<?php

/**
 * @file
 * (Un-) installation tasks for content taxonomy.
 */

/**
 * Implements hook_disable().
 *
 * Allow uninstall of content taxonomy by removing the callback in field
 * configuration. Re-enabling requires to save the field configs to re-insert
 * the callback.
 */
function content_taxonomy_disable() {
  $fields = field_read_fields();
  foreach ($fields as $field) {
    if (isset($field['settings']['options_list_callback']) && $field['settings']['options_list_callback'] == 'content_taxonomy_allowed_values') {
      // We cannot unset this value, because field_update_field() merges in
      // prior settings before saving. Setting it to NULL works.
      $field['settings']['options_list_callback'] = NULL;
    }
    field_update_field($field);
  }
}

/**
 * Implementations of hook_update_N().
 */

/**
 * Fix the default values converted from D6. These values had an empty 'value'
 * value which could cause errors on D7.
 */
function content_taxonomy_update_7100() {
  $params = array(
    'type' => 'taxonomy_term_reference',
  );
  foreach (field_read_fields($params) as $field) {
    foreach (field_read_instances(array('field_name' => $field['field_name'])) as $instance) {
      // If the 'default_value' item doesn't exist there's no point in
      // continuing.
      if (!isset($instance['default_value'])) {
        continue;
      }

      // Keep track of whether fields are actually changed.
      $updated = FALSE;

      // Fix each of the default values.
      foreach ($instance['default_value'] as $key => $defaults) {
        // Need to check isset() and is_null() because the value could be NULL.
        if (isset($instance['default_value'][$key]['value']) || is_null($instance['default_value'][$key]['value'])) {
          // Remove any empty 'value' strings.
          if (empty($instance['default_value'][$key]['value'])) {
            unset($instance['default_value'][$key]['value']);
            $updated = TRUE;
          }

          // Rename the 'value' string to 'tid'.
          elseif (!isset($instance_value['default_value'][$key]['tid'])) {
            $instance_value['default_value'][$key]['tid'] = $instance_value['default_value'][$key]['value'];
            unset($instance_value['default_value'][$key]['value']);
            $updated = TRUE;
          }

          // Look for a junk value carried over from D6.
          if (isset($instance['default_value'][$key]['_error_element'])) {
            unset($instance['default_value'][$key]['_error_element']);
            $updated = TRUE;
          }

          // If the array is empty, just remove it.
          if (empty($instance['default_value'][$key])) {
            unset($instance['default_value'][$key]);
            $updated = TRUE;
          }
        }
      }

      // If there are no default values left, just remove it.
      if (empty($instance['default_value'])) {
        unset($instance['default_value']);
        $updated = TRUE;
      }

      // If the field's definition was changed, save it.
      if ($updated) {
        field_update_instance($instance);
        drupal_set_message(t('Fixed configuration of the "@field_name" field ("@type" content type).', array('@field_name' => $instance['field_name'], '@type' => $instance['bundle'])));
      }
    }
  }
}