<?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/>.

/**
 * Form for creating and modifying a game
 *
 * @package   mod_game
 * @author    Alastair Munro <alastair@catalyst.net.nz>
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 * @copyright  2007 Vasilis Daloukas
 */

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

require_once( $CFG->dirroot.'/course/moodleform_mod.php');
require( 'locallib.php');

/**
 * The class defines the form of game parameters
 *
 * @package    mod_game
 * @copyright  2014 Vasilis Daloukas
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class mod_game_mod_form extends moodleform_mod {

    /**
     * definition
     */
    public function definition() {
        global $CFG, $DB, $COURSE;

        $config = get_config('game');

        $mform =& $this->_form;
        $id = $this->_instance;

        if (!empty($this->_instance)) {
            if ($g = $DB->get_record('game', array('id' => $id))) {
                $gamekind = $g->gamekind;
            } else {
                throw new moodle_exception('game_error', 'game', 'incorrect game');
            }
        } else {
            $gamekind = optional_param('type', '', PARAM_ALPHA);
        }

        // Hidden elements.
        $mform->addElement('hidden', 'gamekind', $gamekind);
        $mform->setDefault('gamekind', $gamekind);
        $mform->setType('gamekind', PARAM_ALPHA);
        $mform->addElement('hidden', 'type', $gamekind);
        $mform->setDefault('type', $gamekind);
        $mform->setType('type', PARAM_ALPHA);

        $mform->addElement( 'hidden', 'gameversion', game_get_version());
        $mform->setType('gameversion', PARAM_INT);

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

        $mform->addElement('text', 'name', get_string('name', 'game'), array('size' => '64'));
        if (!empty($CFG->formatstringstriptags)) {
            $mform->setType('name', PARAM_TEXT);
        } else {
            $mform->setType('name', PARAM_CLEAN);
        }
        if (!isset( $g) && $gamekind != '') {
            $mform->setDefault('name', get_string( 'game_'.$gamekind, 'game'));
        }
        $mform->addRule('name', null, 'required', null, 'client');

        // Introduction.
        if (game_get_moodle_version() >= '02.09') {
            $this->standard_intro_elements(get_string('introduction', 'game'));
        } else {
            $this->add_intro_editor(true);
        }

        $hasglossary = ($gamekind == 'hangman' || $gamekind == 'cross' ||
                $gamekind == 'cryptex' || $gamekind == 'sudoku' ||
                $gamekind == 'hiddenpicture' || $gamekind == 'snakes');

        $questionsourceoptions = array();
        if ($hasglossary) {
            $questionsourceoptions['glossary'] = get_string('modulename', 'glossary');
        }
        $questionsourceoptions['question'] = get_string('sourcemodule_question', 'game');
        if ($gamekind != 'bookquiz') {
            $questionsourceoptions['quiz'] = get_string('modulename', 'quiz');
        }
        $mform->addElement('select', 'sourcemodule', get_string('sourcemodule', 'game'), $questionsourceoptions);

        if ($hasglossary) {
            $a = array();
            $sql = "SELECT id,name,globalglossary,course FROM {$CFG->prefix}glossary ".
            "WHERE course={$COURSE->id} OR globalglossary=1 ORDER BY globalglossary DESC,name";
            if ($recs = $DB->get_records_sql($sql)) {
                foreach ($recs as $rec) {
                    if (($rec->globalglossary != 0) && ($rec->course != $COURSE->id)) {
                        $rec->name = '*'.$rec->name;
                    }
                    $a[$rec->id] = $rec->name;
                }
            }
            $mform->addElement('select', 'glossaryid', get_string('sourcemodule_glossary', 'game'), $a);
            $mform->disabledIf('glossaryid', 'sourcemodule', 'neq', 'glossary');

            $a = $this->get_array_glossary_categories( $a);
            $mform->addElement('select', 'glossarycategoryid', get_string('sourcemodule_glossarycategory', 'game'), $a);
            $mform->disabledIf('glossarycategoryid', 'sourcemodule', 'neq', 'glossary');

            // Only approved.
            $mform->addElement('selectyesno', 'glossaryonlyapproved', get_string('glossary_only_approved', 'game'));
            $mform->disabledIf('subcategories', 'sourcemodule', 'neq', 'glossary');
        }

