moodle-mod_game/locallib.php

<?php  // $Id: locallib.php,v 1.59 2012/08/15 09:26:54 bdaloukas Exp $

if (!defined('MOODLE_INTERNAL')) {
    die('Direct access to this script is forbidden.'); /// It must be included from a Moodle page.
}

/**
 * Include those library functions that are also used by core Moodle or other modules
 */
require_once($CFG->dirroot . '/mod/game/lib.php');
require_once($CFG->dirroot . '/mod/quiz/locallib.php');
/// CONSTANTS ///////////////////////////////////////////////////////////////////

/**#@+
* Options determining how the grades from individual attempts are combined to give
* the overall grade for a user
*/

define( "GAME_GRADEMETHOD_HIGHEST", "1");
define( "GAME_GRADEMETHOD_AVERAGE", "2");
define( "GAME_GRADEMETHOD_FIRST",   "3");
define( "GAME_GRADEMETHOD_LAST",    "4");

$GAME_GRADE_METHOD = array ( GAME_GRADEMETHOD_HIGHEST => get_string("gradehighest", "game"),
                             GAME_GRADEMETHOD_AVERAGE => get_string("gradeaverage", "game"),
                             GAME_GRADEMETHOD_FIRST => get_string("attemptfirst", "game"),
                             GAME_GRADEMETHOD_LAST  => get_string("attemptlast", "game"));                                  

define( "CONST_GAME_TRIES_REPETITION", "3");

/**#@-*/

function game_get_moodle_version()
{
    global $DB;

    static $s_moodle_version = null;
    
    if( $s_moodle_version != null)
        return $s_moodle_version;
        
    $rec = $DB->get_record_select( 'config', "name='release'");
    if( $rec == false)
        return $s_moodle_version='';
    else
    {
        $a = explode( '.', $rec->value); 
        return $s_moodle_version = sprintf( '%02u.%02u', $a[ 0], $a[ 1]);
    }
}

function game_upper( $str, $lang='')
{
    $str = game_strtoupper( $str);

    $strings = get_string_manager()->load_component_strings( 'game', ($lang == '' ? 'en' : $lang));
    if( !isset( $strings[ 'convertfrom']))
        return $str;
    if( !isset( $strings[ 'convertto']))
        return $str;
	
    $from = $strings[ 'convertfrom'];
    $to = $strings[ 'convertto'];
    $len = game_strlen( $from);
    for($i=0; $i < $len; $i++){
        $str = str_replace( game_substr( $from, $i, 1), game_substr( $to, $i, 1), $str);
    }

    return $str;
}


function game_showselectcontrol( $name, $a,  $input, $events=''){
	$ret = "<select id=\"$name\" name=\"$name\" $events>";
	foreach( $a as $key => $caption){
		$ret .= '<option value="'.$key.'" ';
		if( $key == $input){
			$ret .= ' selected="selected" ';
		}
		$ret .= '>'.$caption."</option>\r\n";
	}
	$ret .= "</select>\r\n";
	
	return $ret;
}

function game_showcheckbox( $name, $value)
{
	$a = array();
	$a[ 0] = get_string( 'no');
	$a[ 1] = get_string( 'yes');
	
	return game_showselectcontrol( $name, $a, $value);
	
	$ret = '<input type="checkbox" name="'.$name.'"  value="'.$value.'"';
	if( $value == 1)
		$ret .= 'checked="checked"';
	$ret .= '/>';

	return $ret;
}

//used by hangman
function game_question_shortanswer( $game, $allowspaces=false, $use_repetitions=true)
{
	switch( $game->sourcemodule)
	{
	case 'glossary':
		return game_question_shortanswer_glossary( $game, $allowspaces, $use_repetitions);
	case 'quiz':
		return game_question_shortanswer_quiz( $game, $allowspaces, $use_repetitions);
	case 'question':
		return game_question_shortanswer_question( $game, $allowspaces, $use_repetitions);
	}

	return false;
}

//used by hangman
function game_question_shortanswer_glossary( $game, $allowspaces, $use_repetitions)
{
    global $DB;

	if( $game->glossaryid == 0){
		print_error( get_string( 'must_select_glossary', 'game'));
	}

    $select = "glossaryid={$game->glossaryid}";
	$table = '{glossary_entries} ge';
	if( $game->glossarycategoryid){
		$table .= ',{glossary_entries_categories} gec';
		$select .= ' AND gec.entryid = ge.id '.
					    " AND gec.categoryid = {$game->glossarycategoryid}";
	}
	if( $allowspaces == false){
    	$select .= " AND concept NOT LIKE '% %'  ";
    }

    if( ($id = game_question_selectrandom( $game, $table, $select, 'ge.id', $use_repetitions)) == false)
        return false;
              
    $sql = 'SELECT id, concept as answertext, definition as questiontext, id as glossaryentryid, 0 as questionid, glossaryid, attachment, 0 as answerid'.
           " FROM {glossary_entries} ge WHERE id = $id";
    if( ($rec = $DB->get_record_sql( $sql)) == false)
        return false;
        
    if( $rec->attachment != ''){
        $rec->attachment = "glossary/{$game->glossaryid}/$rec->id/$rec->attachment";
    }
    
    return $rec;
}

//used by hangman
function game_question_shortanswer_quiz( $game, $allowspaces, $use_repetitions)
{
    global $DB;

	if( $game->quizid == 0){
		print_error( get_string( 'must_select_quiz', 'game'));
	}

	$select = "qtype='shortanswer' AND quiz='$game->quizid' ".
					" AND qqi.question=q.id";
	$table = "{question} q,{quiz_question_instances} qqi";
	$fields = "q.id";
	
    if( ($id = game_question_selectrandom( $game, $table, $select, $fields, $use_repetitions)) == false)
        return false;	

	$select = "q.id=$id AND qa.question=$id".
					" AND q.hidden=0 AND qtype='shortanswer'";
	$table = "{question} q,{question_answers} qa";
	$fields = "qa.id as answerid, q.id, q.questiontext as questiontext, ".
	          "qa.answer as answertext, q.id as questionid, ".
	          "0 as glossaryentryid, '' as attachment";
    
    //Maybe there are more answers to one question. I use as correct the one with bigger fraction   
    $sql = "SELECT $fields FROM $table WHERE $select ORDER BY fraction DESC";
	if( ($recs=$DB->get_records_sql( $sql, null, 0, 1)) == false){
	    return false;
	}
	foreach( $recs as $rec){
	    return $rec;
	}
}

//used by hangman
function game_question_shortanswer_question( $game, $allowspaces, $use_repetitions)
{
    global $DB;
	
	if( $game->questioncategoryid == 0){
		print_error( get_string( 'must_select_questioncategory', 'game'));
	}
        		
    $select = 'category='.$game->questioncategoryid;        
    if( $game->subcategories){
        $cats = question_categorylist( $game->questioncategoryid);
        if( count( $cats) > 0){
            $s = implode( ',', $cats);
            $select = 'category in ('.$s.')';
        }
    }
	$select .= " AND qtype='shortanswer'";
	
	$table = '{question} q';
	$fields = 'q.id';

    if( ($id = game_question_selectrandom( $game, $table, $select, $fields, $use_repetitions)) == false)
        return false;	

	$select = "q.id=$id AND qa.question=$id".
					" AND q.hidden=0 AND qtype='shortanswer'";
	$table = "{question} q,{question_answers} qa";
	$fields = "qa.id as answerid, q.id, q.questiontext as questiontext, ".
	          "qa.answer as answertext, q.id as questionid, ".
	          "0 as glossaryentryid, '' as attachment";
    
