<?php

/**
 * @file
 * A simple n-star voting widget, usable in other forms.
 */

include_once dirname(__FILE__) . '/includes/fivestar.field.inc';

/**
 * Implementation of hook_help().
 */
function fivestar_help($path, $arg) {
  $output = '';
  switch ($path) {
    case 'admin/config/content/fivestar':
      $output = t('This page is used to configure site-wide features of the Fivestar module.');
    break;
  }
  return $output;
}

/**
 * Implementation of hook_menu().
 */
function fivestar_menu() {
  $items = array();
  $items['admin/config/content/fivestar'] = array(
    'title'             => 'Fivestar',
    'description'       => 'Configure site-wide widgets used for Fivestar rating.',
    'page callback'     => 'drupal_get_form',
    'page arguments'    => array('fivestar_settings'),
    'access callback'   => 'user_access',
    'access arguments'  => array('administer site configuration'),
    'type'              => MENU_NORMAL_ITEM,
    'file'              => 'includes/fivestar.admin.inc',
  );

  return $items;
}

/**
 * Implements hook_microdata_suggestions().
 */
function fivestar_microdata_suggestions() {
  $mappings = array();

  // Add the review mapping for Schema.org
  $mappings['fields']['fivestar']['schema.org'] = array(
    '#itemprop' => array('aggregateRating'),
    '#is_item' => TRUE,
    '#itemtype' => array('http://schema.org/AggregateRating'),
    'average_rating' => array(
      '#itemprop' => array('ratingValue'),
    ),
    'rating_count' => array(
      '#itemprop' => array('ratingCount'),
    ),
  );

  return $mappings;
}

/**
 * Implementation of hook_permission().
 *
 * Exposes permissions for rating content.
 */
function fivestar_permission() {
  return array(
    'rate content' => array(
      'title' => t('rate content'),
    ),
  );
}

/**
 * Implementation of hook_theme().
 */
function fivestar_theme() {
  return array(
    // Fivestar theme functions.
    'fivestar' => array(
      'render element' => 'element',
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_select' => array(
      'render element' => 'element',
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_static' => array(
      'variables' => array('rating' => NULL, 'stars' => 5, 'tag' => 'vote', 'widget' => array('name' => 'default', 'css' => '')),
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_static_element' => array(
      'variables' => array('star_display' => NULL, 'title' => NULL, 'description' => NULL),
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_summary' => array(
      'variables' => array('user_rating' => NULL, 'average_rating' => NULL, 'votes' => 0, 'stars' => 5, 'microdata' => array()),
      'file' => 'includes/fivestar.theme.inc',
    ),
    // fivestar.admin.inc.
    'fivestar_preview' => array(
      'variables' => array('style' => NULL, 'text' => NULL, 'stars' => NULL, 'unvote' => NULL, 'title' => NULL),
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_preview_widget' => array(
      'variables' => array('css' => NULL, 'name' => NULL),
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_preview_wrapper' => array(
      'variables' => array('content' => NULL, 'type' => 'direct'),
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_settings' => array(
      'render element' => 'form',
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_color_form' => array(
      'render element' => 'form',
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_formatter_default' => array(
      'render element' => 'element',
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_formatter_rating' => array(
      'render element' => 'element',
      'file' => 'includes/fivestar.theme.inc',
    ),
    'fivestar_formatter_percentage' => array(
      'render element' => 'element',
      'file' => 'includes/fivestar.theme.inc',
    ),
  );
}

function _fivestar_variables() {
  return array('fivestar', 'fivestar_unvote', 'fivestar_style', 'fivestar_stars', 'fivestar_comment', 'fivestar_position', 'fivestar_position_teaser', 'fivestar_labels_enable', 'fivestar_labels', 'fivestar_text', 'fivestar_title', 'fivestar_feedback');
}

