/**
 * @author zjj
 */
$.Effect = function () {
	var effects = [], queues = {};
	var interval = null;
	/* 间隔处理 */
	function loopHandler () {
		var timePos = +new Date;
    		for (var i = 0; i < effects.length; i ++) {
    			var ef = effects[i];
    			if(timePos >= ef.finishOn) {
					ef.status = 'finish';
        			remove(ef, true);
        			return;  
      			}
      			if (ef.status == 'idle') {
      				ef.onStart && ef.onStart();
      				ef.status = 'running';	
      			}
    			var pos = (timePos - ef.startOn) / (ef.finishOn - ef.startOn);
    			var frame = Math.round(pos * ef.totalFrames);
      			if(frame > ef.currentFrame) {
      				pos = ef.transition(pos);
      				pos = ef.from + ((ef.to - ef.from) * pos);
        			ef.render(pos * ef.factor,ef.action);
        			ef.currentFrame = frame;
      			}
    		}
	}
	
	/* 删除效果 */
	function remove (effect, toEnd) {
		var ret = 0, length = effects.length, item;
		while (length--) {
			item = effects[length];
			if (item == effect || item.guid == effect) {
				if (toEnd) {
					item.render(
						(item.from + ((item.to - item.from) * item.transition(1))) * item.factor
					);
					item.onFinish && item.onFinish();
					item.status = 'finish';
				}
				item.onRemove && item.onRemove();
				ret ++;
				effects.splice(length, 1);
			}
		}
    		if (effects.length == 0) {
      			clearInterval(interval);
      			interval = false;
    		}
    		return ret;
	}
	
	/* 添加动画 */
	function add (effect) {
		if (effect.onAdd) {
			effect.onAdd();
			delete effect.onAdd;
		}
		var timestamp = +new Date;
		effect = $.extend({
			transition:	$.Effect.Transitions.linear,
			duration:		1.0,   	// 秒
			fps:      		25.0,  	// 25fps由Effect.Queue执行
		  	from:       	0.0,
		  	to:         	1.0,
		  	delay:      	0.0,
		  	factor: 		1,
			action:  		'linear'
		}, effect);
			effect.action = effect.style.action || effect.action;
    		effect.startOn  = effect.delay * 1000 + timestamp;
    		effect.finishOn = effect.startOn + effect.duration * 1000;
    		effect.currentFrame = 0;
    		effect.totalFrames = effect.fps * effect.duration;
    		if ($.isString(effect.transition))
    			effect.transition = $.Effect.Transitions[effect.transition];
    		effect.status = 'idle';
    		effects.push(effect);
    		if(!interval)
    			interval = window.setInterval(loopHandler, 40);
    		return effect;
	}
	
	function addToQueue (effect) {
		var queueId = effect.queue, originOnRemove = effect.onRemove, queue = queues[queueId];
		effect.onRemove = function () {
			if (queues[queueId] && queues[queueId].data.length) {
				var effect = queues[queueId].data.shift();
				queues[queueId].current = effect;
				add (effect);
			} else {
				delete queues[queueId];
			}
			originOnRemove && originOnRemove();
		};
		if (queue) {
			queue.data.push(effect);	
		} else {
			queue = queues[queueId] = {};
			queue.data = [];
			queue.current = effect;
			add(effect);
		}
	}
	function removeQueue (queueId) {
		var queue = queues[queueId];
		if (queue) {
			var current = queue.current;
			delete queues[queueId];
			//remove(current, toEnd);
		}
	}
	function status () {
		$.log('effects:' + effects.length);
		$.log('queues:' + $.keys(queues).length);	
	}
	return {
		add: add,
		addToQueue: addToQueue,
		removeQueue: removeQueue,
		remove: remove,
		status: status
	}	
}();

