<?php

/**
 * @file
 * Main module functions for the uuid module.
 */

/**
 * Include main API functions.
 */
module_load_include('inc', 'uuid', 'uuid');

/**
 * Include the Entity API implementation of the UUID API.
 */
module_load_include('inc', 'uuid', 'uuid.entity');

/**
 * Include implementations for all core modules.
 *
 * Instead of having separate modules for all core implementations this file
 * implements all of them in their own name space. In some cases this adds some
 * unecessary code weight, but instead it saves us from module mania.
 */
module_load_include('inc', 'uuid', 'uuid.core');

/**
 * Implements hook_menu().
 */
function uuid_menu() {
  $items = array();

  $items['uuid'] = array(
    'title' => 'UUID redirector',
    'description' => 'Redirects requests for UUID URIs to the referenced entity.',
    'page callback' => 'uuid_redirector',
    // The access check is handled in the page callback.
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['admin/config/system/uuid'] = array(
    'title' => 'Universally unique identifiers',
    'description' => 'Configure universally unique identifiers.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('uuid_admin_form'),
    'access arguments' => array('administer uuid'),
    'file' => 'uuid.admin.inc',
  );

  // Conditional support for Devel. A good thing for developers.
  if (module_exists('devel')) {
    $entity_types = array(
      'user' => array('path' => 'user/%user/devel/load-by-uuid', 'arg' => 1),
      'node' => array('path' => 'node/%node/devel/load-by-uuid', 'arg' => 1),
      'comment' => array('path' => 'comment/%comment/devel/load-by-uuid', 'arg' => 1),
      'taxonomy_term' => array('path' => 'taxonomy/term/%taxonomy_term/devel/load-by-uuid', 'arg' => 2),
    );
    foreach ($entity_types as $entity_type => $info) {
      $items[$info['path']] = array(
        'title' => 'Load by UUID',
        'page callback' => 'uuid_devel_load_by_uuid',
        'page arguments' => array($entity_type, $info['arg']),
        'access arguments' => array('access devel information'),
        'type' => MENU_LOCAL_TASK,
        'file' => 'uuid.admin.inc',
        'weight' => 100,
      );
    }
  }
  return $items;
}

/**
 * Implements hook_ctools_plugin_directory().
 */
function uuid_ctools_plugin_directory($module, $plugin) {
  if ($module == 'ctools') {
    return 'plugins/' . $plugin;
  }
}

/**
 * Implements hook_permission().
 */
function uuid_permission() {
  return array(
    'administer uuid' => array(
      'title' => t('Administer UUID'),
      'description' => t('Allows configuration of the UUID module and APIs.'),
    ),
  );
}

/**
 * Implements hook_hook_info().
 */
function uuid_hook_info() {
  $hook_names = array(
    'uuid_info',
    'uuid_sync',
    'entity_uuid_load',
    'field_uuid_load',
    'entity_uuid_presave',
    'entity_uuid_save',
    'entity_uuid_delete',
    'field_uuid_presave',
    'uuid_menu_path_to_uri_alter',
    'uuid_menu_uri_to_path_alter',
    'uuid_default_entities',
    'uuid_entities_pre_rebuild',
    'uuid_entities_pre_revert',
    'uuid_entities_post_rebuild',
    'uuid_entities_post_revert',
    'uuid_entities_features_export_entity_alter',
    'uuid_entities_features_export_field_alter',
    'uuid_uri_data',
    'uuid_id_uri_data',
    'uuid_uri_data',
    'uuid_id_uri_data',
  );

  return array_fill_keys($hook_names, array('group' => 'uuid'));
}

/**
 * Implements hook_views_api().
 */
function uuid_views_api() {
  return array(
    'api' => 2,
    'path' => drupal_get_path('module', 'uuid'),
  );
}

/**
 * Implements hook_module_implements_alter().
 *
 * Moves hook_entity_info_alter() implementation to the bottom so it is
 * invoked after all modules relying on the entity API.
 *
 * @see uuid_entity_info_alter()
 */
function uuid_module_implements_alter(&$implementss, $hook) {
  if ($hook == 'entity_info_alter') {
    // Move our hook Implements to the bottom.
    $group = $implementss['uuid'];
    unset($implementss['uuid']);
    $implementss['uuid'] = $group;
  }
}

/**
 * Implements hook_uuid_sync().
 */
function uuid_uuid_sync() {
  foreach (entity_get_info() as $info) {
    if (isset($info['uuid']) && $info['uuid'] == TRUE && !empty($info['entity keys']['uuid'])) {
      _uuid_sync_table($info['base table'], $info['entity keys']['id'], $info['entity keys']['uuid']);
      if (!empty($info['entity keys']['revision uuid'])) {
        _uuid_sync_table($info['revision table'], $info['entity keys']['revision'], $info['entity keys']['revision uuid']);
      }
    }
  }
}

/**
 * Helper function that executes the update on the actual table.
 */
function _uuid_sync_table($table, $id_field, $uuid_field) {
  // Fetch empty records.
  $result = db_select($table, 't')
    ->fields('t', array($id_field))
    ->condition(db_or()->condition($uuid_field, '')->isNull($uuid_field))
    ->execute();

  // Update empty records.
  foreach ($result as $record) {
    db_update($table)
      ->fields(array($uuid_field => uuid_generate()))
      ->condition($id_field, $record->{$id_field})
      ->execute();
  }
}

/**
 * Implements hook_features_api().
 *
 * The Features support consists of exporting entities from a Deploy
 * <em>fetch-only</em> plan. Deploy is only required to generate the feature
 * it self.
 *
 * The reason why we depend on Deploy for the generation of the content is
 * because Deploy has the kind of dependency detection framework we need, to
 * identify all dependencies for all entities.
 */
function uuid_features_api() {
  return array(
    'uuid_entities' => array(
      'name' => t('UUID entities'),
      'default_hook' => 'uuid_default_entities',
      'default_file' => FEATURES_DEFAULTS_INCLUDED,
      'feature_source' => TRUE,
      'file' => drupal_get_path('module', 'uuid') . '/uuid.features.inc',
    ),
  );
}

/**
 * Redirects all UUID URI requests to the appropriate entity page.
 */
function uuid_redirector() {
  $entity_data = uuid_uri_array_to_data(arg());

  $entity_info = entity_get_info($entity_data['entity_type']);
  if (empty($entity_info['uuid'])) {
    return MENU_NOT_FOUND;
  }

  $entities = entity_uuid_load($entity_data['entity_type'], array($entity_data['uuid']));
  if (!count($entities)) {
    return MENU_NOT_FOUND;
  }

  $uri = entity_uri($entity_data['entity_type'], current($entities));

  if (!drupal_valid_path($uri['path'])) {
    return MENU_ACCESS_DENIED;
  }

  drupal_goto($uri['path'], $uri['options'], 301);
}