<?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/>.

/**
 * This file contains the forms to add
 *
 * @package   mod_attendance
 * @copyright  2011 Artem Andreev <andreev.artem@gmail.com>
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

require_once($CFG->libdir.'/formslib.php');

/**
 * class for displaying add form.
 *
 * @copyright  2011 Artem Andreev <andreev.artem@gmail.com>
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class mod_attendance_add_form extends moodleform {

    /**
     * Called to define this moodle form
     *
     * @return void
     */
    public function definition() {

        global $CFG, $USER;
        $mform    =& $this->_form;

        $course        = $this->_customdata['course'];
        $cm            = $this->_customdata['cm'];
        $modcontext    = $this->_customdata['modcontext'];

        $mform->addElement('header', 'general', get_string('addsession', 'attendance'));

        $groupmode = groups_get_activity_groupmode($cm);
        switch ($groupmode) {
            case NOGROUPS:
                $mform->addElement('static', 'sessiontypedescription', get_string('sessiontype', 'attendance'),
                                  get_string('commonsession', 'attendance'));
                $mform->addHelpButton('sessiontypedescription', 'sessiontype', 'attendance');
                $mform->addElement('hidden', 'sessiontype', attendance::SESSION_COMMON);
                $mform->setType('sessiontype', PARAM_INT);
                break;
            case SEPARATEGROUPS:
                $mform->addElement('static', 'sessiontypedescription', get_string('sessiontype', 'attendance'),
                                  get_string('groupsession', 'attendance'));
                $mform->addHelpButton('sessiontypedescription', 'sessiontype', 'attendance');
                $mform->addElement('hidden', 'sessiontype', attendance::SESSION_GROUP);
                $mform->setType('sessiontype', PARAM_INT);
                break;
            case VISIBLEGROUPS:
                $radio = array();
                $radio[] = &$mform->createElement('radio', 'sessiontype', '',
                                                  get_string('commonsession', 'attendance'), attendance::SESSION_COMMON);
                $radio[] = &$mform->createElement('radio', 'sessiontype', '',
                                                  get_string('groupsession', 'attendance'), attendance::SESSION_GROUP);
                $mform->addGroup($radio, 'sessiontype', get_string('sessiontype', 'attendance'), ' ', false);
                $mform->setType('sessiontype', PARAM_INT);
                $mform->addHelpButton('sessiontype', 'sessiontype', 'attendance');
                $mform->setDefault('sessiontype', attendance::SESSION_COMMON);
                break;
        }
        if ($groupmode == SEPARATEGROUPS or $groupmode == VISIBLEGROUPS) {
            if ($groupmode == SEPARATEGROUPS and !has_capability('moodle/site:accessallgroups', $modcontext)) {
                $groups = groups_get_all_groups ($course->id, $USER->id, $cm->groupingid);
            } else {
                $groups = groups_get_all_groups($course->id, 0, $cm->groupingid);
            }
            if ($groups) {
                $selectgroups = array();
                foreach ($groups as $group) {
                    $selectgroups[$group->id] = $group->name;
                }
                $select = &$mform->addElement('select', 'groups', get_string('groups', 'group'), $selectgroups);
                $select->setMultiple(true);
                $mform->disabledIf('groups', 'sessiontype', 'neq', attendance::SESSION_GROUP);
            } else {
                if ($groupmode == VISIBLEGROUPS) {
                    $mform->updateElementAttr($radio, array('disabled' => 'disabled'));
                }
                $mform->addElement('static', 'groups', get_string('groups', 'group'),
                                  get_string('nogroups', 'attendance'));
                if ($groupmode == SEPARATEGROUPS) {
                    return;
                }
            }
        }

        $mform->addElement('checkbox', 'addmultiply', '', get_string('createmultiplesessions', 'attendance'));
        $mform->addHelpButton('addmultiply', 'createmultiplesessions', 'attendance');

        // Students can mark own attendance.
        $mform->addElement('checkbox', 'studentscanmark', '', get_string('studentscanmark', 'attendance'));
        $mform->addHelpButton('studentscanmark', 'studentscanmark', 'attendance');

        $mform->addElement('date_time_selector', 'sessiondate', get_string('sessiondate', 'attendance'));

        for ($i = 0; $i <= 23; $i++) {
            $hours[$i] = sprintf("%02d", $i);
        }
        for ($i = 0; $i < 60; $i += 5) {
            $minutes[$i] = sprintf("%02d", $i);
        }
        $durtime = array();
        $durtime[] =& $mform->createElement('select', 'hours', get_string('hour', 'form'), $hours, false, true);
        $durtime[] =& $mform->createElement('select', 'minutes', get_string('minute', 'form'), $minutes, false, true);
        $mform->addGroup($durtime, 'durtime', get_string('duration', 'attendance'), array(' '), true);

        $mform->addElement('date_selector', 'sessionenddate', get_string('sessionenddate', 'attendance'));
        $mform->disabledIf('sessionenddate', 'addmultiply', 'notchecked');

