<?php

/**
 * @file
 * Hooks and field implementations
 */

// Define choice constants
define('MAKEMEETING_NO', 0);
define('MAKEMEETING_YES', 1);
define('MAKEMEETING_MAYBE', 2);

/**
 * Implements hook_permission().
 */
function makemeeting_permission() {
  return array(
    'answer makemeeting form' => array(
      'title' => t('Provide an answer to makemeeting forms'),
      'description' => t('Give the ability to make a choice in makemeeting answer forms.'),
    ),
    'edit any makemeeting answer' => array(
      'title' => t('Edit any makemeeting answers'),
      'description' => t('Edit answers given by other users.'),
    ),
    'delete any makemeeting answer' => array(
      'title' => t('Delete any makemeeting answers'),
      'description' => t('Delete answers given by other users.'),
    ),
  );
}

/**
 * Implements hook_menu().
 */
function makemeeting_menu() {
  $items['makemeeting/delete-answer/%makemeeting_answer'] = array(
    'title' => 'Remove an answer',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('makemeeting_delete_answer', 2),
    'access callback' => 'makemeeting_delete_answer_access',
    'access arguments' => array(2),
    'type' => MENU_CALLBACK,
  );
  $items['makemeeting/edit-answer/%makemeeting_answer'] = array(
    'title' => 'Edit an answer',
    'page callback' => 'makemeeting_edit_answer',
    'page arguments' => array(2),
    'access callback' => 'makemeeting_edit_answer_access',
    'access arguments' => array(2),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Load an answer
 *
 * @param $answer_id
 * @return mixed
 */
function makemeeting_answer_load($answer_id) {
  $answer = db_select('makemeeting_answers', 'm')
    ->fields('m')
    ->condition('answer_id', $answer_id)
    ->execute()
    ->fetchAssoc();
  $answer['value'] = unserialize($answer['value']);
  return $answer ? (object) $answer : FALSE;
}

/**
 * Access callback: delete an answer
 *
 * @param $answer
 * @return bool
 */
function makemeeting_delete_answer_access($answer) {
  global $user;
  if (user_access('delete any makemeeting answer') || $answer->uid == $user->uid) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Access callback: edit an answer
 *
 * @param $answer
 * @return bool
 */
function makemeeting_edit_answer_access($answer) {
  global $user;
  if (user_access('edit any makemeeting answer') || $answer->uid == $user->uid) {
    return TRUE;
  }
  return FALSE;
}

/**
 * Menu callback: delete an answer
 *
 * @param $answer_id
 */
function makemeeting_delete_answer($form, &$form_state, $answer, $redirect = TRUE) {
  $form['#answer'] = $answer;
  return confirm_form(
    $form,
    t('Are you sure you want to delete the answer?'),
    ''
  );
}

function makemeeting_delete_answer_submit($form, &$form_state) {
  $answer = $form['#answer'];
  db_delete('makemeeting_answers')->condition('answer_id', $answer->answer_id)->execute();
}

/**
 * Menu callback: edit an answer
 *
 * @param $answer The loaded answer object
 * @param string $type Ajax or nojs
 * @return array|void The entire form or just the row depending on ajax
 */
function makemeeting_edit_answer($answer, $type = 'ajax') {
  $entities = entity_load($answer->entity_type, array($answer->entity_id));
  if (empty($entities)) {
    return drupal_not_found();
  }
  $entity = $entities[$answer->entity_id];
  $field = $entity->{$answer->field_name}[$answer->language][$answer->delta];
  $form = drupal_get_form('makemeeting_answers_form_' . $answer->entity_id, $field, (array) $answer, $answer);
  if ($type == 'ajax') {
    $form['#theme'] = 'makemeeting_answer_row';
    // Replace 'ajax' word in form action
    $form['#action'] = str_replace('/ajax/', '/nojs/', $form['#action']);
    $output = '<tr>' . drupal_render($form) . '</tr>';
    $commands = array();
    // See ajax_example_advanced.inc for more details on the available commands
    // and how to use them.
    $commands[] = ajax_command_replace('#answer-' . $answer->answer_id, $output);
    $page = array('#type' => 'ajax', '#commands' => $commands);
    ajax_deliver($page);
  }
  else {
    return $form;
  }
}


/**
 * Implements hook_field_info().
 */
function makemeeting_field_info() {
  return array(
    'makemeeting' => array(
      'label' => t('Makemeeting form'),
      'description' => t('This field stores user choices about some dates in the database.'),
      'default_widget' => 'makemeeting_choices',
      'default_formatter' => 'makemeeting_answers',
    ),
  );
}

/**
 * Implements hook_field_widget_info().
 */
function makemeeting_field_widget_info() {
  return array(
    'makemeeting_choices' => array(
      'label' => t('Makemeeting choices'),
      'field types' => array('makemeeting'),
      'behaviors' => array(
        'default value' => FIELD_BEHAVIOR_NONE,
      ),
    ),
  );
}

/**
 * Implements hook_field_widget_settings_form().
 */
function makemeeting_field_widget_settings_form($field, $instance) {
  $widget = $instance['widget'];
  $settings = $widget['settings'];

  $form = array();
  if ($widget['type'] == 'makemeeting_choices') {
    $form['size'] = array(
      '#type' => 'textfield',
      '#title' => t('Number of dates'),
      '#default_value' => isset($settings['size']) ? $settings['size'] : 1,
      '#element_validate' => array('element_validate_integer'),
      '#required' => TRUE,
      '#size' => 5,
      '#description' => t('Default number of date choices to display. Must be positive or equal to 0.')
    );
  }

  return $form;
}

/**
 * Implements hook_field_widget_form().
 */
function makemeeting_field_widget_form(&$form, &$form_state, $field, $instance, $langcode, $items, $delta, $element) {
  $element += array(
    '#type' => 'fieldset',
  );

