<?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/>.


/**
 * Add/remove members from group.
 *
 * @copyright 2006 The Open University and others, N.D.Freear AT open.ac.uk, J.White AT open.ac.uk and others
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @package   core_group
 */
require_once(__DIR__ . '/../config.php');
require_once(__DIR__ . '/lib.php');
require_once($CFG->dirroot . '/user/selector/lib.php');
require_once($CFG->dirroot . '/course/lib.php');
require_once($CFG->libdir . '/filelib.php');

$groupid = required_param('group', PARAM_INT);
$cancel  = optional_param('cancel', false, PARAM_BOOL);

$group = $DB->get_record('groups', array('id'=>$groupid), '*', MUST_EXIST);
$course = $DB->get_record('course', array('id'=>$group->courseid), '*', MUST_EXIST);

$PAGE->set_url('/group/members.php', array('group'=>$groupid));
$PAGE->set_pagelayout('admin');

require_login($course);
$context = context_course::instance($course->id);
require_capability('moodle/course:managegroups', $context);

$returnurl = $CFG->wwwroot.'/group/index.php?id='.$course->id.'&group='.$group->id;

if ($cancel) {
    redirect($returnurl);
}

$groupmembersselector = new group_members_selector('removeselect', array('groupid' => $groupid, 'courseid' => $course->id));
$potentialmembersselector = new group_non_members_selector('addselect', array('groupid' => $groupid, 'courseid' => $course->id));

if (optional_param('add', false, PARAM_BOOL) && confirm_sesskey()) {
    $userstoadd = $potentialmembersselector->get_selected_users();
    if (!empty($userstoadd)) {
        foreach ($userstoadd as $user) {
            if (!groups_add_member($groupid, $user->id)) {
                throw new \moodle_exception('erroraddremoveuser', 'group', $returnurl);
            }
            $groupmembersselector->invalidate_selected_users();
            $potentialmembersselector->invalidate_selected_users();
        }
    }
}

if (optional_param('remove', false, PARAM_BOOL) && confirm_sesskey()) {
    $userstoremove = $groupmembersselector->get_selected_users();
    if (!empty($userstoremove)) {
        foreach ($userstoremove as $user) {
            if (!groups_remove_member_allowed($groupid, $user->id)) {
                throw new \moodle_exception('errorremovenotpermitted', 'group', $returnurl,
                        $user->fullname);
            }
            if (!groups_remove_member($groupid, $user->id)) {
                throw new \moodle_exception('erroraddremoveuser', 'group', $returnurl);
            }
            $groupmembersselector->invalidate_selected_users();
            $potentialmembersselector->invalidate_selected_users();
        }
    }
}

// Print the page and form
$strgroups = get_string('groups');
$strparticipants = get_string('participants');
$stradduserstogroup = get_string('adduserstogroup', 'group');
$strusergroupmembership = get_string('usergroupmembership', 'group');

$groupname = format_string($group->name);

$PAGE->requires->js('/group/clientlib.js');
$PAGE->navbar->add($strparticipants, new moodle_url('/user/index.php', array('id'=>$course->id)));
$PAGE->navbar->add($strgroups, new moodle_url('/group/index.php', array('id'=>$course->id)));
$PAGE->navbar->add($stradduserstogroup);

/// Print header
$PAGE->set_title("$course->shortname: $strgroups");
$PAGE->set_heading($course->fullname);
echo $OUTPUT->header();
echo $OUTPUT->heading(get_string('adduserstogroup', 'group').": $groupname", 3);

// Store the rows we want to display in the group info.
$groupinforow = array();

// Check if there is a description to display.
if (!empty($group->description)) {
    $grouprenderer = $PAGE->get_renderer('core_group');
    $groupdetailpage = new \core_group\output\group_details($groupid);
    echo $grouprenderer->group_details($groupdetailpage);
}

/// Print the editing form
?>

<div id="addmembersform">
    <form id="assignform" method="post" action="<?php echo $CFG->wwwroot; ?>/group/members.php?group=<?php echo $groupid; ?>">
    <div>
    <input type="hidden" name="sesskey" value="<?php p(sesskey()); ?>" />

    <table class="generaltable generalbox groupmanagementtable boxaligncenter table table-hover" summary="">
    <tr>
      <td id='existingcell'>
          <p>
            <label for="removeselect"><?php print_string('groupmembers', 'group'); ?></label>
          </p>
          <?php $groupmembersselector->display(); ?>
          </td>
      <td id='buttonscell'>
        <p class="arrow_button">
            <input class="btn btn-secondary" name="add" id="add"
                   type="submit" value="<?php echo $OUTPUT->larrow().'&nbsp;'.get_string('add'); ?>"
                   title="<?php print_string('add'); ?>" /><br />
            <input class="btn btn-secondary" name="remove" id="remove"
                   type="submit" value="<?php echo get_string('remove').'&nbsp;'.$OUTPUT->rarrow(); ?>"
                   title="<?php print_string('remove'); ?>" />
        </p>
      </td>
      <td id='potentialcell'>
          <p>
            <label for="addselect"><?php print_string('potentialmembs', 'group'); ?></label>
          </p>
          <?php $potentialmembersselector->display(); ?>
      </td>
      <td>
        <p><?php echo($strusergroupmembership) ?></p>
        <div id="group-usersummary"></div>
      </td>
    </tr>
    <tr><td colspan="3" id='backcell'>
        <input class="btn btn-secondary" type="submit" name="cancel"
               value="<?php print_string('backtogroups', 'group'); ?>" />
    </td></tr>
    </table>
    </div>
    </form>
</div>

<?php
    //outputs the JS array used to display the other groups users are in
    $potentialmembersselector->print_user_summaries($course->id);

    //this must be after calling display() on the selectors so their setup JS executes first
    $PAGE->requires->js_init_call('init_add_remove_members_page', null, false, $potentialmembersselector->get_js_module());

    echo $OUTPUT->footer();
