<?php

/**
 * @file
 * Provides a caption textarea for image fields.
 */

/**
 * Implements hook_theme_registry_alter().
 */
function image_field_caption_theme_registry_alter(&$theme_registry) {
  // Override the image_formatter function and add caption as a variable to be
  // assembled by theme().
  $theme_registry['image_formatter']['theme path'] = drupal_get_path('module', 'image_field_caption');
  $theme_registry['image_formatter']['function'] = 'image_field_caption_image_formatter';
  $theme_registry['picture_formatter']['function'] = 'image_field_caption_picture_formatter';
  $theme_registry['picture_sizes_formatter']['function'] = 'image_field_caption_picture_sizes_formatter';
}

/**
 * Override of theme_image_formatter().
 */
function image_field_caption_image_formatter($variables) {
  $image = theme_image_formatter($variables);
  // Now that Drupal has rendered the image, if there was a caption let's
  // render the image and the caption, otherwise just return the already
  // rendered image.
  if (isset($variables['item']['image_field_caption']) && !empty($variables['item']['image_field_caption']['value'])) {
    return theme('image_field_caption', array(
      'image' => $image,
      'caption' => check_markup($variables['item']['image_field_caption']['value'], $variables['item']['image_field_caption']['format']),
    ));
  }
  else {
    return $image;
  }
}

/**
 * Override of theme_picture_formatter().
 */
function image_field_caption_picture_formatter($variables) {
  $image = theme_picture_formatter($variables);
  // Now that Drupal has rendered the image, if there was a caption let's
  // render the image and the caption, otherwise just return the already
  // rendered image.
  if (isset($variables['item']['image_field_caption']) && !empty($variables['item']['image_field_caption']['value'])) {
    return theme('image_field_caption', array(
      'image' => $image,
      'caption' => check_markup($variables['item']['image_field_caption']['value'], $variables['item']['image_field_caption']['format']),
    ));
  }
  else {
    return $image;
  }
}

/**
 * Override of theme_picture_sizes_formatter().
 */
function image_field_caption_picture_sizes_formatter($variables) {
  $image = theme_picture_sizes_formatter($variables);
  // Now that Drupal has rendered the image, if there was a caption let's
  // render the image and the caption, otherwise just return the already
  // rendered image.
  if (isset($variables['item']['image_field_caption']) && !empty($variables['item']['image_field_caption']['value'])) {
    return theme('image_field_caption', array(
      'image' => $image,
      'caption' => check_markup($variables['item']['image_field_caption']['value'], $variables['item']['image_field_caption']['format']),
    ));
  }
  else {
    return $image;
  }
}

/**
 * Implements hook_theme().
 */
function image_field_caption_theme($existing, $type, $theme, $path) {
  return array(
    'image_field_caption' => array(
      'template' => 'image_field_caption',
      'variables' => array('image' => NULL, 'caption' => NULL),
    ),
  );
}

/**
 * Given an entity type and bundle name, this will return an associative array
 * of image field info instances, keyed by image field machine names. Returns
 * null if no image fields are found.
 */
function image_field_caption_get_image_fields($entity_type = NULL, $bundle = NULL) {
  // TODO: As of Drupal 7.22 use field_info_field_map() instead of field_info_instances();
  $image_fields = array();
  $fields = field_info_instances($entity_type, $bundle);
  foreach ($fields as $field_name => $field) {
    // Skip any deleted and non image widget fields.
    if ($field['deleted'] == 1) {
      continue;
    }

    $field_info = field_info_field($field_name);
    if ($field_info['type'] != 'image') {
      continue;
    }
    $image_fields[$field_name] = $field;
  }

  return $image_fields;
}

/**
 * Implements hook_form_alter().
 */
function image_field_caption_form_field_ui_field_edit_form_alter(&$form, $form_state) {
  $instance = $form['#instance'];
  $field = $form['#field'];

  if ($field['type'] == 'image') {
    $field = $form['#field'];
    if (empty($form['instance']['settings'])) {
      $form['instance']['settings'] = array();
    }
    $form['instance']['settings'] += image_field_caption_field_instance_settings_form($field, $instance);
  }
}

/**
 * Configuration form for editing insert settings for a field instance.
 */
function image_field_caption_field_instance_settings_form($field, $instance) {
  $form['image_field_caption'] = array(
    '#type' => 'fieldset',
    '#title' => t('Caption Settings'),
    '#weight' => 12,
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
  );

  $form['image_field_caption']['enabled'] = array(
    '#type' => 'checkbox',
    '#title' => t('Enable Caption'),
    '#default_value' => $instance['settings']['image_field_caption']['enabled'],
    '#description' => t('Adds an extra text area for captions on image fields.'),
    '#weight' => 12,
  );