    //Maybe there are more answers to one question. I use as correct the one with bigger fraction
    $sql = "SELECT $fields FROM $table WHERE $select ORDER BY fraction DESC"; 
	if( ($recs = $DB->get_records_sql( $sql, null, 0, 1)) == false){
	    return false;
	}
	foreach( $recs as $rec){
	    return $rec;
	}
}

//used by millionaire, game_question_shortanswer_quiz, hidden picture
function game_question_selectrandom( $game, $table, $select, $id_fields='id', $use_repetitions=true)
{
    global $DB, $USER; 

    $count = $DB->get_field_sql( "SELECT COUNT(*) FROM $table WHERE $select");
    
    if( $count == 0)
        return false;
    
    $min_num = 0;
    $min_id = 0;
    for($i=1; $i <= CONST_GAME_TRIES_REPETITION; $i++){
        $sel = mt_rand(0, $count-1);
	    
        $sql  = "SELECT $id_fields,$id_fields FROM ".$table." WHERE $select";
    	if( ($recs = $DB->get_records_sql( $sql, null, $sel, 1)) == false){
            return false;
        }

        $id = 0;
        foreach( $recs as $rec){
            $id = $rec->id;
        }
        if( $min_id == 0){
            $min_id = $id;
        }
        
        if( $use_repetitions == false){
            return $id;
        }
        
        if( $count == 1){
            break;
        }
                
        $questionid = $glossaryentryid = 0;
        if( $game->sourcemodule == 'glossary')
            $glossaryentryid = $id;
        else
            $questionid = $id;
        
        $a = array( 'gameid' => $game->id, 'userid' => $USER->id, 'questionid' => $questionid, 'glossaryentryid' => $glossaryentryid);
        if( ($rec = $DB->get_record( 'game_repetitions', $a, 'id,repetitions r')) != false){
            if( ($rec->r < $min_num) or ($min_num == 0)){
                $min_num = $rec->r;
                $min_id = $id;
            }
        }else
        {
            $min_id = $questionid;
            break;
        }
  
    }

    if( $game->sourcemodule == 'glossary')
        game_update_repetitions( $game->id, $USER->id, 0, $min_id);
    else
        game_update_repetitions( $game->id, $USER->id, $min_id, 0);
    
    return $min_id;
}

function game_update_repetitions( $gameid, $userid, $questionid, $glossaryentryid){
    global $DB;

    $a = array( 'gameid' => $gameid, 'userid' => $userid, 'questionid' => $questionid, 'glossaryentryid' => $glossaryentryid);
    if( ($rec = $DB->get_record( 'game_repetitions', $a, 'id,repetitions r')) != false){
        $updrec = new stdClass();
        $updrec->id = $rec->id;
        $updrec->repetitions = $rec->r + 1;
        if( !$DB->update_record( 'game_repetitions', $updrec)){
           print_error("Update page: can't update game_repetitions id={$updrec->id}");
        }
    }else
    {
        $newrec = new stdClass();
        $newrec->gameid = $gameid;
        $newrec->userid = $userid;
        $newrec->questionid = $questionid;
        $newrec->glossaryentryid = $glossaryentryid;
        $newrec->repetitions = 1;
        
        if( $newrec->questionid == ''){
            $newrec->questionid = 0;
        }
        if( $newrec->glossaryentryid == ''){
            $newrec->glossaryentryid = 0;
        }
            
        if (!$DB->insert_record( 'game_repetitions', $newrec)){
            print_r( $newrec);
            print_error("Insert page: new page game_repetitions not inserted");
        }
    }
}

//used by sudoku
function game_questions_selectrandom( $game, $count=1)
{
	global $DB;

	switch( $game->sourcemodule)
	{
	case 'quiz':

		if( $game->quizid == 0){
			print_error( get_string( 'must_select_quiz', 'game'));
		}
	
		$table = '{question} q, {quiz_question_instances} qqi';
		$select = " qqi.quiz=$game->quizid".
			" AND qqi.question=q.id ".			
			" AND q.qtype in ('shortanswer', 'truefalse', 'multichoice')".
			" AND q.hidden=0";
//todo 'match'
		$field = "q.id as id";
		
		$table2 = 'question';
		$fields2 = 'id as questionid,0 as glossaryentryid,qtype';
		break;
	case 'glossary':
		if( $game->glossaryid == 0){
			print_error( get_string( 'must_select_glossary', 'game'));
		}	
		$table = '{glossary_entries} ge';
		$select = "glossaryid='$game->glossaryid' ";
		if( $game->glossarycategoryid){
		    $table .= ',{glossary_entries_categories} gec';
		    $select .= " AND gec.entryid = ge.id ".
					    " AND gec.categoryid = {$game->glossarycategoryid}";
		}
		$field = 'ge.id';
		$table2 = 'glossary_entries';
		$fields2 = 'id as glossaryentryid, 0 as questionid';
		break;
	case 'question':
		if( $game->questioncategoryid == 0){
			print_error( get_string( 'must_select_questioncategory', 'game'));
		}
		$table = '{question} q';
		
		//inlcude subcategories
        $select = 'category='.$game->questioncategoryid;        
        if( $game->subcategories){
            $cats = question_categorylist( $game->questioncategoryid);
            if( count( $cats))
                $select = 'category in ('.implode( ',', $cats).')';
        }    		
		
		$select .= " AND q.qtype in ('shortanswer', 'truefalse', 'multichoice') ".
			"AND q.hidden=0";
//todo 'match'
		$field = "id";
		
		$table2 = 'question';
		$fields2 = 'id as questionid,0 as glossaryentryid';
		break;
	default:
		print_error( 'No sourcemodule defined');
		break;
	}

	$ids = game_questions_selectrandom_detail( $table, $select, $field, $count);
	if( $ids === false){
		print_error( get_string( 'no_questions', 'game'));
	}

	if( count( $ids) > 1){
		//randomize the array
		shuffle( $ids);
	}
	
	$ret = array();
	foreach( $ids as $id)
	{
		if( $recquestion = $DB->get_record( $table2, array( 'id' => $id), $fields2)){
			$new = new stdClass();
			$new->questionid = (int )$recquestion->questionid;
			$new->glossaryentryid = (int )$recquestion->glossaryentryid;
			$ret[] = $new;
		}
	}

	return $ret;	
}

//used by game_questions_selectrandom
function game_questions_selectrandom_detail( $table, $select, $id_field="id", $count=1)
{
    global $DB;
		
    $sql = "SELECT $id_field FROM $table WHERE $select";
	if( ($recs=$DB->get_records_sql( $sql)) == false)
        return false;

	//the array contains the ids of all questions
	$a = array();
    foreach( $recs as $rec){
        $a[ $rec->id] = $rec->id;
    }

	if( $count >= count( $a)){
		return $a;
	}else
	{
		$id = array_rand(  $a, $count);
		return ( $count == 1  ? array( $id) : $id);
	}
}

//Tries to detect the language of word
function game_detectlanguage( $word){
    global $CFG;
    
    $langs = get_string_manager()->get_list_of_translations();
    
    //English has more priority
    if( array_key_exists( 'en', $langs))
    {
        unset( $langs[ 'en']);
        $langs[ ''] = '';
    }
    ksort( $langs);
    $langs_installed = get_string_manager()->get_list_of_translations();       
    
    foreach( $langs as $lang => $name)
    {
        if( $lang == '')
            $lang = 'en';
            
        if( !array_key_exists( $lang, $langs_installed))
            continue;
            