        // Question Category - Short Answer.
        if ($gamekind != 'bookquiz') {
            $a = $this->get_array_question_categories( $COURSE->id, $gamekind );
            $mform->addElement('select', 'questioncategoryid', get_string('sourcemodule_questioncategory', 'game'), $a);
            $mform->disabledIf('questioncategoryid', 'sourcemodule', 'neq', 'question');

            // Subcategories.
            $mform->addElement('selectyesno', 'subcategories', get_string('sourcemodule_include_subcategories', 'game'));
            $mform->disabledIf('subcategories', 'sourcemodule', 'neq', 'question');
        }

        // Quiz Category.
        if ($gamekind != 'bookquiz') {
            $a = array();
            if ($recs = $DB->get_records('quiz', array( 'course' => $COURSE->id), 'id,name')) {
                foreach ($recs as $rec) {
                    $a[$rec->id] = $rec->name;
                }
            }
            $mform->addElement('select', 'quizid', get_string('sourcemodule_quiz', 'game'), $a);
            $mform->disabledIf('quizid', 'sourcemodule', 'neq', 'quiz');
        }

        // Book.
        if ( $gamekind == 'bookquiz') {
            $a = array();
            if ($recs = $DB->get_records('book', array( 'course' => $COURSE->id), 'id,name')) {
                foreach ($recs as $rec) {
                    $a[$rec->id] = $rec->name;
                }
            }
            $mform->addElement('select', 'bookid', get_string('sourcemodule_book', 'game'), $a);
        }

        // Common settings to all games.
        $mform->addElement('text', 'maxattempts', get_string('cross_max_attempts', 'game'));
        $mform->setType('maxattempts', PARAM_INT);

        // Disable summarize.
        $mform->addElement('selectyesno', 'disablesummarize', get_string('disablesummarize', 'game'));

        // Enable high score.
        $mform->addElement('text', 'highscore', get_string('highscore', 'game'));
        $mform->setType('highscore', PARAM_INT);

        // Grade options.
        $this->standard_grading_coursemodule_elements();
        $mform->removeElement('grade');
        $mform->addElement('text', 'grade', get_string( 'grademax', 'grades'), array('size' => 4));
        $mform->setType('grade', PARAM_INT);

        $gradingtypeoptions = array();
        $gradingtypeoptions[GAME_GRADEHIGHEST] = get_string('gradehighest', 'game');
        $gradingtypeoptions[GAME_GRADEAVERAGE] = get_string('gradeaverage', 'game');
        $gradingtypeoptions[GAME_ATTEMPTFIRST] = get_string('attemptfirst', 'game');
        $gradingtypeoptions[GAME_ATTEMPTLAST] = get_string('attemptlast', 'game');
        $mform->addElement('select', 'grademethod', get_string('grademethod', 'game'), $gradingtypeoptions);

        // Open and close dates.
        $mform->addElement('date_time_selector', 'timeopen', get_string('gameopen', 'game'),
                array('optional' => true, 'step' => 1));
        $mform->addHelpButton('timeopen', 'gameopenclose', 'game');

        $mform->addElement('date_time_selector', 'timeclose', get_string('gameclose', 'game'),
                array('optional' => true, 'step' => 1));

        // Bookquiz options.
        if ($gamekind == 'bookquiz') {
            $mform->addElement('header', 'bookquiz', get_string( 'bookquiz_options', 'game'));
            $bookquizlayoutoptions = array();
            $bookquizlayoutoptions[0] = get_string('bookquiz_layout0', 'game');
            $bookquizlayoutoptions[1] = get_string('bookquiz_layout1', 'game');
            $mform->addElement('select', 'param3',
                get_string('bookquiz_layout', 'game'), $bookquizlayoutoptions);
        }

        // Hangman options.
        if ($gamekind == 'hangman') {
            $mform->addElement('header', 'hangman', get_string( 'hangman_options', 'game'));
            $mform->addElement('text', 'param4', get_string('hangman_maxtries', 'game'), array('size' => 4));
            $mform->setType('param4', PARAM_INT);
            $mform->addElement('selectyesno', 'param1', get_string('hangman_showfirst', 'game'));
            $mform->addElement('selectyesno', 'param2', get_string('hangman_showlast', 'game'));
            $mform->addElement('selectyesno', 'param7', get_string('hangman_allowspaces', 'game'));
            $mform->addElement('selectyesno', 'param8', get_string('hangman_allowsub', 'game'));