  $form['image_field_caption_wrapper'] = array(
    '#type' => 'fieldset',
    '#title' => t('Image field caption settings'),
    '#weight' => 12.1,
    '#collapsible' => FALSE,
    '#collapsed' => FALSE,
    '#states' => array(
      'visible' => array(
        ':input[name="instance[settings][image_field_caption][enabled]"]' => array('checked' => TRUE),
      ),
    ),
  );
  $form['image_field_caption_wrapper']['image_field_caption_default'] = array(
    '#type' => 'text_format',
    '#title' => t('Default caption text'),
    '#default_value' => $instance['settings']['image_field_caption_wrapper']['image_field_caption_default']['value'],
    '#format' => $instance['settings']['image_field_caption_wrapper']['image_field_caption_default']['format'],
    '#weight' => 12.1,
  );
  return $form;
}

function image_field_caption_field_widget_form_alter(&$element, &$form_state, $context) {
  // Add display_field setting to field because file_field_widget_form() assumes it is set.
  $instance = $context['instance'];
  $settings = $instance['settings'];
  $field = $context['field'];
  if (isset($settings['image_field_caption']['enabled']) && $field['type'] == 'image' && $settings['image_field_caption']['enabled']) {
    foreach (element_children($element) as $delta) {
      // Add all extra functionality provided by the image widget.
      $element[$delta]['#process'][] = 'image_field_caption_widget_process';
      $element[$delta]['#settings']['image_field_caption_default'] = $settings['image_field_caption_wrapper']['image_field_caption_default'];
   }
  }
}

/**
 * An element #process callback for the image field type.
 *
 * Expands the image type to include the caption.
 */
function image_field_caption_widget_process($element, &$form_state, $form) {
  $item = $element['#value'];
  // Add the caption field with its value and text format. If there is no file
  // uri then we'll use the instance setting defaults, otherwise there is no
  // way to tell if this is a new image or not.
  $element['image_field_caption'] = array(
    '#title' => t('Caption'),
    '#type' => 'text_format',
    '#default_value' => isset($item['image_field_caption']['value']) ? $item['image_field_caption']['value'] : $element['#settings']['image_field_caption_default']['value'],
    '#access' => (bool) $item['fid'],
    '#format' => isset($item['image_field_caption']['format']) ? $item['image_field_caption']['format'] : $element['#settings']['image_field_caption_default']['format']
  );
  return $element;
}

function image_field_caption_field_info_alter(&$info) {
  // Add a setting to all field types.
  foreach ($info as $field_type => $field_type_info) {
    if ($field_type == 'image') {
      $info['image']['instance_settings'] += array(
        'image_field_caption' => array(
          'enabled' => 0,
        ),
        'image_field_caption_wrapper' => array(
          'image_field_caption_default' => array(
            'value' => '',
            'format' => filter_default_format(),
          ),
        ),
      );
    }
  }
}

/**
 * Implements hook_field_attach_insert().
 */
function image_field_caption_field_attach_insert($entity_type, $entity) {
  image_field_caption_field_attach_update($entity_type, $entity);
}

/**
 * Implements hook_field_attach_update().
 */
function image_field_caption_field_attach_update($entity_type, $entity) {
  list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);

  if (!isset($vid)) {
    $vid = $id;
  }

  $image_fields = image_field_caption_get_image_fields($entity_type, $bundle);

  foreach ($image_fields as $field_name => $image_field) {

    // Skip the caption when it isn't present, or if it is disabled.
    if (
      !isset($image_field['settings']['image_field_caption']) ||
      !$image_field['settings']['image_field_caption']['enabled']
    ) { continue; }

    $field = field_info_field($field_name);
    $table_name = 'field_image_field_caption';
    $revision_name = 'field_image_field_caption_revision';

    $all_languages = field_available_languages($entity_type, $field);
    if (!isset($entity->$field_name)) { continue; }
    $field_languages = array_intersect($all_languages, array_keys((array) $entity->$field_name));

    // Delete and insert, rather than update, in case a value was added.
    // Delete languages present in the incoming $entity->$field_name.
    // Delete all languages if $entity->$field_name is empty.
    $languages = !empty($entity->$field_name) ? $field_languages : $all_languages;
    if ($languages) {
      db_delete($table_name)
        ->condition('field_name', $field_name)
        ->condition('entity_type', $entity_type)
        ->condition('entity_id', $id)
        ->condition('language', $languages, 'IN')
        ->execute();
      db_delete($revision_name)
        ->condition('field_name', $field_name)
        ->condition('entity_type', $entity_type)
        ->condition('entity_id', $id)
        ->condition('revision_id', $vid)
        ->condition('language', $languages, 'IN')
        ->execute();
    }

