/**
 * Like {@link swapshuffle()}, but works on associative arrays
 *
 * @param array $array The associative array to be rearranged
 * @return array
 */
function swapshuffle_assoc($array)
{
    $newarray = array();
    $newkeys = swapshuffle(array_keys($array));
    foreach ($newkeys as $newkey) {
        $newarray[$newkey] = $array[$newkey];
    }
    return $newarray;
}

<?php

include "util.inc.php";
global $config;
include INC_DIR . "config.inc.php";
include INC_DIR . "db.inc.php";
ini_set("memory_limit", "32M");
$config = new Config();
$db = new Db();
$names = swapshuffle(createNames());
$query = "SELECT COUNT(*) AS num_caves FROM Cave GROUP BY NULL";
$db_result = $db->query($query);
if (!$db_result || $db_result->isEmpty()) {
    echo "Fehler bei der Abfrage der Anzahl der Höhlen. (1.a.)\n";
    return -1;
}
$row = $db_result->nextrow(MYSQL_ASSOC);
$num_caves = $row['num_caves'];
if ($num_caves > sizeof($names)) {
    echo "Zu wenig Namen für alle Höhlen. (2.a.)\n";
    return -2;
}
// hier wird davon ausgegangen, dass die Höhlen mit 1 beginnend fortlaufend durchnummeriert sind.
for ($i = 0; $i < $num_caves; ++$i) {
    $query = "UPDATE Cave SET name = '" . $names[$i] . "' WHERE caveID = " . ($i + 1);
    $db_result = $db->query($query);
    if (!$db_result || $db->affected_rows() != 1) {
        echo "Fehler beim Ändern des Höhlennamen: (" . ($i + 1) . ") " . $names[$i] . ". (3.a.)\n";
        echo mysql_errno() . ": " . mysql_error() . "\n";
        return -3;
    }

 function create_session_and_responses(&$question, &$state, $cmoptions, $attempt)
 {
     // create an array of answerids ??? why so complicated ???
     $answerids = array_values(array_map(create_function('$val', 'return $val->id;'), $question->options->answers));
     // Shuffle the answers if required
     if (!empty($cmoptions->shuffleanswers) and !empty($question->options->shuffleanswers)) {
         $answerids = swapshuffle($answerids);
     }
     $state->options->order = $answerids;
     // Create empty responses
     if ($question->options->single) {
         $state->responses = array('' => '');
     } else {
         $state->responses = array();
     }
     return true;
 }

 function create_session_and_responses(&$question, &$state, $cmoptions, $attempt)
 {
     // Choose a random shortanswer question from the category:
     // We need to make sure that no question is used more than once in the
     // quiz. Therfore the following need to be excluded:
     // 1. All questions that are explicitly assigned to the quiz
     // 2. All random questions
     // 3. All questions that are already chosen by an other random question
     global $QTYPES;
     if (!isset($cmoptions->questionsinuse)) {
         $cmoptions->questionsinuse = $cmoptions->questions;
     }
     if ($question->options->subcats) {
         // recurse into subcategories
         $categorylist = question_categorylist($question->category);
     } else {
         $categorylist = $question->category;
     }
     $saquestions = $this->get_sa_candidates($categorylist, $cmoptions->questionsinuse);
     $count = count($saquestions);
     $wanted = $question->options->choose;
     $errorstr = '';
     if ($count < $wanted && isteacherinanycourse()) {
         if ($count >= 2) {
             $errorstr = "Error: could not get enough Short-Answer questions!\n                 Got {$count} Short-Answer questions, but wanted {$wanted}.\n                 Reducing number to choose from to {$count}!";
             $wanted = $question->options->choose = $count;
         } else {
             $errorstr = "Error: could not get enough Short-Answer questions!\n                 This can happen if all available Short-Answer questions are already\n                 taken up by other Random questions or Random Short-Answer question.\n                 Another possible cause for this error is that Short-Answer\n                 questions were deleted after this Random Short-Answer question was\n                 created.";
         }
         notify($errorstr);
         $errorstr = '<span class="notifyproblem">' . $errorstr . '</span>';
     }
     if ($count < $wanted) {
         $question->questiontext = "{$errorstr}<br /><br />Insufficient selection options are\n             available for this question, therefore it is not available in  this\n             quiz. Please inform your teacher.";
         // Treat this as a description from this point on
         $question->qtype = DESCRIPTION;
         return true;
     }
     $saquestions = draw_rand_array($saquestions, $question->options->choose);
     // from bug 1889
     foreach ($saquestions as $key => $wrappedquestion) {
         if (!$QTYPES[$wrappedquestion->qtype]->get_question_options($wrappedquestion)) {
             return false;
         }
         // Now we overwrite the $question->options->answers field to only
         // *one* (the first) correct answer. This loop can be deleted to
         // take all answers into account (i.e. put them all into the
         // drop-down menu.
         $foundcorrect = false;
         foreach ($wrappedquestion->options->answers as $answer) {
             if ($foundcorrect || $answer->fraction != 1.0) {
                 unset($wrappedquestion->options->answers[$answer->id]);
             } else {
                 if (!$foundcorrect) {
                     $foundcorrect = true;
                 }
             }
         }
         if (!$QTYPES[$wrappedquestion->qtype]->create_session_and_responses($wrappedquestion, $state, $cmoptions, $attempt)) {
             return false;
         }
         $wrappedquestion->name_prefix = $question->name_prefix;
         $wrappedquestion->maxgrade = $question->maxgrade;
         $cmoptions->questionsinuse .= ",{$wrappedquestion->id}";
         $state->options->subquestions[$key] = clone $wrappedquestion;
     }
     // Shuffle the answers (Do this always because this is a random question type)
     $subquestionids = array_values(array_map(create_function('$val', 'return $val->id;'), $state->options->subquestions));
     $subquestionids = swapshuffle($subquestionids);
     // Create empty responses
     foreach ($subquestionids as $val) {
         $state->responses[$val] = '';
     }
     return true;
 }

