/**

 * Functionality specific to Twenty Thirteen.

 *

 * Provides helper functions to enhance the theme experience.

 */

( function( $ ) {

	var body    = $( 'body' ),

	    _window = $( window ),

		nav, button, menu;

	nav = $( '#site-navigation' );

	button = nav.find( '.menu-toggle' );

	menu = nav.find( '.nav-menu' );

	/**

	 * Adds a top margin to the footer if the sidebar widget area is higher

	 * than the rest of the page, to help the footer always visually clear

	 * the sidebar.

	 */

	$( function() {

		if ( body.is( '.sidebar' ) ) {

			var sidebar   = $( '#secondary .widget-area' ),

			    secondary = ( 0 === sidebar.length ) ? -40 : sidebar.height(),

			    margin    = $( '#tertiary .widget-area' ).height() - $( '#content' ).height() - secondary;

			if ( margin > 0 && _window.innerWidth() > 999 ) {

				$( '#colophon' ).css( 'margin-top', margin + 'px' );

			}

		}

	} );

	/**

	 * Enables menu toggle for small screens.

	 */

	( function() {

		if ( ! nav.length || ! button.length ) {

			return;

		}

		// Hide button if menu is missing or empty.

		if ( ! menu.length || ! menu.children().length ) {

			button.hide();

			return;

		}

		button.on( 'click.twentythirteen', function() {

			nav.toggleClass( 'toggled-on' );

			if ( nav.hasClass( 'toggled-on' ) ) {

				$( this ).attr( 'aria-expanded', 'true' );

				menu.attr( 'aria-expanded', 'true' );

			} else {

				$( this ).attr( 'aria-expanded', 'false' );

				menu.attr( 'aria-expanded', 'false' );

			}

		} );

		// Fix sub-menus for touch devices.

		if ( 'ontouchstart' in window ) {

			menu.find( '.menu-item-has-children > a, .page_item_has_children > a' ).on( 'touchstart.twentythirteen', function( e ) {

				var el = $( this ).parent( 'li' );

				if ( ! el.hasClass( 'focus' ) ) {

					e.preventDefault();

					el.toggleClass( 'focus' );

					el.siblings( '.focus' ).removeClass( 'focus' );

				}

			} );

		}

		// Better focus for hidden submenu items for accessibility.

		menu.find( 'a' ).on( 'focus.twentythirteen blur.twentythirteen', function() {

			$( this ).parents( '.menu-item, .page_item' ).toggleClass( 'focus' );

		} );

	} )();

	/**

	 * Add or remove ARIA attributes.

	 *

	 * Uses jQuery's width() function to determine the size of the window and add

	 * the default ARIA attributes for the menu toggle if it's visible.

	 *

	 * @since Twenty Thirteen 1.5

	 */

	function onResizeARIA() {

		if ( 643 > _window.width() ) {

			button.attr( 'aria-expanded', 'false' );

			menu.attr( 'aria-expanded', 'false' );

			button.attr( 'aria-controls', 'primary-menu' );

		} else {

			button.removeAttr( 'aria-expanded' );

			menu.removeAttr( 'aria-expanded' );

			button.removeAttr( 'aria-controls' );

		}

	}

	_window

		.on( 'load.twentythirteen', onResizeARIA )

		.on( 'resize.twentythirteen', function() {

			onResizeARIA();

	} );

	/**

	 * Makes "skip to content" link work correctly in IE9 and Chrome for better

	 * accessibility.

	 *

	 * @link http://www.nczonline.net/blog/2013/01/15/fixing-skip-to-content-links/

	 */

	_window.on( 'hashchange.twentythirteen', function() {

		var element = document.getElementById( location.hash.substring( 1 ) );

		if ( element ) {

			if ( ! /^(?:a|select|input|button|textarea)$/i.test( element.tagName ) ) {

				element.tabIndex = -1;

			}

			element.focus();

		}

	} );

	/**

	 * Arranges footer widgets vertically.

	 */

	$( function() {

		var columnWidth, widgetArea;

		if ( ! $.isFunction( $.fn.masonry ) ) {

			return;

		}

		columnWidth = body.is( '.sidebar' ) ? 228 : 245;

		widgetArea = $( '#secondary .widget-area' );

		widgetArea.masonry( {

			itemSelector: '.widget',

			columnWidth: columnWidth,

			gutterWidth: 20,

			isRTL: body.is( '.rtl' )

		} );

		if ( 'undefined' !== typeof wp && wp.customize && wp.customize.selectiveRefresh ) {

			// Retain previous masonry-brick initial position.

			wp.customize.selectiveRefresh.bind( 'partial-content-rendered', function( placement ) {

				var copyPosition = (

					placement.partial.extended( wp.customize.widgetsPreview.WidgetPartial ) &&

					placement.removedNodes instanceof jQuery &&

					placement.removedNodes.is( '.masonry-brick' ) &&

					placement.container instanceof jQuery

				);

				if ( copyPosition ) {

					placement.container.css( {

						position: placement.removedNodes.css( 'position' ),

						top: placement.removedNodes.css( 'top' ),

						left: placement.removedNodes.css( 'left' )

					} );

				}

			} );

			// Re-arrange footer widgets when sidebar is updated via selective refresh in the Customizer.

			wp.customize.selectiveRefresh.bind( 'sidebar-updated', function( sidebarPartial ) {

				if ( 'sidebar-1' === sidebarPartial.sidebarId ) {

					widgetArea.masonry( 'reloadItems' );

					widgetArea.masonry( 'layout' );

				}

			} );

		}

	} );

} )( jQuery );