/**
 * @external SliderView
 */
( function () {
	/**
	 * Module containing presentation logic for the arrow buttons
	 *
	 * @class SliderArroView
	 * @param {SliderView} sliderView
	 * @constructor
	 */
	var SliderArrowView = function ( sliderView ) {
		this.sliderView = sliderView;
	};

	/**
	 * @class mw.libs.revisionSlider.SliderArrowView
	 */
	$.extend( SliderArrowView.prototype, {
		/**
		 * @type {SliderView}
		 */
		sliderView: null,

		/**
		 * Renders the backwards arrow button, returns it
		 * and renders and adds the popup for it.
		 *
		 * @return {OO.ui.ButtonWidget}
		 */
		renderBackwardArrow: function () {
			var backwardArrowButton,
				backwardArrowPopup;

			backwardArrowButton = new OO.ui.ButtonWidget( {
				icon: 'previous',
				width: 20,
				height: 140,
				framed: true,
				classes: [ 'mw-revslider-arrow', 'mw-revslider-arrow-backwards' ]
			} );

			backwardArrowPopup = new OO.ui.PopupWidget( {
				$content: $( '<p>' ).text( mw.msg( 'revisionslider-arrow-tooltip-older' ) ),
				$floatableContainer: backwardArrowButton.$element,
				width: 200,
				classes: [ 'mw-revslider-tooltip', 'mw-revslider-arrow-tooltip' ]
			} );

			backwardArrowButton.connect( this, {
				click: [ 'arrowClickHandler', backwardArrowButton ]
			} );

			backwardArrowButton.$element
				.attr( 'data-dir', -1 )
				.children().attr( 'aria-label', mw.msg( 'revisionslider-arrow-tooltip-older' ) )
				.on( 'mouseover', { button: backwardArrowButton, popup: backwardArrowPopup }, this.showPopup )
				.on( 'mouseout', { popup: backwardArrowPopup }, this.hidePopup )
				.on( 'focusin', { button: backwardArrowButton }, this.arrowFocusHandler );

			$( 'body' ).append( backwardArrowPopup.$element );

			return backwardArrowButton;
		},

		/**
		 * Renders the forwards arrow button, returns it
		 * and renders and adds the popup for it.
		 *
		 * @return {OO.ui.ButtonWidget}
		 */
		renderForwardArrow: function () {
			var forwardArrowButton,
				forwardArrowPopup;

			forwardArrowButton = new OO.ui.ButtonWidget( {
				icon: 'next',
				width: 20,
				height: 140,
				framed: true,
				classes: [ 'mw-revslider-arrow', 'mw-revslider-arrow-forwards' ]
			} );

			forwardArrowPopup = new OO.ui.PopupWidget( {
				$content: $( '<p>' ).text( mw.msg( 'revisionslider-arrow-tooltip-newer' ) ),
				$floatableContainer: forwardArrowButton.$element,
				width: 200,
				classes: [ 'mw-revslider-tooltip', 'mw-revslider-arrow-tooltip' ]
			} );

			forwardArrowButton.connect( this, {
				click: [ 'arrowClickHandler', forwardArrowButton ]
			} );

			forwardArrowButton.$element
				.attr( 'data-dir', 1 )
				.children().attr( 'aria-label', mw.msg( 'revisionslider-arrow-tooltip-newer' ) )
				.on( 'mouseover', { button: forwardArrowButton, popup: forwardArrowPopup }, this.showPopup )
				.on( 'mouseout', { popup: forwardArrowPopup }, this.hidePopup )
				.on( 'focusin', { button: forwardArrowButton }, this.arrowFocusHandler );

			$( 'body' ).append( forwardArrowPopup.$element );

			return forwardArrowButton;
		},

		showPopup: function ( e ) {
			var button = e.data.button,
				popup = e.data.popup;
			if ( typeof button !== 'undefined' && button.isDisabled() ) {
				return;
			}
			popup.$element.css( {
				left: $( this ).offset().left + $( this ).outerWidth() / 2 + 'px',
				top: $( this ).offset().top + $( this ).outerHeight() + 'px'
			} );
			popup.toggle( true );
		},

		hidePopup: function ( e ) {
			var popup = e.data.popup;
			popup.toggle( false );
		},

		/**
		 * @param {OO.ui.ButtonWidget} button
		 */
		arrowClickHandler: function ( button ) {
			if ( button.isDisabled() ) {
				return;
			}
			mw.track( 'counter.MediaWiki.RevisionSlider.event.arrowClick' );
			this.sliderView.slideView( button.$element.data( 'dir' ) );
		},

		/**
		 * Disabled oo.ui.ButtonWidgets get focused when clicked. In particular cases
		 * (arrow gets clicked when disabled, none other elements gets focus meanwhile, the other arrow is clicked)
		 * previously disabled arrow button still has focus and has OOUI focused button styles
		 * applied (blue border) which is not what is wanted. And generally setting a focus on disabled
		 * buttons does not seem right in case of RevisionSlider's arrow buttons.
		 * This method removes focus from the disabled button if such case happens.
		 *
		 * @param {jQuery.Event} e
		 */
		arrowFocusHandler: function ( e ) {
			var button = e.data.button;
			if ( button.isDisabled() ) {
				button.$element.find( 'a.oo-ui-buttonElement-button' ).trigger( 'blur' );
			}
		}
	} );

	mw.libs.revisionSlider = mw.libs.revisionSlider || {};
	mw.libs.revisionSlider.SliderArrowView = SliderArrowView;
}() );