=false) {

    global $USER;



    if ($userid === false) {

        $userid = $USER->id;

    }



    if (!record_exists('forum_track_prefs', 'userid', $userid, 'forumid', $forumid)) {

        $track_prefs = new object();

        $track_prefs->userid = $userid;

        $track_prefs->forumid = $forumid;

        insert_record('forum_track_prefs', $track_prefs);

    }



    return forum_tp_delete_read_records($userid, -1, -1, $forumid);

}





/**

 * Clean old records from the forum_read table.

 */

function forum_tp_clean_read_records() {

    global $CFG;



    if (!isset($CFG->forum_oldpostdays)) {

        return;

    }

// Look for records older than the cutoffdate that are still in the forum_read table.

    $cutoffdate = time() - ($CFG->forum_oldpostdays*24*60*60);



    //first get the oldest tracking present - we need tis to speedup the next delete query

    $sql = "SELECT MIN(fp.modified) AS first

              FROM {$CFG->prefix}forum_posts fp

                   JOIN {$CFG->prefix}forum_read fr ON fr.postid=fp.id";

    if (!$first = get_field_sql($sql)) {

        // nothing to delete;

        return;

    }



    // now delete old tracking info

    $sql = "DELETE

              FROM {$CFG->prefix}forum_read

             WHERE postid IN (SELECT fp.id

                                FROM {$CFG->prefix}forum_posts fp

                               WHERE fp.modified >= $first AND fp.modified < $cutoffdate)";

    execute_sql($sql, false);

}



/**

 * Sets the last post for a given discussion

 **/

function forum_discussion_update_last_post($discussionid) {

    global $CFG, $db;



// Check the given discussion exists

    if (!record_exists('forum_discussions', 'id', $discussionid)) {

        return false;

    }



// Use SQL to find the last post for this discussion

    $sql = 'SELECT id, userid, modified '.

           'FROM '.$CFG->prefix.'forum_posts '.

           'WHERE discussion='.$discussionid.' '.

           'ORDER BY modified DESC ';



// Lets go find the last post

    if (($lastpost = get_record_sql($sql, true))) {

        $discussionobject = new Object;

        $discussionobject->id = $discussionid;

        $discussionobject->usermodified = $lastpost->userid;

        $discussionobject->timemodified = $lastpost->modified;

        if (update_record('forum_discussions', $discussionobject)) {

            return $lastpost->id;

        }

    }



// To get here either we couldn't find a post for the discussion (weird)

// or we couldn't update the discussion record (weird x2)

    return false;

}





/**

 *

 */

function forum_get_view_actions() {

    return array('view discussion','search','forum','forums','subscribers');

}



/**

 *

 */

function forum_get_post_actions() {

    return array('add discussion','add post','delete discussion','delete post','move discussion','prune post','update post');

}



/**

 * this function returns all the separate forum ids, given a courseid

 * @param int $courseid

 * @return array

 */

function forum_get_separate_modules($courseid) {



    global $CFG,$db;

    $forummodule = get_record("modules", "name", "forum");



    $sql = 'SELECT f.id, f.id FROM '.$CFG->prefix.'forum f, '.$CFG->prefix.'course_modules cm WHERE

           f.id = cm.instance AND cm.module ='.$forummodule->id.' AND cm.visible = 1 AND cm.course = '.$courseid.'

           AND cm.groupmode ='.SEPARATEGROUPS;



    return get_records_sql($sql);



}



/**

 *

 */

function forum_check_throttling($forum, $cm=null) {

    global $USER, $CFG;



    if (is_numeric($forum)) {

        $forum = get_record('forum','id',$forum);

    }

    if (!is_object($forum)) {

        return false;  // this is broken.

    }



    if (empty($forum->blockafter)) {

        return true;

    }



    if (empty($forum->blockperiod)) {

        return true;

    }



    if (!$cm) {

        if (!$cm = get_coursemodule_from_instance('forum', $forum->id, $forum->course)) {

            error('Course Module ID was incorrect');

        }

    }



    $modcontext = get_context_instance(CONTEXT_MODULE, $cm->id);

    if(!has_capability('mod/forum:throttlingapplies', $modcontext)) {

        return true;

    }



    // get the number of posts in the last period we care about

    $timenow = time();

    $timeafter = $timenow - $forum->blockperiod;



    $numposts = count_records_sql('SELECT COUNT(p.id) FROM '.$CFG->prefix.'forum_posts p'

                                  .' JOIN '.$CFG->prefix.'forum_discussions d'