        $strings = get_string_manager()->load_component_strings( 'game', $lang);
        if( isset( $strings[ 'lettersall']))
        {
            $letters = $strings[ 'lettersall'];
            $word2 = game_upper( $word, $lang);

            if( hangman_existall( $word2, $letters))
                return $lang;
       }
    }

    return false;
}

//The words maybe are in two languages e.g. greek or english
//so I try to find the correct one.
function game_getallletters( $word, $lang='')
{
    for(;;)
    {
        $strings = get_string_manager()->load_component_strings( 'game', ($lang == '' ? 'en' : $lang));
        if( isset( $strings[ 'lettersall']))
        {
            $letters = $strings[ 'lettersall'];
            $word2 = game_upper( $word, $lang);
            if( hangman_existall( $word2, $letters))
                return $letters;
        }

        if( $lang == '')
            break;
        else
            $lang = '';   
    }

    
    return '';
}

function hangman_existall( $str, $strfind)
{
    $n = game_strlen( $str);
    for( $i=0; $i < $n; $i++)
    {
		$pos = game_strpos( $strfind, game_substr( $str, $i, 1));
        if( $pos === false)
            return false;
    }
  
    return true;
}

//used by cross
function game_questions_shortanswer( $game)
{
	switch( $game->sourcemodule)
	{
	case 'glossary':
		$recs = game_questions_shortanswer_glossary( $game);
		break;
	case 'quiz';
		$recs = game_questions_shortanswer_quiz( $game);
		break;
	case 'question';
		$recs = game_questions_shortanswer_question( $game);
		break;
	}

	return $recs;
}

//used by cross
function game_questions_shortanswer_glossary( $game)
{
    global $DB;
    
    $select = "glossaryid={$game->glossaryid}";
    $table = '{glossary_entries} ge';
    if( $game->glossarycategoryid){
		$table .= ',{glossary_entries_categories} gec';
		$select .= ' AND gec.entryid = ge.id '.
					    ' AND gec.categoryid = '.$game->glossarycategoryid;
    }        

    $sql = 'SELECT ge.id, concept as answertext, definition as questiontext, ge.id as glossaryentryid, 0 as questionid, attachment '.
           " FROM $table WHERE $select";

	return $DB->get_records_sql( $sql);

}
//used by cross
function game_questions_shortanswer_quiz( $game)
{
    global $DB;
	
    if( $game->quizid == 0){
        print_error( get_string( 'must_select_quiz', 'game'));
    }	
    		
	$select = "qtype='shortanswer' AND quiz='$game->quizid' ".
					" AND qqi.question=q.id".
					" AND qa.question=q.id".
					" AND q.hidden=0";
	$table = "{question} q,{quiz_question_instances} qqi,{question_answers} qa";
	$fields = "qa.id as qaid, q.id, q.questiontext as questiontext, ".
				   "qa.answer as answertext, q.id as questionid,".
				   " 0 as glossaryentryid,'' as attachment";

	return game_questions_shortanswer_question_fraction( $table, $fields, $select);
}

//used by cross
function game_questions_shortanswer_question( $game)
{
    if( $game->questioncategoryid == 0){
        print_error( get_string( 'must_select_questioncategory', 'game'));
    }
    		
    //include subcategories    		
    $select = 'q.category='.$game->questioncategoryid;        
    if( $game->subcategories){
        $cats = question_categorylist( $game->questioncategoryid);
        if( count( $cats)){
            $select = 'q.category in ('.implode(',', $cats).')';
        }
    }    		
    		
	$select .= " AND qtype='shortanswer' ".
					" AND qa.question=q.id".
					" AND q.hidden=0";
	$table = "{question} q,{question_answers} qa";
	$fields = "qa.id as qaid, q.id, q.questiontext as questiontext, ".
				   "qa.answer as answertext, q.id as questionid";
	
	return game_questions_shortanswer_question_fraction( $table, $fields, $select);
}
	
function game_questions_shortanswer_question_fraction( $table, $fields, $select)
{
    global $DB;
    
	$sql = "SELECT $fields FROM ".$table." WHERE $select ORDER BY fraction DESC";
    
	$recs = $DB->get_records_sql( $sql);
	if( $recs == false){
	    print_error( get_string( 'no_questions', 'game'));
	}
	
	$recs2 = array();
	$map = array();
	foreach( $recs as $rec){	  
	    if( array_key_exists( $rec->questionid, $map)){
	        continue;
	    }
	    $rec2 = new stdClass();
	    $rec2->id = $rec->id;
	    $rec2->questiontext = $rec->questiontext;
	    $rec2->answertext = $rec->answertext;
	    $rec2->questionid = $rec->questionid;
	    $rec2->glossaryentryid = 0;
	    $rec2->attachment = '';
	    $recs2[] = $rec2;
	    
	    $map[ $rec->questionid] = $rec->questionid;
	}

	return $recs2;
}


	function game_setchar( &$s, $pos, $char)
	{
		$ret = "";
		
		if( $pos > 0){
			$ret .= game_substr( $s, 0, $pos);
		}
		
		$s = $ret . $char . game_substr( $s, $pos+1);
	}


	function game_insert_record( $table, $rec)
	{
		global $DB;
		
		if( $DB->get_record($table, array('id' => $rec->id), 'id,id') == false){
    		$sql = 'INSERT INTO {'.$table.'}(id) VALUES('.$rec->id.')';
	    	if( !$DB->execute( $sql)){
	    		print_error( "Cannot insert an empty $table with id=$rec->id");
	    		return false;
	    	}
	    }
		if( isset( $rec->question)){
    		$temp = $rec->question;
	    	$rec->question = addslashes( $rec->question);
	    }
		$ret = $DB->update_record( $table, $rec);

		if( isset( $rec->question)){
    		$rec->question = $temp;
    	}
		
		return $ret;
	}

	//if score is negative doesn't update the record
	//score is between 0 and 1
	function game_updateattempts( $game, $attempt, $score, $finished)
	{
        global $DB, $USER;

	    if( $attempt != false){
    	    $updrec = new stdClass();
		    $updrec->id = $attempt->id;
    		$updrec->timelastattempt = time();
    		$updrec->lastip = getremoteaddr();
	    	if( isset( $_SERVER[ 'REMOTE_HOST'])){
	    		$updrec->lastremotehost = $_SERVER[ 'REMOTE_HOST'];
	    	}
	    	else{
	    		$updrec->lastremotehost = gethostbyaddr( $updrec->lastip);
	    	}
            $updrec->lastip = substr( $updrec->lastip, 0, 30);
	    	$updrec->lastremotehost = substr( $updrec->lastremotehost, 0, 50);

	    	if( $score >= 0){
	    		$updrec->score = $score;
	    	}

	    	if( $finished){
	    		$updrec->timefinish = $updrec->timelastattempt;
		    }
		
    		$updrec->attempts = $attempt->attempts + 1;

	    	if( !$DB->update_record( 'game_attempts', $updrec)){
	    		print_error( "game_updateattempts: Can't update game_attempts id=$updrec->id");
	    	}
	    	
            // update grade item and send all grades to gradebook
            game_grade_item_update( $game);
            game_update_grades( $game);    
	    }
		
		//Update table game_grades
		if( $finished){
			game_save_best_score( $game);
		}
	}

	function game_updateattempts_maxgrade( $game, $attempt, $grade, $finished)
	{
        global $DB;