/**
 * Internal function to handle vote casting, flood control, XSS, IP based
 * voting, etc...
 */

function _fivestar_cast_vote($entity_type, $id, $value, $tag = NULL, $uid = NULL, $skip_validation = FALSE, $vote_source = NULL) {
  global $user;
  $tag = empty($tag) ? 'vote' : $tag;
  $uid = isset($uid) ? $uid : $user->uid;
  // Bail out if the user's trying to vote on an invalid object.
  if (!$skip_validation && !fivestar_validate_target($entity_type, $id, $tag, $uid)) {
    return array();
  }
  // Sanity-check the incoming values.
  if (is_numeric($id) && is_numeric($value)) {
    if ($value > 100) {
      $value = 100;
    }

    // Get the user's current vote.
    $criteria = array('entity_type' => $entity_type, 'entity_id' => $id, 'tag' => $tag, 'uid' => $uid);
    // Get the unique identifier for the user (IP Address if anonymous).

    if ($vote_source != NULL) {
      $user_criteria = array('vote_source' => $vote_source);
      $limit = 1;
    }
    else {
      $user_criteria = votingapi_current_user_identifier();
      $limit = 0;
    }
    $user_votes = votingapi_select_votes($criteria + $user_criteria, $limit);

    if ($value == 0) {
      votingapi_delete_votes($user_votes);
    }
    else {
      $votes = $criteria += array('value' => $value);
      votingapi_set_votes($votes);
    }

    // Moving the calculationg after saving/deleting the vote but before getting the votes.
    votingapi_recalculate_results($entity_type, $id);
    return fivestar_get_votes($entity_type, $id, $tag, $uid);
  }
}

/**
 * Utility function to retrieve VotingAPI votes.
 *
 * Note that this should not be used for general vote retrieval, instead the
 * VotingAPI function votingapi_select_results() should be used, which is more
 * efficient when retrieving multiple votes.
 *
 * @param $entity_type
 *   The Entity type for which to retrieve votes.
 * @param $id
 *   The ID for which to retrieve votes.
 * @param $tag
 *   The VotingAPI tag for which to retrieve votes.
 * @param $uid
 *   Optional. A user ID for which to retrieve votes.
 * @return
 *   An array of the following keys:
 *   - average: An array of VotingAPI results, including the average 'value'.
 *   - count: An array of VotingAPI results, including the count 'value'.
 *   - user: An array of VotingAPI results, including the user's vote 'value'.
 */
function fivestar_get_votes_multiple($entity_type, $ids, $tag = 'vote', $uid = NULL) {
  global $user;

  if (!isset($uid)) {
    $uid = $user->uid;
  }

  $criteria = array(
    'entity_type' => $entity_type,
    'entity_id' => $ids,
    'value_type' => 'percent',
    'tag' => $tag,
  );

  $votes = array();

  // Initialize defaults.
  foreach($ids as $id) {
    $votes[$entity_type][$id] = array(
      'average' => array(),
      'count' => array(),
      'user' => array(),
    );
  }

  $results = votingapi_select_results($criteria);
  $user_votes = array();
  if(!empty($results)) {
    foreach(votingapi_select_votes($criteria += array('uid' => $uid)) as $uv) {
      $user_votes[$uv['entity_type']][$uv['entity_id']] = $uv;
    }
  }

  foreach ($results as $result) {
    if ($result['function'] == 'average') {
      $votes[$result['entity_type']][$result['entity_id']]['average'] = $result;
    }
    if ($result['function'] == 'count') {
      $votes[$result['entity_type']][$result['entity_id']]['count'] = $result;
    }
	  if ($uid) {
	    if (!empty($user_votes[$result['entity_type']][$result['entity_id']])) {
        $votes[$result['entity_type']][$result['entity_id']]['user'] = $user_votes[$result['entity_type']][$result['entity_id']];
        $votes[$result['entity_type']][$result['entity_id']]['user']['function'] = 'user';
	    }
	  }
	  else {
	    // If the user is anonymous, we never bother loading their existing votes.
	    // Not only would it be hit-or-miss, it would break page caching. Safer to always
	    // show the 'fresh' version to anon users.
      $votes[$result['entity_type']][$result['entity_id']]['user'] = array('value' => 0);
	  }
  }

  return $votes;
}

function fivestar_get_votes($entity_type, $id, $tag = 'vote', $uid = NULL) {
  $multiple = fivestar_get_votes_multiple($entity_type, array($id), $tag, $uid);
  return $multiple[$entity_type][$id];
}

