/**
 * @file
 */

(function ($) {

  Drupal.behaviors.fieldPermissionsSettings = {
    attach: function (context) {
      // For user fields, we want the "Create own value for field X" permission
      // row to only be displayed when it's meaningful (i.e., when the "Display
      // on user registration form" checkbox is checked).
      var $user_register_form_checkbox, $required_field_checkbox, $create_permission_row;
      $user_register_form_checkbox = $('.form-item-instance-settings-user-register-form .form-checkbox', context);
      if ($user_register_form_checkbox.length) {
        // The "Required field" checkbox can cause the user registration checkbox
        // to change, so we need it also.
        $required_field_checkbox = $('.form-item-instance-required .form-checkbox', context);
        if ($required_field_checkbox.length) {
          // Get the permissions table row corresponding to the "Create own value
          // for field X" permission. The theme_user_admin_permissions() function
          // does not give us a good way to directly detect which row contains
          // the create permissions, so we have rely on the fact that it will be
          // the first row.
          $create_permission_row = $('table#permissions tbody tr', context).filter(':first');
          new Drupal.fieldPermissions.HideCreatePermission($user_register_form_checkbox, $required_field_checkbox, $create_permission_row);
        }
      }

      // Show a warning if there's no available permissions matrix.
      $('#edit-field-field-permissions-permission-warning').toggle(!$('#permissions').length);

      $('[name="field[field_permissions][type]"]').bind('change', function(option) {
        $('#edit-field-field-permissions-permission-warning').toggle(!$('#permissions').length);
      });
    }
  };

  Drupal.fieldPermissions = {};

  /**
 * Constructor for the HideCreatePermission object.
 *
 * This object hides and shows the "Create own value for field X" permission
 * for user fields when it is appropriate to do so, depending on the state of
 * the "Display on user registration form" and "Required field" checkboxes.
 */
  Drupal.fieldPermissions.HideCreatePermission = function ($user_register_form_checkbox, $required_field_checkbox, $create_permission_row) {
    this.$user_register_form_checkbox = $user_register_form_checkbox;
    this.$create_permission_row = $create_permission_row;
    // Start off by making sure the create permission row has the correct
    // visibility.
    this.setCreatePermissionVisibility();
    // Set the row's visibility again whenever the user registration checkbox
    // changes, or when the required field checkbox (which controls it) changes.
    $user_register_form_checkbox.bind('change', $.proxy(this.setCreatePermissionVisibility, this));
    $required_field_checkbox.bind('change', $.proxy(this.setCreatePermissionVisibility, this));
  };

  /**
   * Set the correct visibility of the "Create own value for field X" permission.
   */
  Drupal.fieldPermissions.HideCreatePermission.prototype.setCreatePermissionVisibility = function () {
    // Granting permissions for "Create own value for field X" only makes sense
    // when the field is configured to appear on the user registration form, so
    // only show the row in the permissions table then.
    if (this.$user_register_form_checkbox.is(':checked')) {
      this.$create_permission_row.show();
    }
    else {
      this.$create_permission_row.hide();
    }
  };

})(jQuery);