<?php

function multichoice_perm() {
  return array('administer multichoice');
}

function multichoice_node_name($node) {
  return t('multichoice');
}

function multichoice_menu($may_cache) {
  $items = array();
  if (!$may_cache) {
    $items[] = array('path' => 'node/add/multichoice', 'title' => t('multichoice'),
      'access' => user_access('administer multichoice'));
  }
  return $items;
}

function multichoice_form(&$node) {
  $output = '';

  if (function_exists('taxonomy_node_form')) {
    $output .= implode('', taxonomy_node_form('multichoice', $node));
  }

  $output .= form_textarea(t('multichoice'), 'body', $node->body, 60, 5, '', NULL, TRUE);
  $output .= filter_form('format', $node->format);
  $output .= form_checkbox(t('Multiple answers'), 'multiple', 1, $node->multiple);
  $rows = array();
  $answers = $node->answers;
  for ($i = 0; $i < $node->rows; $i++) {
    $rows[] = array(
      form_checkbox('', 'answers]['. $i .'][0', 1, $answers[$i][0]),
      form_textarea('', 'answers]['. $i .'][1', $answers[$i][1], 20, 5),
      form_textarea('', 'answers]['. $i .'][2', $answers[$i][2], 20, 5));
  }
  $header = array(
    array('data' => t('Correct')),
    array('data' => t('Answer'), 'style' => 'width:250px;'),
    array('data' => t('Feedback'), 'style' => 'width:250px;'));
  $output .= theme('table', $header, $rows);
  $output .= form_checkbox(t('I need more answers'), 'more');

  return $output;
}

function multichoice_validate(&$node) {
  if (!$node->rows) {
     $node->rows = $node->answers ? count($node->answers) : 5;
  }
  if ($node->more) {
    $node->rows += 5;
  }
  if (!$node->nid && empty($_POST)) return;
  if (!$node->body) {
    form_set_error('body', t('multichoice is empty'));
  }
  $corrects = 0;
  foreach ($node->answers as $key => $answer) {
    if ($answer[0]) {
      if ($corrects && !$node->multiple) {
        form_set_error('multiple', t('Single choice yet multiple correct answers are present'));
      }
      $corrects++;
    }
    if (empty($answer[0]) && empty($answer[1]) && empty($answer[2])) {
      unset($node->answers[$key]);
    }
  }
  /* nincs valasz, de van mas illetve correctnek van jelolve de nincs valasz */
  if (!$corrects) { // untested
    form_set_error('answers][0][0', t('No correct choice(s)'));
  }
  if (!count($node->answers)) { // untested
    form_set_error('answers][0][0', t('No answers.'));
  }
}

function multichoice_insert($node) {
  db_query("INSERT INTO multichoice (nid, multiple_answers, answers) VALUES (%d, %d, '%s')", $node->nid, $node->multiple, serialize($node->answers));
}

function multichoice_update($node) {
  db_query("UPDATE multichoice SET multiple_answers = %d, answers = '%s' WHERE nid = %d", $node->multiple, serialize($node->answers), $node->nid);
}

function multichoice_load($node) {
  $additions = db_fetch_object(db_query('SELECT * FROM multichoice WHERE nid = %d', $node->nid));
  $additions->answers = unserialize($additions->answers);
  return $additions;
}

function multichoice_view(&$node, $teaser = FALSE, $page = FALSE) {
  if (user_access('administer multichoice')) {
    if (!$teaser) {
      $submit_message = t('Submit');
      if ($_POST['quiz_op'] == $submit_message) {
        $points = multichoice_evaluate_question($node);
      }
      $question = multichoice_render_question($node);
      $question .= form_submit($submit_message, 'quiz_op');
      $node->body = form($question);
      if (isset($points)) {
        $node->body .= ($points ? 1 : 0) .' point';
      }
    }
  }
  else if ($teaser) {
    $node->teaser = t('This is a quiz question, not to be viewed independently.');
    $node->body = $node->teaser; // we do not need Read more...
  }
  else {
    drupal_access_denied();
  }
}

function multichoice_render_question($node) {
  $rows = array();
  $submit_message = t('Submit');
  foreach ($node->answers as $key => $answer) {
    $rows[] = array(form_checkbox('', 'tries]['. $key, 1), $answer[1]);
  }
  $header = header('', '');
  $form = theme('table', $header, $rows);
  return $node->body . $form;
}

function multichoice_evaluate_question($node) {
  $points = 0;
  foreach ($_POST['edit']['tries'] as $key => $try) {
    $points += ($try == $node->answers[$key][0]);
  }
  return ($points == count($node->answers));
}

function multichoice_list_questions() {
  $result = db_query("SELECT nid, body, format FROM node WHERE type='%s'", 'multichoice');
  $questions = array();
  while ($node = db_fetch_object($result)) {
    $question =& new stdClass();
    $question->question = check_output($node->body, $node->format);
    $question->nid = $node->nid;
    $questions[] = $question;
  }
  return $questions;
}
?>