/**
 * Check that an item being voted upon is a valid vote.
 *
 * @param $entity_type
 *   Type of target.
 * @param $id
 *   Identifier within the type.
 * @param $tag
 *   The VotingAPI tag string.
 * @param $uid
 *   The user trying to cast the vote.
 *
 * @return boolean
 */
function fivestar_validate_target($entity_type, $id, $tag, $uid = NULL) {
  if (!isset($uid)) {
    $uid = $GLOBALS['user']->uid;
  }

  $access = module_invoke_all('fivestar_access', $entity_type, $id, $tag, $uid);
  foreach ($access as $result) {
    if ($result == TRUE) {
      return TRUE;
    }
    if ($result === FALSE) {
      return FALSE;
    }
  }
}

/**
 * Implementation of hook_fivestar_access().
 *
 * This hook is called before every vote is cast through Fivestar. It allows
 * modules to allow voting on any type of entity, such as nodes, users, or
 * comments.
 *
 * @param $entity_type
 *   Type entity.
 * @param $id
 *   Identifier within the type.
 * @param $tag
 *   The VotingAPI tag string.
 * @param $uid
 *   The user ID trying to cast the vote.
 *
 * @return boolean or NULL
 *   Returns TRUE if voting is supported on this object.
 *   Returns NULL if voting is not supported on this object by this module.
 *   If needing to absolutely deny all voting on this object, regardless
 *   of permissions defined in other modules, return FALSE. Note if all
 *   modules return NULL, stating no preference, then access will be denied.
 */
function fivestar_fivestar_access($entity_type, $id, $tag, $uid) {
  // Check to see if there is a field instance on this entity.
  $fields = field_read_fields(array('module' => 'fivestar'));
  foreach ($fields as $field) {
    if ($field['settings']['axis'] == $tag) {
      $params = array(
        'entity_type' => $entity_type,
        'field_name' => $field['field_name'],
      );
      $instance = field_read_instances($params);
      if (!empty($instance)) {
        return TRUE;
      }
    }
  }
}

/**
 * Implementation of hook_form_comment_form_alter().
 *
 * This hook removes the parent node, together with the fivestar field, from
 * the comment preview page. If this is left in, when the user presses the
 * "Save" button after the preview page has been displayed, the fivestar widget
 * gets the input rather than the comment; the user's input is lost. Based on a
 * suggestion by ChristianAdamski in issue 1289832-3.
 */
function fivestar_form_comment_form_alter(&$form, &$form_state, $form_id) {
  $is_fivestar = FALSE;
  if (isset($form['comment_output_below'])) {
    foreach($form['comment_output_below'] as $key => $value) {
      if (is_array($value) && !empty($value['#field_type'])) {
        if ($value['#field_type'] =='fivestar') {
          $is_fivestar = TRUE;
          $fivestar_key = $key;
        }
      }
    }
  }
  if ($is_fivestar) {
    unset($form['comment_output_below'][$fivestar_key]);
  }
}

/**
 * Implementation of hook_fivestar_widgets().
 *
 * This hook allows other modules to create additional custom widgets for
 * the fivestar module.
 *
 * @return array
 *   An array of key => value pairs suitable for inclusion as the #options in a
 *   select or radios form element. Each key must be the location of a css
 *   file for a fivestar widget. Each value should be the name of the widget.
 */
function fivestar_fivestar_widgets() {
  $widgets = &drupal_static(__FUNCTION__);
  if (!isset($widgets)) {
    $cache = cache_get(__FUNCTION__);
    if ($cache) {
      $widgets = $cache->data;
    }
  }

  if (!isset($widgets)) {
    $widgets_directory = drupal_get_path('module', 'fivestar') . '/widgets';
    $files = file_scan_directory($widgets_directory, '/\.css$/');
    foreach ($files as $file) {
      if (strpos($file->filename, '-rtl.css') === FALSE) {
        $widgets[$file->uri] = drupal_ucfirst(str_replace('-color', '', $file->name));
      }
    }
    cache_set(__FUNCTION__, $widgets);
  }
  return $widgets;
}

