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

  $items['cart'] = array(
    'title' => 'Shopping cart',
    'page callback' => 'commerce_cart_view',
    'access arguments' => array('access content'),
    'file' => 'includes/commerce_cart.pages.inc',
  );

  $items['cart/my'] = array(
    'title' => 'Shopping cart (# items)',
    'title callback' => 'commerce_cart_menu_item_title',
    'title arguments' => array(TRUE),
    'page callback' => 'commerce_cart_menu_item_redirect',
    'access arguments' => array('access content'),
    'type' => MENU_SUGGESTED_ITEM,
  );

  $items['checkout'] = array(
    'title' => 'Checkout',
    'page callback' => 'commerce_cart_checkout_router',
    'access arguments' => array('access checkout'),
    'type' => MENU_CALLBACK,
    'file' => 'includes/commerce_cart.pages.inc',
  );

  // If the Order UI module is installed, add a local action to it that lets an
  // administrator execute a cart order refresh on the order. Modules that
  // define their own order edit menu item are also responsible for defining
  // their own local action menu items if needed.
  if (module_exists('commerce_order_ui')) {
    $items['admin/commerce/orders/%commerce_order/edit/refresh'] = array(
      'title' => 'Apply pricing rules',
      'description' => 'Executes the cart order refresh used to apply all current pricing rules on the front end.',
      'page callback' => 'drupal_get_form',
      'page arguments' => array('commerce_cart_order_refresh_form', 3),
      'access callback' => 'commerce_cart_order_refresh_form_access',
      'access arguments' => array(3),
      'type' => MENU_LOCAL_ACTION,
      'file' => 'includes/commerce_cart.admin.inc',
    );
  }

  return $items;
}

/**
 * Returns the title of the shopping cart menu item with an item count.
 */
function commerce_cart_menu_item_title() {
  global $user;

  // Default to a static title.
  $title = t('Shopping cart');

  // If the user actually has a cart order...
  if ($order = commerce_cart_order_load($user->uid)) {
    // Count the number of product line items on the order.
    $wrapper = entity_metadata_wrapper('commerce_order', $order);
    $quantity = commerce_line_items_quantity($wrapper->commerce_line_items, commerce_product_line_item_types());

    // If there are more than 0 product line items on the order...
    if ($quantity > 0) {
      // Use the dynamic menu item title.
      $title = format_plural($quantity, 'Shopping cart (1 item)', 'Shopping cart (@count items)');
    }
  }

  return $title;
}