		$recgrade = $DB->get_field( 'game_attempts', 'score', array( 'id' => $attempt->id));

		if( $recgrade >  $grade){
			$grade = -1;		//don't touch the grade
		}
		
		game_updateattempts( $game, $attempt, $grade, $finished);
	}

	function game_update_queries( $game, $attempt, $query, $score, $studentanswer, $updatetries=false)
	{
		global $DB, $USER;
		
		if( $query->id != 0){
			$select = "id=$query->id";
		}else
		{
			$select = "attemptid = $attempt->id AND sourcemodule = '{$query->sourcemodule}'";
			switch( $query->sourcemodule)
			{
			case 'quiz':
				$select .= " AND questionid='$query->questionid' ";
				break;
			case 'glossary':
				$select .= " AND glossaryentryid='$query->glossaryentryid'";
				break;
			}		
		}

		if( ($recq = $DB->get_record_select( 'game_queries', $select)) === false)
		{
			$recq = new stdClass();
			$recq->gamekind = $game->gamekind;
			$recq->gameid = $attempt->gameid;
			$recq->userid = $attempt->userid;
			$recq->attemptid = $attempt->id;
			$recq->sourcemodule = $query->sourcemodule;
			$recq->questionid = $query->questionid;
			$recq->glossaryentryid = $query->glossaryentryid;
			if ($updatetries)
				$recq->tries = 1;

			if (!($recq->id = $DB->insert_record( 'game_queries', $recq))){
				print_error( 'Insert page: new page game_queries not inserted');
			}
		}
		
		$updrec = new stdClass();
		$updrec->id = $recq->id;
		$updrec->timelastattempt = time();
		
        if( $score >= 0){
            $updrec->score = $score;
        }
		
		if( $studentanswer != ''){
			$updrec->studentanswer = $studentanswer;
		}
		
		if ($updatetries)
			$updrec->tries = $recq->tries + 1;
			
		if (!($DB->update_record( 'game_queries', $updrec))){
			print_error( "game_update_queries: not updated id=$updrec->id");
		}
	}
	

	function game_getattempt( $game, &$detail, $autoadd=false)
	{
		global $DB, $USER;
		
		$select = "gameid=$game->id AND userid=$USER->id and timefinish=0 ";
		if( $USER->id == 1){
			$key = 'mod/game:instanceid'.$game->id;
			if( array_key_exists( $key, $_SESSION)){
				$select .= ' AND id="'.$_SESSION[ $key].'"';
			}else{
				$select .= ' AND id=-1';
			}
		}

		if( ($recs=$DB->get_records_select( 'game_attempts', $select))){
			foreach( $recs as $attempt){
				if( $USER->id == 1){
					$_SESSION[ $key] = $attempt->id;
				}
				
				$detail = $DB->get_record( 'game_'.$game->gamekind, array( 'id' => $attempt->id));

				return $attempt;
			}
		};
		
		if( $autoadd)
		{
		    game_addattempt( $game);
		    return game_getattempt( $game, $detail, false);
		}
		
		return false;
	}

/**
 * @param integer $gameid the game id.
 * @param integer $userid the userid.
 * @param string $status 'all', 'finished' or 'unfinished' to control
 * @return an array of all the user's attempts at this game. Returns an empty array if there are none.
 */
function game_get_user_attempts( $gameid, $userid, $status = 'finished') {
    global $DB;

    $status_condition = array(
        'all' => '',
        'finished' => ' AND timefinish > 0',
        'unfinished' => ' AND timefinish = 0'
    );
    if ($attempts = $DB->get_records_select( 'game_attempts',
            "gameid = ? AND userid = ? AND preview = 0" . $status_condition[$status],
            array( $gameid, $userid), 'attempt ASC')) {
        return $attempts;
    } else {
        return array();
    }
}


/**
 * Returns an unfinished attempt (if there is one) for the given
 * user on the given game. This function does not return preview attempts.
 *
 * @param integer $gameid the id of the game.
 * @param integer $userid the id of the user.
 *
 * @return mixed the unfinished attempt if there is one, false if not.
 */
function game_get_user_attempt_unfinished( $gameid, $userid) {
    $attempts = game_get_user_attempts( $gameid, $userid, 'unfinished');
    if ($attempts) {
        return array_shift($attempts);
    } else {
        return false;
    }
}

/**
 * Get the best current score for a particular user in a game.
 *
 * @param object $game the game object.
 * @param integer $userid the id of the user.
 * @return float the user's current grade for this game.
 */
function game_get_best_score($game, $userid) {
    global $DB;

    $score = $DB->get_field( 'game_grades', 'score', array( 'gameid' => $game->id, 'userid' => $userid));

    // Need to detect errors/no result, without catching 0 scores.
    if (is_numeric($score)) {
        return $score;
    } else {
        return NULL;
    }
}

function game_get_best_grade($game, $userid) {
    $score = game_get_best_score( $game, $userid);
	
	if( is_numeric( $score)){
		return round( $score * $game->grade, $game->decimalpoints);
	}else
	{
        return NULL;
    }
}


function game_score_to_grade($score, $game) {
    if ($score) {
        return round($score*$game->grade, $game->decimalpoints);
    } else {
        return 0;
    }
}

/**
 * Determine review options
 *
 * @param object $game the game instance.
 * @param object $attempt the attempt in question.
 * @param $context the roles and permissions context,
 *          normally the context for the game module instance.
 *
 * @return object an object with boolean fields responses, scores, feedback,
 *          correct_responses, solutions and general feedback
 */
function game_get_reviewoptions($game, $attempt, $context=null) {

    $options = new stdClass;
    $options->readonly = true;
    // Provide the links to the question review and comment script
    $options->questionreviewlink = '/mod/game/reviewquestion.php';

    if ($context /* && has_capability('mod/game:viewreports', $context) */ and !$attempt->preview) {
        // The teacher should be shown everything except during preview when the teachers
        // wants to see just what the students see
        $options->responses = true;
        $options->scores = true;
        $options->feedback = true;
        $options->correct_responses = true;
        $options->solutions = false;
        $options->generalfeedback = true;
        $options->overallfeedback = true;

        // Show a link to the comment box only for closed attempts
        if ($attempt->timefinish) {
            $options->questioncommentlink = '/mod/game/comment.php';
        }
    } else {
        if (((time() - $attempt->timefinish) < 120) || $attempt->timefinish==0) {
            $game_state_mask = GAME_REVIEW_IMMEDIATELY;
        } else if (!$game->timeclose or time() < $game->timeclose) {
            $game_state_mask = GAME_REVIEW_OPEN;
        } else {
            $game_state_mask = GAME_REVIEW_CLOSED;
        }
        $options->responses = ($game->review & $game_state_mask & GAME_REVIEW_RESPONSES) ? 1 : 0;
        $options->scores = ($game->review & $game_state_mask & GAME_REVIEW_SCORES) ? 1 : 0;
        $options->feedback = ($game->review & $game_state_mask & GAME_REVIEW_FEEDBACK) ? 1 : 0;
        $options->correct_responses = ($game->review & $game_state_mask & GAME_REVIEW_ANSWERS) ? 1 : 0;
        $options->solutions = ($game->review & $game_state_mask & GAME_REVIEW_SOLUTIONS) ? 1 : 0;
        $options->generalfeedback = ($game->review & $game_state_mask & GAME_REVIEW_GENERALFEEDBACK) ? 1 : 0;
        $options->overallfeedback = $attempt->timefinish && ($game->review & $game_state_mask & GAME_REVIEW_FEEDBACK);
    }

    return $options;
}


function game_compute_attempt_layout( $game, &$attempt)
{
    global $DB;

	$ret = '';
	$recs = $DB->get_records_select( 'game_queries', "attemptid=$attempt->id", null, '', 'id,questionid,sourcemodule,glossaryentryid');
	if( $recs){
		foreach( $recs as $rec){
			if( $rec->sourcemodule == 'glossary'){
				$ret .= $rec->glossaryentryid.'G,';
			}else{
				$ret .= $rec->questionid.',';
			}
		}
	}
	