/**
 * Form builder; Build a custom Fivestar rating widget with arbitrary settings.
 *
 * This function is usually not called directly, instead call
 * drupal_get_form('fivestar_custom_widget', $values, $settings) when wanting
 * to display a widget.
 *
 * @param $form_state
 *   The form state provided by Form API.
 * @param $values
 *   An array of current vote values from 0 to 100, with the following array
 *   keys:
 *   - user: The user's current vote.
 *   - average: The average vote value.
 *   - count: The total number of votes so far on this content.
 * @param $settings
 *   An array of settings that configure the properties of the rating widget.
 *   Available keys for the settings include:
 *   - content_type: The type of content which will be voted upon.
 *   - content_id: The content ID which will be voted upon.
 *   - stars: The number of stars to display in this widget, from 2 to 10.
 *     Defaults to 5.
 *   - autosubmit: Whether the form should be submitted upon star selection.
 *     Defaults to TRUE.
 *   - allow_clear: Whether or not to show the "Clear current vote" icon when
 *     showing the widget. Defaults to FALSE.
 *   - required: Whether this field is required before the form can be
 *     submitted. Defaults to FALSE.
 *   - tag: The VotingAPI tag that will be registered by this widget. Defaults
 *     to "vote".
 */
function fivestar_custom_widget($form, &$form_state, $values, $settings) {
  $form = array(
    '#attributes' => array(
      'class' => array('fivestar-widget')
    ),
  );
  $form['#submit'][] = 'fivestar_form_submit';

  $form_state['settings'] = $settings;

  $form['vote'] = array(
    '#type' => 'fivestar',
    '#stars' => $settings['stars'],
    '#auto_submit' => isset($settings['autosubmit']) ? $settings['autosubmit'] : TRUE,
    '#allow_clear' => $settings['allow_clear'],
    '#allow_revote' => $settings['allow_revote'],
    '#allow_ownvote' => $settings['allow_ownvote'],
    '#required' => isset($settings['required']) ? $settings['required'] : FALSE,
    '#widget' => isset($settings['widget']) ? $settings['widget'] : array('name' => 'default', 'css' => 'default'),
    '#values' => $values,
    '#settings' => $settings,
    '#description' => $settings['description'],
  );

  $form['fivestar_submit'] = array(
    '#type' => 'submit',
    '#value' => t('Rate'),
    '#attributes' => array('class' => array('fivestar-submit')),
  );

  return $form;
}

/**
 * Submit handler for the above form (non-javascript version).
 */
function fivestar_form_submit($form, &$form_state) {

  // Cast the vote.
  _fivestar_cast_vote($form_state['settings']['content_type'], $form_state['settings']['content_id'], $form_state['values']['vote'], $form_state['settings']['tag']);

  // Set a message that the vote was received.
  if ($form_state['values']['vote'] === '0') {
    drupal_set_message(t('Your vote has been cleared.'));
  }
  elseif (is_numeric($form_state['values']['vote'])) {
    drupal_set_message(t('Thank you for your vote.'));
  }
}

/**
 * AJAX submit handler for fivestar_custom_widget
 */
function fivestar_ajax_submit($form, $form_state) {
  if (!empty($form_state['settings']['content_id'])) {
    $entity = entity_load($form_state['settings']['entity_type'], array($form_state['settings']['entity_id']));
    $entity = reset($entity);
    _fivestar_update_field_value($form_state['settings']['content_type'], $entity, $form_state['settings']['field_name'], $form_state['settings']['langcode'], $form_state['values']['vote']);
    $votes = _fivestar_cast_vote($form_state['settings']['content_type'], $form_state['settings']['content_id'], $form_state['values']['vote'], $form_state['settings']['tag']);
  }