  $item =& $items[$delta];

  // Simple options form elements about the poll
  $element['hidden'] = array(
    '#title' => t('Hidden poll'),
    '#description' => t('Confidential participation: only you and administrators can see the answers.'),
    '#type' => 'checkbox',
    '#default_value' => isset($item['hidden']) ? $item['hidden'] : '',
  );
  $element['one_option'] = array(
    '#title' => t('Participant can only choose one option'),
    '#description' => t('By default all options are selectable. This setting limits the choice to one option per participant.'),
    '#type' => 'checkbox',
    '#default_value' => isset($item['one_option']) ? $item['one_option'] : '',
  );
  $element['limit'] = array(
    '#title' => t('Limit the number of participants per option'),
    '#description' => t('Poll as registration form: As soon as the indicated limit has been reached, the respective option is no longer available. 0 for unlimited'),
    '#type' => 'textfield',
    '#default_value' => isset($item['limit']) ? $item['limit'] : 0,
    '#element_validate' => array('element_validate_integer'),
  );
  $element['yesnomaybe'] = array(
    '#title' => t('Provide a "Maybe" option'),
    '#description' => t('Provide a third "Maybe" option in case users may be available.'),
    '#type' => 'checkbox',
    '#default_value' => isset($item['yesnomaybe']) ? $item['yesnomaybe'] : '',
    // Hide if one_option is checked
    '#states' => array(
      'visible' => array(
        ':input[name$="[one_option]"]' => array('checked' => FALSE),
      ),
    ),
  );
  $element['closed'] = array(
    '#title' => t('Closed'),
    '#description' => t('Check this when you want to close the poll.'),
    '#type' => 'checkbox',
    '#default_value' => isset($item['closed']) ? $item['closed'] : '',
  );

  // Now let's take care of the choices part
  // $process is a callback that we will attach to the wrapper in order
  // to add parents to the form elements. This is so we can store
  // nested values in the DB table with field storage API.
  $fieldset_info = element_info('fieldset');
  $process = array_merge($fieldset_info['#process'], array('_makemeeting_rebuild_parents'));
  $element['choices_wrapper'] = array(
    '#tree' => FALSE,
    '#prefix' => '<div class="clearfix" id="makemeeting-choices-wrapper">',
    '#suffix' => '</div>',
    '#process' => $process,
  );

  // Container just for the poll choices.
  $element['choices_wrapper']['choices'] = array(
    '#prefix' => '<div id="makemeeting-choices">',
    '#suffix' => '</div>',
    '#theme' => 'makemeeting_choices',
  );

  // Fill the item values with previously submitted values
  if (!empty($form_state['values'])) {
    $submitted_values = drupal_array_get_nested_value($form_state['values'], $element['#field_parents']);
    $submitted_values = $submitted_values[$element['#field_name']][$element['#language']][$element['#delta']];
    if (isset($submitted_values['choices'])) {
      $item['choices'] = $submitted_values['choices'];
    }
  }

  // Calculate the suggestion count
  if (empty($form_state['suggestion_count'])) {
    $form_state['suggestion_count'] = 1;
  }
  if (isset($item['choices'])) {
    foreach ($item['choices'] as $choice) {
      if ($form_state['suggestion_count'] < count($choice['chsuggestions'])) {
        $form_state['suggestion_count'] = count($choice['chsuggestions']);
      }
    }
  }

  // Determine choice count if not provided
  if (!isset($form_state['choice_count'])) {
    try {
      list($entity_id) = entity_extract_ids($element['#entity_type'], $element['#entity']);
    } catch (Exception $e) {
      // Fail silently if the field is not attached to any entity yet.
    }
    // If the entity isn't created yet, offer the default number of choices,
    // else the number of previous choices, or 0 if none
    if (!isset($entity_id)) {
      $widget = $instance['widget'];
      $settings = $widget['settings'];
      $form_state['choice_count'] = isset($settings['size']) ? $settings['size'] : 1;
    }
    else {
      $form_state['choice_count'] = isset($item['choices']) ? count($item['choices']) : 0;
    }
  }

  // Add the current choices to the form.
  $delta = 0;
  if (isset($item['choices']) && $form_state['choice_count']) {
    // Sort choices by their dates
    asort($item['choices']);
    $delta = count($item['choices']);
    foreach ($item['choices'] as $key => $choice) {
      $element['choices_wrapper']['choices'][$key] =
        _makemeeting_choice_form($key, $choice['chdate'], $choice['chsuggestions'], $form_state['suggestion_count']);
    }
  }

  // Add choices as required.
  if ($form_state['choice_count']) {
    // Add a day to the last option's timestamp for the new default date
    $last_option_timestamp = isset($choice['chdate']) ? _makemeeting_date_timestamp($choice['chdate']) : REQUEST_TIME;
    $existing_delta = $delta;
    for (; $delta < $form_state['choice_count']; $delta++) {
      $additional_stamp = strtotime('+1 day', $last_option_timestamp);
      // Build default date
      $default_date = array(
        'month' => date('n', $additional_stamp),
        'day' => date('j', $additional_stamp),
        'year' => date('Y', $additional_stamp)
      );
      $key = 'new:' . ($delta - $existing_delta);
      $element['choices_wrapper']['choices'][$key] =
        _makemeeting_choice_form($key, $default_date, NULL, $form_state['suggestion_count']);
      // Repeat
      $last_option_timestamp = $additional_stamp;
    }
  }