        $sdays = array();
        if ($CFG->calendar_startwday === '0') { // Week start from sunday.
            $sdays[] =& $mform->createElement('checkbox', 'Sun', '', get_string('sunday', 'calendar'));
        }
        $sdays[] =& $mform->createElement('checkbox', 'Mon', '', get_string('monday', 'calendar'));
        $sdays[] =& $mform->createElement('checkbox', 'Tue', '', get_string('tuesday', 'calendar'));
        $sdays[] =& $mform->createElement('checkbox', 'Wed', '', get_string('wednesday', 'calendar'));
        $sdays[] =& $mform->createElement('checkbox', 'Thu', '', get_string('thursday', 'calendar'));
        $sdays[] =& $mform->createElement('checkbox', 'Fri', '', get_string('friday', 'calendar'));
        $sdays[] =& $mform->createElement('checkbox', 'Sat', '', get_string('saturday', 'calendar'));
        if ($CFG->calendar_startwday !== '0') { // Week start from sunday.
            $sdays[] =& $mform->createElement('checkbox', 'Sun', '', get_string('sunday', 'calendar'));
        }
        $mform->addGroup($sdays, 'sdays', get_string('sessiondays', 'attendance'), array('&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'), true);
        $mform->disabledIf('sdays', 'addmultiply', 'notchecked');

        $period = array(1 => 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
                        21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36);
        $periodgroup = array();
        $periodgroup[] =& $mform->createElement('select', 'period', '', $period, false, true);
        $periodgroup[] =& $mform->createElement('static', 'perioddesc', '', get_string('week', 'attendance'));
        $mform->addGroup($periodgroup, 'periodgroup', get_string('period', 'attendance'), array(' '), false);
        $mform->disabledIf('periodgroup', 'addmultiply', 'notchecked');

        // Select which status set to use.
        $maxstatusset = attendance_get_max_statusset($this->_customdata['att']->id);
        if ($maxstatusset > 0) {
            $opts = array();
            for ($i = 0; $i <= $maxstatusset; $i++) {
                $opts[$i] = att_get_setname($this->_customdata['att']->id, $i);
            }
            $mform->addElement('select', 'statusset', get_string('usestatusset', 'mod_attendance'), $opts);
        } else {
            $mform->addElement('hidden', 'statusset', 0);
            $mform->setType('statusset', PARAM_INT);
        }

        $mform->addElement('editor', 'sdescription', get_string('description', 'attendance'), null,
            array('maxfiles' => EDITOR_UNLIMITED_FILES, 'noclean' => true, 'context' => $modcontext));
        $mform->setType('sdescription', PARAM_RAW);

        $mform->addElement('hidden', 'coursestartdate', $course->startdate);
        $mform->setType('coursestartdate', PARAM_INT);

        $mform->addElement('hidden', 'previoussessiondate', 0);
        $mform->setType('previoussessiondate', PARAM_INT);

        $submitstring = get_string('addsession', 'attendance');
        $this->add_action_buttons(false, $submitstring);
    }

    /**
     * Perform minimal validation on the settings form
     * @param array $data
     * @param array $files
     */
    public function validation($data, $files) {
        $errors = parent::validation($data, $files);

        if (!empty($data['addmultiply']) && $data['sessiondate'] != 0 && $data['sessionenddate'] != 0 &&
                   $data['sessionenddate'] < $data['sessiondate']) {
            $errors['sessionenddate'] = get_string('invalidsessionenddate', 'attendance');
        }

        if ($data['sessiontype'] == attendance::SESSION_GROUP and empty($data['groups'])) {
            $errors['groups'] = get_string('errorgroupsnotselected', 'attendance');
        }

        $addmulti = isset($data['addmultiply']) ? (int)$data['addmultiply'] : 0;
        if (($addmulti != 0) && (!array_key_exists('sdays', $data) || empty($data['sdays']))) {
            $data['sdays'] = array();
            $errors['sdays'] = get_string('required', 'attendance');
        }
        if (isset($data['sdays'])) {
            if (!$this->checkweekdays($data['sessiondate'], $data['sessionenddate'], $data['sdays']) ) {
                $errors['sdays'] = get_string('checkweekdays', 'attendance');
            }
        }
        if ($addmulti && ceil(($data['sessionenddate'] - $data['sessiondate']) / YEARSECS) > 1) {
            $errors['sessionenddate'] = get_string('timeahead', 'attendance');
        }

        if ($data['sessiondate'] < $data['coursestartdate'] && $data['sessiondate'] != $data['previoussessiondate']) {
            $errors['sessiondate'] = get_string('priorto', 'attendance',
                userdate($data['coursestartdate'], get_string('strftimedmy', 'attendance')));
            $this->_form->setConstant('previoussessiondate', $data['sessiondate']);
        }

        return $errors;
    }

    private function checkweekdays($sessiondate, $sessionenddate, $sdays) {

        $found = false;

        $daysofweek = array(0 => "Sun", 1 => "Mon", 2 => "Tue", 3 => "Wed", 4 => "Thu", 5 => "Fri", 6 => "Sat");
        $start = new DateTime( date("Y-m-d", $sessiondate) );
        $interval = new DateInterval('P1D');
        $end = new DateTime( date("Y-m-d", $sessionenddate) );
        $end->add( new DateInterval('P1D') );

        $period = new DatePeriod($start, $interval, $end);
        foreach ($period as $date) {
            if (!$found) {
                foreach ($sdays as $name => $value) {
                    $key = array_search($name, $daysofweek);
                    if ($date->format("w") == $key) {
                        $found = true;
                        break;
                    }
                }
            }
        }

        return $found;
    }
}