<?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/>.

/**
 * Manual enrolment plugin main library file.
 *
 * @package    enrol
 * @subpackage manual
 * @copyright  2010 Petr Skoda {@link http://skodak.org}
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

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

class enrol_manual_plugin extends enrol_plugin {

    public function roles_protected() {
        // users may tweak the roles later
        return false;
    }

    public function allow_enrol(stdClass $instance) {
        // users with enrol cap may unenrol other users manually manually
        return true;
    }

    public function allow_unenrol(stdClass $instance) {
        // users with unenrol cap may unenrol other users manually manually
        return true;
    }

    public function allow_manage(stdClass $instance) {
        // users with manage cap may tweak period and status
        return true;
    }

    /**
     * Returns link to manual enrol UI if exists.
     * Does the access control tests automatically.
     *
     * @param object $instance
     * @return moodle_url
     */
    public function get_manual_enrol_link($instance) {
        $name = $this->get_name();
        if ($instance->enrol !== $name) {
            throw new coding_exception('invalid enrol instance!');
        }

        if (!enrol_is_enabled($name)) {
            return NULL;
        }

        $context = get_context_instance(CONTEXT_COURSE, $instance->courseid, MUST_EXIST);

        if (!has_capability('enrol/manual:manage', $context) or !has_capability('enrol/manual:enrol', $context) or !has_capability('enrol/manual:unenrol', $context)) {
            return NULL;
        }

        return new moodle_url('/enrol/manual/manage.php', array('enrolid'=>$instance->id, 'id'=>$instance->courseid));
    }

    /**
     * Returns enrolment instance manage link.
     *
     * By defaults looks for manage.php file and tests for manage capability.
     *
     * @param object $instance
     * @return moodle_url;
     */
    public function add_course_navigation($instancesnode, stdClass $instance) {
        if ($instance->enrol !== 'manual') {
             throw new coding_exception('Invalid enrol instance type!');
        }

        $context = get_context_instance(CONTEXT_COURSE, $instance->courseid);
        if (has_capability('enrol/manual:config', $context)) {
            $managelink = new moodle_url('/enrol/manual/edit.php', array('courseid'=>$instance->courseid));
            $instancesnode->add($this->get_instance_name($instance), $managelink, navigation_node::TYPE_SETTING);
        }
    }

    /**
     * Returns edit icons for the page with list of instances
     * @param stdClass $instance
     * @return array
     */
    public function get_action_icons(stdClass $instance) {
        global $OUTPUT;

        if ($instance->enrol !== 'manual') {
            throw new coding_exception('invalid enrol instance!');
        }
        $context = get_context_instance(CONTEXT_COURSE, $instance->courseid);

        $icons = array();

        if (has_capability('enrol/manual:manage', $context)) {
            $managelink = new moodle_url("/enrol/manual/manage.php", array('enrolid'=>$instance->id));
            $icons[] = $OUTPUT->action_icon($managelink, new pix_icon('i/users', get_string('enrolusers', 'enrol_manual'), 'core', array('class'=>'iconsmall')));
        }
        if (has_capability('enrol/manual:config', $context)) {
            $editlink = new moodle_url("/enrol/manual/edit.php", array('courseid'=>$instance->courseid));
            $icons[] = $OUTPUT->action_icon($editlink, new pix_icon('i/edit', get_string('edit'), 'core', array('class'=>'icon')));
        }

        return $icons;
    }

    /**
     * Returns link to page which may be used to add new instance of enrolment plugin in course.
     * @param int $courseid
     * @return moodle_url page url
     */
    public function get_newinstance_link($courseid) {
        global $DB;

        $context = get_context_instance(CONTEXT_COURSE, $courseid, MUST_EXIST);

        if (!has_capability('moodle/course:enrolconfig', $context) or !has_capability('enrol/manual:config', $context)) {
            return NULL;
        }

        if ($DB->record_exists('enrol', array('courseid'=>$courseid, 'enrol'=>'manual'))) {
            return NULL;
        }

        return new moodle_url('/enrol/manual/edit.php', array('courseid'=>$courseid));
    }

    /**
     * Add new instance of enrol plugin with default settings.
     * @param object $course
     * @return int id of new instance, null if can not be created
     */
    public function add_default_instance($course) {
        $fields = array('status'=>$this->get_config('status'), 'enrolperiod'=>$this->get_config('enrolperiod', 0), 'roleid'=>$this->get_config('roleid', 0));
        return $this->add_instance($course, $fields);
    }

    /**
     * Add new instance of enrol plugin.
     * @param object $course
     * @param array instance fields
     * @return int id of new instance, null if can not be created
     */
    public function add_instance($course, array $fields = NULL) {
        global $DB;

        if ($DB->record_exists('enrol', array('courseid'=>$course->id, 'enrol'=>'manual'))) {
            // only one instance allowed, sorry
            return NULL;
        }

        return parent::add_instance($course, $fields);
    }
}

/**
 * Indicates API features that the enrol plugin supports.
 *
 * @param string $feature
 * @return mixed True if yes (some features may use other values)
 */
function enrol_manual_supports($feature) {
    switch($feature) {
        case ENROL_RESTORE_TYPE: return ENROL_RESTORE_EXACT;

        default: return null;
    }
}