define([
	"./_base/lang",
	"./Evented",
	"./_base/kernel",
	"./_base/array",
	"./aspect",
	"./_base/fx",
	"./dom",
	"./dom-style",
	"./dom-geometry",
	"./ready",
	"require" // for context sensitive loading of Toggler
], function(lang, Evented, dojo, arrayUtil, aspect, baseFx, dom, domStyle, geom, ready, require){

	// module:
	//		dojo/fx
	
	// For back-compat, remove in 2.0.
	if(!dojo.isAsync){
		ready(0, function(){
			var requires = ["./fx/Toggler"];
			require(requires);	// use indirection so modules not rolled into a build
		});
	}

	var coreFx = dojo.fx = {
		// summary:
		//		Effects library on top of Base animations
	};

	var _baseObj = {
			_fire: function(evt, args){
				if(this[evt]){
					this[evt].apply(this, args||[]);
				}
				return this;
			}
		};

	var _chain = function(animations){
		this._index = -1;
		this._animations = animations||[];
		this._current = this._onAnimateCtx = this._onEndCtx = null;

		this.duration = 0;
		arrayUtil.forEach(this._animations, function(a){
			this.duration += a.duration;
			if(a.delay){ this.duration += a.delay; }
		}, this);
	};
	_chain.prototype = new Evented();
	lang.extend(_chain, {
		_onAnimate: function(){
			this._fire("onAnimate", arguments);
		},
		_onEnd: function(){
			this._onAnimateCtx.remove();
			this._onEndCtx.remove();
			this._onAnimateCtx = this._onEndCtx = null;
			if(this._index + 1 == this._animations.length){
				this._fire("onEnd");
			}else{
				// switch animations
				this._current = this._animations[++this._index];
				this._onAnimateCtx = aspect.after(this._current, "onAnimate", lang.hitch(this, "_onAnimate"), true);
				this._onEndCtx = aspect.after(this._current, "onEnd", lang.hitch(this, "_onEnd"), true);
				this._current.play(0, true);
			}
		},
		play: function(/*int?*/ delay, /*Boolean?*/ gotoStart){
			if(!this._current){ this._current = this._animations[this._index = 0]; }
			if(!gotoStart && this._current.status() == "playing"){ return this; }
			var beforeBegin = aspect.after(this._current, "beforeBegin", lang.hitch(this, function(){
					this._fire("beforeBegin");
				}), true),
				onBegin = aspect.after(this._current, "onBegin", lang.hitch(this, function(arg){
					this._fire("onBegin", arguments);
				}), true),
				onPlay = aspect.after(this._current, "onPlay", lang.hitch(this, function(arg){
					this._fire("onPlay", arguments);
					beforeBegin.remove();
					onBegin.remove();
					onPlay.remove();
				}));
			if(this._onAnimateCtx){
				this._onAnimateCtx.remove();
			}
			this._onAnimateCtx = aspect.after(this._current, "onAnimate", lang.hitch(this, "_onAnimate"), true);
			if(this._onEndCtx){
				this._onEndCtx.remove();
			}
			this._onEndCtx = aspect.after(this._current, "onEnd", lang.hitch(this, "_onEnd"), true);
			this._current.play.apply(this._current, arguments);
			return this;
		},
		pause: function(){
			if(this._current){
				var e = aspect.after(this._current, "onPause", lang.hitch(this, function(arg){
						this._fire("onPause", arguments);
						e.remove();
					}), true);
				this._current.pause();
			}
			return this;
		},
		gotoPercent: function(/*Decimal*/percent, /*Boolean?*/ andPlay){
			this.pause();
			var offset = this.duration * percent;
			this._current = null;
			arrayUtil.some(this._animations, function(a){
				if(a.duration <= offset){
					this._current = a;
					return true;
				}
				offset -= a.duration;
				return false;
			});
			if(this._current){
				this._current.gotoPercent(offset / this._current.duration, andPlay);
			}
			return this;
		},
		stop: function(/*boolean?*/ gotoEnd){
			if(this._current){
				if(gotoEnd){
					for(; this._index + 1 < this._animations.length; ++this._index){
						this._animations[this._index].stop(true);
					}
					this._current = this._animations[this._index];
				}
				var e = aspect.after(this._current, "onStop", lang.hitch(this, function(arg){
						this._fire("onStop", arguments);
						e.remove();
					}), true);
				this._current.stop();
			}
			return this;
		},
		status: function(){
			return this._current ? this._current.status() : "stopped";
		},
		destroy: function(){
			if(this._onAnimateCtx){ this._onAnimateCtx.remove(); }
			if(this._onEndCtx){ this._onEndCtx.remove(); }
		}
	});
	lang.extend(_chain, _baseObj);