 public function create_session_and_responses(&$question, &$state, $cmoptions, $attempt)
 {
     // Choose a random shortanswer question from the category:
     // We need to make sure that no question is used more than once in the
     // quiz. Therfore the following need to be excluded:
     // 1. All questions that are explicitly assigned to the quiz
     // 2. All random questions
     // 3. All questions that are already chosen by an other random question.
     global $QTYPES, $OUTPUT, $USER;
     if (!isset($cmoptions->questionsinuse)) {
         $cmoptions->questionsinuse = $cmoptions->questions;
     }
     if ($question->options->subcats) {
         // Recurse into subcategories.
         $categorylist = question_categorylist($question->category);
     } else {
         $categorylist = array($question->category);
     }
     $saquestions = $this->get_sa_candidates($categorylist, $cmoptions->questionsinuse);
     $count = count($saquestions);
     $wanted = $question->options->choose;
     if ($count < $wanted) {
         $question->questiontext = "Insufficient selection options are\n                available for this question, therefore it is not available in  this\n                quiz. Please inform your teacher.";
         // Treat this as a description from this point on.
         $question->qtype = 'description';
         return true;
     }
     $saquestions = draw_rand_array($saquestions, $question->options->choose);
     // From bug 1889.
     foreach ($saquestions as $key => $wrappedquestion) {
         if (!$QTYPES[$wrappedquestion->qtype]->get_question_options($wrappedquestion)) {
             return false;
         }
         // Now we overwrite the $question->options->answers field to only
         // *one* (the first) correct answer. This loop can be deleted to
         // take all answers into account (i.e. put them all into the
         // drop-down menu.
         $foundcorrect = false;
         foreach ($wrappedquestion->options->answers as $answer) {
             if ($foundcorrect || $answer->fraction != 1.0) {
                 unset($wrappedquestion->options->answers[$answer->id]);
             } else {
                 if (!$foundcorrect) {
                     $foundcorrect = true;
                 }
             }
         }
         if (!$QTYPES[$wrappedquestion->qtype]->create_session_and_responses($wrappedquestion, $state, $cmoptions, $attempt)) {
             return false;
         }
         $wrappedquestion->name_prefix = $question->name_prefix;
         $wrappedquestion->maxgrade = $question->maxgrade;
         $cmoptions->questionsinuse .= ",{$wrappedquestion->id}";
         $state->options->subquestions[$key] = clone $wrappedquestion;
     }
     // Shuffle the answers (Do this always because this is a random question type).
     $subquestionids = array_values(array_map(create_function('$val', 'return $val->id;'), $state->options->subquestions));
     $subquestionids = swapshuffle($subquestionids);
     // Create empty responses.
     foreach ($subquestionids as $val) {
         $state->responses[$val] = '';
     }
     return true;
 }

 function create_session_and_responses(&$question, &$state, $cmoptions, $attempt)
 {
     // Find out how many datasets are available
     global $CFG, $DB, $QTYPES, $OUTPUT;
     $maxnumber = (int) $DB->get_field_sql("SELECT MIN(a.itemcount)\n               FROM {question_dataset_definitions} a, {question_datasets} b\n              WHERE b.question = ? AND a.id = b.datasetdefinition", array($question->id));
     if (!$maxnumber) {
         print_error('cannotgetdsforquestion', 'question', '', $question->id);
     }
     $sql = "SELECT i.*\n                  FROM {question_datasets} d, {question_dataset_definitions} i\n                 WHERE d.question = ? AND d.datasetdefinition = i.id AND i.category != 0";
     if (!$question->options->synchronize || !($records = $DB->get_records_sql($sql, array($question->id)))) {
         $synchronize_calculated = false;
     } else {
         // i.e records is true so test coherence
         $coherence = true;
         $a = new stdClass();
         $a->qid = $question->id;
         $a->qcat = $question->category;
         foreach ($records as $def) {
             if ($def->category != $question->category) {
                 $a->name = $def->name;
                 $a->sharedcat = $def->category;
                 $coherence = false;
                 break;
             }
         }
         if (!$coherence) {
             echo $OUTPUT->notification(get_string('nocoherencequestionsdatyasetcategory', 'qtype_calculated', $a));
         }
         $synchronize_calculated = true;
     }
     // Choose a random dataset
     // maxnumber sould not be breater than 100
     if ($maxnumber > CALCULATEDQUESTIONMAXITEMNUMBER) {
         $maxnumber = CALCULATEDQUESTIONMAXITEMNUMBER;
     }
     if ($synchronize_calculated === false) {
         $state->options->datasetitem = rand(1, $maxnumber);
     } else {
         $state->options->datasetitem = intval($maxnumber * substr($attempt->timestart, -2) / 100);
         if ($state->options->datasetitem < 1) {
             $state->options->datasetitem = 1;
         } else {
             if ($state->options->datasetitem > $maxnumber) {
                 $state->options->datasetitem = $maxnumber;
             }
         }
     }
     $state->options->dataset = $this->pick_question_dataset($question, $state->options->datasetitem);
     // create an array of answerids ??? why so complicated ???
     $answerids = array_values(array_map(create_function('$val', 'return $val->id;'), $question->options->answers));
     // Shuffle the answers if required
     if (!empty($cmoptions->shuffleanswers) and !empty($question->options->shuffleanswers)) {
         $answerids = swapshuffle($answerids);
     }
     $state->options->order = $answerids;
     // Create empty responses
     if ($question->options->single) {
         $state->responses = array('' => '');
     } else {
         $state->responses = array();
     }
     return true;
 }