define(['backbone', 'text!./../templates/layer.html'],
	function (Backbone, layerTemplate) {
	/**
	 * @class LayerView
	 * */
	return Backbone.View.extend({

		events:{
			'click': 'updateIndex',
		},

		template: _.template(layerTemplate),

		initialize: function(o) {
			this.stackModel = o.stackModel || {};
			this.config = o.config || {};
			this.pfx = this.config.stylePrefix || '';
			this.className = this.pfx + 'layer';
			this.sorter = o.sorter || null;
			this.listenTo(this.model, 'destroy remove', this.remove);
			this.listenTo(this.model, 'change:value', this.valueChanged);
			this.listenTo(this.model, 'change:props', this.showProps);
			this.events['click #' + this.pfx + 'close-layer'] = 'remove';
			this.events['mousedown > #' + this.pfx + 'move'] = 'initSorter';

			if( !this.model.get('preview') ){
				this.$el.addClass(this.pfx + 'no-preview');
			}
			this.$el.data('model', this.model);
			this.delegateEvents();
		},

		/**
		 * Delegate sorting
		 * @param	{Event} e
		 * */
		initSorter: function(e){
			if(this.sorter)
				this.sorter.startSort(this.el);
		},

		/**
		 * Returns properties
		 * @return {Collection|null}
		 */
		getProps: function(){
			if(this.stackModel.get)
				return this.stackModel.get('properties');
			else
				return null;
		},

		/**
		 * Emitted when the value is changed
		 */
		valueChanged: function(){
			var preview = this.model.get('preview');

			if(!preview)
				return;

			if(!this.$preview)
					this.$preview = this.$el.find('#' + this.pfx + 'preview');

			var prw = '';
			if(typeof preview === "function")
				preview(this.getProps(), this.$preview);
			else
				this.onPreview(this.getProps(), this.$preview);
		},

		/**
		 * Default method for changing preview box
		 * @param {Collection} props
		 * @param {Element} $el
		 */
		onPreview: function(props, $el){
			var	aV = this.model.get('value').split(' ');
			var lim = 3;
			var nV = '';
			props.each(function(p, index){
				var v = aV[index] || '';
				if(v){
					if(p.get('type') == 'integer'){
						var vI	= parseInt(v, 10),
						u	= v.replace(vI,'');
						vI	= !isNaN(vI) ? vI : 0;
						if(vI > lim)
							vI = lim;
						if(vI < -lim)
							vI = -lim;
						v = vI + u;
					}
				}
				nV	+= v + ' ';
			});

			if(this.stackModel.get){
				var property = this.stackModel.get('property');
				if(property)
					this.$preview.get(0).style[property] = nV;
			}
		},

		/**
		 * Show inputs on this layer
		 * */
		showProps:function(){
			this.$props = this.model.get('props');
			this.$el.find('#' + this.pfx + 'inputs').html(this.$props.show());
			this.model.set({props: null }, {silent: true });
		},

		/** @inheritdoc */
		remove: function(e){
			// Prevent from revoming all events on props
			if(this.$props)
				this.$props.detach();

			if(e && e.stopPropagation)
				e.stopPropagation();

			Backbone.View.prototype.remove.apply(this, arguments);

			//---
			if(this.model.collection.contains(this.model))
				this.model.collection.remove(this.model);

			if(this.stackModel && this.stackModel.set){
				this.stackModel.set({stackIndex: null}, {silent: true});
				this.stackModel.trigger('updateValue');
			}
		},

		/**
		 * Update index
		 * @param Event
		 *
		 * @return void
		 * */
		updateIndex: function(e){
			var i = this.getIndex();
			this.stackModel.set('stackIndex', i);

			if(this.model.collection)
				this.model.collection.trigger('deselectAll');

			this.$el.addClass(this.pfx + 'active');
		},

		/**
		 * Fetch model index
		 * @return {number} Index
		 */
		getIndex: function(){
			var index = 0;

			if(this.model.collection)
				index = this.model.collection.indexOf(this.model);

			return index;
		},

		render : function(){
			this.$el.html( this.template({
				label: 'Layer ' + this.model.get('index'),
				pfx: this.pfx,
			}));
			this.$el.attr('class', this.className);
			this.valueChanged();
			return this;
		},

	});
});