  $values = array();
  $values['user'] = isset($votes['user']['value']) ? $votes['user']['value'] : 0;
  $values['average'] = isset($votes['average']['value']) ? $votes['average']['value'] : 0;
  $values['count'] = isset($votes['count']['value']) ? $votes['count']['value'] : 0;

  // We need to process the 'fivestar' element with the new values.
  $form['vote']['#values'] = $values;
  $new_element = fivestar_expand($form['vote']);
  // Update the description. Since it doesn't account of our cast vote above.
  // TODO: Look into all this, I honestly don't like it and it's a bit weird.
  $form['vote']['vote']['#description'] = isset($new_element['vote']['#description']) ? $new_element['vote']['#description'] : '';

  return array(
    '#type' => 'ajax',
    '#commands' => array(
      array(
        'command' => 'fivestarUpdate',
        'data' => drupal_render($form['vote']),
      ),
    ),
  );
}

/**
 * Implementation of hook_elements().
 *
 * Defines 'fivestar' form element type
 */
function fivestar_element_info() {
  $type['fivestar'] = array(
    '#input' => TRUE,
    '#stars' => 5,
    '#allow_clear' => FALSE,
    '#allow_revote' => FALSE,
    '#allow_ownvote' => FALSE,
    '#auto_submit' => FALSE,
    '#process' => array('fivestar_expand'),
    '#theme_wrappers' => array('form_element'),
    '#widget' => array(
      'name' => 'default',
      'css' => 'default',
    ),
    '#values' => array(
      'user' => 0,
      'average' => 0,
      'count' => 0,
    ),
    '#settings' => array(
      'style' => 'user',
      'text' => 'none',
    ),
  );
  return $type;
}

/**
 * Process callback for fivestar_element -- see fivestar_element()
 */
function fivestar_expand($element) {
  if (!_fivestar_allow_vote($element)){
    $element['#input'] = FALSE;
  }

  // Add CSS and JS
  $path = drupal_get_path('module', 'fivestar');
  $element['#attached']['js'][] = $path . '/js/fivestar.js';
  $element['#attached']['css'][] = $path . '/css/fivestar.css';
  $settings = $element['#settings'];
  $values = $element['#values'];
  $class[] = 'clearfix';

  $options = array('-' => t('Select rating'));
  for ($i = 1; $i <= $element['#stars']; $i++) {
    $this_value = ceil($i * 100/$element['#stars']);
    $options[$this_value] = t('Give it @star/@count', array('@star' => $i, '@count' => $element['#stars']));
  }
  // Display clear button only if enabled.
  if ($element['#allow_clear'] == TRUE) {
    $options[0] = t('Cancel rating');
  }

  $element['vote'] = array(
    '#type' => 'select',
    '#options' => $options,
    '#required' => $element['#required'],
    '#attributes' => $element['#attributes'],
    '#theme' => _fivestar_allow_vote($element) ? 'fivestar_select' : 'fivestar_static',
    '#default_value' => _fivestar_get_element_default_value($element),
    '#weight' => -2,
  );

  if (isset($element['#parents'])) {
    $element['vote']['#parents'] = $element['#parents'];
  }

  switch ($settings['text']) {
    case 'user':
      $element['vote']['#description'] = theme('fivestar_summary', array(
        'user_rating' => $values['user'],
        'votes' => $settings['style'] == 'dual' ? NULL : $values['count'],
        'stars' => $settings['stars'],
        'microdata' => $settings['microdata'],
      ));
      $class[] = 'fivestar-user-text';
      break;
    case 'average':
      $element['vote']['#description'] = $settings['style'] == 'dual' ? NULL : theme('fivestar_summary', array(
        'average_rating' => $values['average'],
        'votes' => $values['count'],
        'stars' => $settings['stars'],
        'microdata' => $settings['microdata'],
      ));
      $class[] = 'fivestar-average-text';
      break;
    case 'smart':
      $element['vote']['#description'] = ($settings['style'] == 'dual' && !$values['user']) ? NULL : theme('fivestar_summary', array(
        'user_rating' => $values['user'],
        'average_rating' => $values['user'] ? NULL : $values['average'],
        'votes' => $settings['style'] == 'dual' ? NULL : $values['count'],
        'stars' => $settings['stars'],
        'microdata' => $settings['microdata'],
      ));
      $class[] = 'fivestar-smart-text';
      $class[] = $values['user'] ? 'fivestar-user-text' : 'fivestar-average-text';
      break;
    case 'dual':
      $element['vote']['#description'] = theme('fivestar_summary', array(
        'user_rating' => $values['user'],
        'average_rating' => $settings['style'] == 'dual' ? NULL : $values['average'],
        'votes' => $settings['style'] == 'dual' ? NULL : $values['count'],
        'stars' => $settings['stars'],
        'microdata' => $settings['microdata'],
      ));
      $class[] = ' fivestar-combo-text';
      break;
    case 'none':
      $element['vote']['#description'] = NULL;
      break;
  }

