dojo.provide("dojox.gfx.fx");

dojo.require("dojox.gfx.matrix");

(function(){
	var d = dojo, g = dojox.gfx, m = g.matrix;

	// Generic interpolators. Should they be moved to dojox.fx?

	var InterpolNumber = function(start, end){
		this.start = start, this.end = end;
	};
	d.extend(InterpolNumber, {
		getValue: function(r){
			return (this.end - this.start) * r + this.start;
		}
	});

	var InterpolUnit = function(start, end, units){
		this.start = start, this.end = end;
		this.units = units;
	};
	d.extend(InterpolUnit, {
		getValue: function(r){
			return (this.end - this.start) * r + this.start + this.units;
		}
	});

	var InterpolColor = function(start, end){
		this.start = start, this.end = end;
		this.temp = new dojo.Color();
	};
	d.extend(InterpolColor, {
		getValue: function(r){
			return d.blendColors(this.start, this.end, r, this.temp);
		}
	});

	var InterpolValues = function(values){
		this.values = values;
		this.length = values.length;
	};
	d.extend(InterpolValues, {
		getValue: function(r){
			return this.values[Math.min(Math.floor(r * this.length), this.length - 1)];
		}
	});

	var InterpolObject = function(values, def){
		this.values = values;
		this.def = def ? def : {};
	};
	d.extend(InterpolObject, {
		getValue: function(r){
			var ret = dojo.clone(this.def);
			for(var i in this.values){
				ret[i] = this.values[i].getValue(r);
			}
			return ret;
		}
	});

	var InterpolTransform = function(stack, original){
		this.stack = stack;
		this.original = original;
	};
	d.extend(InterpolTransform, {
		getValue: function(r){
			var ret = [];
			dojo.forEach(this.stack, function(t){
				if(t instanceof m.Matrix2D){
					ret.push(t);
					return;
				}
				if(t.name == "original" && this.original){
					ret.push(this.original);
					return;
				}
				if(!(t.name in m)){ return; }
				var f = m[t.name];
				if(typeof f != "function"){
					// constant
					ret.push(f);
					return;
				}
				var val = dojo.map(t.start, function(v, i){
								return (t.end[i] - v) * r + v;
							}),
					matrix = f.apply(m, val);
				if(matrix instanceof m.Matrix2D){
					ret.push(matrix);
				}
			}, this);
			return ret;
		}
	});

	var transparent = new d.Color(0, 0, 0, 0);

	var getColorInterpol = function(prop, obj, name, def){
		if(prop.values){
			return new InterpolValues(prop.values);
		}
		var value, start, end;
		if(prop.start){
			start = g.normalizeColor(prop.start);
		}else{
			start = value = obj ? (name ? obj[name] : obj) : def;
		}
		if(prop.end){
			end = g.normalizeColor(prop.end);
		}else{
			if(!value){
				value = obj ? (name ? obj[name] : obj) : def;
			}
			end = value;
		}
		return new InterpolColor(start, end);
	};

	var getNumberInterpol = function(prop, obj, name, def){
		if(prop.values){
			return new InterpolValues(prop.values);
		}
		var value, start, end;
		if(prop.start){
			start = prop.start;
		}else{
			start = value = obj ? obj[name] : def;
		}
		if(prop.end){
			end = prop.end;
		}else{
			if(typeof value != "number"){
				value = obj ? obj[name] : def;
			}
			end = value;
		}
		return new InterpolNumber(start, end);
	};