  // We prefix our buttons with 'makemeeting' to avoid conflicts
  // with other modules using Ajax-enabled buttons with the id 'more'.
  $default_submit = array(
    '#type' => 'submit',
    '#limit_validation_errors' => array(array('choices')),
    '#submit' => array('makemeeting_choices_submit'),
    '#ajax' => array(
      'callback' => 'makemeeting_choice_js',
      'wrapper' => 'makemeeting-choices',
      'effect' => 'fade',
    ),
  );
  $element['choices_wrapper']['makemeeting_more_choices'] = $default_submit + array(
    '#value' => t('More choices'),
    '#attributes' => array(
      'title' => t("If the amount of rows above isn't enough, click here to add more choices."),
    ),
    '#weight' => 1,
  );
  $element['choices_wrapper']['makemeeting_more_suggestions'] = $default_submit + array(
    '#value' => t('More suggestions'),
    '#attributes' => array(
      'title' => t("If the amount of boxes above isn't enough, click here to add more suggestions."),
    ),
    '#weight' => 2,
  );
  $element['choices_wrapper']['makemeeting_copy_suggestions'] = $default_submit + array(
    '#value' => t('Copy and paste first row'),
    '#attributes' => array(
      'title' => t("Copy the suggestions from the first to the other rows."),
    ),
    '#weight' => 3,
  );
  return $element;
}

/**
 * Implements hook_field_validate().
 */
function makemeeting_field_validate($entity_type, $entity, $field, $instance, $langcode, $items, &$errors) {
  foreach ($items as $delta => $item) {
    if (isset($item['choices'])) {
      // Verify that we do not have duplicate dates
      $dates = array();
      foreach ($item['choices'] as $chid => $chvalue) {
        $date = implode('', $chvalue['chdate']);
        if (in_array($date, $dates)) {
          // Register an error with the choice id
          $errors[$field['field_name']][$langcode][$delta][] = array(
            'error' => 'duplicate_dates',
            'message' => t('%name: you can\'t have duplicate dates.', array('%name' => $instance['label'])),
            'chid' => $chid,
          );
        }
        else {
          $dates[] = $date;
        }
      }
    }
  }
}

/**
 * Implements hook_field_widget_error().
 */
function makemeeting_field_widget_error($element, $error) {
  // Show our error concerning duplicate dates here
  $choices = $element['choices_wrapper']['choices'];
  form_error($choices[$error['chid']]['chdate'], $error['message']);
}

/**
 * Submit handler to add more choices or suggestions to a poll form,
 * or to copy the first row of suggestions to the others
 *
 * This handler is run regardless of whether JS is enabled or not. It makes
 * changes to the form state. If the button was clicked with JS disabled, then
 * the page is reloaded with the complete rebuilt form. If the button was
 * clicked with JS enabled, then ajax_form_callback() calls makemeeting_choice_js() to
 * return just the changed part of the form.
 */
function makemeeting_choices_submit($form, &$form_state) {
  $clicked_button = $form_state['clicked_button'];

  // Get the element
  $element =& drupal_array_get_nested_value($form_state['input'], $clicked_button['#parents']);

  // If clicked button is 'Remove', unset corresponding choice
  if ($clicked_button['#value'] == t('Remove')) {
    unset($element['choices'][$clicked_button['#name']]);
    $form_state['choice_count'] = count($element['choices']);
  }

  // Affect timestamp as key to each choice
  $choices = array();
  if (isset($element['choices'])) {
    foreach ($element['choices'] as $choice) {
      $choices['choices'][_makemeeting_date_timestamp($choice['chdate'])] = $choice;
    }
  }

  // Handle other operations
  if (!empty($form_state['values']['op'])) {
    switch ($form_state['values']['op']) {
      // Add 1 more choice to the form.
      case t('More choices'):
        // Increment choice count
        $form_state['choice_count'] = count($element['choices']) + 1;
        break;

      // Add 1 more suggestion to the form.
      case t('More suggestions'):
        $form_state['suggestion_count']++;
        break;

      // Copy first row suggestions to the other rows.
      case t('Copy and paste first row');
        $first = reset($choices['choices']);
        foreach (array_keys($choices['choices']) as $key) {
          $choices['choices'][$key]['chsuggestions'] = $first['chsuggestions'];
        }
        break;
    }
  }

  // Replace submitted values by our own work
  drupal_array_set_nested_value($form_state['input'], $clicked_button['#parents'], $choices);
  drupal_array_set_nested_value($form_state['values'], $clicked_button['#parents'], $choices);

  // Require the widget form to rebuild the choices
  // with the values in $form_state
  $form_state['rebuild'] = TRUE;
}

/**
 * Ajax callback in response to new choices being added to the form.
 *
 * This returns the new page content to replace the page content made obsolete
 * by the form submission.
 */
function makemeeting_choice_js($form, $form_state) {
  // Get the element from the parents of the clicked button
  $element = drupal_array_get_nested_value($form, $form_state['clicked_button']['#parents']);
  return $element['choices_wrapper']['choices'];
}