	$attempt->layout = $ret.'0';
}

/**
 * Combines the review options from a number of different game attempts.
 * Returns an array of two ojects, so he suggested way of calling this
 * funciton is:
 * list($someoptions, $alloptions) = game_get_combined_reviewoptions(...)
 *
 * @param object $game the game instance.
 * @param array $attempts an array of attempt objects.
 * @param $context the roles and permissions context,
 *          normally the context for the game module instance.
 *
 * @return array of two options objects, one showing which options are true for
 *          at least one of the attempts, the other showing which options are true
 *          for all attempts.
 */
function game_get_combined_reviewoptions($game, $attempts, $context=null) {
    $fields = array('readonly', 'scores', 'feedback', 'correct_responses', 'solutions', 'generalfeedback', 'overallfeedback');
    $someoptions = new stdClass;
    $alloptions = new stdClass;
    foreach ($fields as $field) {
        $someoptions->$field = false;
        $alloptions->$field = true;
    }
    foreach ($attempts as $attempt) {
        $attemptoptions = game_get_reviewoptions( $game, $attempt, $context);
        foreach ($fields as $field) {
            $someoptions->$field = $someoptions->$field || $attemptoptions->$field;
            $alloptions->$field = $alloptions->$field && $attemptoptions->$field;
        }
    }
    return array( $someoptions, $alloptions);
}

/**
 * Save the overall grade for a user at a game in the game_grades table
 *
 * @param object $quiz The game for which the best grade is to be calculated and then saved.
 * @param integer $userid The userid to calculate the grade for. Defaults to the current user.
 * @return boolean Indicates success or failure.
 */
function game_save_best_score($game) {
    global $DB, $USER;

    // Get all the attempts made by the user
    if (!$attempts = game_get_user_attempts( $game->id, $USER->id, 'all')) {
        print_error( 'Could not find any user attempts gameid='.$game->id.' userid='.$USER->id);
    }

    // Calculate the best grade
    $bestscore = game_calculate_best_score( $game, $attempts);

    // Save the best grade in the database
    if ($grade = $DB->get_record('game_grades', array( 'gameid' => $game->id, 'userid' => $USER->id))) {
        $grade->score = $bestscore;
        $grade->timemodified = time();
        if (!$DB->update_record('game_grades', $grade)) {
            print_error('Could not update best grade');
        }
    } else {
        $grade = new stdClass();
        $grade->gameid = $game->id;
        $grade->userid = $USER->id;
        $grade->score = $bestscore;
        $grade->timemodified = time();
        if (!$DB->insert_record( 'game_grades', $grade)) {
            print_error( 'Could not insert new best grade');
        }
    }
    
    // update gradebook
    $grades = new stdClass();
    $grades->userid = $USER->id;
    $grades->rawgrade = game_score_to_grade($bestscore, $game);
    $grades->datesubmitted = time();
    game_grade_item_update( $game, $grades);

    return true;
}

/**
* Calculate the overall score for a game given a number of attempts by a particular user.
*
* @return double         The overall score
* @param object $game    The game for which the best score is to be calculated
* @param array $attempts An array of all the attempts of the user at the game
*/
function game_calculate_best_score($game, $attempts) {

    switch ($game->grademethod) {

        case GAME_GRADEMETHOD_FIRST:
            foreach ($attempts as $attempt) {
                return $attempt->score;
            }
            break;

        case GAME_GRADEMETHOD_LAST:
            foreach ($attempts as $attempt) {
                $final = $attempt->score;
            }
            return $final;

        case GAME_GRADEMETHOD_AVERAGE:
            $sum = 0;
            $count = 0;
            foreach ($attempts as $attempt) {
                $sum += $attempt->score;
                $count++;
            }
            return (float)$sum/$count;

        default:
        case GAME_GRADEMETHOD_HIGHEST:
            $max = 0;
            foreach ($attempts as $attempt) {
                if ($attempt->score > $max) {
                    $max = $attempt->score;
                }
            }
            return $max;
    }
}

/**
* Return the attempt with the best score for a game
*
* Which attempt is the best depends on $game->grademethod. If the grade
* method is GRADEAVERAGE then this function simply returns the last attempt.
* @return object         The attempt with the best grade
* @param object $game    The game for which the best grade is to be calculated
* @param array $attempts An array of all the attempts of the user at the game
*/
function game_calculate_best_attempt($game, $attempts) {

    switch ($game->grademethod) {

        case GAME_ATTEMPTFIRST:
            foreach ($attempts as $attempt) {
                return $attempt;
            }
            break;

        case GAME_GRADEAVERAGE: // need to do something with it :-)
        case GAME_ATTEMPTLAST:
            foreach ($attempts as $attempt) {
                $final = $attempt;
            }
            return $final;

        default:
        case GAME_GRADEHIGHEST:
            $max = -1;
            foreach ($attempts as $attempt) {
                if ($attempt->sumgrades > $max) {
                    $max = $attempt->sumgrades;
                    $maxattempt = $attempt;
                }
            }
            return $maxattempt;
    }
}


/**
* Loads the most recent state of each question session from the database
*
* For each question the most recent session state for the current attempt
* is loaded from the game_questions table and the question type specific data
*
* @return array           An array of state objects representing the most recent
*                         states of the question sessions.
* @param array $questions The questions for which sessions are to be restored or
*                         created.
* @param object $cmoptions
* @param object $attempt  The attempt for which the question sessions are
*                         to be restored or created.
* @param mixed either the id of a previous attempt, if this attmpt is
*                         building on a previous one, or false for a clean attempt.
*/
function game_get_question_states(&$questions, $cmoptions, $attempt, $lastattemptid = false) {
    global $DB, $QTYPES;

    // get the question ids
    $ids = array_keys( $questions);
    $questionlist = implode(',', $ids);

    $statefields = 'questionid as question, manualcomment, score as grade';

    $sql = "SELECT $statefields".
           "  FROM {game_questions} ".
           " WHERE attemptid = '$attempt->id'".
           "   AND questionid IN ($questionlist)";
    $states = $DB->get_records_sql($sql);
	
    // loop through all questions and set the last_graded states
    foreach ($ids as $i) {	
		// Create the empty question type specific information
        if (!$QTYPES[$questions[$i]->qtype]->create_session_and_responses(
			$questions[$i], $states[$i], $cmoptions, $attempt)) {
				return false;
		}

		$states[$i]->last_graded = clone($states[$i]);
    }
    return $states;
}

function game_sudoku_getquestions( $questionlist)
{
    global $DB;

    // Load the questions
    if (!$questions = $DB->get_records_select( 'question', "id IN ($questionlist)")) {
        print_error( get_string( 'no_questions', 'game'));
    }

    // Load the question type specific information
    if (!get_question_options($questions)) {
        print_error('Could not load question options');
    }
	
    return $questions;
}

function game_filterglossary( $text, $entryid, $contextid, $courseid)
{
    global $CFG, $DB;

    for(;;)
    {
        $find='@@PLUGINFILE@@';
        $pos = strpos( $text, $find);
        if( $pos === false)
            break;
        
        $pos2 = strpos( $text,'/', $pos);
        if( $pos2 === false)
            break;
            
        $pos3 = strpos( $text,'"', $pos);
        if( $pos3 === false)
            break;
            
        $file = substr( $text, $pos2+1, $pos3-$pos2-1);
       
        $new = $CFG->wwwroot."/pluginfile.php/$contextid/mod_glossary/entry/$entryid/$file";
        $text = substr( $text, 0, $pos).$new.substr( $text,$pos3);
    }
    $questiontext = str_replace( '$$'.'\\'.'\\'.'frac', '$$\\'.'frac', $text);
    return game_filtertext( $text, $courseid);
    
}

function game_filterquestion( $questiontext, $questionid, $contextid, $courseid)
{
    global $CFG, $DB;

    for(;;)
    {
        $find='@@PLUGINFILE@@';
        $pos = strpos( $questiontext, $find);
        if( $pos === false)
            break;
        