            $mform->addElement('text', 'param10', get_string( 'hangman_maximum_number_of_errors', 'game'), array('size' => 4));
            $mform->setType('param10', PARAM_INT);

            if (!isset( $config->hangmanimagesets)) {
                $number = 1;
            } else {
                $number = $config->hangmanimagesets;
            }
            if ($number > 1) {
                $a = array();
                for ($i = 1; $i <= $number; $i++) {
                    $a[$i] = $i;
                }
                $mform->addElement('select', 'param3', get_string('hangman_imageset', 'game'), $a);
            }

            $mform->addElement('selectyesno', 'param5', get_string('hangman_showquestion', 'game'));
            $mform->setDefault('param5', 1);
            $mform->addElement('selectyesno', 'param6', get_string('hangman_showcorrectanswer', 'game'));

            $a = array();
            $a = get_string_manager()->get_list_of_translations();
            $a[''] = '----------';
            $a['user'] = get_string('language_user_defined', 'game');
            ksort( $a);
            $mform->addElement('select', 'language', get_string('hangman_language', 'game'), $a);

            $mform->addElement('text', 'userlanguage', get_string('language_user_defined', 'game'));
            $mform->setType('userlanguage', PARAM_TEXT);
            $mform->disabledIf('userlanguage', 'language', 'neq', 'user');
        }

        // Crossword options.
        if ($gamekind == 'cross') {
            $mform->addElement('header', 'cross', get_string( 'cross_options', 'game'));
            $mform->addElement('text', 'param1', get_string('cross_maxcols', 'game'));
            $mform->setType('param1', PARAM_INT);
            $mform->addElement('text', 'param4', get_string('cross_minwords', 'game'));
            $mform->setType('param4', PARAM_INT);
            $mform->addElement('text', 'param2', get_string('cross_maxwords', 'game'));
            $mform->setType('param2', PARAM_INT);
            $mform->addElement('selectyesno', 'param7', get_string('hangman_allowspaces', 'game'));
            $crosslayoutoptions = array();
            $crosslayoutoptions[0] = get_string('cross_layout0', 'game');
            $crosslayoutoptions[1] = get_string('cross_layout1', 'game');
            $mform->addElement('select', 'param3', get_string('cross_layout', 'game'), $crosslayoutoptions);
            $mform->setType('param5', PARAM_INT);
            $mform->addElement('selectyesno', 'param6', get_string('cross_disabletransformuppercase', 'game'));
            $mform->addElement('text', 'param8', get_string('cross_maxcomputetime', 'game'));
            $mform->setType('param8', PARAM_INT);
        }

        // Cryptex options.
        if ($gamekind == 'cryptex') {
            $mform->addElement('header', 'cryptex', get_string( 'cryptex_options', 'game'));
            $mform->addElement('text', 'param1', get_string('cross_maxcols', 'game'));
            $mform->setType('param1', PARAM_INT);
            $mform->addElement('text', 'param4', get_string('cross_minwords', 'game'));
            $mform->setType('param4', PARAM_INT);
            $mform->addElement('text', 'param2', get_string('cross_maxwords', 'game'));
            $mform->setType('param2', PARAM_INT);
            $mform->addElement('selectyesno', 'param7', get_string('hangman_allowspaces', 'game'));
            $mform->addElement('text', 'param8', get_string('cryptex_maxtries', 'game'));
            $mform->setType('param8', PARAM_INT);
            $mform->addElement('text', 'param3', get_string('cross_maxcomputetime', 'game'));
            $mform->setType('param3', PARAM_INT);
        }

        // Millionaire options.
        if ($gamekind == 'millionaire') {
            global $OUTPUT, $PAGE;

            $mform->addElement('header', 'millionaire', get_string( 'millionaire_options', 'game'));
            $mform->addElement('text', 'param8', get_string('millionaire_background', 'game'));
            $mform->setDefault('param8', '#408080');
            $mform->setType('param8', PARAM_TEXT);

            $mform->addElement('selectyesno', 'shuffle', get_string('millionaire_shuffle', 'game'));
        }

