Sindbad~EG File Manager

( function( $ ) {
	function LP_Advertisement_Slider( el, options ) {
		this.options = $.extend( {}, options || {} );
		let $el = $( el ),
			$items = $el.find( '.slide-item' ),
			$controls = $( '<div class="slider-controls"><div class="prev-item"></div><div class="next-item"></div></div>' ),
			$wrapItems = $( '<div class="slider-items"></div>' ).append( $items ),
			itemIndex = 0,
			timer = null;

		function init() {
			createHTML();
			bindEvents();
			activeItem();
		}

		function createHTML() {
			$el.append( $wrapItems );
			$items.each( function() {
				$( this ).append( $controls.clone() );
			} );
		}

		function activeItem( index ) {
			index = index !== undefined ? index : itemIndex;
			const activeItem = $items.eq( index );

			activeItem.show();
			// A ha???
			setTimeout( function() {
				activeItem.addClass( 'slide-active' );
			}, 1 );

			activeItem.siblings().removeClass( 'slide-active' );

			timer && clearTimeout( timer );
			timer = setTimeout( function() {
				activeItem.siblings().hide();
			}, 500 );
		}

		function nextItem() {
			if ( itemIndex < $items.length - 1 ) {
				itemIndex++;
			} else {
				itemIndex = 0;
			}
			activeItem( itemIndex );
		}

		function prevItem() {
			if ( itemIndex > 0 ) {
				itemIndex--;
			} else {
				itemIndex = $items.length - 1;
			}
			activeItem( itemIndex );
		}

		function bindEvents() {
			$el.on( 'click', '.next-item', nextItem );
			$el.on( 'click', '.prev-item', prevItem );
		}

		init();
	}

	$.fn.LP( 'Advertisement', function( opts ) {
		return $.each( this, function() {
			let $slider = $( this ).data( 'LP_Advertisement_Slider' );
			if ( ! $slider ) {
				$slider = new LP_Advertisement_Slider( this, opts );
				$( this ).data( 'LP_Advertisement_Slider', $slider );
			}
			return this;
		} );
	} );
}( jQuery ) );