<?php
// $Id: i18n_field.module,v 1.1.2.3 2011-02-14 11:36:29 jareyero Exp $

/**
 * @file
 * Internationalization (i18n) module - Field handling
 * 
 * Notes:
 * - Field titles are already translated with t(), which is a pity, but nothing to do here
 * 
 * For string keys we use:
 * - field:[field_name]:[bundle]:property, when it is an instance property (linked to bundle)
 * - field:[field_name]:#property..., when it is a field property (that may have multiple values)
 */

/**
 * Implements hook_i18n_string_info()
 */
function i18n_field_i18n_string_info() {
  $groups['field'] = array(
    'title' => t('Fields'),
    'description' => t('Configurable fields descriptions, defaults, options, etc.'),
    'format' => FALSE, // This group doesn't have formatted strings
  );
  return $groups;
}

/**
 * Implements hook_i18n_string_list()
 */
function i18n_field_i18n_string_list($group) {
  if ($group == 'field'  || $group == 'all') {
    
  } 
}

/**
 * Implements hook_field_attach_form().
 * 
 * After the form fields are built
 */
function i18n_field_field_attach_form($entity_type, $entity, $form, $form_state, $langcode) {
}

/**
 * Implements hook_field_info_alter().
 * 
 * Cached, invoked only after field info is rebuilt
 */
function i18n_field_field_info_alter(&$info) {
}

/**
 * Implements hook_field_formatter_info().
 */
function i18n_field_field_formatter_info() {
  $types = array();
  foreach (i18n_field_type_info() as $type => $info) {
    if (!empty($info['translate_options'])) {
      $types[] = $type;
    }
  }
  return array(
    'i18n_list_default' => array(
      'label' => t('Default translated'),
      'field types' => $types,
    ),
  );
}

/**
 * Implements hook_field_formatter_view().
 */
function i18n_field_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $element = array();

  switch ($display['type']) {
    case 'i18n_list_default':
      if (($translate = i18n_field_type_info($field['type'], 'translate_options'))) {
        $allowed_values = $translate($field, $langcode);
      }
      else {
        // Defaults to list_default behavior
        $allowed_values = list_allowed_values($field);
      }
      foreach ($items as $delta => $item) {
        if (isset($allowed_values[$item['value']])) {
          $output = field_filter_xss($allowed_values[$item['value']]);
        }
        else {
          // If no match was found in allowed values, fall back to the key.
          $output = field_filter_xss($item['value']);
        }
        $element[$delta] = array('#markup' => $output);
      }
      break;
  }

  return $element;
}

/**
 * Implements hook_field_widget_info_alter()
 * 
 * Cached, invoked only after widget info is rebuilt
 */
function i18n_field_field_widget_info_alter(&$info) {
}

/**
 * Implements hook_field_widget_properties_alter().
 * 
 * This is called for the entity edit form and for the fields edit form
 */
function i18n_field_field_widget_properties_alter(&$widget, $context) {
  // Skip the node type edit fields by checking for existing entity
  if (!empty($context['entity']) && !empty($widget['module']) && function_exists($function = $widget['module'] . '_field_widget_form')) {
    $widget['module'] = 'i18n_field';
    $widget['i18n_field_callbacks'][] = $function;
  }
}

function i18n_field_field_extra_fields_display_alter(&$displays, $context) {
  
}

/**
 * Implements hook_field_display_alter().
 * 
 * Called only when refreshing cache
 */
function i18n_field_field_display_alter(&$display, $context) {

}

function i18n_field_field_storage_info_alter(&$info) {

}

/**
 * Field API callback to rewrite field element
 * 
 * Translate:
 * - Description (help)
 * - Default value
 * @see field_default_form()
 */
function i18n_field_field_widget_form($form, $form_state, $field, $instance, $langcode, $items, $delta, $element) {
  global $language;
  // The field language may affect some variables (default) but not others (description will be in current page language)
  $langcode = empty($element['#language']) || $element['#language'] == LANGUAGE_NONE ? $language->language : $element['#language']; 
  $delta = $element['#delta'];

  $translate = array(
    'description' => array('filter' => 'field_filter_xss'),
    //'default_value' => array('langcode' => $langcode),
  );

  foreach ($translate as $property => $options) {
   
  }
  // Translate field description if set
  if (!empty($instance['description'])) {
    $element['#description'] = i18n_field_translate_property($instance, 'description');
  }  
  // Translate default value if exists and the current value is the default
  if (($translate = i18n_field_type_info($field['type'], 'translate_default')) && !empty($instance['default_value'][$delta]['value']) && !empty($items[$delta]['value']) && $instance['default_value'][$delta]['value'] === $items[$delta]['value']) {
    $items[$delta]['value'] = $translate($instance, $items[$delta]['value'], $langcode);
  }
  // Translate list options
  if (($translate = i18n_field_type_info($field['type'], 'translate_options')) && !empty($field['settings']['allowed_values'])) {
    $field['settings']['allowed_values'] = $translate($field, $langcode);
  }
  // Redirect through original module_field_widget_form()
  if (!empty($instance['widget']['i18n_field_callbacks'])) {
    foreach ($instance['widget']['i18n_field_callbacks'] as $function) {
      $element = $function($form, $form_state, $field, $instance, $langcode, $items, $delta, $element);
    }
  }
  return $element;
}

