<?php

/**
 * @file
 * Coffee primary module file
 *
 * Implements hook_perm, hook_menu, hook_init
 * and a function to handle the result for Coffee.
 */

/**
 * Implements hook_permission().
 */
function coffee_permission() {
  return array(
    'access coffee' => array(
      'title' => t('Access Coffee'),
      'description' => t('Access the Coffee search box to navigate fast between admin pages'),
    ),
    'administer coffee' => array(
      'title' => t('Administer Coffee'),
      'description' => t('Administer the Coffee search module'),
    ),
  );
}

/**
 * Implements hook_menu().
 */
function coffee_menu() {
  $items = array();
  $path = drupal_get_path('module', 'coffee');

  // Define callback for menu structure callback.
  $items['admin/coffee/menu'] = array(
    'title' => 'Coffee Menu Response',
    'page callback' => 'coffee_get_menu_response',
    'access arguments' => array('access coffee'),
    'type' => MENU_CALLBACK,
  );

  $items['admin/config/user-interface/coffee'] = array(
    'title' => 'Coffee',
    'description' => 'Configuration for the Coffee module.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('coffee_admin_settings'),
    'access arguments' => array('administer coffee'),
    'type' => MENU_NORMAL_ITEM,
    'file' => 'coffee.admin.inc',
    'file path' => $path,
  );

  return $items;
}

/**
 * Implements hook_page_build().
 */
function coffee_page_build() {
  // Only users with the permission "access coffee" can use Coffee.
  if (user_access('access coffee')) {
    // Add the javascript and css files.
    drupal_add_library('system', 'ui.autocomplete');
    drupal_add_js(drupal_get_path('module', 'coffee') . '/js/coffee.js', array('type' => 'file'));
    drupal_add_css(drupal_get_path('module', 'coffee') . '/css/coffee.css', array('type' => 'file'));
  }
}

/**
 * Implements hook_hook_info().
 */
function coffee_hook_info() {
  $hooks = array(
    'coffee_commands' => array(
      'group' => 'coffee',
    ),
  );

  return $hooks;
}

/**
 * Function coffee_traverse_below().
 *
 * Helper function to traverse down through a menu structure.
 */
function coffee_traverse_below($link, &$output, $command = NULL) {
  $l = isset($link['link']) ? $link['link'] : array();

  // Only add if user has access.
  if (isset($l['access']) && $l['access']) {
    $label = (!empty($l['title']) ? $l['title'] : $l['link_title']);
    $output[] = array(
      'value' => $l['link_path'],
      'label' => $label,
      'command' => $command,
      'parent' => !empty($link['parent']) ? $link['parent'] : NULL,
    );
  }

  if (isset($link['below']) && is_array($link['below'])) {
    foreach ($link['below'] as $below_link) {
      if (isset($label)) {
        $below_link['parent'] = $label;
      }
      coffee_traverse_below($below_link, $output);
    }
  }
}

/**
 * Function coffee_get_menu_response().
 *
 * Menu callback function which outputs the menu structure as JSON ready for
 * populating the autocomplete data source.
 */
function coffee_get_menu_response() {
  global $user, $language;
  $output = array();

  // Get the commands list from the cache if possible.
  $cid = 'coffee_commands:' . $user->uid . ':' . $language->language;
  if ($cache = cache_get($cid, 'cache_coffee')) {
    if (isset($cache->data)) {
      $output = $cache->data;
    }
  }

  // Nothing from cache, rebuild and then cache.
  if (empty($output)) {
    // Grab menu data.
    $menus = variable_get('coffee_settings_menus', array('management', 'user-menu'));
    foreach ($menus as $v) {
      if ($v == '0') {
        continue;
      }

      $menu = menu_tree_all_data($v);

      foreach ($menu as $k => $link) {
        $command = $v == 'user-menu' ? ':user' : NULL ;

        coffee_traverse_below($link, $output, $command);
      }
    }

    // Include the commands.
    // Include the default hooks for Coffee.
    module_load_include('inc', 'coffee', 'coffee.hooks');

    // Invoke all implementations of hook_coffee_commands().
    $commands = array();

    foreach (module_implements('coffee_commands') as $module) {
      $commands = array_merge($commands, module_invoke($module, 'coffee_commands', ''));
    }

    if (!empty($commands)) {
      $output = array_merge($output, $commands);
    }

    foreach ($output as $k => $v) {
      // If there are links to <front> remove them.
      if ($v['value'] === '<front>') {
        unset($output[$k]);

        continue;
      }

      if (!empty($v['parent'])) {
        $output[$k]['parent'] = $v['parent'];
      }

      // Prevent any nasty commands from getting through.
      $output[$k]['label'] = filter_xss($output[$k]['label']);

      // If clean URLs are turned off, alter the command URLs.
      if (empty($GLOBALS['conf']['clean_url'])) {
        $output[$k]['value'] = '?q=' . $output[$k]['value'];
      }
    }

    // Re-index the array, it matters to jQuery if we've removed items.
    $output = array_values($output);

    // Set the cache for this user.
    cache_set($cid, $output, 'cache_coffee');
  }

  drupal_json_output($output);
  drupal_exit();
}

/**
 * Implements hook_flush_caches().
 *
 * The following caching implemented is lifted from the
 * awesome admin_menu module.
 */
function coffee_flush_caches($uid = NULL) {
  // A call to menu_rebuild() will trigger potentially thousands of calls into
  // menu_link_save(), for which admin_menu has to implement the corresponding
  // CRUD hooks, in order to take up any menu link changes, since any menu link
  // change could affect the admin menu (which essentially is an aggregate) and
  // since there is no other way to get notified about stale caches. The cache
  // only needs to be flushed once though, so we prevent a ton of needless
  // subsequent calls with this static.
  // @see http://drupal.org/node/918538
  $was_flushed = &drupal_static(__FUNCTION__, array());
  // $uid can be NULL. PHP automatically converts that into '' (empty string),
  // which is different to uid 0 (zero).
  if (isset($was_flushed[$uid])) {
    return;
  }
  $was_flushed[$uid] = TRUE;

  $cid = 'coffee_commands:';
  if (isset($uid)) {
    $cid .= $uid . ':';
  }

  // db_table_exists() required for SimpleTest.
  if (db_table_exists('cache_coffee')) {
    cache_clear_all(isset($uid) ? $cid : '*', 'cache_coffee', TRUE);
  }
}

/**
 * Implements hook_menu_alter().
 */
function coffee_menu_alter(&$items) {
  coffee_flush_caches();
}

/**
 * Implements hook_menu_link_insert().
 */
function coffee_menu_link_insert($link) {
  coffee_flush_caches();
}

/**
 * Implements hook_menu_link_update().
 */
function coffee_menu_link_update($link) {
  coffee_flush_caches();
}

/**
 * Implements hook_menu_link_delete().
 */
function coffee_menu_link_delete($link) {
  coffee_flush_caches();
}