    // Prepare the multi-insert query.
    $do_insert = FALSE;
    $columns = array('field_name', 'entity_type', 'entity_id', 'revision_id', 'bundle', 'delta', 'language', 'caption', 'caption_format');
    $query = db_insert($table_name)->fields($columns);
    $revision_query = db_insert($revision_name)->fields($columns);

    foreach ($field_languages as $langcode) {

      $items = (array) $entity->{$field_name}[$langcode];
      $delta_count = 0;
      foreach ($items as $delta => $item) {
        if (empty($item['image_field_caption']['value'])) { continue; }
        // We now know we have someting to insert.
        $do_insert = TRUE;
        $record = array(
          'field_name' => $field_name,
          'entity_type' => $entity_type,
          'entity_id' => $id,
          'revision_id' => $vid,
          'bundle' => $bundle,
          'delta' => $delta,
          'language' => $langcode,
          'caption' => $item['image_field_caption']['value'],
          'caption_format' => $item['image_field_caption']['format'],
        );
        $query->values($record);
        if (isset($vid)) {
          $revision_query->values($record);
        }

        if ($field['cardinality'] != FIELD_CARDINALITY_UNLIMITED && ++$delta_count == $field['cardinality']) {
          break;
        }
      }
    }

    // Execute the query if we have values to insert.
    if ($do_insert) {
      $query->execute();
      $revision_query->execute();
    }
  }
}

/**
 * Implements hook_field_attach_load().
 */
function image_field_caption_field_attach_load($entity_type, $entities, $age, $options) {
  foreach ($entities as $entity) {
    list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);
    if (!isset($vid)) {
      $vid = $id;
    }

    $load_current = $age == FIELD_LOAD_CURRENT;

    $table = $load_current ? 'field_image_field_caption' : 'field_image_field_caption_revision';

    $query = db_select($table, 't')
      ->fields('t')
      ->condition('entity_type', $entity_type)
      ->condition($load_current ? 'entity_id' : 'revision_id', $load_current ? $id : $vid)
      ->orderBy('delta');

    $results = $query->execute();

    foreach ($results as $row) {
      $field = field_info_instance($entity_type, $row->field_name, $bundle);
      if (
        !isset($field['settings']['image_field_caption']) ||
        !$field['settings']['image_field_caption']['enabled']
      ) { continue; }

      $item['image_field_caption']['value'] = $row->caption;
      $item['image_field_caption']['format'] = $row->caption_format;

      // Add the item to the field values for the entity.
      $entities[$row->entity_id]->{$row->field_name}[$row->language][$row->delta]['image_field_caption']['value'] = $row->caption;
      $entities[$row->entity_id]->{$row->field_name}[$row->language][$row->delta]['image_field_caption']['format'] = $row->caption_format;
    }
  }
}

/**
 * Implements hook_field_attach_delete().
 */
function image_field_caption_field_attach_delete($entity_type, $entity) {
  list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);

  foreach (field_info_instances($entity_type, $bundle) as $instance) {
    $field = field_info_field_by_id($instance['field_id']);
    image_field_caption_field_attach_purge($entity_type, $entity, $field, $instance);
  }
}

/**
 * Implements hook_field_attach_purge().
 */
function image_field_caption_field_attach_purge($entity_type, $entity, $field, $instance) {
  list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);

  $field_name = is_object($field) ? $field->field_name : $field['field_name'];

  $table_name = 'field_image_field_caption';
  $revision_name = 'field_image_field_caption_revision';
  db_delete($table_name)
    ->condition('entity_type', $entity_type)
    ->condition('entity_id', $id)
    ->condition('field_name', $field_name)
    ->execute();
  db_delete($revision_name)
    ->condition('entity_type', $entity_type)
    ->condition('entity_id', $id)
    ->condition('field_name', $field_name)
    ->execute();
}


/**
 * Implements hook_field_attach_delete_revision().
 */
function image_field_caption_field_attach_delete_revision($entity_type, $entity) {
  list($id, $vid, $bundle) = entity_extract_ids($entity_type, $entity);

  if (isset($vid)) {
    $revision_name = 'field_image_field_caption_revision';
    db_delete($revision_name)
      ->condition('entity_type', $entity_type)
      ->condition('entity_id', $id)
      ->condition('revision_id', $vid)
      ->execute();
  }
}

/**
 * Implements field_diff_view_alter().
 */
function image_field_caption_field_diff_view_alter(&$values, $items, $context) {
  $field = $context['field'];
  $instance = $context['instance'];
  $settings = $context['settings'];

  // Only handle image fields
  if ($field['type'] != 'image' || !$instance['settings']['image_field_caption']) {
    return;
  }

  foreach ($items as $delta => $item) {
    $format_id = empty($item['image_field_caption']['format']) ? filter_fallback_format() : $item['image_field_caption']['format'];
    if ($format = filter_format_load($format_id)) {
      $format_text = $format->name;
    }
    else {
      $format_text = t('Missing format !format', array('!format' => $format_id));
    }

    if (!is_array($values[$delta])) {
      $values[$delta] = array($values[$delta]);
    }

    $values[$delta][] = t('Caption (!text_format):', array('!text_format' => $format_text));

    // Allow users to optionally clean system specific characters.
    $values[$delta][] = diff_normalise_text($item['image_field_caption']['value']);
  }
}


/**
 * Implements of hook_views_api().
 */
function image_field_caption_views_api() {
  return array(
    'api' => 3,
    'path' => drupal_get_path('module', 'image_field_caption') . '/views',
  );
}