        // Sudoku options.
        if ($gamekind == 'sudoku') {
            $mform->addElement('header', 'sudoku', get_string( 'sudoku_options', 'game'));
            $mform->addElement('text', 'param2', get_string('sudoku_maxquestions', 'game'));
            $mform->setType('param2', PARAM_INT);
        }

        // Snakes and Ladders options.
        if ($gamekind == 'snakes') {
            $mform->addElement('header', 'snakes', get_string( 'snakes_options', 'game'));
            $snakesandladdersbackground = array();
            if ($recs = $DB->get_records( 'game_snakes_database', null, 'id,name')) {
                foreach ($recs as $rec) {
                    $snakesandladdersbackground[$rec->id] = $rec->name;
                }
            }

            $snakeslayoutoptions = array();
            $snakeslayoutoptions[0] = get_string('snakes_layout0', 'game');
            $snakeslayoutoptions[1] = get_string('snakes_layout1', 'game');
            $mform->addElement('select', 'param8', get_string('bookquiz_layout', 'game'), $snakeslayoutoptions);

            if (count($snakesandladdersbackground) == 0) {
                require("{$CFG->dirroot}/mod/game/db/importsnakes.php");

                if ($recs = $DB->get_records('game_snakes_database', null, 'id,name')) {
                    foreach ($recs as $rec) {
                        $snakesandladdersbackground[$rec->id] = $rec->name;
                    }
                }
            }
            $snakesandladdersbackground[0] = get_string( 'userdefined', 'game');
            ksort( $snakesandladdersbackground);
            $mform->addElement('select', 'param3', get_string('snakes_background', 'game'), $snakesandladdersbackground);

            // Param3 = background.
            // Param4 = itemid for file_storage.
            // Param5 (=1 means dirty file and and have to be computed again).
            // Param6 = width of autogenerated picture.
            // Param7 = height of autogenerated picture.
            // Param8 = layout.

            $attachmentoptions = array('subdirs' => false, 'maxfiles' => 1);
            $mform->addElement('filepicker', 'param4', get_string('snakes_file', 'game'), $attachmentoptions);
            $mform->disabledIf('param4', 'param3', 'neq', '0');

            $mform->addElement('textarea', 'snakes_data', get_string('snakes_data', 'game'), 'rows="2" cols="70"');
            $mform->disabledIf('snakes_data', 'param3', 'neq', '0');

            $mform->addElement('text', 'snakes_cols', get_string('snakes_cols', 'game'), array('size' => 4));
            $mform->disabledIf('snakes_cols', 'param3', 'neq', '0');
            $mform->setType('snakes_cols', PARAM_INT);

            $mform->addElement('text', 'snakes_rows', get_string('snakes_rows', 'game'), array('size' => 4));
            $mform->disabledIf('snakes_rows', 'param3', 'neq', '0');
            $mform->setType('snakes_rows', PARAM_INT);

            $mform->addElement('text', 'snakes_headerx', get_string('snakes_headerx', 'game'), array('size' => 4));
            $mform->disabledIf('snakes_headerx', 'param3', 'neq', '0');
            $mform->setType('snakes_headerx', PARAM_INT);

            $mform->addElement('text', 'snakes_headery', get_string('snakes_headery', 'game'), array('size' => 4));
            $mform->disabledIf('snakes_headery', 'param3', 'neq', '0');
            $mform->setType('snakes_headery', PARAM_INT);

            $mform->addElement('text', 'snakes_footerx', get_string('snakes_footerx', 'game'), array('size' => 4));
            $mform->disabledIf('snakes_footerx', 'param3', 'neq', '0');
            $mform->setType('snakes_footerx', PARAM_INT);

            $mform->addElement('text', 'snakes_footery', get_string('snakes_footery', 'game'), array('size' => 4));
            $mform->disabledIf('snakes_footery', 'param3', 'neq', '0');
            $mform->setType('snakes_footery', PARAM_INT);

            $mform->addElement('text', 'snakes_width', get_string('hiddenpicture_width', 'game'), array('size' => 6));
            $mform->setType('snakes_width', PARAM_INT);

            $mform->addELement('text', 'snakes_height', get_string('hiddenpicture_height', 'game'), array('size' => 6));
            $mform->setType('snakes_height', PARAM_INT);
        }