        $pos2 = strpos( $questiontext,'/', $pos);
        if( $pos2 === false)
            break;
            
        $pos3 = strpos( $questiontext,'"', $pos);
        if( $pos3 === false)
            break;
            
        $file = substr( $questiontext, $pos2+1, $pos3-$pos2-1);
       
        $new = $CFG->wwwroot."/pluginfile.php/$contextid/mod_game/questiontext/$questionid/$file";
        $questiontext = substr( $questiontext, 0, $pos).$new.substr( $questiontext,$pos3);
    }
    $questiontext = str_replace( '$$'.'\\'.'\\'.'frac', '$$\\'.'frac', $questiontext);
    return game_filtertext( $questiontext, $courseid);
    
}

function game_filterquestion_answer( $questiontext, $questionid, $contextid, $courseid)
{
    global $CFG, $DB;

    for(;;)
    {
        $find='@@PLUGINFILE@@';
        $pos = strpos( $questiontext, $find);
        if( $pos === false)
            break;
        
        $pos2 = strpos( $questiontext,'/', $pos);
        if( $pos2 === false)
            break;
            
        $pos3 = strpos( $questiontext,'"', $pos);
        if( $pos3 === false)
            break;
            
        $file = substr( $questiontext, $pos2+1, $pos3-$pos2-1);
       
        $new = $CFG->wwwroot."/pluginfile.php/$contextid/mod_game/answer/$questionid/$file";
        $questiontext = substr( $questiontext, 0, $pos).$new.substr( $questiontext,$pos3);
    }
    
    return game_filtertext( $questiontext, $courseid);
}

function game_filtertext( $text, $courseid){
    $formatoptions = new stdClass();
    $formatoptions->noclean = true;
    $formatoptions->filter = 1;    
    $text = trim( format_text( $text, FORMAT_MOODLE, $formatoptions, $courseid));

    $start = '<div class="text_to_html">';
    if( substr( $text, 0, strlen( $start)) == $start){
        if( substr( $text, -6) == '</div>'){
            $text = substr( $text, strlen( $start), -6);
        }
    }
    if( substr( $text, 0, 3) == '<p>'){
        if( substr( $text, -4) == '</p>'){
            $text = substr( $text, 3, -4);
        }
    }
    
    return $text;
}

function game_tojavascriptstring( $text)
{
    $from = array('"',"\r", "\n");
    $to = array('\"', ' ', ' ');
    
    $from[] = '<script ';   $to[] = '<" + "script ';
    $from[] = '</script>';   $to[] = '<" + "/script>';
    
    $text = str_replace( $from, $to, $text);
        
    return $text;
}

function game_repairquestion( $s){
    if( substr( $s, 0, 3) == '<p>'){
        $s = substr( $s, 3);
    } 
    if( substr( $s, -4) == '</p>'){
        $s = substr( $s, 0, -4);
    }
    if( substr( $s, 0, 4) == '<br>'){
        $s = substr( $s, 4);
    }
    if( substr( $s, 0, 6) == '<br />'){
        $s = substr( $s, 6);
    }		
    if( substr( $s, 0, 5) == '<div ' and substr( $s, -6) == '</div>'){
        $pos = strpos( $s, '>');
        if( $pos != false){
            $s = substr( $s, $pos+1);
        }
        $s = substr( $s, 0, -6);
    }
    $s = str_replace( array("\'", '\"'), array("'", '"'), $s);

    return $s;
}

/**
 * Delete a game attempt.
 */
function game_delete_attempt($attempt, $game) {
    global $DB;

    if (is_numeric($attempt)) {
        if (!$attempt = $DB->get_record('game_attempts', 'id', $attempt)) {
            return;
        }
    }

    if ($attempt->gameid != $game->id) {
        debugging("Trying to delete attempt $attempt->id which belongs to game $attempt->gameid " .
                "but was passed gameid $game->id.");
        return;
    }

    $DB->delete_records('game_attempts', array( 'id' => $attempt->id));

    // Search game_attempts for other instances by this user.
    // If none, then delete record for this game, this user from game_grades
    // else recalculate best grade

    $userid = $attempt->userid;
    if (!$DB->record_exists('game_attempts', array( 'userid' => $userid, 'gameid' => $game->id))) {
        $DB->delete_records('game_grades', array( 'userid' => $userid, 'gameid' => $game->id));
    } else {
        game_save_best_score( $game);
    }

    game_update_grades( $game, $userid);
}

/**
 * Returns the most recent attempt by a given user on a given game.
 * May be finished, or may not.
 *
 * @param integer $gameid the id of the game.
 * @param integer $userid the id of the user.
 *
 * @return mixed the attempt if there is one, false if not.
 */
function game_get_latest_attempt_by_user($gameid, $userid) {
    global $DB;

    $attempt = $DB->get_records_sql('SELECT qa.* FROM {game_attempts} qa
            WHERE qa.gameid=? AND qa.userid= ? ORDER BY qa.timestart DESC, qa.id DESC', array($gameid, $userid), 0, 1);

    if ($attempt) {
        return array_shift( $attempt);
    } else {
        return false;
    }
}

/**
 * @param int $option one of the values GAME_GRADEHIGHEST, GAME_GRADEAVERAGE, GAME_ATTEMPTFIRST or GAME_ATTEMPTLAST.
 * @return the lang string for that option.
 */
function game_get_grading_option_name($option) {
    if( $option == 0)
        $option = GAME_GRADEHIGHEST;

    $strings = game_get_grading_options();
    return $strings[$option];
}

function game_right_to_left( $lang){
    return ( get_string_manager()->get_string('thisdirection', 'langconfig', NULL, $lang) == 'rtl');
}

function game_compute_reserve_print( $attempt, &$wordrtl, &$reverseprint){
    if( function_exists( 'right_to_left')){
        if( $attempt->language != '')
            $wordrtl = game_right_to_left( $attempt->language);
        else
            $wordrtl = right_to_left();
        $reverseprint = ($wordrtl != right_to_left());
    }else{
        $reverseprint = false;
        $wordrtl = 'ltr';
    }
}

function game_select_from_repetitions( $game, $recs, $need){
    global $DB, $USER;

    $ret = array();

    $field = ($game->sourcemodule == 'glossary' ? 'glossaryentryid' : 'questionid');

    if( count($recs) <= $need){
        foreach( $recs as $rec)
        {
            //$a = array( 'gameid' => $game->id, 'userid' => $USER->id, 'questionid' => $rec->questionid, 'glossaryentryid' => $rec->glossaryentryid);
            $id = $rec->$field;        
            $ret[ $id] = 1;
        }

        return $ret;
    }

    $countzero = 0;
    foreach( $recs as $rec){
        $a = array( 'gameid' => $game->id, 'userid' => $USER->id, 'questionid' => $rec->questionid, 'glossaryentryid' => $rec->glossaryentryid);
        $id = $rec->$field;
        if( ($rec = $DB->get_record( 'game_repetitions', $a, 'id,repetitions r')) != false){
            $reps[ $id] = $rec->r;
        }else
        {
            $reps[ $id] = 0;
            if( ++$countzero >= $need)
                break;
        }
    }
    asort( $reps);
    foreach( $reps as $id => $r){
        $ret[ $id] = 1;
        if( count( $ret) >= $need)
            break;
    }

    return $ret;
}

function game_grade_responses( $question, $responses, $maxgrade, &$answertext)
{
    if( $question->qtype == 'multichoice')
    {
        $name = "resp{$question->id}_";
        $value = $responses->$name;
        $answer = $question->options->answers[ $value];
        $answertext = $answer->answer;
    
        return $answer->fraction * $maxgrade;
    }else
    {
        $name = "resp{$question->id}_";
        $answertext = game_upper( $responses->$name);
        
        foreach( $question->options->answers as $answer)
        {
            if( game_upper( $answer->answer) == $answertext)
                return $answer->fraction * $maxgrade;                    
        }
        
        return 0;
    }
}

function game_print_question( $game, $question, $context)
{
    if( $question->qtype == 'multichoice')
        game_print_question_multichoice( $game, $question, $context);
    else if( $question->qtype == 'shortanswer')
        game_print_question_shortanswer( $game, $question, $context);
}

function game_print_question_multichoice( $game, $question, $context)
{
    global $CFG;

