<?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/>.

/**
 * Completion external API
 *
 * @package    core_completion
 * @category   external
 * @copyright  2015 Juan Leyva <juan@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @since      Moodle 2.9
 */

defined('MOODLE_INTERNAL') || die;

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

/**
 * Completion external functions
 *
 * @package    core_completion
 * @category   external
 * @copyright  2015 Juan Leyva <juan@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @since      Moodle 2.9
 */
class core_completion_external extends external_api {

    /**
     * Describes the parameters for update_activity_completion_status_manually.
     *
     * @return external_external_function_parameters
     * @since Moodle 2.9
     */
    public static function update_activity_completion_status_manually_parameters() {
        return new external_function_parameters (
            array(
                'cmid' => new external_value(PARAM_INT, 'course module id'),
                'completed' => new external_value(PARAM_BOOL, 'activity completed or not'),
            )
        );
    }

    /**
     * Update completion status for the current user in an activity, only for activities with manual tracking.
     * @param  int $cmid      Course module id
     * @param  bool $completed Activity completed or not
     * @return array            Result and possible warnings
     * @since Moodle 2.9
     * @throws moodle_exception
     */
    public static function update_activity_completion_status_manually($cmid,  $completed) {

        // Validate and normalize parameters.
        $params = self::validate_parameters(self::update_activity_completion_status_manually_parameters(),
            array('cmid' => $cmid, 'completed' => $completed));
        $cmid = $params['cmid'];
        $completed = $params['completed'];

        $warnings = array();

        $context = context_module::instance($cmid);
        self::validate_context($context);

        list($course, $cm) = get_course_and_cm_from_cmid($cmid);

        // Set up completion object and check it is enabled.
        $completion = new completion_info($course);
        if (!$completion->is_enabled()) {
            throw new moodle_exception('completionnotenabled', 'completion');
        }

        // Check completion state is manual.
        if ($cm->completion != COMPLETION_TRACKING_MANUAL) {
            throw new moodle_exception('cannotmanualctrack', 'error');
        }

        $targetstate = ($completed) ? COMPLETION_COMPLETE : COMPLETION_INCOMPLETE;
        $completion->update_state($cm, $targetstate);

        $result = array();
        $result['status'] = true;
        $result['warnings'] = $warnings;
        return $result;
    }

    /**
     * Describes the update_activity_completion_status_manually return value.
     *
     * @return external_single_structure
     * @since Moodle 2.9
     */
    public static function update_activity_completion_status_manually_returns() {

        return new external_single_structure(
            array(
                'status'    => new external_value(PARAM_BOOL, 'status, true if success'),
                'warnings'  => new external_warnings(),
            )
        );
    }

}