        // Hidden Picture options.
        if ($gamekind == 'hiddenpicture') {
            $mform->addElement('header', 'hiddenpicture', get_string( 'hiddenpicture_options', 'game'));
            $mform->addElement('text', 'param1', get_string('hiddenpicture_across', 'game'));
            $mform->setType('param1', PARAM_INT);
            $mform->setDefault('param1', 3);
            $mform->addElement('text', 'param2', get_string('hiddenpicture_down', 'game'));
            $mform->setType('param2', PARAM_INT);
            $mform->setDefault('param2', 3);

            $a = array();
            if ($recs = $DB->get_records('glossary', array( 'course' => $COURSE->id), 'id,name')) {
                foreach ($recs as $rec) {
                    $cmg = get_coursemodule_from_instance('glossary', $rec->id, $COURSE->id);
                    $context = game_get_context_module_instance( $cmg->id);
                    if ($DB->record_exists( 'files', array( 'contextid' => $context->id))) {
                        $a[$rec->id] = $rec->name;
                    }
                }
            }
            $mform->addElement('select', 'glossaryid2', get_string('hiddenpicture_pictureglossary', 'game'), $a);

            $mform->addElement('text', 'param4', get_string('hiddenpicture_width', 'game'));
            $mform->setType('param4', PARAM_INT);
            $mform->addELement('text', 'param5', get_string('hiddenpicture_height', 'game'));
            $mform->setType('param5', PARAM_INT);
            $mform->addElement('selectyesno', 'param7', get_string('hangman_allowspaces', 'game'));
        }

        // Header/Footer options.

        $mform->addElement('header', 'headerfooteroptions', get_string('header_footer_options', 'game'));
        $mform->addElement('editor', 'toptext', get_string('toptext', 'game'));
        $mform->addElement('editor', 'bottomtext', get_string('bottomtext', 'game'));

        $features = new stdClass;
        $this->standard_coursemodule_elements($features);

        // Buttons.
        $this->add_action_buttons();
    }

    /**
     * Computes the categories of all glossaries of the current course;
     *
     * @param array $a array of id of glossaries to each name
     *
     * @return array of glossary categories
     */
    public function get_array_glossary_categories( $a) {
        global $CFG, $DB;

        if (count( $a) == 0) {
            $select = 'gc.glossaryid = -1';
        } else if (count($a) == 1) {
            foreach ($a as $id => $name) {
                $select = 'gc.glossaryid = '.$id;
                break;
            }
        } else {
            $select = '';
            foreach ($a as $id => $name) {
                $select .= ','.$id;
            }
            $select = 'gc.glossaryid IN ('.substr( $select, 1).')';
        }

        $a = array();

        // Fills with the count of entries in each glossary.
        $a[0] = '';
        // Fills with the count of entries in each category.
        $sql2 = "SELECT COUNT(*) ".
        " FROM {$CFG->prefix}glossary_entries ge, {$CFG->prefix}glossary_entries_categories gec".
        " WHERE gec.categoryid=gc.id AND gec.entryid=ge.id";
        $sql = "SELECT gc.id,gc.name,g.name as name2,g.globalglossary,g.course, ($sql2) as c ".
        " FROM {$CFG->prefix}glossary_categories gc, {$CFG->prefix}glossary g".
        " WHERE $select AND gc.glossaryid=g.id".
        " ORDER BY g.name, gc.name";
        if ($recs = $DB->get_records_sql( $sql)) {
            foreach ($recs as $rec) {
                $a[$rec->id] = $rec->name2.' -> '.$rec->name.' ('.$rec->c.')';
            }
        }

        return $a;
    }

    /**
     * Computes the categories of all question of the current course;
     *
     * @param int $courseid
     * @param string $gamekind
     *
     * @return array of question categories
     */
    public function get_array_question_categories( $courseid, $gamekind) {
        global $CFG, $DB;

        $context = game_get_context_course_instance( $courseid);