  switch ($settings['style']) {
    case 'average':
      $class[] = 'fivestar-average-stars';
      break;
    case 'user':
      $class[] = 'fivestar-user-stars';
      break;
    case 'smart':
      $class[] = 'fivestar-smart-stars ' . ($values['user'] ? 'fivestar-user-stars' : 'fivestar-average-stars');
      break;
    case 'dual':
      $class[] = 'fivestar-combo-stars';
      $static_average = theme('fivestar_static', array(
        'rating' => $values['average'],
        'stars' => $settings['stars'],
        'tag' => $settings['tag'],
        'widget' => $settings['widget'],
      ));
      if ($settings['text'] != 'none') {
        $static_description = theme('fivestar_summary', array(
          'average_rating' => $settings['text'] == 'user' ? NULL : (isset($values['average']) ? $values['average'] : 0),
          'votes' => isset($values['count']) ? $values['count'] : 0,
          'stars' => $settings['stars'],
        ));
      }
      else {
        $static_description = '&nbsp;';
      }
      $element['average'] = array(
        '#type' => 'markup',
        '#markup' => theme('fivestar_static_element', array(
          'star_display' => $static_average,
          'title' => '',
          'description' => $static_description,
        )),
        '#weight' => -1,
      );
      break;
  }
  $class[] = 'fivestar-form-item';
  $class[] = 'fivestar-' . $element['#widget']['name'];
  if ($element['#widget']['name'] != 'default') {
    $element['#attached']['css'][] = $element['#widget']['css'];
  }
  $element['#prefix'] = '<div ' . drupal_attributes(array('class' => $class)) . '>';
  $element['#suffix'] = '</div>';

  // Add AJAX handling if necessary.
  if (!empty($element['#auto_submit'])) {
    $element['vote']['#ajax'] = array(
      'callback' => 'fivestar_ajax_submit',
    );
    $element['vote']['#attached']['js'][] = $path . '/js/fivestar.ajax.js';
  }

  if (empty($element['#input'])) {
    $static_stars = theme('fivestar_static', array(
      'rating' => $element['vote']['#default_value'],
      'stars' => $settings['stars'],
      'tag' => $settings['tag'],
      'widget' => $settings['widget'],
    ));

    $element['vote'] = array(
      '#type' => 'markup',
      '#markup' => theme('fivestar_static_element', array(
        'star_display' => $static_stars,
        'title' => '',
        'description' => $element['vote']['#description'],
      )),
    );
  }

  // Add validation function that considers a 0 value as empty.
  $element['#element_validate'] = array('fivestar_validate');

  return $element;
}

/**
 * Helper function to get the correct default value for a fivestar element.
 *
 * @param $element
 *   The fivestar element
 * @return
 *   The default value for the element.
 */
function _fivestar_get_element_default_value($element) {
  if (isset($element['#default_value'])) {
    $default_value = $element['#default_value'];
  }
  else {
    switch ($element['#settings']['style']) {
      case 'average':
        $default_value = $element['#values']['average'];
        break;
      case 'user':
        $default_value = $element['#values']['user'];
        break;
      case 'smart':
        $default_value = (!empty($element['#values']['user']) ? $element['#values']['user'] : $element['#values']['average']);
        break;
      case 'dual':
        $default_value = $element['#values']['user'];
        break;
      default:
        $default_value = $element['#values']['average'];
    }
  }

  for ($i = 0; $i <= $element['#stars']; $i++) {
    $this_value = ceil($i * 100/$element['#stars']);
    $next_value = ceil(($i+1) * 100/$element['#stars']);