/**
 * Ajax callback in response to an answer that has been edited.
 *
 * This returns the new form content to replace the form content made obsolete
 * by the form submission.
 */
function makemeeting_answer_js($form, $form_state) {
  $values = $form_state['values'];
  $answer = $values['answer_edited'];
  $entities = entity_load($answer->entity_type, array($answer->entity_id));
  if (empty($entities)) {
    return drupal_not_found();
  }
  $entity = $entities[$answer->entity_id];
  $field = $entity->{$answer->field_name}[$answer->language][$answer->delta];
  // We need to empty POST data to prevent the form
  // from being processed as submitted
  $_POST = array();
  $new_form = drupal_get_form('makemeeting_answers_form_' . $answer->entity_id, $field, $values);
  // AJaX processing overrides form action, now retrieving the correct one
  $query = parse_url($form['#action']);
  $parameters = drupal_get_query_array($query['query']);
  $new_form['#action'] = $parameters['destination'];
  return $new_form;
}

/**
 * Implements hook_field_is_empty().
 */
function makemeeting_field_is_empty($item) {
  return empty($item['choices']);
}

/**
 * Implements hook_field_formatter_info().
 */
function makemeeting_field_formatter_info() {
  return array(
    'makemeeting_answers' => array(
      'label' => t('Makemeeting answers'),
      'field types' => array('makemeeting'),
    ),
  );
}

/**
 * Implements hook_field_formatter_view().
 *
 * Build a renderable array for a field value.
 *
 * @param $entity_type
 *   The type of $entity.
 * @param $entity
 *   The entity being displayed.
 * @param $field
 *   The field structure.
 * @param $instance
 *   The field instance.
 * @param $langcode
 *   The language associated with $items.
 * @param $items
 *   Array of values for this field.
 * @param $display
 *   The display settings to use, as found in the 'display' entry of instance
 *   definitions. The array notably contains the following keys and values;
 *   - type: The name of the formatter to use.
 *   - settings: The array of formatter settings.
 *
 * @return
 *   A renderable array for the $items, as an array of child elements keyed
 *   by numeric indexes starting from 0.
 *
 * We only have a display type so no need to test $display['type']
 */
function makemeeting_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $content = array();
  foreach ($items as $delta => $item) {
    list($entity_id) = entity_extract_ids($entity_type, $entity);
    $instance += array(
      'entity_id' => $entity_id,
      'language' => $langcode,
      'delta' => $delta
    );
    $content[] = drupal_get_form('makemeeting_answers_form_' . $instance['entity_id'], $item, $instance);
  }
  return $content;
}

/**
 * Implements hook_forms().
 */
function makemeeting_forms($form_id, $args) {
  if (preg_match('/^makemeeting_answers_form_\d+?$/', $form_id)) {
    return array($form_id => array(
      'callback' => 'makemeeting_answers_form',
    ));
  }
}

/**
 * Form callback: enables users to answer a makemeeting poll
 */
function makemeeting_answers_form($form, $form_state, $item, $instance, $answer = NULL) {
  global $user;
  $form = array();
  $form['#item'] = $item;
  $form['#theme'] = 'makemeeting_answers';

  // Force the id of the form as it might get overriden in AJAX-loaded forms
  $form['#id'] = 'makemeeting-answers-form';

  // Pass entity-related values in the form
  foreach (array('field_name', 'entity_type', 'deleted', 'entity_id',
             'language', 'delta') as $info) {
    $form[$info] = array(
      '#type' => 'value',
      '#value' => $instance[$info],
    );
  }

  // Pass answer being edited
  if ($answer) {
    $form['answer_edited'] = array(
      '#type' => 'value',
      '#value' => $answer,
    );
  }

  // Include the name of the current user
  $form['name'] = array(
    '#type' => 'textfield',
    '#size' => 22,
  );
  if (!user_is_logged_in()) {
    // This is an HTML5 attribute
    $form['name']['#attributes'] = array('placeholder' => t('Your name (required)'));
    $form['name']['#required'] = TRUE;
  }
  else {
    $form['name']['#default_value'] = format_username($user);
    $form['name']['#disabled'] = TRUE;
  }
  if (!empty($answer)) {
    if ($answer->uid > 0) {
      $account = user_load($answer->uid);
      $form['name']['#default_value'] = format_username($account);
    }
    else {
      $form['name']['#default_value'] = $answer->name;
    }
  }

  // If the form is limited, fetch already submitted answers
  $answers = array();
  if ($item['limit'] > 0) {
    $select = db_select('makemeeting_answers', 'ma')->fields('ma', array('value'));
    foreach (array('field_name', 'entity_type', 'deleted', 'entity_id', 'language', 'delta') as $info) {
      $select->condition($info, $instance[$info]);
    }
    // Filter out answer being edited
    if ($answer) {
      $select->condition('answer_id', $answer->answer_id, '!=');
    }
    $results = $select->execute();
    // And add each answer to our results array for futher use
    foreach ($results as $result) {
      $_answer = unserialize($result->value);
      if (is_array($_answer)) {
        foreach ($_answer as $key => $value) {
          if ($value) {
            $answers[$key] = empty($answers[$key]) ? 1 : $answers[$key] + 1;
          }
        }
      }
      elseif (is_string($_answer) && $_answer) {
        $answers[$_answer] = empty($answers[$_answer]) ? 1 : $answers[$_answer] + 1;
      }
    }
  }

  // Possible answers
  $form['answers'] = array();
  foreach ($item['choices'] as $choice) {
    $chdate = _makemeeting_date_timestamp($choice['chdate']);
    $count = 0;
    foreach ($choice['chsuggestions'] as $id => $text) {
      // Add a form element only if there's a suggestion label
      // or it is the first suggestion for this date
      if ($text || (!$text && !$count)) {
        _makemeeting_answer_element($form, $item, $id, $chdate, $text, $answers, $answer);
      }
      $count++;
    }
  }