$.Effect.extend = function (effects) {
	var toExtend = {};
	$.each(effects, function (_sets, name) {
		if (!_sets.style)
			_sets = { style : _sets };
		toExtend[name] = function (elem) {
			var sets = $.extend({}, _sets), args = $.toArray(arguments);
			args.shift(); //elem
			if (args[0] && typeof args[0] == 'number') {
				sets.duration = args.shift();
				args.shift();
			}
			var onFinish = args.shift(), customSets = args.shift();
			if (onFinish) {
				var originOnFinish = sets.onFinish;
				sets.onFinish = function () {
					onFinish.call(elem);
					originOnFinish && originOnFinish();	
				};
			}
			if (customSets) $.extend(sets, customSets);
			return $.elements.effect.call(this, elem, sets);
		};	
	});
	$.elements.extend(toExtend);
};

$.Effect.Transitions = {
	linear: function (pos) { return pos; }
};

function extendElementEffect(sets) {
	var elem = this, $elem = $(elem);
	if (!sets.style) 	return;
	var styles = sets.style, names = [];
	if (styles.START) {
		var originOnStart = sets.onStart;
		sets.onStart = function () {
			typeof styles.START == 'function' ?
				styles.START.call(elem) :
				$elem.css(styles.START);
			originOnStart && originOnStart.call(elem);
		};
	} else
		sets.onStart && (sets.onStart = sets.onStart.bind(elem));	
	if (styles.END) {
		var originOnFinish = sets.onFinish;
		sets.onFinish = function () {
			typeof styles.END == 'function' ?
				styles.END.call(elem) :
				$elem.css(styles.END);
			originOnFinish && originOnFinish.call(elem);
		};	
	} else
		sets.onFinish && (sets.onFinish = sets.onFinish.bind(elem));
	styles.INIT && $elem.css(styles.INIT);
	
	$.each(styles, function (val, name) {
		if (' INIT START END '.indexOf(' ' + name + ' ') >= 0) return;
		var from = parseFloat($.css(elem, name, true)) || 0, to,
		takens = val.toString().match(/^([-+]=)?([\d+-.]+)(.*)$/);
		if (takens) {
			to = parseFloat(takens[2]), unit = takens[3] || 'px';	
			if (unit != 'px') {
				$.css(elem, name, to + unit);
				from = (to / parseFloat($.css(elem, name, true))) * from;
				$.css(elem, name, from + unit);
			}
			if (takens[1])
				to = (takens[1] == '-=' ? -1 : 1) * to + from;
			names.push({
				name : name,
				color : styles.color ,
				from : from,
				to : to,
				unit : takens[3] || ''	
			});
		}
	});
	var handle = sets.handle;
	sets.render = function (pos,effects) {
		for (var i = 0, n = names.length; i < n; i ++) {
			style = names[i];	
			var fn = $effects[effects] == undefined ?  $effects['linear'] : $effects[effects];
			if (style.unit)
				pos += style.unit;
			//$.output('set {0} : {1}; from : {2}, to : {3}'.format(names[i], value, style.from, style.to));
			$.css(elem, style.name, fn(pos, style.from, (style.to - style.from) ,1));
		}
		handle && handle.call(elem, pos);
	};
}

$.elements.extend({
	effect: function (elem,sets) {
		if (!sets.style)
			sets = { style : sets };
		if (sets.queue !== false)
			sets.queue = $.data(elem);
		sets.guid = $.data(elem);
		sets.onAdd = extendElementEffect.bind(elem, sets);
		$.Effect[sets.queue ? 'addToQueue' : 'add'](sets);	
		return this;
	},
	stop: function (elem, clearQueue, toEnd) {
		var guid = $.data(elem);
		clearQueue && $.Effect.removeQueue(guid);
		$.Effect.remove(guid, toEnd);
		return this;	
	}
});