    // Round up the default value to the next exact star value if needed.
    if ($this_value < $default_value && $next_value > $default_value) {
      $default_value = $next_value;
    }
  }

  return $default_value;
}

/**
 * An #element_validate function for "fivestar" elements.
 */
function fivestar_validate($element, &$form_state) {
  if ($element['#required'] && (empty($element['#value']) || $element['#value'] == '-')) {
    form_error($element, t('@name field is required.', array('@name' => $element['#title'])));
  }
}

/**
 * Implementation of hook_votingapi_metadata_alter().
 */
function fivestar_votingapi_metadata_alter(&$data) {
  foreach (fivestar_get_tags() as $tag) {
    // Add several custom tags that are being used by fivestar.
    $data['tags'][$tag] = array(
      'name' => t($tag),
      'description' => t('@tag used by fivestar.', array('@tag' => $tag)),
      'module' => 'fivestar',
    );
  }
}

function fivestar_get_tags() {
  $tags_txt = variable_get('fivestar_tags', 'vote');
  $tags_exploded = explode(',', $tags_txt);

  $tags = array();
  $got_vote = FALSE;
  foreach ($tags_exploded as $tag) {
    $tag_trimmed = trim($tag);
    if ($tag_trimmed) {
      $tags[$tag_trimmed] = $tag_trimmed;
      if ($tag_trimmed == 'vote') {
        $got_vote = TRUE;
      }
    }
  }

  if (!$got_vote) {
    $tags['vote'] = 'vote';
  }
  return $tags;
}

function fivestar_get_targets($field, $instance, $key = FALSE, $entity = FALSE, $langcode = LANGUAGE_NONE) {
  $options = array();
  $targets = module_invoke_all('fivestar_target_info', $field, $instance);
  if ($key == FALSE) {
    foreach ($targets as $target => $info) {
      $options[$target] = $info['title'];
    }
    return $options;
  }
  else {
    if (isset($targets[$key]) && !empty($targets[$key]['callback']) && function_exists($targets[$key]['callback'])) {
      return call_user_func($targets[$key]['callback'], $entity, $field, $instance, $langcode);
    }
  }
}

/**
 * Implements hook_fivestar_target_info().
 */
function fivestar_fivestar_target_info($field, $instance) {
  $entity_type = $instance['entity_type'];
  $bundle = $instance['bundle'];
  $options = array(
    'none' => array(
      'title' => t('None'),
    ),
  );
  // Add node_referrence support.
  if (module_exists('node_reference')) {
    $field_names = array_keys(field_read_fields(array('module' => 'node_reference')));
    if (!empty($field_names)) {
      $field_instances = field_read_instances(array('entity_type' => $entity_type, 'bundle' => $bundle, 'field_name' => $field_names));
      if (!empty($field_instances)) {
        foreach ($field_instances as $field_instance) {
          $options[$field_instance['field_name']] = array(
            'title' => t('Node reference: @field', array('@field' => $field_instance['field_name'])),
            'callback' => '_fivestar_target_node_reference'
          );
        }
      }
    }
  }

  // Add entityreference support.
  if (module_exists('entityreference')) {
    $field_names = array_keys(field_read_fields(array('module' => 'entityreference')));
    if (!empty($field_names)) {
      $field_instances = field_read_instances(array('entity_type' => $entity_type, 'bundle' => $bundle, 'field_name' => $field_names));
      if (!empty($field_instances)) {
        foreach ($field_instances as $field_instance) {
          $options[$field_instance['field_name']] = array(
            'title' => t('Entity reference: @field', array('@field' => $field_instance['field_name'])),
            'callback' => '_fivestar_target_entityreference'
          );
        }
      }
    }
  }

