<?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/>.

/**
 * This file contains the course criteria type.
 *
 * @package core_completion
 * @category completion
 * @copyright 2009 Catalyst IT Ltd
 * @author Aaron Barnes <aaronb@catalyst.net.nz>
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

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

/**
 * Course completion critieria - completion on course completion
 *
 * This course completion criteria depends on another course with
 * completion enabled to be marked as complete for this user
 *
 * @package core_completion
 * @category completion
 * @copyright 2009 Catalyst IT Ltd
 * @author Aaron Barnes <aaronb@catalyst.net.nz>
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class completion_criteria_course extends completion_criteria {

    /* @var int Criteria type constant */
    public $criteriatype = COMPLETION_CRITERIA_TYPE_COURSE;

    /**
     * Finds and returns a data_object instance based on params.
     *
     * @param array $params associative arrays varname=>value
     * @return data_object instance of data_object or false if none found.
     */
    public static function fetch($params) {
        $params['criteriatype'] = COMPLETION_CRITERIA_TYPE_COURSE;
        return self::fetch_helper('course_completion_criteria', __CLASS__, $params);
    }

    /**
     * Add appropriate form elements to the critieria form
     *
     * @param moodle_form $mform Moodle forms object
     * @param stdClass $data data used to define default value of the form
     */
    public function config_form_display(&$mform, $data = null) {
        global $CFG;

        $link = "<a href=\"{$CFG->wwwroot}/course/view.php?id={$data->id}\">".s($data->fullname).'</a>';
        $mform->addElement('checkbox', 'criteria_course['.$data->id.']', $link);

        if ($this->id) {
            $mform->setDefault('criteria_course['.$data->id.']', 1);
        }
    }

    /**
     * Update the criteria information stored in the database
     *
     * @param array $data Form data
     */
    public function update_config(&$data) {

        if (!empty($data->criteria_course) && is_array($data->criteria_course)) {

            $this->course = $data->id;

            foreach ($data->criteria_course as $course) {

                $this->courseinstance = $course;
                $this->id = NULL;
                $this->insert();
            }
        }
    }

    /**
     * Review this criteria and decide if the user has completed
     *
     * @param completion_completion $completion The user's completion record
     * @param bool $mark Optionally set false to not save changes to database
     * @return bool
     */
    public function review($completion, $mark = true) {
        global $DB;

        $course = $DB->get_record('course', array('id' => $this->courseinstance));
        $info = new completion_info($course);

        // If the course is complete
        if ($info->is_course_complete($completion->userid)) {

            if ($mark) {
                $completion->mark_complete();
            }

            return true;
        }

        return false;
    }

    /**
     * Return criteria title for display in reports
     *
     * @return string
     */
    public function get_title() {
        return get_string('prerequisitescompleted', 'completion');
    }

    /**
     * Return a more detailed criteria title for display in reports
     *
     * @return string
     */
    public function get_title_detailed() {
        global $DB;

        $prereq = $DB->get_record('course', array('id' => $this->courseinstance));
        $coursecontext = get_context_instance(CONTEXT_COURSE, $prereq->id, MUST_EXIST);
        $fullname = format_string($prereq->fullname, true, array('context' => $coursecontext));
        return shorten_text(urldecode($fullname));
    }

    /**
     * Return criteria type title for display in reports
     *
     * @return string
     */
    public function get_type_title() {
        return get_string('prerequisites', 'completion');
    }

    /**
     * Find user's who have completed this criteria
     */
    public function cron() {

        global $DB;

        // Get all users who meet this criteria
        $sql = "
            SELECT DISTINCT
                c.id AS course,
                cr.id AS criteriaid,
                ra.userid AS userid,
                cc.timecompleted AS timecompleted
            FROM
                {course_completion_criteria} cr
            INNER JOIN
                {course} c
             ON cr.course = c.id
            INNER JOIN
                {context} con
             ON con.instanceid = c.id
            INNER JOIN
                {role_assignments} ra
              ON ra.contextid = con.id
            INNER JOIN
                {course_completions} cc
             ON cc.course = cr.courseinstance
            AND cc.userid = ra.userid
            LEFT JOIN
                {course_completion_crit_compl} ccc
             ON ccc.criteriaid = cr.id
            AND ccc.userid = ra.userid
            WHERE
                cr.criteriatype = ".COMPLETION_CRITERIA_TYPE_COURSE."
            AND con.contextlevel = ".CONTEXT_COURSE."
            AND c.enablecompletion = 1
            AND ccc.id IS NULL
            AND cc.timecompleted IS NOT NULL
        ";

        // Loop through completions, and mark as complete
        $rs = $DB->get_recordset_sql($sql);
        foreach ($rs as $record) {
            $completion = new completion_criteria_completion((array) $record, DATA_OBJECT_FETCH_BY_KEY);
            $completion->mark_complete($record->timecompleted);
        }
        $rs->close();
    }

    /**
     * Return criteria progress details for display in reports
     *
     * @param completion_completion $completion The user's completion record
     * @return array An array with the following keys:
     *     type, criteria, requirement, status
     */
    public function get_details($completion) {
        global $CFG, $DB;

        // Get completion info
        $course = new stdClass();
        $course->id = $completion->course;
        $info = new completion_info($course);

        $prereq = $DB->get_record('course', array('id' => $this->courseinstance));
        $coursecontext = get_context_instance(CONTEXT_COURSE, $prereq->id, MUST_EXIST);
        $fullname = format_string($prereq->fullname, true, array('context' => $coursecontext));

        $prereq_info = new completion_info($prereq);

        $details = array();
        $details['type'] = $this->get_title();
        $details['criteria'] = '<a href="'.$CFG->wwwroot.'/course/view.php?id='.$this->courseinstance.'">'.s($fullname).'</a>';
        $details['requirement'] = get_string('coursecompleted', 'completion');
        $details['status'] = '<a href="'.$CFG->wwwroot.'/blocks/completionstatus/details.php?course='.$this->courseinstance.'">'.get_string('seedetails', 'completion').'</a>';

        return $details;
    }
}