	g.fx.animateStroke = function(/*Object*/ args){
		// summary:
		//	Returns an animation which will change stroke properties over time
		// example:
		//	|	dojox.gfx.fx.animateStroke{{
		//	|		shape: shape,
		//	|		duration: 500,
		//	|		color: {start: "red", end: "green"},
		//	|		width: {end: 15},
		//	|		join:  {values: ["miter", "bevel", "round"]}
		//	|	}).play();
		if(!args.easing){ args.easing = d._defaultEasing; }
		var anim = new d.Animation(args), shape = args.shape, stroke;
		d.connect(anim, "beforeBegin", anim, function(){
			stroke = shape.getStroke();
			var prop = args.color, values = {}, value, start, end;
			if(prop){
				values.color = getColorInterpol(prop, stroke, "color", transparent);
			}
			prop = args.style;
			if(prop && prop.values){
				values.style = new InterpolValues(prop.values);
			}
			prop = args.width;
			if(prop){
				values.width = getNumberInterpol(prop, stroke, "width", 1);
			}
			prop = args.cap;
			if(prop && prop.values){
				values.cap = new InterpolValues(prop.values);
			}
			prop = args.join;
			if(prop){
				if(prop.values){
					values.join = new InterpolValues(prop.values);
				}else{
					start = prop.start ? prop.start : (stroke && stroke.join || 0);
					end = prop.end ? prop.end : (stroke && stroke.join || 0);
					if(typeof start == "number" && typeof end == "number"){
						values.join = new InterpolNumber(start, end);
					}
				}
			}
			this.curve = new InterpolObject(values, stroke);
		});
		d.connect(anim, "onAnimate", shape, "setStroke");
		return anim; // dojo.Animation
	};

	g.fx.animateFill = function(/*Object*/ args){
		// summary:
		//	Returns an animation which will change fill color over time.
		//	Only solid fill color is supported at the moment
		// example:
		//	|	dojox.gfx.fx.animateFill{{
		//	|		shape: shape,
		//	|		duration: 500,
		//	|		color: {start: "red", end: "green"}
		//	|	}).play();
		if(!args.easing){ args.easing = d._defaultEasing; }
		var anim = new d.Animation(args), shape = args.shape, fill;
		d.connect(anim, "beforeBegin", anim, function(){
			fill = shape.getFill();
			var prop = args.color, values = {};
			if(prop){
				this.curve = getColorInterpol(prop, fill, "", transparent);
			}
		});
		d.connect(anim, "onAnimate", shape, "setFill");
		return anim; // dojo.Animation
	};

	g.fx.animateFont = function(/*Object*/ args){
		// summary:
		//	Returns an animation which will change font properties over time
		// example:
		//	|	dojox.gfx.fx.animateFont{{
		//	|		shape: shape,
		//	|		duration: 500,
		//	|		variant: {values: ["normal", "small-caps"]},
		//	|		size:  {end: 10, units: "pt"}
		//	|	}).play();
		if(!args.easing){ args.easing = d._defaultEasing; }
		var anim = new d.Animation(args), shape = args.shape, font;
		d.connect(anim, "beforeBegin", anim, function(){
			font = shape.getFont();
			var prop = args.style, values = {}, value, start, end;
			if(prop && prop.values){
				values.style = new InterpolValues(prop.values);
			}
			prop = args.variant;
			if(prop && prop.values){
				values.variant = new InterpolValues(prop.values);
			}
			prop = args.weight;
			if(prop && prop.values){
				values.weight = new InterpolValues(prop.values);
			}
			prop = args.family;
			if(prop && prop.values){
				values.family = new InterpolValues(prop.values);
			}
			prop = args.size;
			if(prop && prop.units){
				start = parseFloat(prop.start ? prop.start : (shape.font && shape.font.size || "0"));
				end = parseFloat(prop.end ? prop.end : (shape.font && shape.font.size || "0"));
				values.size = new InterpolUnit(start, end, prop.units);
			}
			this.curve = new InterpolObject(values, font);
		});
		d.connect(anim, "onAnimate", shape, "setFont");
		return anim; // dojo.Animation
	};

	g.fx.animateTransform = function(/*Object*/ args){
		// summary:
		//	Returns an animation which will change transformation over time
		// example:
		//	|	dojox.gfx.fx.animateTransform{{
		//	|		shape: shape,
		//	|		duration: 500,
		//	|		transform: [
		//	|			{name: "translate", start: [0, 0], end: [200, 200]},
		//	|			{name: "original"}
		//	|		]
		//	|	}).play();
		if(!args.easing){ args.easing = d._defaultEasing; }
		var anim = new d.Animation(args), shape = args.shape, original;
		d.connect(anim, "beforeBegin", anim, function(){
			original = shape.getTransform();
			this.curve = new InterpolTransform(args.transform, original);
		});
		d.connect(anim, "onAnimate", shape, "setTransform");
		return anim; // dojo.Animation
	};
})();