  // Add user reference support.
  if (module_exists('user_reference')) {
    $field_names = array_keys(field_read_fields(array('module' => 'user_reference')));
    if (!empty($field_names)) {
      $field_instances = field_read_instances(array('entity_type' => $entity_type, 'bundle' => $bundle, 'field_name' => $field_names));
      if (!empty($field_instances)) {
        foreach ($field_instances as $field_instance) {
          $options[$field_instance['field_name']] = array(
            'title' => t('User reference: @field', array('@field' => $field_instance['field_name'])),
            'callback' => '_fivestar_target_user_reference'
          );
        }
      }
    }
  }

  // Add comment module support.
  if ($instance['entity_type'] == 'comment') {
    $options['parent_node'] = array(
      'title' => t('Parent Node'),
      'callback' => '_fivestar_target_comment_parent_node'
    );
  }

  return $options;
}

/**
 *
 * @return array
 *   array('entity_type', 'entity_id').
 */
function _fivestar_target_node_reference($entity, $field, $instance, $langcode) {
  $target = array();

  $node_reference = $instance['settings']['target'];
  if (isset($entity->{$node_reference}[$langcode][0]) && is_numeric($entity->{$node_reference}[$langcode][0]['nid'])) {
    $target['entity_id'] = $entity->{$node_reference}[$langcode][0]['nid'];
    $target['entity_type'] = 'node';
  }

  return $target;
}

/**
 * @return (array) array('entity_type', 'entity_id')
 */
function _fivestar_target_entityreference($entity, $field, $instance, $langcode) {
  $target = array();

  $entityreference = $instance['settings']['target'];

  // Retrieve entity settings for the referenced field.
  $field_info = field_info_field($entityreference);

  if (isset($entity->{$entityreference}[$langcode][0]) && isset($entity->{$entityreference}[$langcode][0]['target_id']) && is_numeric($entity->{$entityreference}[$langcode][0]['target_id'])) {
    $target['entity_id'] = $entity->{$entityreference}[$langcode][0]['target_id'];
    $target['entity_type'] = $field_info['settings']['target_type'];
  }

  return $target;
}

/**
 *
 * @return array
 *   array('entity_type', 'entity_id').
 */
function _fivestar_target_user_reference($entity, $field, $instance, $langcode) {
  $target = array();

  $user_reference = $instance['settings']['target'];
  if (isset($entity->{$user_reference}[$langcode][0]) && is_numeric($entity->{$user_reference}[$langcode][0]['uid'])) {
    $target['entity_id'] = $entity->{$user_reference}[$langcode][0]['uid'];
    $target['entity_type'] = 'user';
  }

  return $target;
}

function _fivestar_target_comment_parent_node($entity, $field, $instance, $langcode) {
  return array(
    'entity_id' => $entity->nid,
    'entity_type' => 'node',
  );
}

/**
 * Helper function to determine if a user can vote on content.
 *
 * @return Boolean
 */
function _fivestar_allow_vote($element) {
  global $user;

  // Check allowed to re-vote.
  $can_revote = FALSE;
  if ($element['#allow_revote']) {
    $can_revote = TRUE;
  }
  else {
    $criteria = array(
      'entity_id' => isset($element['#settings']['content_id']) ? $element['#settings']['content_id'] : NULL,
      'entity_type' => isset($element['#settings']['content_type']) ? $element['#settings']['content_type'] : NULL,
      'uid' => $user->uid,
    );

  $can_revote = !votingapi_select_votes($criteria);
  }
  if (!$can_revote) {
    return FALSE;
  }
  // Check allowed own vote.
  if ($element['#allow_ownvote']) {
    return TRUE;
  }
  // Check that we have entity details, allow if not.
  if (!isset($element['#settings']['entity_id']) || !isset($element['#settings']['entity_type'])) {
    return TRUE;
  }
  $entity_id = $element['#settings']['entity_id'];
  $entity = entity_load($element['#settings']['entity_type'], array($entity_id));
  $entity = $entity[$entity_id];
  $uid1 = $entity->uid;
  $uid2 = $user->uid;
  return $entity->uid != $user->uid;
}