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit'),
  );
  if (!empty($answer)) {
    // Modify form submit to include ajax behavior
    $form['submit']['#ajax'] = array(
      'callback' => 'makemeeting_answer_js',
      'wrapper' => 'makemeeting-answers-form',
      'effect' => 'fade',
    );
  }

  return $form;
}

function makemeeting_answers_form_validate($form, &$form_state) {
  // The required attribute won't work, so we display a single message
  if (!$form_state['values']['name']) {
    drupal_set_message(t('You must enter your name.'), 'error');
  }
  // Check is the user has already voted
  if (user_is_logged_in() && empty($form_state['values']['answer_edited'])) {
    global $user;
    $select = db_select('makemeeting_answers', 'ma');
    foreach (array('field_name', 'entity_type', 'deleted', 'entity_id',
               'language', 'delta') as $info) {
      $select->condition($info, $form_state['values'][$info]);
    }
    $result = $select->condition('uid', $user->uid)->countQuery()->execute()->fetchField();
    if ($result) {
      form_error($form, t('You already voted on this poll.'));
    }
  }
}

function makemeeting_answers_form_submit($form, $form_state) {
  global $user;
  if (!empty($form_state['values']['answer_edited'])) {
    db_update('makemeeting_answers')
      ->fields(array(
      'value' => serialize($form_state['values']['answers']),
    ))
      ->condition('answer_id', $form_state['values']['answer_edited']->answer_id)
      ->execute();
  }
  else {
    $fields = array();
    foreach (array('field_name', 'entity_type', 'deleted', 'entity_id',
               'language', 'delta', 'name') as $field) {
      $fields[$field] = $form_state['values'][$field];
    }
    db_insert('makemeeting_answers')->fields($fields + array(
      'value' => serialize($form_state['values']['answers']),
      'uid' => $user->uid,
    ))->execute();
  }
}

/**
 * Function used to render answers' table
 */
function theme_makemeeting_answers($vars) {
  global $user;
  $form = $vars['form'];
  $item = $form['#item'];

  // Add appropriate CSS.
  drupal_add_css(drupal_get_path('module', 'makemeeting') . '/makemeeting.css');

  // Initialize variables
  $header = $day_cell = $row_form = $tree = $rows = array();

  // First construct tree of suggestions for headers
  foreach ($item['choices'] as $choice) {
    $chdate = _makemeeting_date_timestamp($choice['chdate']);
    $month = format_date($chdate, 'custom', 'F Y');
    $day = format_date($chdate, 'custom', 'D. j');
    $count = 0;
    foreach ($choice['chsuggestions'] as $text) {
      if (!$text && isset($tree[$month][$day]) && $count) {
        continue;
      }
      elseif (!$text) {
        $text = "-";
      }
      $tree[$month][$day][] = $text;
      $count++;
    }
  }

  // Now construct headers based on tree
  $headers = $row_days = $row_suggestions = array('');
  // Add month-related classes
  $months_total = count($tree);
  $months_count = 0;
  foreach ($tree as $month => $days) {
    $header['colspan'] = 0;
    $header['data'] = $month;

    $header['class'] = array('date-month');
    _makemeeting_define_class_suffix($header, $months_count, $months_total, 'date-month');
    $months_count++;

    // Add day-related classes
    $days_total = count($days);
    $days_count = 0;
    foreach ($days as $day => $suggestions) {
      $day_cell['colspan'] = 0;
      $day_cell['data'] = $day;

      $day_cell['class'] = array('date');
      _makemeeting_define_class_suffix($day_cell, $days_count, $days_total, 'date');
      $days_count++;

      // Add suggestion-related classes
      $suggestions_total = count($suggestions);
      $suggestion_count = 0;
      foreach ($suggestions as $text) {
        $suggestion = array('data' => $text, 'class' => array('suggestion'));
        _makemeeting_define_class_suffix($suggestion, $suggestion_count, $suggestions_total, 'suggestion');
        $suggestion_count++;

        $row_suggestions[] = $suggestion;

        // Set colspan
        $header['colspan']++;
        $day_cell['colspan']++;
      }
      $row_days[] = $day_cell;
    }
    $headers[] = $header;
  }
  array_push($rows, $row_days, $row_suggestions);

  // Initialize totals labels
  $totals = array();
  $options = _makemeeting_options($item['yesnomaybe']);
  foreach ($options as $key => $label) {
    $totals[$key]['table'] = array(array('data' => t('Totals ' . $label), 'class' => 'total-title'));
    foreach ($item['choices'] as $choice) {
      $count = 0;
      foreach ($choice['chsuggestions'] as $text) {
        if ($text || (!$text && !$count)) {
          // Initialize totals count
          $totals[$key]['count'][] = 0;
        }
        $count++;
      }
    }
  }

  // Display already submitted answers
  $select = db_select('makemeeting_answers', 'ma')->fields('ma');
  foreach (array('field_name', 'entity_type', 'deleted', 'entity_id',
             'language', 'delta') as $info) {
    $select->condition($info, $form[$info]['#value']);
  }
  // Filter out answer being edited
  if (!empty($form['answer_edited'])) {
    $select->condition('answer_id', $form['answer_edited']['#value']->answer_id, '!=');
  }
  $results = $select->execute()->fetchAllAssoc('answer_id');
  $uids = array();
  foreach ($results as $result) {
    $uids[] = $result->uid;
    $row = array();
    // Display name of the person that has answered
    $row[] = _makemeeting_render_cell_name($result->uid, $result->name, $result->answer_id);

    // Display his/her answers
    $answers = unserialize($result->value);
    foreach (element_children($form['answers']) as $answer_key) {
      $row_count = count($row);