	coreFx.chain = function(/*dojo/_base/fx.Animation[]*/ animations){
		// summary:
		//		Chain a list of `dojo.Animation`s to run in sequence
		//
		// description:
		//		Return a `dojo.Animation` which will play all passed
		//		`dojo.Animation` instances in sequence, firing its own
		//		synthesized events simulating a single animation. (eg:
		//		onEnd of this animation means the end of the chain,
		//		not the individual animations within)
		//
		// example:
		//	Once `node` is faded out, fade in `otherNode`
		//	|	fx.chain([
		//	|		dojo.fadeIn({ node:node }),
		//	|		dojo.fadeOut({ node:otherNode })
		//	|	]).play();
		//
		return new _chain(animations); // dojo/_base/fx.Animation
	};

	var _combine = function(animations){
		this._animations = animations||[];
		this._connects = [];
		this._finished = 0;

		this.duration = 0;
		arrayUtil.forEach(animations, function(a){
			var duration = a.duration;
			if(a.delay){ duration += a.delay; }
			if(this.duration < duration){ this.duration = duration; }
			this._connects.push(aspect.after(a, "onEnd", lang.hitch(this, "_onEnd"), true));
		}, this);

		this._pseudoAnimation = new baseFx.Animation({curve: [0, 1], duration: this.duration});
		var self = this;
		arrayUtil.forEach(["beforeBegin", "onBegin", "onPlay", "onAnimate", "onPause", "onStop", "onEnd"],
			function(evt){
				self._connects.push(aspect.after(self._pseudoAnimation, evt,
					function(){ self._fire(evt, arguments); },
				true));
			}
		);
	};
	lang.extend(_combine, {
		_doAction: function(action, args){
			arrayUtil.forEach(this._animations, function(a){
				a[action].apply(a, args);
			});
			return this;
		},
		_onEnd: function(){
			if(++this._finished > this._animations.length){
				this._fire("onEnd");
			}
		},
		_call: function(action, args){
			var t = this._pseudoAnimation;
			t[action].apply(t, args);
		},
		play: function(/*int?*/ delay, /*Boolean?*/ gotoStart){
			this._finished = 0;
			this._doAction("play", arguments);
			this._call("play", arguments);
			return this;
		},
		pause: function(){
			this._doAction("pause", arguments);
			this._call("pause", arguments);
			return this;
		},
		gotoPercent: function(/*Decimal*/percent, /*Boolean?*/ andPlay){
			var ms = this.duration * percent;
			arrayUtil.forEach(this._animations, function(a){
				a.gotoPercent(a.duration < ms ? 1 : (ms / a.duration), andPlay);
			});
			this._call("gotoPercent", arguments);
			return this;
		},
		stop: function(/*boolean?*/ gotoEnd){
			this._doAction("stop", arguments);
			this._call("stop", arguments);
			return this;
		},
		status: function(){
			return this._pseudoAnimation.status();
		},
		destroy: function(){
			arrayUtil.forEach(this._connects, function(handle){
				handle.remove();
			});
		}
	});
	lang.extend(_combine, _baseObj);

	coreFx.combine = function(/*dojo/_base/fx.Animation[]*/ animations){
		// summary:
		//		Combine a list of `dojo.Animation`s to run in parallel
		//
		// description:
		//		Combine an array of `dojo.Animation`s to run in parallel,
		//		providing a new `dojo.Animation` instance encompasing each
		//		animation, firing standard animation events.
		//
		// example:
		//	Fade out `node` while fading in `otherNode` simultaneously
		//	|	fx.combine([
		//	|		dojo.fadeIn({ node:node }),
		//	|		dojo.fadeOut({ node:otherNode })
		//	|	]).play();
		//
		// example:
		//	When the longest animation ends, execute a function:
		//	|	var anim = fx.combine([
		//	|		dojo.fadeIn({ node: n, duration:700 }),
		//	|		dojo.fadeOut({ node: otherNode, duration: 300 })
		//	|	]);
		//	|	aspect.after(anim, "onEnd", function(){
		//	|		// overall animation is done.
		//	|	}, true);
		//	|	anim.play(); // play the animation
		//
		return new _combine(animations); // dojo/_base/fx.Animation
	};

