Rickshaw.namespace('Rickshaw.Graph.Behavior.Series.Highlight');

Rickshaw.Graph.Behavior.Series.Highlight = function(args) {

	this.graph = args.graph;
	this.legend = args.legend;

	var self = this;

	var colorSafe = {};
	var activeLine = null;

	var disabledColor = args.disabledColor || function(seriesColor) {
		return d3.interpolateRgb(seriesColor, d3.rgb('#d8d8d8'))(0.8).toString();
	};

	this.addHighlightEvents = function (l) {

		l.element.addEventListener( 'mouseover', function(e) {

			if (activeLine) return;
			else activeLine = l;

			self.legend.lines.forEach( function(line) {

				if (l === line) {

					// if we're not in a stacked renderer bring active line to the top
					if (self.graph.renderer.unstack && (line.series.renderer ? line.series.renderer.unstack : true)) {

						var seriesIndex = self.graph.series.indexOf(line.series);
						line.originalIndex = seriesIndex;

						var series = self.graph.series.splice(seriesIndex, 1)[0];
						self.graph.series.push(series);
					}
					return;
				}

				colorSafe[line.series.name] = colorSafe[line.series.name] || line.series.color;
				line.series.color = disabledColor(line.series.color);

			} );

			self.graph.update();

		}, false );

		l.element.addEventListener( 'mouseout', function(e) {

			if (!activeLine) return;
			else activeLine = null;

			self.legend.lines.forEach( function(line) {

				// return reordered series to its original place
				if (l === line && line.hasOwnProperty('originalIndex')) {

					var series = self.graph.series.pop();
					self.graph.series.splice(line.originalIndex, 0, series);
					delete line.originalIndex;
				}

				if (colorSafe[line.series.name]) {
					line.series.color = colorSafe[line.series.name];
				}
			} );

			self.graph.update();

		}, false );
	};

	if (this.legend) {
		this.legend.lines.forEach( function(l) {
			self.addHighlightEvents(l);
		} );
	}

};