        $a = array();
        $table = "{$CFG->prefix}question q";
        $select = '';
        if ($gamekind == 'millionaire') {
            if (game_get_moodle_version() < '02.06') {
                $table = "{$CFG->prefix}question q, {$CFG->prefix}question_multichoice qmo";
                $select = " AND q.qtype='multichoice' AND qmo.single = 1 AND qmo.question=q.id";
            } else {
                $table = "{$CFG->prefix}question q, {$CFG->prefix}qtype_multichoice_options qmo";
                $select = " AND q.qtype='multichoice' AND qmo.single = 1 AND qmo.questionid=q.id";
            }
        } else if (($gamekind == 'hangman') || ($gamekind == 'cryptex') || ($gamekind == 'cross')) {
            // Single answer questions.
            $select = " AND q.qtype='shortanswer'";
        }
        if (game_get_moodle_version() >= '04.00') {
            $sql2 = "SELECT COUNT(DISTINCT questionbankentryid) FROM $table,{$CFG->prefix}question_bank_entries qbe,{$CFG->prefix}question_versions qv ".
                " WHERE qbe.questioncategoryid = qc.id AND qbe.id=qv.questionbankentryid AND q.id=qv.questionid $select";
        } else {
            $sql2 = "SELECT COUNT(*) FROM $table WHERE q.category = qc.id $select";
        }
        $sql = "SELECT id,name,($sql2) as c FROM {$CFG->prefix}question_categories qc WHERE contextid = $context->id";
        if ($recs = $DB->get_records_sql( $sql)) {
            foreach ($recs as $rec) {
                $a[$rec->id] = $rec->name.' ('.$rec->c.')';
            }
        }

        return $a;
    }

    /**
     * data_preprocessing
     *
     * @param stdClass $toform
     */
    public function data_preprocessing(&$toform) {
        if (isset($toform['grade'])) {
            // Convert to a real number, so we don't get 0.0000.
            $toform['grade'] = $toform['grade'] + 0;
        }

        // Completion settings check.
        if (empty($toform['completionusegrade'])) {
            $toform['completionpass'] = 0; // Forced unchecked.
        }
    }

    /**
     * validation
     *
     * @param stdClass $data
     * @param array $files
     *
     * @return moodle_url
     */
    public function validation($data, $files) {
        global $CFG, $DB;

        $errors = parent::validation($data, $files);

        // Check open and close times are consistent.
        if ($data['timeopen'] != 0 && $data['timeclose'] != 0 &&
                $data['timeclose'] < $data['timeopen']) {
            $errors['timeclose'] = get_string('closebeforeopen', 'quiz');
        }

        if (array_key_exists( 'glossarycategoryid', $data)) {
            if ($data['glossarycategoryid'] != 0) {
                $sql = "SELECT glossaryid FROM {$CFG->prefix}glossary_categories ".
                " WHERE id=".$data['glossarycategoryid'];
                $rec = $DB->get_record_sql( $sql);
                if ($rec != false) {
                    if ($data['glossaryid'] != $rec->glossaryid) {
                        $s = get_string( 'different_glossary_category', 'game');
                        $errors['glossaryid'] = $s;
                        $errors['glossarycategoryid'] = $s;
                    }
                }
            }
        }

        if (array_key_exists('completion', $data) && $data['completion'] == COMPLETION_TRACKING_AUTOMATIC) {
            $completionpass = isset($data['completionpass']) ? $data['completionpass'] : $this->current->completionpass;

            // Show an error if require passing grade was selected and the grade to pass was set to 0.
            if ($completionpass && (empty($data['gradepass']) || grade_floatval($data['gradepass']) == 0)) {
                if (isset($data['completionpass'])) {
                    $errors['completionpassgroup'] = get_string('gradetopassnotset', 'quiz');
                } else {
                    $errors['gradepass'] = get_string('gradetopassmustbeset', 'quiz');
                }
            }
        }
        // Check book.
        if ($data['gamekind'] == 'bookquiz' && empty( $data['bookid'])) {
            $errors['bookid'] = get_string('missingbook', 'game');
        }

        return $errors;
    }

    /**
     * Set data
     *
     * @param array $defaultvalues
     */
    public function set_data( $defaultvalues) {
        global $DB;

        if (isset( $defaultvalues->type)) {
            // Default values for every game.
            if ($defaultvalues->type == 'hangman') {
                $defaultvalues->param10 = 6;    // Maximum number of wrongs.
                $defaultvalues->param3 = 2;
            } else if ($defaultvalues->type == 'snakes') {
                $defaultvalues->gamekind = $defaultvalues->type;
                $defaultvalues->param3 = 3;
                $defaultvalues->questioncategoryid = 0;
            } else if ($defaultvalues->type == 'millionaire') {
                $defaultvalues->shuffle = 1;
            }
        }