var $effects = {
     	linear: function (t, b, c, d) { return c*t/d + b; },
        easeIn: function (t, b, c, d) { return c*(t/=d)*t + b; },
        easeOut: function (t, b, c, d) { return -c *(t/=d)*(t-2) + b;},
        easeBoth: function (t, b, c, d) { if ((t/=d/2) < 1) { return c/2*t*t + b; } return -c/2 * ((--t)*(t-2) - 1) + b; },
        easeInStrong: function (t, b, c, d) { return c*(t/=d)*t*t*t + b; },
        easeOutStrong: function (t, b, c, d) { return -c * ((t=t/d-1)*t*t*t - 1) + b; },
        easeBothStrong: function (t, b, c, d) { if ((t/=d/2) < 1) { return c/2*t*t*t*t + b; } return -c/2 * ((t-=2)*t*t*t - 2) + b; },
        elasticIn: function (t, b, c, d, a, p) { if (t === 0) {  return b;  } if ( (t /= d) == 1 ) { return b+c;  } if (!p) { p=d*0.3;  } if (!a || a < Math.abs(c)) { a = c;  var s = p/4; } else { var s = p/(2*Math.PI) * Math.asin (c/a); } return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b; },
        elasticOut: function (t, b, c, d, a, p) { if (t === 0) { return b; } if ( (t /= d) == 1 ) { return b+c; } if (!p) { p=d*0.3; } if (!a || a < Math.abs(c)) { a = c; var s = p / 4; } else { var s = p/(2*Math.PI) * Math.asin (c/a); } return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b; },
        elasticBoth: function (t, b, c, d, a, p) { if (t === 0) { return b; } if ( (t /= d/2) == 2 ) { return b+c; } if (!p) { p = d*(0.3*1.5); } if ( !a || a < Math.abs(c) ) { a = c;  var s = p/4; } else { var s = p/(2*Math.PI) * Math.asin (c/a); } if (t < 1) { return - 0.5*(a*Math.pow(2,10*(t-=1)) *  Math.sin( (t*d-s)*(2*Math.PI)/p )) + b; } return a*Math.pow(2,-10*(t-=1)) *  Math.sin( (t*d-s)*(2*Math.PI)/p )*0.5 + c + b; },
        backIn: function (t, b, c, d, s) { if (typeof s == 'undefined') { s = 1.70158; } return c*(t/=d)*t*((s+1)*t - s) + b;},
        backOut: function (t, b, c, d, s) { if (typeof s == 'undefined') { s = 1.70158; } return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b; },
        backBoth: function (t, b, c, d, s) { if (typeof s == 'undefined') { s = 1.70158;  } if ((t /= d/2 ) < 1) { return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b; } return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b; },
        bounceIn: function (t, b, c, d) { return c - $effects['bounceOut'](d-t, 0, c, d) + b; },
        bounceOut: function (t, b, c, d) { if ((t/=d) < (1/2.75)) { return c*(7.5625*t*t) + b; } else if (t < (2/2.75)) { return c*(7.5625*(t-=(1.5/2.75))*t + 0.75) + b; } else if (t < (2.5/2.75)) { return c*(7.5625*(t-=(2.25/2.75))*t + 0.9375) + b; } return c*(7.5625*(t-=(2.625/2.75))*t + 0.984375) + b; },
        bounceBoth: function (t, b, c, d) { if (t < d/2) { return $effects['bounceIn'](t*2, 0, c, d) * 0.5 + b; } return $effects['bounceOut'](t*2-d, 0, c, d) * 0.5 + c*0.5 + b; }
        ///*
//        easeInQuad: function (t, b, c, d) { return c*(t/=d)*t + b; },
//        easeOutQuad: function ( t, b, c, d) { return -c *(t/=d)*(t-2) + b; },
//        easeInOutQuad: function ( t, b, c, d) { if ((t/=d/2) < 1){return c/2*t*t + b;}  return -c/2 * ((--t)*(t-2) - 1) + b; },
//        easeInCubic: function ( t, b, c, d) { return c*(t/=d)*t*t + b; },
//        easeOutCubic: function ( t, b, c, d) { return c*((t=t/d-1)*t*t + 1) + b; },
//        easeInOutCubic: function ( t, b, c, d) { if ((t/=d/2) < 1){ return c/2*t*t*t + b; } return c/2*((t-=2)*t*t + 2) + b; },
//        easeInQuart: function ( t, b, c, d) { return c*(t/=d)*t*t*t + b; },
//        easeOutQuart: function ( t, b, c, d) { return -c * ((t=t/d-1)*t*t*t - 1) + b; },
//        easeInOutQuart: function ( t, b, c, d) { if ((t/=d/2) < 1){ return c/2*t*t*t*t + b; }  return -c/2 * ((t-=2)*t*t*t - 2) + b; },
//        easeInQuint: function ( t, b, c, d) { return c*(t/=d)*t*t*t*t + b; },
//        easeOutQuint: function ( t, b, c, d) { return c*((t=t/d-1)*t*t*t*t + 1) + b;},
