<?php
# MantisBT - A PHP based bugtracking system

# MantisBT is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# MantisBT 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with MantisBT.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Last Visited API
 *
 * @package CoreAPI
 * @subpackage LastVisitedAPI
 * @copyright Copyright (C) 2000 - 2002  Kenzaburo Ito - kenito@300baud.org
 * @copyright Copyright (C) 2002 - 2011  MantisBT Team - mantisbt-dev@lists.sourceforge.net
 * @link http://www.mantisbt.org
 *
 * @uses bug_api.php
 * @uses config_api.php
 * @uses constant_inc.php
 * @uses current_user_api.php
 * @uses database_api.php
 * @uses tokens_api.php
 */

require_api( 'bug_api.php' );
require_api( 'config_api.php' );
require_api( 'constant_inc.php' );
require_api( 'current_user_api.php' );
require_api( 'database_api.php' );
require_api( 'tokens_api.php' );

/**
 * Determine if last visited feature is enabled
 *
 * @return true: enabled; false: otherwise.
 * @access public
 */
function last_visited_enabled() {
	return !( OFF == config_get( 'recently_visited' ) || current_user_is_anonymous() );
}

/**
 * This method should be called from view, update, print pages for issues,
 * mantisconnect.
 *
 * @param issue_id	The issue id that was justed visited.
 * @param user_id	The user id that visited the issue, or null for current
 * 				logged in user.
 * @access public
 */
function last_visited_issue( $p_issue_id, $p_user_id = null ) {
	if( !last_visited_enabled() ) {
		return;
	}

	$c_issue_id = db_prepare_int( $p_issue_id );

	$t_value = token_get_value( TOKEN_LAST_VISITED, $p_user_id );
	if( is_null( $t_value ) ) {
		$t_value = $c_issue_id;
	} else {
		$t_ids = explode( ',', $p_issue_id . ',' . $t_value );
		$t_ids = array_unique( $t_ids );
		$t_ids = array_slice( $t_ids, 0, config_get( 'recently_visited_count' ) );
		$t_value = implode( ',', $t_ids );
	}

	token_set( TOKEN_LAST_VISITED, $t_value, TOKEN_EXPIRY_LAST_VISITED, $p_user_id );
}

/**
 * Get an array of the last visited bug ids.  We intentionally don't check
 * if the ids still exists to avoid performance degradation.
 *
 * @param user_id	The user id to get the last visited issues for,
 * 				or null for current logged in user.
 * @return An array of issue ids or an empty array if none found.
 * @access public
 */
function last_visited_get_array( $p_user_id = null ) {
	$t_value = token_get_value( TOKEN_LAST_VISITED, $p_user_id );

	if( is_null( $t_value ) ) {
		return array();
	}

	# we don't slice the array here to optimise for performance.  If the user reduces the number of recently
	# visited to track, then he/she will get the extra entries until visiting an issue.
	$t_ids = explode( ',', $t_value );

	bug_cache_array_rows( $t_ids );
	return $t_ids;
}