<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle 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 3 of the License, or
// (at your option) any later version.
//
// Moodle 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 Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Message deleted event.
 *
 * @package    core
 * @copyright  2015 Mark Nelson <markn@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace core\event;

defined('MOODLE_INTERNAL') || die();

/**
 * Message deleted event class.
 *
 * @property-read array $other {
 *      Extra information about event.
 *
 *      - string $messagetable: the table we marked the message as deleted from (message/message_read).
 *      - int messageid: the id of the message.
 *      - int useridfrom: the id of the user who received the message.
 *      - int useridto: the id of the user who sent the message.
 * }
 *
 * @package    core
 * @since      Moodle 3.0
 * @copyright  2015 Mark Nelson <markn@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class message_deleted extends base {

    /**
     * Create event using ids.
     *
     * @param int $userfromid the user who the message was from.
     * @param int $usertoid the user who the message was sent to.
     * @param int $userdeleted the user who deleted it.
     * @param string $messagetable the table we are marking the message as deleted in.
     * @param int $messageid the id of the message that was deleted.
     * @return message_deleted
     */
    public static function create_from_ids($userfromid, $usertoid, $userdeleted, $messagetable, $messageid) {
        // Check who was deleting the message.
        if ($userdeleted == $userfromid) {
            $relateduserid = $usertoid;
        } else {
            $relateduserid = $userfromid;
        }

        // We set the userid to the user who deleted the message, nothing to do
        // with whether or not they sent or received the message.
        $event = self::create(array(
            'userid' => $userdeleted,
            'context' => \context_system::instance(),
            'relateduserid' => $relateduserid,
            'other' => array(
                'messagetable' => $messagetable,
                'messageid' => $messageid,
                'useridfrom' => $userfromid,
                'useridto' => $usertoid
            )
        ));

        return $event;
    }

    /**
     * Init method.
     */
    protected function init() {
        $this->data['crud'] = 'u';
        $this->data['edulevel'] = self::LEVEL_OTHER;
    }

    /**
     * Returns localised general event name.
     *
     * @return string
     */
    public static function get_name() {
        return get_string('eventmessagedeleted', 'message');
    }

    /**
     * Returns description of what happened.
     *
     * @return string
     */
    public function get_description() {
        // Check if the person who deleted the message received or sent it.
        if ($this->userid == $this->other['useridto']) {
            $str = 'from';
        } else {
            $str = 'to';
        }

        return "The user with id '$this->userid' deleted a message sent $str the user with id '$this->relateduserid'.";
    }

    /**
     * Custom validation.
     *
     * @throws \coding_exception
     * @return void
     */
    protected function validate_data() {
        parent::validate_data();

        if (!isset($this->relateduserid)) {
            throw new \coding_exception('The \'relateduserid\' must be set.');
        }

        if (!isset($this->other['messagetable'])) {
            throw new \coding_exception('The \'messagetable\' value must be set in other.');
        }

        if (!isset($this->other['messageid'])) {
            throw new \coding_exception('The \'messageid\' value must be set in other.');
        }

        if (!isset($this->other['useridfrom'])) {
            throw new \coding_exception('The \'useridfrom\' value must be set in other.');
        }

        if (!isset($this->other['useridto'])) {
            throw new \coding_exception('The \'useridto\' value must be set in other.');
        }
    }

    public static function get_other_mapping() {
        // Messages are not backed up, so no need to map them on restore.
        $othermapped = array();
        // The messageid table varies so it cannot be mapped.
        $othermapped['messageid'] = array('db' => base::NOT_MAPPED, 'restore' => base::NOT_MAPPED);
        $othermapped['useridfrom'] = array('db' => 'user', 'restore' => base::NOT_MAPPED);
        $othermapped['useridto'] = array('db' => 'user', 'restore' => base::NOT_MAPPED);
        return $othermapped;
    }
}