/**
 * Implements hook_field_create_field()
 */
function i18n_field_field_create_field($field) {
  i18n_field_field_update_strings($field);
}

/**
 * Implements hook_field_create_instance();
 */
function i18n_field_field_create_instance($instance) {
  i18n_field_instance_update_strings($instance);
}

/**
 * Implements hook_field_delete_instance();
 */
function i18n_field_field_delete_instance($instance) {
  foreach (array('description', 'default_value') as $property) {
    i18n_string_remove(array('field', $instance['bundle'], $instance['field_name'], $property));
  }
}

/**
 * Implements hook_field_update_instance();
 */
function i18n_field_field_update_instance($instance, $prior_instance) {
  i18n_field_instance_update_strings($instance);
}

/**
 * Implements hook_field_update_field()
 */
function i18n_field_field_update_field($field) {
  i18n_field_field_update_strings($field);
}

/**
 * Update field strings
 */
function i18n_field_field_update_strings($field) {
  // For select fields field:field_name
  if (!empty($field['settings']['allowed_values']) && i18n_field_type_info($field['type'], 'translate_options')) {
    i18n_string_update(array('field', $field['field_name'],'#allowed_values'), $field['settings']['allowed_values']);
  }  
}

/**
 * Update field instance strings
 */
function i18n_field_instance_update_strings($instance) {
  $field = field_info_field($instance['field_name']);
  if (isset($instance['description'])) {
    i18n_string_update(array('field', $instance['field_name'], $instance['bundle'], 'description'), $instance['description']);
  }
  // Only for text field types
  if (isset($instance['default_value']) && i18n_field_type_info($field['type'], 'translate_default')) {
    $format = isset($instance['default_value'][0]['format']) ? $instance['default_value'][0]['format'] : NULL;
    i18n_string_update(array('field', $instance['field_name'], $instance['bundle'], 'default_value'), $instance['default_value'][0]['value'], array('format' => $format));
  }

}

/**
 * Returns the array of translated allowed values for a list field.
 *
 * The strings are not safe for output. Keys and values of the array should be
 * sanitized through field_filter_xss() before being displayed.
 *
 * @param $field
 *   The field definition.
 *
 * @return
 *   The array of allowed values. Keys of the array are the raw stored values
 *   (number or text), values of the array are the display labels.
 */
function i18n_field_translate_allowed_values($field, $langcode = NULL) {
  if (!empty($field['settings']['allowed_values'])) {
    return i18n_string_translate(array('field', $field['field_name'], '#allowed_values'), $field['settings']['allowed_values'], array('langcode' => $langcode));
  }
  else {
    return array();
  }
}

/**
 * Translate field default
 */
function i18n_field_translate_default($instance, $value, $langcode = NULL) {
  return i18n_string_translate(array('field', $instance['field_name'], $instance['bundle'], 'default_value'), $value, array('langcode' => $langcode));
}

/**
 * Translate field property
 */
function i18n_field_translate_property($instance, $property, $langcode = NULL) {
  return i18n_string_translate(array('field', $instance['field_name'], $instance['bundle'], $property), $instance[$property], array('langcode' => $langcode));
}

/**
 * Get i18n information for fields
 */
function i18n_field_type_info($type = NULL, $property = NULL) {
  $info = &drupal_static(__FUNCTION__);
  if (!isset($info)) {
    $info = module_invoke_all('i18n_field_info');
    drupal_alter('i18n_field_info', $info);
  }
  if ($property) {
    return isset($info[$type]) && isset($info[$type][$property]) ? $info[$type][$property] : NULL;
  }
  elseif ($type) {
    return isset($info[$type]) ? $info[$type] : array();
  }
  else {
    return $info;
  }
}

/**
 * Implements hook_i18n_field_info()
 */
function i18n_field_i18n_field_info() {
  $info['text'] = $info['text_long'] = $info['text_with_summary'] = array(
    'translate_default' => 'i18n_field_translate_default',
  );
  $info['list_text'] = $info['list_boolean'] = array(
    'translate_options' => 'i18n_field_translate_allowed_values',
  );
  return $info;
}