<?php

/*
 +--------------------------------------------------------------------+
 | CiviCRM version 4.0                                                |
 +--------------------------------------------------------------------+
 | Copyright CiviCRM LLC (c) 2004-2011                                |
 +--------------------------------------------------------------------+
 | This file is a part of CiviCRM.                                    |
 |                                                                    |
 | CiviCRM is free software; you can copy, modify, and distribute it  |
 | under the terms of the GNU Affero General Public License           |
 | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
 |                                                                    |
 | CiviCRM is distributed in the hope that it will be useful, but     |
 | WITHOUT ANY WARRANTY; without even the implied warranty of         |
 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
 | See the GNU Affero General Public License for more details.        |
 |                                                                    |
 | You should have received a copy of the GNU Affero General Public   |
 | License and the CiviCRM Licensing Exception along                  |
 | with this program; if not, contact CiviCRM LLC                     |
 | at info[AT]civicrm[DOT]org. If you have questions about the        |
 | GNU Affero General Public License or the licensing of CiviCRM,     |
 | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
 +--------------------------------------------------------------------+
*/

/**
 *
 * @package CRM
 * @copyright CiviCRM LLC (c) 2004-2011
 * $Id$
 *
 */

class CRM_ACL_API {

    /**
     * The various type of permissions
     * 
     * @var int
     */
    const
        EDIT   = 1,
        VIEW   = 2,
        DELETE = 3,
        CREATE = 4,
        SEARCH = 5,
        ALL    = 6;
    


    /**
     * given a permission string, check for access requirements
     *
     * @param string $str       the permission to check
     * @param int    $contactID the contactID for whom the check is made
     *
     * @return boolean true if yes, else false
     * @static
     * @access public
     */
    static function check( $str, $contactID = null ) {
        if ( $contactID == null ) {
            $session   = CRM_Core_Session::singleton( );
            $contactID =  $session->get( 'userID' );
        }

        if ( ! $contactID ) {
            $contactID = 0; // anonymous user
        }

        require_once 'CRM/ACL/BAO/ACL.php';
        return CRM_ACL_BAO_ACL::check( $str, $contactID );
    }

    /**
     * Get the permissioned where clause for the user
     *
     * @param int $type the type of permission needed
     * @param  array $tables (reference ) add the tables that are needed for the select clause
     * @param  array $whereTables (reference ) add the tables that are needed for the where clause
     * @param int    $contactID the contactID for whom the check is made
     * @param bool   $onlyDeleted  whether to include only deleted contacts
     * @param bool   $skipDeleteClause don't add delete clause if this is true, 
     *               this means it is handled by generating query
     *
     * @return string the group where clause for this user
     * @access public
     */
    public static function whereClause( $type,
                                        &$tables,
                                        &$whereTables,
                                        $contactID = null,
                                        $onlyDeleted = false,
                                        $skipDeleteClause = false ) {
        // the default value which is valid for rhe final AND
        $deleteClause = ' ( 1 ) ';
        if ( ! $skipDeleteClause ) {
            if (CRM_Core_Permission::check('access deleted contacts') and $onlyDeleted) {
                $deleteClause = '(contact_a.is_deleted)';
            } else {
                // CRM-6181
                $deleteClause = '(contact_a.is_deleted = 0)';
            }
        }

        // first see if the contact has edit / view all contacts
        if ( CRM_Core_Permission::check( 'edit all contacts' ) ||
             ( $type == self::VIEW &&
               CRM_Core_Permission::check( 'view all contacts' ) ) ) {
            return $skipDeleteClause ? ' ( 1 ) ' : $deleteClause;
        }

        if ( $contactID == null ) {
            $session   = CRM_Core_Session::singleton( );
            $contactID =  $session->get( 'userID' );
        }

        if ( ! $contactID ) {
            $contactID = 0; // anonymous user
        }

        require_once 'CRM/ACL/BAO/ACL.php';
        return implode( ' AND ',
                        array( CRM_ACL_BAO_ACL::whereClause( $type,
                                                             $tables,
                                                             $whereTables,
                                                             $contactID ),
                               $deleteClause ) );
    }
    
    /**
     * get all the groups the user has access to for the given operation
     *
     * @param int $type the type of permission needed
     * @param int    $contactID the contactID for whom the check is made
     *
     * @return array the ids of the groups for which the user has permissions
     * @access public
     */
    public static function group( $type, $contactID = null, 
                                  $tableName = 'civicrm_saved_search', 
                                  $allGroups = null, 
                                  $includedGroups = null ) {
        if ( $contactID == null ) {
            $session   = CRM_Core_Session::singleton( );
            $contactID =  $session->get( 'userID' );
        }

        if ( ! $contactID ) {
            $contactID = 0; // anonymous user
        }

        require_once 'CRM/ACL/BAO/ACL.php';
        return CRM_ACL_BAO_ACL::group( $type, $contactID, $tableName, $allGroups, $includedGroups );
    }

    /**
     * check if the user has access to this group for operation $type
     *
     * @param int $type the type of permission needed
     * @param int    $contactID the contactID for whom the check is made
     *
     * @return array the ids of the groups for which the user has permissions
     * @access public
     */
    public static function groupPermission( $type, $groupID, $contactID = null,
                                            $tableName = 'civicrm_saved_search',
                                            $allGroups = null,
                                            $includedGroups = null ) {
        static $cache = array( );

        $key = "{$tableName}_{$type}_{$contactID}";
        if ( array_key_exists( $key, $cache ) ) {
            $groups =& $cache[$key];
        } else {
            $groups =& self::group( $type, $contactID, $tableName, $allGroups, $includedGroups );
            $cache[$key] = $groups;
        }

        return in_array( $groupID, $groups ) ? true : false;
    }
}