//        easeInOutQuint: function ( t, b, c, d) { if ((t/=d/2) < 1){ return c/2*t*t*t*t*t + b;} return c/2*((t-=2)*t*t*t*t + 2) + b; },
//        easeInSine: function ( t, b, c, d) { return -c * Math.cos(t/d * (Math.PI/2)) + c + b; },
//        easeOutSine: function ( t, b, c, d) { return c * Math.sin(t/d * (Math.PI/2)) + b; },
//        easeInOutSine: function ( t, b, c, d) { return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b; },
//        easeInExpo: function ( t, b, c, d) { return (t===0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b; },
//        easeOutExpo: function ( t, b, c, d) { return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b; },
//        easeInOutExpo: function ( t, b, c, d) {
//            if (t===0) return b;
//            if (t==d) return b+c;
//            if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b;
//            return c/2 * (-Math.pow(2, -10 * --t) + 2) + b;
//        },
//        easeInCirc: function ( t, b, c, d) { return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;},
//        easeOutCirc: function ( t, b, c, d) {  return c * Math.sqrt(1 - (t=t/d-1)*t) + b; },
//        easeInOutCirc: function ( t, b, c, d) {
//            if ((t/=d/2) < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b;
//            return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b;
//        },
//        easeInElastic: function ( t, b, c, d) {
//            var s=1.70158;var p=0;var a=c;
//            if (t===0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*0.3;
//            if (a < Math.abs(c)) { a=c; var s=p/4; }
//            else var s = p/(2*Math.PI) * Math.asin (c/a);
//            return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
//        },
//        easeOutElastic: function ( t, b, c, d) {
//            var s=1.70158;var p=0;var a=c;
//            if (t===0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*0.3;
//            if (a < Math.abs(c)) { a=c; var s=p/4; }
//            else var s = p/(2*Math.PI) * Math.asin (c/a);
//            return a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b;
//        },
//        easeInOutElastic: function ( t, b, c, d) {
//            var s=1.70158;var p=0;var a=c;
//            if (t===0) return b;  if ((t/=d/2)==2) return b+c;  if (!p) p=d*(0.3*1.5);
//            if (a < Math.abs(c)) { a=c; var s=p/4; }
//            else var s = p/(2*Math.PI) * Math.asin (c/a);
//            if (t < 1) return -0.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
//            return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*0.5 + c + b;
//        },
//        easeInBack: function ( t, b, c, d, s) { if (s == undefined){ s = 1.70158;} return c*(t/=d)*t*((s+1)*t - s) + b; },
//        easeOutBack: function ( t, b, c, d, s) { if (s == undefined){ s = 1.70158;} return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b; },
//        easeInOutBack: function ( t, b, c, d, s) { if (s == undefined) {s = 1.70158; } if ((t/=d/2) < 1){ return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b; } return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b; },
//        easeInBounce: function ( t, b, c, d) { return c - $effects['easeOutBounce']( d-t, 0, c, d) + b; },
//        easeOutBounce: function ( t, b, c, d) { if ((t/=d) < (1/2.75)) { return c*(7.5625*t*t) + b; } else if (t < (2/2.75)) { return c*(7.5625*(t-=(1.5/2.75))*t + 0.75) + b; } else if (t < (2.5/2.75)) { return c*(7.5625*(t-=(2.25/2.75))*t + 0.9375) + b; } else { return c*(7.5625*(t-=(2.625/2.75))*t + 0.984375) + b; } },
//        easeInOutBounce: function ( t, b, c, d) { if (t < d / 2) { return $effects['easeInBounce']( t*2, 0, c, d) * 0.5 + b; } return $effects['easeOutBounce']( t*2-d, 0, c, d) * 0.5 + c*0.5 + b;}
};