<?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/>.

/**
 * Remove oneself or someone else from a course, unassigning all roles one might have
 *
 * This will not delete any of their data from the course, but will remove them
 * from the participant list and prevent any course email being sent to them.
 *
 * @copyright 1999 Martin Dougiamas  http://dougiamas.com
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @package course
 */

require_once("../config.php");
require_once("lib.php");

$id      = required_param('id', PARAM_INT);               //course
$userid  = optional_param('user', 0, PARAM_INT);          //course
$confirm = optional_param('confirm', 0, PARAM_BOOL);

$PAGE->set_url('/course/unenrol.php', array('id'=>$id));

if($userid == $USER->id){
    // the rest of this code assumes $userid=0 means
    // you are unassigning yourself, so set this for the
    // correct capabiliy checks & language later
    $userid = 0;
}

if (!$course = $DB->get_record('course', array('id'=>$id))) {
    print_error('invalidcourseid');
}

if (! $context = get_context_instance(CONTEXT_COURSE, $course->id)) {
    print_error('invalidcontext');
}

require_login($course->id);

if ($course->metacourse) {
    print_error('cantunenrollfrommetacourse', '', $CFG->wwwroot.'/course/view.php?id='.$course->id);
}

if ($userid) {   // Unenrolling someone else
    require_capability('moodle/role:assign', $context, NULL, false);

    $roles = get_user_roles($context, $userid, false);

    // verify user may unassign all roles at course context
    foreach($roles as $role) {
        if (!user_can_assign($context, $role->roleid)) {
            print_error('cannotunassignrolefrom', '', '',
                    $role->roleid);
        }
    }

} else {         // Unenrol yourself
    require_capability('moodle/role:unassignself', $context, NULL, false);
}

if (!empty($USER->access['rsw'][$context->path])) {
    print_error('cantunenrollinthisrole', '',
                $CFG->wwwroot.'/course/view.php?id='.$course->id);
}

if ($confirm and confirm_sesskey()) {
    if ($userid) {
        if (! role_unassign(0, $userid, 0, $context->id)) {
            print_error("unenrolerror");
        }

        add_to_log($course->id, 'course', 'unenrol',
                "view.php?id=$course->id", $course->id);
        redirect($CFG->wwwroot.'/user/index.php?id='.$course->id);

    } else {
        if (! role_unassign(0, $USER->id, 0, $context->id)) {
            print_error("unenrolerror");
        }

        // force a refresh of mycourses
        unset($USER->mycourses);
        add_to_log($course->id, 'course', 'unenrol',
                "view.php?id=$course->id", $course->id);

        redirect($CFG->wwwroot);
    }
}


$strunenrol = get_string('unenrol');
$PAGE->navbar->add($strunenrol);
$PAGE->set_title("$course->shortname: $strunenrol");
$PAGE->set_heading($course->fullname);
echo $OUTPUT->header();
if ($userid) {
    if (!$user = $DB->get_record('user', array('id'=>$userid))) {
        print_error('nousers');
    }
    $strunenrolsure  = get_string('unenrolsure', '', fullname($user, true));
    echo $OUTPUT->confirm($strunenrolsure, "unenrol.php?id=$id&user=$user->id&confirm=yes", $PAGE->url);
} else {
    $strunenrolsure  = get_string('unenrolsure', '', get_string("yourself"));
    echo $OUTPUT->confirm($strunenrolsure, "unenrol.php?id=$id&confirm=yes", $PAGE->url);
}

echo $OUTPUT->footer();