      // Determine choice based on choice type
      if ($item['one_option']) {
        $key = $answers == $answer_key ? MAKEMEETING_YES : MAKEMEETING_NO;
      }
      else {
        $key = isset($answers[$answer_key]) ? intval($answers[$answer_key]) : FALSE;
      }
      $label = isset($options[$key]) ? $options[$key] : FALSE;

      if ($key !== FALSE && $label !== FALSE) {
        // Add corresponding classes for the answer
        $classes = array('answer', 'answer-' . $key);
        foreach (array('suggestion-first', 'suggestion-medium', 'suggestion-last') as $class) {
          if (in_array($class, $row_suggestions[$row_count]['class'])) {
            $classes[] = str_replace('suggestion', 'answer', $class);
          }
        }

        // Store answer (will an background image according to class)
        $row[] = array('data' => '&nbsp;', 'class' => $classes);

        // Increment key answer counter
        $totals[$key]['count'][$row_count - 1]++;
      }
      else {
        $row[] = t('No answer');
      }
    }
    $rows[] = array('data' => $row, 'id' => 'answer-' . $result->answer_id);
  }

  // Add participant count
  $rows[1][0] = format_plural(count($results), '@count participant', '@count participants');

  // Display answer form if ... not limited,
  $limited = $item['limit'] > 0 && $item['limit'] * count($row_suggestions) - 1 <= count($results);
  // ... not closed,
  $closed = $item['closed'] || $limited;
  $submitted = user_is_logged_in() && in_array($user->uid, array_values($uids));
  // ... user has access and has not already submitted
  $show_form = user_access('answer makemeeting form') && !$closed && !$submitted;
  if ($show_form) {
    $row_form[] = drupal_render($form['name']);
    foreach (element_children($form['answers']) as $answer_key) {
      $row_form[] = array(
        'data' => drupal_render($form['answers'][$answer_key]),
        'class' => $form['answers'][$answer_key]['#type'],
      );
    }
    $rows[] = array(
      'data' => $row_form,
      'class' => array('answer-form-row'),
    );
  }

  // Get total maxima
  $totals_max = array();
  foreach ($totals as $key => &$table) {
    if (empty($table['count'])) {
      $table['count'][] = 0;
    }
    $totals_max[$key] = max($table['count']);
  }
  // Display totals
  foreach ($options as $key => $label) {
    foreach ($totals[$key]['count'] as $choice => $count) {
      $classes = array('total-count', 'total-' . $key);
      if ($count) {
        // Indicate first / last suggestion item
        foreach (array('suggestion-first', 'suggestion-medium', 'suggestion-last') as $class) {
          if (in_array($class, $row_suggestions[$choice + 1]['class'])) {
            $classes[] = str_replace('suggestion', 'total', $class);
          }
        }
      }
      // Indicate max count
      if (!empty($totals_max[$key]) && $count == $totals_max[$key]) {
        $classes[] = 'total-max';
      }
      $totals[$key]['table'][] = array('data' => $count, 'class' => $classes);
    }
    $classes = array('total-row');

    // Change labels for two choices
    if (!$item['yesnomaybe']) {
      $totals[$key]['table'][0]['data'] = t('Totals');
    }
    // Do not display other totals for two choices
    if ($item['yesnomaybe'] || !$item['yesnomaybe'] && $key == MAKEMEETING_YES) {
      $classes[] = 'total-row-' . ($key ? ($key == MAKEMEETING_YES ? 'last' : 'medium') : 'first');
      $rows[] = array('data' => $totals[$key]['table'], 'class' => $classes);
    }
  }

  // Apply classes to the two first rows
  $rows[0] = array('data' => $rows[0], 'class' => array('dates'));
  $rows[1] = array('data' => $rows[1], 'class' => array('suggestions'));

  $suggestion = array(
    '#theme' => 'table',
    '#header' => $headers,
    '#rows' => $rows,
    '#attributes' => array('class' => array('makemeeting-table')),
  );
  if ($show_form) {
    return drupal_render($suggestion) . drupal_render_children($form);
  }
  return drupal_render($suggestion);
}

/**
 * Function used to render a single answer row as a form
 */
function theme_makemeeting_answer_row($vars) {
  $form = $vars['form'];
  $element = array(
    'first_cell' => array(),
    'other_cells' => array('#markup' => '')
  );

  // Render suggestions
  foreach (element_children($form['answers']) as $answer_key) {
    $element['other_cells']['#markup'] .= _theme_table_cell(array(
      'data' => drupal_render($form['answers'][$answer_key]),
      'class' => $form['answers'][$answer_key]['#type'],
    ));
  }

  // Render name, submit and the rest of hidden children
  $first_cell = drupal_render($form['name']) . drupal_render($form['submit']);
  $first_cell .= drupal_render_children($form);
  $element['first_cell']['#markup'] = _theme_table_cell($first_cell);