                                  .' ON p.discussion = d.id WHERE d.forum = '.$forum->id

                                  .' AND p.userid = '.$USER->id.' AND p.created > '.$timeafter);



    $a = new object();

    $a->blockafter = $forum->blockafter;

    $a->numposts = $numposts;

    $a->blockperiod = get_string('secondstotime'.$forum->blockperiod);



    if ($forum->blockafter <= $numposts) {

        print_error('forumblockingtoomanyposts', 'error', $CFG->wwwroot.'/mod/forum/view.php?f='.$forum->id, $a);

    }

    if ($forum->warnafter <= $numposts) {

        notify(get_string('forumblockingalmosttoomanyposts','forum',$a));

    }





}





/**

 * Removes all grades from gradebook

 * @param int $courseid

 * @param string optional type

 */

function forum_reset_gradebook($courseid, $type='') {

    global $CFG;



    $type = $type ? "AND f.type='$type'" : '';



    $sql = "SELECT f.*, cm.idnumber as cmidnumber, f.course as courseid

              FROM {$CFG->prefix}forum f, {$CFG->prefix}course_modules cm, {$CFG->prefix}modules m

             WHERE m.name='forum' AND m.id=cm.module AND cm.instance=f.id AND f.course=$courseid $type";



    if ($forums = get_records_sql($sql)) {

        foreach ($forums as $forum) {

            forum_grade_item_update($forum, 'reset');

        }

    }

}



/**

 * This function is used by the reset_course_userdata function in moodlelib.

 * This function will remove all posts from the specified forum

 * and clean up any related data.

 * @param $data the data submitted from the reset course.

 * @return array status array

 */

function forum_reset_userdata($data) {

    global $CFG;

    require_once($CFG->libdir.'/filelib.php');



    $componentstr = get_string('modulenameplural', 'forum');

    $status = array();



    $removeposts = false;

    if (!empty($data->reset_forum_all)) {

        $removeposts = true;

        $typesql     = "";

        $typesstr    = get_string('resetforumsall', 'forum');

        $types       = array();



    } else if (!empty($data->reset_forum_types)){

        $removeposts = true;

        $typesql     = "";

        $types       = array();

        $forum_types_all = forum_get_forum_types_all();

        foreach ($data->reset_forum_types as $type) {

            if (!array_key_exists($type, $forum_types_all)) {

                continue;

            }

            $typesql .= " AND f.type='$type'";

            $types[] = $forum_types_all[$type];

        }

        $typesstr = get_string('resetforums', 'forum').': '.implode(', ', $types);



    }



    $alldiscussionssql = "SELECT fd.id

                            FROM {$CFG->prefix}forum_discussions fd, {$CFG->prefix}forum f

                           WHERE f.course={$data->courseid} AND f.id=fd.forum";



    $allforumssql      = "SELECT f.id

                            FROM {$CFG->prefix}forum f

                           WHERE f.course={$data->courseid}";



    $allpostssql       = "SELECT fp.id

                            FROM {$CFG->prefix}forum_posts fp, {$CFG->prefix}forum_discussions fd, {$CFG->prefix}forum f

                           WHERE f.course={$data->courseid} AND f.id=fd.forum AND fd.id=fp.discussion";



    if ($removeposts) {

        $discussionssql = "$alldiscussionssql $typesql";

        $forumssql      = "$allforumssql $typesql";

        $postssql       = "$allpostssql $typesql";



        // first delete all read flags

        delete_records_select('forum_read', "forumid IN ($forumssql)");



        // remove tracking prefs

        delete_records_select('forum_track_prefs', "forumid IN ($forumssql)");



        // remove posts from queue

        delete_records_select('forum_queue', "discussionid IN ($discussionssql)");



        // remove ratings

        delete_records_select('forum_ratings', "post IN ($postssql)");



        // all posts - initial posts must be kept in single simple discussion forums

        delete_records_select('forum_posts', "discussion IN ($discussionssql) AND parent <> 0"); // first all children

        delete_records_select('forum_posts', "discussion IN ($discussionssql AND f.type <> 'single') AND parent = 0"); // now the initial posts for non single simple



        // finally all discussions except single simple forums

        delete_records_select('forum_discussions', "forum IN ($forumssql AND f.type <> 'single')");



        // now get rid of all attachments

        if ($forums = get_records_sql($forumssql)) {

            foreach ($forums as $forumid=>$unused) {

                fulldelete($CFG->dataroot.'/'.$data->courseid.'/moddata/forum/'.$forumid);

            }

        }



        // remove all grades from gradebook

        if (empty($data->reset_gradebook_grades)) {

            if (empty($types)) {

                forum_reset_gradebook($data->courseid);