    $i=0;
    $questiontext = $question->questiontext;
    $answerprompt = get_string( 'singleanswer', 'quiz');
    $feedback = '';
    $anss = array();
    foreach( $question->options->answers as $a)
    {
        $answer = new stdClass();
        if( substr( $a->answer, 0, 3) == '<p>' or substr( $a->answer, 0, 3) == '<P>')
        {
            $a->answer = substr( $a->answer, 3);
            $s = rtrim( $a->answer);
            if( substr( $s, 0, -3) == '<p>' or substr( $s, 0, -3) == '<P>')
                $a->answer = substr( $a->answer, 0, -3);
        }
        $a->answer = game_filterquestion_answer(str_replace( '\"', '"', $a->answer), $a->id, $context->id, $game->course);
        $answer->control = "<input  id=\"resp{$question->id}_{$a->id}\" name=\"resp{$question->id}_\"  type=\"radio\" value=\"{$a->id}\" /> ".$a->answer;
        $answer->class = 'radio';
        $answer->id = $a->id;
        $answer->text = $a->answer;
        $answer->feedbackimg = '';
        $answer->feedback = '';
        $anss[] = $answer;
    }
?>
<div class="qtext">
    <?php echo game_filterquestion(str_replace( '\"', '"', $questiontext), $question->id, $context->id, $game->course); ?>
</div>


<div class="ablock clearfix">
    <div class="prompt">
        <?php echo $answerprompt; ?>
    </div>

    <table class="answer">
        <?php $row = 1; foreach ($anss as $answer) { ?>
        <tr class="<?php echo 'r'.$row = $row ? 0 : 1; ?>">
            <td>
                <?php echo $answer->control; ?>
            </td>
        </tr>
        <?php } ?>        
    </table>
</div>
<?php
}

function game_print_question_shortanswer( $game, $question, $context)
{
    $questiontext = $question->questiontext;
    
?>
<div class="qtext">
  <?php echo game_filterquestion(str_replace( '\"', '"', $questiontext), $question->id, $context->id, $game->course); ?>
</div>

<div class="ablock clearfix">
  <div class="prompt">
    <?php echo get_string("answer", "quiz").': '; ?>
  </div>
  <div class="answer">
    <input type="text" name="resp<?php echo $question->id; ?>_" size="80"/>
  </div>
</div>
<?php
}

function game_snakes_get_board( $game)
{
    global $CFG, $DB;

    if( $game->param3 != 0)
    {
	    $board = $DB->get_record( 'game_snakes_database', array( 'id' => $game->param3));
        if( $board == false)
        {
            require_once(dirname(__FILE__) . '/../db/importsnakes.php');
        	$board = $DB->get_record( 'game_snakes_database', array( 'id' => $game->param3));
        }
        if( $board == false)
            print_error( 'No board');
        $board->imagesrc = $CFG->wwwroot.'/mod/game/snakes/boards/'.$board->fileboard;
        list( $board->width, $board->height) = getimagesize( __DIR__.'/snakes/boards/'.$board->fileboard);
    }else
    {
        //user defined board
        $board = game_snakes_create_user_defined_board( $game);
    }

    return $board;
}

function game_snakes_create_user_defined_board( &$game)
{
    global $CFG, $DB;

    $board = game_snakes_get_board_params( $game);

    $cmg = get_coursemodule_from_instance('game', $game->id, $game->course);
    $modcontext = get_context_instance(CONTEXT_MODULE, $cmg->id);
        
    if( $game->param5)
    {
        //param5 means dirty image. Create it again
        require("snakes/createboard.php");
        $fs = get_file_storage();
        $files = $fs->get_area_files($modcontext->id, 'mod_game', 'snakes_file', $game->id);
        $f = false;
        foreach ($files as $f) {
            if( $f->is_directory())
                continue;
            break;
        }
        if( $f === false)
            print_error( 'No image specified');
        $im=game_createsnakesboard($f->get_content(), $board->cols, $board->rows, $board->headery, $board->headery, $board->footerx, $board->headerx, $board->data, $board->width, $board->height);
        ob_start();
        imagepng($im);
        $data = ob_get_contents();
        ob_end_clean();
        $fileinfo = array(
            'contextid' => $modcontext->id, // ID of context
            'component' => 'mod_game',      // usually = table name
            'filearea' => 'snakes_board',   // usually = table name
            'itemid' => $game->id,          // usually = ID of row in table
            'filepath' => '/',              // any path beginning and ending in /
            'filename' => 'board.png');     // any filename 
        $fs->delete_area_files($modcontext->id, 'mod_game', 'snakes_board', $game->id);
        $file=$fs->create_file_from_string($fileinfo, $data);
        $imageinfo = $file->get_imageinfo();
        $game->param6 = $imageinfo[ 'width'];
        $game->param7 = $imageinfo[ 'height'];
        $sql = "UPDATE {$CFG->prefix}game SET param5=0,param6=$game->param6,param7=$game->param7 WHERE id=$game->id";
        if( !$DB->execute( $sql))
            error('problem in '.$sql);
    }
    
    $board->imagesrc = "{$CFG->wwwroot}/pluginfile.php/{$modcontext->id}/mod_game/{$game->id}/snakes_board/board.png";
    $board->width = $game->param6;
    $board->height = $game->param7;
    $board->direction = 1;
    $board->fileboard = 'board.png';

    return $board;
}

function game_snakes_get_board_params( $game)
{
    $board = new stdClass();

    $a = explode( '#',$game->param9);
    foreach( $a as $s){
        $pos = strpos( $s, ':');
        if( $pos){
            $name = substr( $s, 0, $pos);
            if( substr( $name, 0, 7) == 'snakes_')
                $name = substr( $name, 7);
            $board->$name = substr( $s, $pos+1);
        }
     }

    return $board;
}

function game_export_createtempdir(){
    global $CFG;
        
    // create a random upload directory in temp
    $newdir = $CFG->dataroot."/temp/game";
    if (!file_exists( $newdir)) 
        mkdir( $newdir);

    srand( (double)microtime()*1000000); 
    while(true)
    {
        $r_basedir = "game/". date("Y-m-d H.i.s-").rand(0,10000);
        $newdir = $CFG->dataroot.'/temp/'.$r_basedir;
        if (!file_exists( $newdir)) 
        {
            mkdir( $newdir);
            return $newdir;
        }
    }
}

function game_create_zip( $srcdir, $courseid, $filename){
    global $CFG;
        
    $dir = $CFG->dataroot . '/' . $courseid;
    $filezip = $dir . "/export/{$filename}";

    if (file_exists( $filezip)){
        unlink( $filezip);
    }
        
    if (!file_exists( $dir)){
        mkdir( $dir);
    }
        
    if (!file_exists( $dir.'/export')){
        mkdir( $dir.'/export');
    }
        
    $srcfiles = get_directory_list( $srcdir, '', true, true, true);
    $fullsrcfiles = array();
    foreach( $srcfiles as $file){
        $fullsrcfiles[] = $srcdir.'/'.$file;
    }
                
    zip_files( $fullsrcfiles, $filezip);

    return (file_exists( $filezip) ? $filezip : '');
}

function game_get_string_lang( $identifier, $module, $lang)
{
    global $CFG;
    
