/**
* Start a normal, new, quiz attempt.
*
* @param quiz $quizobj the quiz object to start an attempt for.
* @param question_usage_by_activity $quba
* @param object $attempt
* @param integer $attemptnumber starting from 1
* @param integer $timenow the attempt start time
* @param array $questionids slot number => question id. Used for random questions, to force the choice
* of a particular actual question. Intended for testing purposes only.
* @param array $forcedvariantsbyslot slot number => variant. Used for questions with variants,
* to force the choice of a particular variant. Intended for testing
* purposes only.
* @throws moodle_exception
* @return object modified attempt object
*/
function quiz_start_new_attempt($quizobj, $quba, $attempt, $attemptnumber, $timenow, $questionids = array(), $forcedvariantsbyslot = array())
{
// Usages for this user's previous quiz attempts.
$qubaids = new \mod_quiz\question\qubaids_for_users_attempts($quizobj->get_quizid(), $attempt->userid);
// Fully load all the questions in this quiz.
$quizobj->preload_questions();
$quizobj->load_questions();
// First load all the non-random questions.
$randomfound = false;
$slot = 0;
$questions = array();
$maxmark = array();
$page = array();
foreach ($quizobj->get_questions() as $questiondata) {
$slot += 1;
$maxmark[$slot] = $questiondata->maxmark;
$page[$slot] = $questiondata->page;
if ($questiondata->qtype == 'random') {
$randomfound = true;
continue;
}
if (!$quizobj->get_quiz()->shuffleanswers) {
$questiondata->options->shuffleanswers = false;
}
$questions[$slot] = question_bank::make_question($questiondata);
}
// Then find a question to go in place of each random question.
if ($randomfound) {
$slot = 0;
$usedquestionids = array();
foreach ($questions as $question) {
if (isset($usedquestions[$question->id])) {
$usedquestionids[$question->id] += 1;
} else {
$usedquestionids[$question->id] = 1;
}
}
$randomloader = new \core_question\bank\random_question_loader($qubaids, $usedquestionids);
foreach ($quizobj->get_questions() as $questiondata) {
$slot += 1;
if ($questiondata->qtype != 'random') {
continue;
}
// Deal with fixed random choices for testing.
if (isset($questionids[$quba->next_slot_number()])) {
if ($randomloader->is_question_available($questiondata->category, (bool) $questiondata->questiontext, $questionids[$quba->next_slot_number()])) {
$questions[$slot] = question_bank::load_question($questionids[$quba->next_slot_number()], $quizobj->get_quiz()->shuffleanswers);
continue;
} else {
throw new coding_exception('Forced question id not available.');
}
}
// Normal case, pick one at random.
$questionid = $randomloader->get_next_question_id($questiondata->category, (bool) $questiondata->questiontext);
if ($questionid === null) {
throw new moodle_exception('notenoughrandomquestions', 'quiz', $quizobj->view_url(), $questiondata);
}
$questions[$slot] = question_bank::load_question($questionid, $quizobj->get_quiz()->shuffleanswers);
}
}
// Finally add them all to the usage.
ksort($questions);
foreach ($questions as $slot => $question) {
$newslot = $quba->add_question($question, $maxmark[$slot]);
if ($newslot != $slot) {
throw new coding_exception('Slot numbers have got confused.');
}
}
// Start all the questions.
$variantstrategy = new core_question\engine\variants\least_used_strategy($quba, $qubaids);
if (!empty($forcedvariantsbyslot)) {
$forcedvariantsbyseed = question_variant_forced_choices_selection_strategy::prepare_forced_choices_array($forcedvariantsbyslot, $quba);
$variantstrategy = new question_variant_forced_choices_selection_strategy($forcedvariantsbyseed, $variantstrategy);
}
$quba->start_all_questions($variantstrategy, $timenow);
// Work out the attempt layout.
$sections = $quizobj->get_sections();
foreach ($sections as $i => $section) {
if (isset($sections[$i + 1])) {
$sections[$i]->lastslot = $sections[$i + 1]->firstslot - 1;
} else {
$sections[$i]->lastslot = count($questions);
}
}
$layout = array();
foreach ($sections as $section) {
if ($section->shufflequestions) {
$questionsinthissection = array();
for ($slot = $section->firstslot; $slot <= $section->lastslot; $slot += 1) {
$questionsinthissection[] = $slot;
}
shuffle($questionsinthissection);
$questionsonthispage = 0;
foreach ($questionsinthissection as $slot) {
if ($questionsonthispage && $questionsonthispage == $quizobj->get_quiz()->questionsperpage) {
$layout[] = 0;
$questionsonthispage = 0;
}
$layout[] = $slot;
$questionsonthispage += 1;
}
} else {
$currentpage = $page[$section->firstslot];
for ($slot = $section->firstslot; $slot <= $section->lastslot; $slot += 1) {
if ($currentpage !== null && $page[$slot] != $currentpage) {
$layout[] = 0;
}
$layout[] = $slot;
$currentpage = $page[$slot];
}
}
// Each section ends with a page break.
$layout[] = 0;
}
$attempt->layout = implode(',', $layout);
return $attempt;
}