            } else {

                foreach ($types as $type) {

                    forum_reset_gradebook($data->courseid, $type);

                }

            }

        }



        $status[] = array('component'=>$componentstr, 'item'=>$typesstr, 'error'=>false);

    }



    // remove all ratings

    if (!empty($data->reset_forum_ratings)) {

        delete_records_select('forum_ratings', "post IN ($allpostssql)");

        // remove all grades from gradebook

        if (empty($data->reset_gradebook_grades)) {

            forum_reset_gradebook($data->courseid);

        }

    }



    // remove all subscriptions unconditionally - even for users still enrolled in course

    if (!empty($data->reset_forum_subscriptions)) {

        delete_records_select('forum_subscriptions', "forum IN ($allforumssql)");

        $status[] = array('component'=>$componentstr, 'item'=>get_string('resetsubscriptions','forum'), 'error'=>false);

    }



    // remove all tracking prefs unconditionally - even for users still enrolled in course

    if (!empty($data->reset_forum_track_prefs)) {

        delete_records_select('forum_track_prefs', "forumid IN ($allforumssql)");

        $status[] = array('component'=>$componentstr, 'item'=>get_string('resettrackprefs','forum'), 'error'=>false);

    }



    /// updating dates - shift may be negative too

    if ($data->timeshift) {

        shift_course_mod_dates('forum', array('assesstimestart', 'assesstimefinish'), $data->timeshift, $data->courseid);

        $status[] = array('component'=>$componentstr, 'item'=>get_string('datechanged'), 'error'=>false);

    }



    return $status;

}



/**

 * Called by course/reset.php

 * @param $mform form passed by reference

 */

function forum_reset_course_form_definition(&$mform) {

    $mform->addElement('header', 'forumheader', get_string('modulenameplural', 'forum'));



    $mform->addElement('checkbox', 'reset_forum_all', get_string('resetforumsall','forum'));



    $mform->addElement('select', 'reset_forum_types', get_string('resetforums', 'forum'), forum_get_forum_types_all(), array('multiple' => 'multiple'));

    $mform->setAdvanced('reset_forum_types');

    $mform->disabledIf('reset_forum_types', 'reset_forum_all', 'checked');



    $mform->addElement('checkbox', 'reset_forum_subscriptions', get_string('resetsubscriptions','forum'));

    $mform->setAdvanced('reset_forum_subscriptions');



    $mform->addElement('checkbox', 'reset_forum_track_prefs', get_string('resettrackprefs','forum'));

    $mform->setAdvanced('reset_forum_track_prefs');

    $mform->disabledIf('reset_forum_track_prefs', 'reset_forum_all', 'checked');



    $mform->addElement('checkbox', 'reset_forum_ratings', get_string('deleteallratings'));

    $mform->disabledIf('reset_forum_ratings', 'reset_forum_all', 'checked');

}



/**

 * Course reset form defaults.

 */

function forum_reset_course_form_defaults($course) {

    return array('reset_forum_all'=>1, 'reset_forum_subscriptions'=>0, 'reset_forum_track_prefs'=>0, 'reset_forum_ratings'=>1);

}



/**

 * Converts a forum to use the Roles System

 * @param $forum        - a forum object with the same attributes as a record

 *                        from the forum database table

 * @param $forummodid   - the id of the forum module, from the modules table

 * @param $teacherroles - array of roles that have moodle/legacy:teacher

 * @param $studentroles - array of roles that have moodle/legacy:student

 * @param $guestroles   - array of roles that have moodle/legacy:guest

 * @param $cmid         - the course_module id for this forum instance

 * @return boolean      - forum was converted or not

 */

function forum_convert_to_roles($forum, $forummodid, $teacherroles=array(),

                                $studentroles=array(), $guestroles=array(), $cmid=NULL) {



    global $CFG;



    if (!isset($forum->open) && !isset($forum->assesspublic)) {

        // We assume that this forum has already been converted to use the

        // Roles System. Columns forum.open and forum.assesspublic get dropped

        // once the forum module has been upgraded to use Roles.

        return false;

    }



    if ($forum->type == 'teacher') {



        // Teacher forums should be converted to normal forums that

        // use the Roles System to implement the old behavior.

        // Note:

        //   Seems that teacher forums were never backed up in 1.6 since they

        //   didn't have an entry in the course_modules table.

        require_once($CFG->dirroot.'/course/lib.php');



        if (count_records('forum_discussions', 'forum', $forum->id) == 0) {

            // Delete empty teacher forums.

            delete_records('forum', 'id', $forum->id);

        } else {

            // Create a course module for the forum and assign it to

            // section 0 in the course.