  return drupal_render($element);
}

/**
 * Render the cell containing the submitter's name with
 * a possible option to delete the answer
 */
function _makemeeting_render_cell_name($uid, $name, $answer_id) {
  global $user;
  if ($uid) {
    $account = user_load($uid);
    $username = theme('username', array('account' => user_load($account->uid)));
  }
  else {
    $username = $name;
  }
  if (!user_access('delete any makemeeting answer') && $uid != $user->uid) {
    return $username;
  }
  $images_path = drupal_get_path('module', 'makemeeting') . '/images/';
  $cell[] = array(
    '#prefix' => '<div class="answer-edit">',
    'delete-link' => array(
      '#type' => 'link',
      '#title' => theme_image(array('path' => $images_path . 'trash.png',
        'attributes' => array('title' => t('Delete answer')))),
      '#href' => 'makemeeting/delete-answer/' . $answer_id,
      '#options' => array(
        'query' => drupal_get_destination(),
        'html' => TRUE,
        'attributes' => array('rel' => 'nofollow'),
      ),
    ),
    'edit-link' => array(
      '#type' => 'link',
      '#title' => theme_image(array('path' => $images_path . 'pen.png',
        'attributes' => array('title' => t('Edit answer')))),
      // Note the /nojs portion of the href - if javascript is enabled,
      // this part will be stripped from the path before it is called.
      '#href' => 'makemeeting/edit-answer/' . $answer_id . '/nojs/',
      '#options' => array(
        'query' => drupal_get_destination(),
        'html' => TRUE,
        'attributes' => array('rel' => 'nofollow'),
      ),
      '#ajax' => array(
        'wrapper' => 'answer-' . $answer_id,
        'method' => 'html',
      ),
    ),
    '#suffix' => '</div>',
  );
  $cell[] = array('#markup' => $username);
  return '<div class="answer-editable">' . drupal_render($cell) . '</div>';
}

/**
 * Implements hook_field_presave().
 */
function makemeeting_field_presave($entity_type, $entity, $field, $instance, $langcode, &$items) {
  if ($field['type'] == 'makemeeting') {
    foreach ($items as $delta => $item) {
      if (isset($item['choices'])) {
        // Sort the choices by date
        $choices = array_values($item['choices']);
        usort($choices, '_makemeeting_sort_choices');
        // Affect timestamp as keys
        $timestamped_choices = array();
        foreach ($choices as $choice) {
          $timestamped_choices[_makemeeting_date_timestamp($choice['chdate'])] = $choice;
        }
        // Serialize the whole array
        $items[$delta]['choices'] = serialize($timestamped_choices);
      }
    }
  }
}

/**
 * Implements hook_field_load().
 */
function makemeeting_field_load($entity_type, $entities, $field, $instances, $langcode, &$items, $age) {
  // Unserialize array values
  foreach ($entities as $id => $entity) {
    foreach ($items[$id] as $delta => $item) {
      if ($field['type'] == 'makemeeting' && is_string($items[$id][$delta]['choices'])) {
        $items[$id][$delta]['choices'] = unserialize($items[$id][$delta]['choices']);
      }
    }
  }
}


/**
 * Implements hook_theme().
 */
function makemeeting_theme($existing, $type, $theme, $path) {
  return array(
    'makemeeting_choices' => array(
      'render element' => 'form',
    ),
    'makemeeting_answers' => array(
      'render element' => 'form',
    ),
    'makemeeting_answer_row' => array(
      'render element' => 'form',
    ),
  );
}

/**
 * Returns HTML for an admin poll form for choices.
 */
function theme_makemeeting_choices($variables) {
  $form = $variables['form'];

  // Add appropriate CSS.
  drupal_add_css(drupal_get_path('module', 'makemeeting') . '/makemeeting.css');

  $rows = array();
  $headers = array(t('Date'));
  $headers_added = FALSE;

  foreach (element_children($form) as $key) {
    // Build the table rows.
    $row = array();
    $row[] = array(
      'data' => drupal_render($form[$key]['chdate']) . drupal_render($form[$key]['chremove']),
      'class' => 'makemeeting-choice-date',
    );
    $delta = 0;
    foreach (element_children($form[$key]['chsuggestions']) as $key2) {
      $delta++;
      // Add sugesstion headers for the first line
      if (!$headers_added) {
        $headers[] = t('Suggestion %num', array('%num' => $delta));
      }
      $row[] = drupal_render($form[$key]['chsuggestions'][$key2]);
    }
    $headers_added = TRUE;
    $rows[] = $row;
  }

  $output = theme('table', array(
    'header' => $headers,
    'rows' => $rows,
    'attributes' => array('id' => 'poll-choice-table')
  ));
  $output .= drupal_render_children($form);
  return $output;
}

/**
 * Helper function to update the form elements parents. This is required
 * for the element to be saved properly by the Field API (see #process)
 *
 * @param $element
 * @return mixed
 */
function _makemeeting_rebuild_parents(&$element) {
  $parents = array_diff($element['#array_parents'], $element['#parents']);
  $elements = array('makemeeting_more_choices', 'makemeeting_more_suggestions', 'makemeeting_copy_suggestions');
  foreach ($elements as $e) {
    $element[$e]['#parents'] = $parents;
    $element[$e]['#limit_validation_errors'][0] = array_merge($parents,
      $element[$e]['#limit_validation_errors'][0]);
  }
  $element['makemeeting_more_suggestions']['#parents'] = $parents;
  $element['makemeeting_copy_suggestions']['#parents'] = $parents;
  foreach (element_children($element['choices']) as $key1) {
    foreach (element_children($element['choices'][$key1]) as $key2) {
      $keys = element_children($element['choices'][$key1][$key2]);
      if (empty($keys)) {
        $element['choices'][$key1][$key2]['#parents'] = array_merge($parents,
          $element['choices'][$key1][$key2]['#parents']);
      }
      else {
        foreach ($keys as $key3) {
          $element['choices'][$key1][$key2][$key3]['#parents'] = array_merge($parents,
            $element['choices'][$key1][$key2][$key3]['#parents']);
        }
      }
    }
  }
  return $element;
}

/**
 * Helper function to construct a row of the widget form
 *
 * @param $key
 * @param string $value
 * @param array $suggestions
 * @param int $size
 * @return array
 */
function _makemeeting_choice_form($key, $value = '', $suggestions = array(), $size = 1) {
  $form = array(
    '#tree' => TRUE,
  );