    $langfile = "{$CFG->dirroot}/mod/game/lang/$lang/game.php";

    if ($result = get_string_from_file( $identifier, $langfile, "\$ret")) {
        eval($result);
        if( $ret != '')
            return $ret;
    }

    return get_string( $identifier, $module);
}

function get_string_from_file($identifier, $langfile, $destination) {
    static $strings;    // Keep the strings cached in memory.

    if (empty($strings[$langfile])) {
        $string = array();
        include ($langfile);
        $strings[$langfile] = $string;
    } else {
        $string = &$strings[$langfile];
    }

    if (!isset ($string[$identifier])) {
        return false;
    }

    return $destination .'= sprintf("'. $string[$identifier] .'");';
}

	
//inserts a record to game_attempts
function game_addattempt( $game)
{
    global $DB, $USER;
		
    $newrec = new stdClass();
    $newrec->gamekind = $game->gamekind;
    $newrec->gameid = $game->id;
    $newrec->userid = $USER->id;
    $newrec->timestart = time();
    $newrec->timefinish = 0;
    $newrec->timelastattempt = 0;
    $newrec->preview = 0;
    $params = array( 'gameid' => $game->id, 'userid' => $USER->id);
    $newrec->attempt = $DB->get_field( 'game_attempts', 'max(attempt)', $params) + 1;
    $newrec->score = 0;

    if (!($newid = $DB->insert_record( 'game_attempts', $newrec))){
		print_error("Insert game_attempts: new rec not inserted");
	}
		
	if( $USER->username == 'guest'){
		$key = 'mod/game:instanceid'.$game->id;
		$_SESSION[ $key] = $newid;
	}

	return $DB->get_record_select( 'game_attempts', 'id='.$newid);
}

function game_print_r( $title, $a)
{
    echo "\r\n<hr><b>$title</b><br>";print_r( $a);echo "<hr>\r\n";
}

function game_get_contexts(){
    global $CFG, $COURSE;

    require( $CFG->dirroot.'/question/editlib.php');
    $thiscontext = get_context_instance(CONTEXT_COURSE, $COURSE->id);
    $contexts = new question_edit_contexts( $thiscontext);
    $caps = array( 'moodle/question:viewmine', 'moodle/question:viewall');

    return $contexts->having_one_cap( $caps);
}

function game_export_split_files( $courseid, $context, $filearea, $id, $line, $destdir, &$files)
{
    global $CFG, $DB;

    $contextcourse = false;
    
    $fs = get_file_storage();
    
    for(;;)
    {
        $pos1 = strpos( $line, '@@PLUGINFILE@@');
        if( $pos1 === false)
            break;
            
        $pos2 = strpos( $line, '"', $pos1);
        if( $pos2 === false)
            break;

        $file = urldecode( substr( $line, $pos1+15, $pos2-$pos1-15));
        
        $posext = strrpos( $file, '.');
        $filenoext = substr( $file, $posext);
        $ext = substr( $file, $posext+1);
        $oldfile = $CFG->wwwroot."/pluginfile.php/$context->id/mod_game/$filearea/$id/$file";
        for($i=0;;$i++)
        {
            $newfile = $filenoext.$i;
            $newfile = md5( $newfile).'.'.$ext;
            if( !array_search( $newfile, $files))
                break;
        }
        
        $line = substr( $line, 0, $pos1).'images/'.$newfile.substr( $line, $pos2);
        $files[ $oldfile] = $newfile;
        
        //Have to copy the files
        if( count( $files) == 1)
            mkdir( $destdir.'/images');

        if( $contextcourse === false)
        {
            if (!$contextcourse = get_context_instance(CONTEXT_COURSE, $courseid)) {
                print_error('nocontext');
            }
        }
        $params = array( 'component' => 'question', 'filearea' => $filearea, 
            'itemid' => $id, 'filename' => $file, 'contextid' => $contextcourse->id);
        $rec = $DB->get_record( 'files', $params);
        if( $rec == false)
            print_r( $params);            

        if (!$file = $fs->get_file_by_hash($rec->pathnamehash) or $file->is_directory())
            continue;
        $file->copy_content_to( $destdir.'/images/'.$newfile);
    }

    return $line;
}

function game_grade_questions( $questions)
{
    $grades = array();
    foreach( $_POST as $key => $value)
    {
        $id = game_question_get_id_from_name_prefix( $key);
        if( $id === false)
            continue;
            
        $grade = new stdClass();
        $grade->id = $id;
        $grade->response = $value;
        $grade->grade = 0;
        
        $question = $questions[ $id];
        if( $question->qtype == 'multichoice')
        {
            $answer = $question->options->answers[ $value];
            $grade->grade = $answer->fraction;
        }else if( $question->qtype == 'shortanswer')
        {
            foreach( $question->options->answers as $answerid => $answer)
            {
                if( game_upper( $answer->answer == $value)){
                    $grade->grade = $answer->fraction;
                    break;
                }
            }
        }
            
        $grades[ $grade->id] = $grade;
    }

    return $grades;
}

/**
 * Extract question id from the prefix of form element names
 *
 * @return integer      The question id
 * @param string $name  The name that contains a prefix that was
 *                      constructed with {@link question_make_name_prefix()}
 */
function game_question_get_id_from_name_prefix($name) {
    if (!preg_match('/^resp([0-9]+)_/', $name, $matches)) {
        return false;
    }
    return (integer) $matches[1];
}

function game_debug_array( $title, $a)
{
    echo '<br>'.$title.' ';
    print_r( $a);
    echo '<br>';
}

function game_get_version()
{
    global $DB;
    
    if( ($rec = $DB->get_record( 'modules', array( 'name' => 'game'), 'id,version')) === false)
        return '';
        
    return $rec->version;
}

function game_can_start_new_attempt( $game)
{
    global $DB, $USER;
    
    if( $game->maxattempts == 0)
        return true;
    
    $sql = "SELECT COUNT(*) as c FROM {game_attempts} WHERE gameid={$game->id} AND userid={$USER->id}";
    if( ($rec = $DB->get_record_sql( $sql)) === false)
        return true;
        
    if( $rec->c >= $game->maxattempts)
        return false;
    else
        return true;
}

function game_strlen( $str)
{
    if( game_get_moodle_version() >= '02.04')
        return textlib::strlen( $str);
    else
        return textlib_get_instance()->strlen( $str);
}

function game_substr()
{
    $num = func_num_args();
    $a = func_get_args();

    if( $num == 3)
    {
        if( game_get_moodle_version() >= '02.04')
            return textlib::substr( $a[ 0], $a[ 1], $a[ 2]);
        else
            return textlib_get_instance()->substr( $a[ 0], $a[ 1], $a[ 2]);
    }else if( $num == 2)
    {
        if( game_get_moodle_version() >= '02.04')
            return textlib::substr( $a[ 0], $a[ 1]);
        else
            return textlib_get_instance()->substr( $a[ 0], $a[ 1]);
    }else
        die( 'Substr requires 2 or 3 parameters');
}

function game_strtoupper( $str)
{
    if( game_get_moodle_version() >= '02.04')
        return textlib::strtoupper( $str);
    else if( game_get_moodle_version() >= '02.01')
        return textlib_get_instance()->strtoupper( $str);
    else
        return textlib_get_instance()->qstrtoupper( $str);
}

function game_strpos( $haystack, $needle, $offset = 0)
{
    if( game_get_moodle_version() >= '02.04')
        return textlib::strpos( $haystack, $needle, $offset);
    else
        return textlib_get_instance()->strpos( $haystack, $needle, $offset);
}