	coreFx.wipeIn = function(/*Object*/ args){
		// summary:
		//		Expand a node to it's natural height.
		//
		// description:
		//		Returns an animation that will expand the
		//		node defined in 'args' object from it's current height to
		//		it's natural height (with no scrollbar).
		//		Node must have no margin/border/padding.
		//
		// args: Object
		//		A hash-map of standard `dojo.Animation` constructor properties
		//		(such as easing: node: duration: and so on)
		//
		// example:
		//	|	fx.wipeIn({
		//	|		node:"someId"
		//	|	}).play()
		var node = args.node = dom.byId(args.node), s = node.style, o;

		var anim = baseFx.animateProperty(lang.mixin({
			properties: {
				height: {
					// wrapped in functions so we wait till the last second to query (in case value has changed)
					start: function(){
						// start at current [computed] height, but use 1px rather than 0
						// because 0 causes IE to display the whole panel
						o = s.overflow;
						s.overflow = "hidden";
						if(s.visibility == "hidden" || s.display == "none"){
							s.height = "1px";
							s.display = "";
							s.visibility = "";
							return 1;
						}else{
							var height = domStyle.get(node, "height");
							return Math.max(height, 1);
						}
					},
					end: function(){
						return node.scrollHeight;
					}
				}
			}
		}, args));

		var fini = function(){
			s.height = "auto";
			s.overflow = o;
		};
		aspect.after(anim, "onStop", fini, true);
		aspect.after(anim, "onEnd", fini, true);

		return anim; // dojo/_base/fx.Animation
	};

	coreFx.wipeOut = function(/*Object*/ args){
		// summary:
		//		Shrink a node to nothing and hide it.
		//
		// description:
		//		Returns an animation that will shrink node defined in "args"
		//		from it's current height to 1px, and then hide it.
		//
		// args: Object
		//		A hash-map of standard `dojo.Animation` constructor properties
		//		(such as easing: node: duration: and so on)
		//
		// example:
		//	|	fx.wipeOut({ node:"someId" }).play()

		var node = args.node = dom.byId(args.node), s = node.style, o;

		var anim = baseFx.animateProperty(lang.mixin({
			properties: {
				height: {
					end: 1 // 0 causes IE to display the whole panel
				}
			}
		}, args));

		aspect.after(anim, "beforeBegin", function(){
			o = s.overflow;
			s.overflow = "hidden";
			s.display = "";
		}, true);
		var fini = function(){
			s.overflow = o;
			s.height = "auto";
			s.display = "none";
		};
		aspect.after(anim, "onStop", fini, true);
		aspect.after(anim, "onEnd", fini, true);

		return anim; // dojo/_base/fx.Animation
	};

	coreFx.slideTo = function(/*Object*/ args){
		// summary:
		//		Slide a node to a new top/left position
		//
		// description:
		//		Returns an animation that will slide "node"
		//		defined in args Object from its current position to
		//		the position defined by (args.left, args.top).
		//
		// args: Object
		//		A hash-map of standard `dojo.Animation` constructor properties
		//		(such as easing: node: duration: and so on). Special args members
		//		are `top` and `left`, which indicate the new position to slide to.
		//
		// example:
		//	|	.slideTo({ node: node, left:"40", top:"50", units:"px" }).play()

		var node = args.node = dom.byId(args.node),
			top = null, left = null;

		var init = (function(n){
			return function(){
				var cs = domStyle.getComputedStyle(n);
				var pos = cs.position;
				top = (pos == 'absolute' ? n.offsetTop : parseInt(cs.top) || 0);
				left = (pos == 'absolute' ? n.offsetLeft : parseInt(cs.left) || 0);
				if(pos != 'absolute' && pos != 'relative'){
					var ret = geom.position(n, true);
					top = ret.y;
					left = ret.x;
					n.style.position="absolute";
					n.style.top=top+"px";
					n.style.left=left+"px";
				}
			};
		})(node);
		init();

		var anim = baseFx.animateProperty(lang.mixin({
			properties: {
				top: args.top || 0,
				left: args.left || 0
			}
		}, args));
		aspect.after(anim, "beforeBegin", init, true);

		return anim; // dojo/_base/fx.Animation
	};

	return coreFx;
});