            $mod = new object;

            $mod->course = $forum->course;

            $mod->module = $forummodid;

            $mod->instance = $forum->id;

            $mod->section = 0;

            $mod->visible = 0;     // Hide the forum

            $mod->visibleold = 0;  // Hide the forum

            $mod->groupmode = 0;



            if (!$cmid = add_course_module($mod)) {

                error('Could not create new course module instance for the teacher forum');

            } else {

                $mod->coursemodule = $cmid;

                if (!$sectionid = add_mod_to_section($mod)) {

                    error('Could not add converted teacher forum instance to section 0 in the course');

                } else {

                    if (!set_field('course_modules', 'section', $sectionid, 'id', $cmid)) {

                        error('Could not update course module with section id');

                    }

                }

            }



            // Change the forum type to general.

            $forum->type = 'general';

            if (!update_record('forum', $forum)) {

                error('Could not change forum from type teacher to type general');

            }



            $context = get_context_instance(CONTEXT_MODULE, $cmid);



            // Create overrides for default student and guest roles (prevent).

            foreach ($studentroles as $studentrole) {

                assign_capability('mod/forum:viewdiscussion', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:viewhiddentimedposts', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:replypost', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:viewrating', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:viewanyrating', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:rate', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:createattachment', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:deleteownpost', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:deleteanypost', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:splitdiscussions', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:movediscussions', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:editanypost', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:viewqandawithoutposting', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:viewsubscribers', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:managesubscriptions', CAP_PREVENT, $studentrole->id, $context->id);

                assign_capability('mod/forum:throttlingapplies', CAP_PREVENT, $studentrole->id, $context->id);

            }

            foreach ($guestroles as $guestrole) {

                assign_capability('mod/forum:viewdiscussion', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:viewhiddentimedposts', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:replypost', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:viewrating', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:viewanyrating', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:rate', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:createattachment', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:deleteownpost', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:deleteanypost', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:splitdiscussions', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:movediscussions', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:editanypost', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:viewqandawithoutposting', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:viewsubscribers', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:managesubscriptions', CAP_PREVENT, $guestrole->id, $context->id);

                assign_capability('mod/forum:throttlingapplies', CAP_PREVENT, $guestrole->id, $context->id);

            }

        }

    } else {

        // Non-teacher forum.



        if (empty($cmid)) {

            // We were not given the course_module id. Try to find it.

            if (!$cm = get_coursemodule_from_instance('forum', $forum->id)) {

                notify('Could not get the course module for the forum');

                return false;

            } else {

                $cmid = $cm->id;

            }

        }

        $context = get_context_instance(CONTEXT_MODULE, $cmid);



        // $forum->open defines what students can do:

        //   0 = No discussions, no replies

        //   1 = No discussions, but replies are allowed

        //   2 = Discussions and replies are allowed

        switch ($forum->open) {

            case 0:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $studentrole->id, $context->id);

                    assign_capability('mod/forum:replypost', CAP_PREVENT, $studentrole->id, $context->id);

                }

                break;

            case 1:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:startdiscussion', CAP_PREVENT, $studentrole->id, $context->id);

                    assign_capability('mod/forum:replypost', CAP_ALLOW, $studentrole->id, $context->id);

                }

                break;

            case 2:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:startdiscussion', CAP_ALLOW, $studentrole->id, $context->id);

                    assign_capability('mod/forum:replypost', CAP_ALLOW, $studentrole->id, $context->id);

                }

                break;

        }



        // $forum->assessed defines whether forum rating is turned

        // on (1 or 2) and who can rate posts:

        //   1 = Everyone can rate posts

        //   2 = Only teachers can rate posts

        switch ($forum->assessed) {

            case 1:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:rate', CAP_ALLOW, $studentrole->id, $context->id);

                }

                foreach ($teacherroles as $teacherrole) {

                    assign_capability('mod/forum:rate', CAP_ALLOW, $teacherrole->id, $context->id);

                }

                break;

            case 2:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:rate', CAP_PREVENT, $studentrole->id, $context->id);

                }

                foreach ($teacherroles as $teacherrole) {

                    assign_capability('mod/forum:rate', CAP_ALLOW, $teacherrole->id, $context->id);

                }

                break;

        }



        // $forum->assesspublic defines whether students can see

        // everybody's ratings:

        //   0 = Students can only see their own ratings

        //   1 = Students can see everyone's ratings

        switch ($forum->assesspublic) {

            case 0:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:viewanyrating', CAP_PREVENT, $studentrole->id, $context->id);