  // We'll manually set the #parents property of these fields so that
  // their values appear in the $form_state['values']['choices'] array
  // They are to be updated later in #process as we don't know here the
  // hierarchy of the parents
  $form['chdate'] = array(
    '#type' => 'date',
    '#title' => t('Date'),
    '#title_display' => 'invisible',
    '#default_value' => $value,
    '#parents' => array('choices', $key, 'chdate'),
  );
  $form['chremove'] = array(
    '#type' => 'submit',
    '#parents' => array(),
    '#submit' => array('makemeeting_choices_submit'),
    '#limit_validation_errors' => array(array('choices')),
    '#ajax' => array(
      'callback' => 'makemeeting_choice_js',
      'wrapper' => 'makemeeting-choices',
      'effect' => 'fade',
    ),
    '#value' => t('Remove'),
    // Assigning key as name to make each 'Remove' button unique
    '#name' => $key,
  );

  $form['chsuggestions'] = array(
    '#tree' => TRUE,
    '#parents' => array('choices', $key, 'chsuggestions'),
  );

  for ($i = 0; $i < $size; $i++) {
    $key2 = 'sugg:' . ($i);
    $form['chsuggestions'][$key2] = array(
      '#type' => 'textfield',
      '#title_display' => 'invisible',
      '#default_value' => isset($suggestions[$key2]) ? $suggestions[$key2] : '',
      '#size' => 5,
      '#maxlength' => 255,
      '#parents' => array('choices', $key, 'chsuggestions', $key2),
    );
  }
  return $form;
}

/**
 * Helper function to sort choice dates
 */
function _makemeeting_sort_choices($a, $b) {
  if ($a['chdate']['year'] == $b['chdate']['year']) {
    if ($a['chdate']['month'] == $b['chdate']['month']) {
      if ($a['chdate']['day'] == $b['chdate']['day']) {
        return 0;
      }
      else {
        return (int) $a['chdate']['day'] < (int) $b['chdate']['day'] ? -1 : 1;
      }
    }
    else {
      return (int) $a['chdate']['month'] < (int) $b['chdate']['month'] ? -1 : 1;
    }
  }
  else {
    return (int) $a['chdate']['year'] < (int) $b['chdate']['year'] ? -1 : 1;
  }
}

/**
 * Helper function to convert date field value into an Unix timestamp
 *
 * @param $array array Date field value (month, day and year)
 * @return int Unix timestamp
 */
function _makemeeting_date_timestamp($array) {
  date_default_timezone_set('UTC');
  $timestamp = mktime(0, 0, 0, $array['month'], $array['day'], $array['year']);
  date_default_timezone_set(drupal_get_user_timezone());
  return $timestamp;
}

/**
 * Helper function for selecting choices
 *
 * @param bool $three_choices If should be returning three choices
 * @return array An array of options for radios
 */
function _makemeeting_options($three_choices = FALSE) {
  $options = array(
    MAKEMEETING_NO => t('No'),
    MAKEMEETING_MAYBE => t('Maybe'),
    MAKEMEETING_YES => t('Yes'),
  );
  if (!$three_choices) {
    unset($options[MAKEMEETING_MAYBE]);
  }
  return $options;
}

/**
 * Helper function to provide an answer form element
 *
 * @param $form
 *  Form to be modified
 * @param $item
 *  Item providing settings for the answer form
 * @param $id
 *  Suggestion id
 * @param $chdate
 *  Suggestion date
 * @param $text
 *  Suggestion text
 * @param $answers
 *  Already submitted answers
 */
function _makemeeting_answer_element(&$form, $item, $id, $chdate, $text, $answers = array(), $answer = NULL) {
  $key = $chdate . ':' . $id;
  // If the limit is reached for this option, display a markup text
  if ($item['limit'] > 0 && isset($answers[$key]) && $answers[$key] >= $item['limit']) {
    $form['answers'][$key] = array(
      '#markup' => t('Unavailable'),
    );
  }
  // Else add a form element
  else {
    $title = format_date($chdate, 'custom', 'l j F Y') . ' ' . $text;
    $form['answers'][$key] = array(
      '#type' => $item['one_option'] ? 'radio' : ($item['yesnomaybe'] ? 'radios' : 'checkbox'),
      '#attributes' => array('title' => check_plain($title)),
      '#parents' => array('answers', $key),
    );

    if ($item['one_option']) {
      $form['answers'][$key]['#parents'] = array('answers');
      $form['answers'][$key]['#return_value'] = $key;
    }
    else {
      $form['answers'][$key]['#options'] = _makemeeting_options($item['yesnomaybe']);
    }
    if ($item['yesnomaybe']) {
      $form['answers'][$key]['#default_value'] = MAKEMEETING_NO;
    }
    // Display previous choice if answer is being edited
    if ($answer && !empty($answer->value[$key])) {
      $form['answers'][$key]['#default_value'] = $answer->value[$key];
    }
  }
}

/**
 * Helper function to define classes based on a count and a total
 *
 * @param $element
 * @param $count
 * @param $total
 */
function _makemeeting_define_class_suffix(&$element, $count, $total, $prefix = '') {
  if ($prefix) {
    $prefix .= '-';
  }
  if ($count == 0) {
    $element['class'][] = $prefix . 'first';
  }
  elseif ($count == ($total - 1)) {
    $element['class'][] = $prefix . 'last';
  }
  else {
    $element['class'][] = $prefix . 'medium';
  }
}