<?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/>.

/**
 * Payment subsystem callback implementation for enrol_fee.
 *
 * @package    enrol_fee
 * @category   payment
 * @copyright  2020 Shamim Rezaie <shamim@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace enrol_fee\payment;

/**
 * Payment subsystem callback implementation for enrol_fee.
 *
 * @copyright  2020 Shamim Rezaie <shamim@moodle.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class service_provider implements \core_payment\local\callback\service_provider {

    /**
     * Callback function that returns the enrolment cost and the accountid
     * for the course that $instanceid enrolment instance belongs to.
     *
     * @param string $paymentarea Payment area
     * @param int $instanceid The enrolment instance id
     * @return \core_payment\local\entities\payable
     */
    public static function get_payable(string $paymentarea, int $instanceid): \core_payment\local\entities\payable {
        global $DB;

        $instance = $DB->get_record('enrol', ['enrol' => 'fee', 'id' => $instanceid], '*', MUST_EXIST);

        return new \core_payment\local\entities\payable($instance->cost, $instance->currency, $instance->customint1);
    }

    /**
     * Callback function that returns the URL of the page the user should be redirected to in the case of a successful payment.
     *
     * @param string $paymentarea Payment area
     * @param int $instanceid The enrolment instance id
     * @return \moodle_url
     */
    public static function get_success_url(string $paymentarea, int $instanceid): \moodle_url {
        global $DB;

        $courseid = $DB->get_field('enrol', 'courseid', ['enrol' => 'fee', 'id' => $instanceid], MUST_EXIST);

        return new \moodle_url('/course/view.php', ['id' => $courseid]);
    }

    /**
     * Callback function that delivers what the user paid for to them.
     *
     * @param string $paymentarea
     * @param int $instanceid The enrolment instance id
     * @param int $paymentid payment id as inserted into the 'payments' table, if needed for reference
     * @param int $userid The userid the order is going to deliver to
     * @return bool Whether successful or not
     */
    public static function deliver_order(string $paymentarea, int $instanceid, int $paymentid, int $userid): bool {
        global $DB;

        $instance = $DB->get_record('enrol', ['enrol' => 'fee', 'id' => $instanceid], '*', MUST_EXIST);

        $plugin = enrol_get_plugin('fee');

        if ($instance->enrolperiod) {
            $timestart = time();
            $timeend   = $timestart + $instance->enrolperiod;
        } else {
            $timestart = 0;
            $timeend   = 0;
        }

        $plugin->enrol_user($instance, $userid, $instance->roleid, $timestart, $timeend);

        return true;
    }
}