                }

                foreach ($teacherroles as $teacherrole) {

                    assign_capability('mod/forum:viewanyrating', CAP_ALLOW, $teacherrole->id, $context->id);

                }

                break;

            case 1:

                foreach ($studentroles as $studentrole) {

                    assign_capability('mod/forum:viewanyrating', CAP_ALLOW, $studentrole->id, $context->id);

                }

                foreach ($teacherroles as $teacherrole) {

                    assign_capability('mod/forum:viewanyrating', CAP_ALLOW, $teacherrole->id, $context->id);

                }

                break;

        }



        if (empty($cm)) {

            $cm = get_record('course_modules', 'id', $cmid);

        }



        // $cm->groupmode:

        // 0 - No groups

        // 1 - Separate groups

        // 2 - Visible groups

        switch ($cm->groupmode) {

            case 0:

                break;

            case 1:

                foreach ($studentroles as $studentrole) {

                    assign_capability('moodle/site:accessallgroups', CAP_PREVENT, $studentrole->id, $context->id);

                }

                foreach ($teacherroles as $teacherrole) {

                    assign_capability('moodle/site:accessallgroups', CAP_ALLOW, $teacherrole->id, $context->id);

                }

                break;

            case 2:

                foreach ($studentroles as $studentrole) {

                    assign_capability('moodle/site:accessallgroups', CAP_ALLOW, $studentrole->id, $context->id);

                }

                foreach ($teacherroles as $teacherrole) {

                    assign_capability('moodle/site:accessallgroups', CAP_ALLOW, $teacherrole->id, $context->id);

                }

                break;

        }

    }

    return true;

}



/**

 * Returns array of forum aggregate types

 */

function forum_get_aggregate_types() {

    return array (FORUM_AGGREGATE_NONE  => get_string('aggregatenone', 'forum'),

                  FORUM_AGGREGATE_AVG   => get_string('aggregateavg', 'forum'),

                  FORUM_AGGREGATE_COUNT => get_string('aggregatecount', 'forum'),

                  FORUM_AGGREGATE_MAX   => get_string('aggregatemax', 'forum'),

                  FORUM_AGGREGATE_MIN   => get_string('aggregatemin', 'forum'),

                  FORUM_AGGREGATE_SUM   => get_string('aggregatesum', 'forum'));

}



/**

 * Returns array of forum layout modes

 */

function forum_get_layout_modes() {

    return array (FORUM_MODE_FLATOLDEST => get_string('modeflatoldestfirst', 'forum'),

                  FORUM_MODE_FLATNEWEST => get_string('modeflatnewestfirst', 'forum'),

                  FORUM_MODE_THREADED   => get_string('modethreaded', 'forum'),

                  FORUM_MODE_NESTED     => get_string('modenested', 'forum'));

}



/**

 * Returns array of forum types

 */

function forum_get_forum_types() {

    return array ('general'  => get_string('generalforum', 'forum'),

                  'eachuser' => get_string('eachuserforum', 'forum'),

                  'single'   => get_string('singleforum', 'forum'),

                  'qanda'    => get_string('qandaforum', 'forum'));

}



/**

 * Returns array of all forum layout modes

 */

function forum_get_forum_types_all() {

    return array ('news'     => get_string('namenews','forum'),

                  'social'   => get_string('namesocial','forum'),

                  'general'  => get_string('generalforum', 'forum'),

                  'eachuser' => get_string('eachuserforum', 'forum'),

                  'single'   => get_string('singleforum', 'forum'),

                  'qanda'    => get_string('qandaforum', 'forum'));

}



/**

 * Returns array of forum open modes

 */

function forum_get_open_modes() {

    return array ('2' => get_string('openmode2', 'forum'),

                  '1' => get_string('openmode1', 'forum'),

                  '0' => get_string('openmode0', 'forum') );

}



/**

 * Returns all other caps used in module

 */

function forum_get_extra_capabilities() {

    return array('moodle/site:accessallgroups', 'moodle/site:viewfullnames', 'moodle/site:trustcontent');

}



/**

 * Returns creation time of the first user's post in given discussion

 * @global object $DB

 * @param int $did Discussion id

 * @param int $userid User id

 * @return int|bool post creation time stamp or return false

 */

function forum_get_user_posted_time($did, $userid) {

    global $CFG;



    $posttime = get_field('forum_posts', 'MIN(created)', 'userid', $userid, 'discussion', $did);

    if (empty($posttime)) {

        return false;

    }

    return $posttime;

}



?>