        if (isset( $defaultvalues->gamekind)) {
            if ($defaultvalues->gamekind == 'hangman') {
                if ($defaultvalues->param10 == 0) {
                    $defaultvalues->param10 = 6;
                }
            } else if ($defaultvalues->gamekind == 'millionaire') {
                if (isset( $defaultvalues->param8)) {
                    $defaultvalues->param8 = '#'.substr( '000000'.strtoupper( dechex( $defaultvalues->param8)), -6);
                }
            } else if ($defaultvalues->gamekind == 'cross') {
                if ($defaultvalues->param5 == null) {
                    $defaultvalues->param5 = 1;
                }
            }

            if ($defaultvalues->gamekind == 'snakes') {
                if (isset( $defaultvalues->param9)) {
                    $a = explode( '#', $defaultvalues->param9);
                    foreach ($a as $s) {
                        $pos = strpos( $s, ':');
                        if ($pos) {
                            $name = substr( $s, 0, $pos);
                            $defaultvalues->$name = substr( $s, $pos + 1);
                        }
                    }
                }
            }
        }

        if (!isset( $defaultvalues->gamekind)) {
            $defaultvalues->gamekind = $defaultvalues->type;
        }
        if ($defaultvalues->gamekind == 'snakes') {
            if (isset( $defaultvalues->param3)) {
                $board = $defaultvalues->param3;
                if ($board != 0) {
                    $rec = $DB->get_record( 'game_snakes_database', array( 'id' => $board));
                    $defaultvalues->snakes_data = $rec->data;
                    $defaultvalues->snakes_cols = $rec->usedcols;
                    $defaultvalues->snakes_rows = $rec->usedrows;
                    $defaultvalues->snakes_headerx = $rec->headerx;
                    $defaultvalues->snakes_headery = $rec->headery;
                    $defaultvalues->snakes_footerx = $rec->footerx;
                    $defaultvalues->snakes_footery = $rec->footery;
                }
            }
        } else if ($defaultvalues->gamekind == 'cross') {
            if (!isset( $defaultvalues->param8)) {
                $defaultvalues->param8 = 2;
            }
        } else if ($defaultvalues->gamekind == 'cryptex') {
            if (!isset( $defaultvalues->param3)) {
                $defaultvalues->param3 = 2;
            }
        }

        if (isset( $defaultvalues->toptext)) {
            $a = array();
            $a['text'] = $defaultvalues->toptext;
            $defaultvalues->toptext = $a;
        }

        if (isset( $defaultvalues->bottomtext)) {
            $a = array();
            $a['text'] = $defaultvalues->bottomtext;
            $defaultvalues->bottomtext = $a;
        }

        parent::set_data( $defaultvalues);
    }

    /**
     * Display module-specific activity completion rules.
     * Part of the API defined by moodleform_mod
     * @return array Array of string IDs of added items, empty array if none
     */
    public function add_completion_rules() {
        $mform = $this->_form;
        $items = array();

        $group = array();
        $group[] = $mform->createElement('advcheckbox', 'completionpass', null, get_string('completionpass', 'game'),
                array('group' => 'cpass'));
        $mform->disabledIf('completionpass', 'completionusegrade', 'notchecked');
        $group[] = $mform->createElement('advcheckbox', 'completionattemptsexhausted', null,
                get_string('completionattemptsexhausted', 'quiz'),
                array('group' => 'cattempts'));
        $mform->disabledIf('completionattemptsexhausted', 'completionpass', 'notchecked');
        $mform->addGroup($group, 'completionpassgroup', get_string('completionpass', 'game'), ' &nbsp; ', false);
        $mform->addHelpButton('completionpassgroup', 'completionpass', 'game');
        $items[] = 'completionpassgroup';
        return $items;
    }

    /**
     * Called during validation. Indicates whether a module-specific completion rule is selected.
     *
     * @param array $data Input data (not yet validated)
     * @return bool True if one or more rules is enabled, false if none are.
     */
    public function completion_rule_enabled($data) {
        return !empty($data['completionattemptsexhausted']) || !empty($data['completionpass']);
    }
}
