/*
 * Yuichi Tateno. <hotchpotch@N0!spam@gmail.com>
 * http://rails2u.com/
 * 
 * The MIT License
 * --------
 * Copyright (c) 2007 Yuichi Tateno.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 */
function getJSTweener(){
	var JSTweener = {
	    looping: false,
	    frameRate: 60,
	    objects: [],
	    defaultOptions: {
	        time: 1,
	        transition: 'easeoutexpo',
	        delay: 0,
	        prefix: {},
	        suffix: {},
	        onStart: undefined,
	        onStartParams: undefined,
	        onUpdate: undefined,
	        onUpdateParams: undefined,
	        onComplete: undefined,
	        onCompleteParams: undefined
	    },
	    inited: false,
	    easingFunctionsLowerCase: {},
	    init: function() {
	        this.inited = true;
	        for (var key in JSTweener.easingFunctions) {
	            this.easingFunctionsLowerCase[key.toLowerCase()] = JSTweener.easingFunctions[key];
	        }
	    },
	    toNumber: function(value, prefix, suffix) {
	        // for style
	        if (!suffix) suffix = 'px';

	        return value.toString().match(/[0-9]/) ? Number(value.toString().replace(
	                                                        new RegExp(suffix + '$'), ''
	                                                       ).replace(
	                                                        new RegExp('^' + (prefix ? prefix : '')), ''
	                                                       ))
	                                               : 0;
	    },
	    addTween: function(obj, options, overWrite) {

			var self = this;

			if(overWrite){
				this.stopAll();
/*				for(var i=0; i < self.objects.length; i++){
					if(self.objects[i].target == obj){
						self.objects.splice(i, 1);;
						break;
					}
				}*/
			}

	        if (!this.inited) this.init();
	        var o = {};
	        o.target = obj;
	        o.targetPropeties = {};
        
	        for (var key in this.defaultOptions) {
	            if (typeof options[key] != 'undefined') {
	                o[key] = options[key];
	                delete options[key];
	            } else {
	                o[key] = this.defaultOptions[key];
	            }
	        }

	        if (typeof o.transition == 'function') {
	            o.easing = o.transition;
	        } else {
	            o.easing = this.easingFunctionsLowerCase[o.transition.toLowerCase()];
	        }

	        for (var key in options) {
	            if (!o.prefix[key]) o.prefix[key] = '';
	            if (!o.suffix[key]) o.suffix[key] = '';
	            var sB = this.toNumber(obj[key], o.prefix[key],  o.suffix[key]);
	            o.targetPropeties[key] = {
	                b: sB,
	                c: options[key] - sB
	            };
	        }

	        setTimeout(function() {
	            o.startTime = (new Date() - 0);
	            o.endTime = o.time * 1000 + o.startTime;

	            if (typeof o.onStart == 'function') {
	                if (o.onStartParams) {
	                    o.onStart.apply(o, o.onStartParams);
	                } else {
	                    o.onStart();
	                }
	            }

	            self.objects.push(o);
	            if (!self.looping) { 
	                self.looping = true;
	                self.eventLoop.call(self);
	            }
	        }, o.delay * 1000);
	    },
	    eventLoop: function() {

	        var now = (new Date() - 0);
	        for (var i = 0; i < this.objects.length; i++) {
	            var o = this.objects[i];
	            var t = now - o.startTime;
	            var d = o.endTime - o.startTime;

	            if (t >= d) {
	                for (var property in o.targetPropeties) {
	                    var tP = o.targetPropeties[property];
	                    try {
	                        o.target[property] = o.prefix[property] + (tP.b + tP.c) + o.suffix[property];
	                    } catch(e) {}
	                }
	                this.objects.splice(i, 1);

	                if (typeof o.onUpdate == 'function') {
	                    if (o.onUpdateParams) {
	                        o.onUpdate.apply(o, o.onUpdateParams);
	                    } else {
	                        o.onUpdate();
	                    }
	                }

	                if (typeof o.onComplete == 'function') {
	                    if (o.onCompleteParams) {
	                        o.onComplete.apply(o, o.onCompleteParams);
	                    } else {
	                        o.onComplete();
	                    }
	                }
	            } else {
	                for (var property in o.targetPropeties) {
	                    var tP = o.targetPropeties[property];
	                    var val = o.easing(t, tP.b, tP.c, d);
	                    try {
	                        // FIXME:For IE. A Few times IE (style.width||style.height) = value is throw error...
	                        o.target[property] = o.prefix[property] + val + o.suffix[property];
	                    } catch(e) {}
	                }

	                if (typeof o.onUpdate == 'function') {
	                    if (o.onUpdateParams) {
	                        o.onUpdate.apply(o, o.onUpdateParams);
	                    } else {
	                        o.onUpdate();
	                    }
	                }
	            }
	        }

	        if (this.objects.length > 0) {
	            var self = this;
	            this.timeout = setTimeout(function() { self.eventLoop() }, 1000/self.frameRate);
	        } else {
	            this.looping = false;
	        }
	    }
	};

	JSTweener.Utils = {
	    bezier2: function(t, p0, p1, p2) {
	         return (1-t) * (1-t) * p0 + 2 * t * (1-t) * p1 + t * t * p2;
	    },
	    bezier3: function(t, p0, p1, p2, p3) {
	         return Math.pow(1-t, 3) * p0 + 3 * t * Math.pow(1-t, 2) * p1 + 3 * t * t * (1-t) * p2 + t * t * t * p3;
	    },
	    allSetStyleProperties: function(element) {
	         var css;
	         if (document.defaultView && document.defaultView.getComputedStyle) {
	             css = document.defaultView.getComputedStyle(element, null);
	         } else {
	             css = element.currentStyle
	         }
	         for (var key in css) {
	             if (!key.match(/^\d+$/)) {
	                 try {
	                 element.style[key] = css[key];
	                 } catch(e) {};
	             }
	         }
	    }
	}

/*
	 * JSTweener.easingFunctions is
	 * Tweener's easing functions (Penner's Easing Equations) porting to JavaScript.
	 * http://code.google.com/p/tweener/
	 */

	JSTweener.easingFunctions = {
	    easeNone: function(t, b, c, d) {
	        return c*t/d + 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;
	    },    
	    easeOutInCubic: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutCubic(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInCubic((t*2)-d, b+c/2, c/2, d);
	    },    
	    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;
	    },    
	    easeOutInQuart: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutQuart(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInQuart((t*2)-d, b+c/2, c/2, d);
	    },    
	    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;
	    },    
	    easeOutInQuint: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutQuint(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInQuint((t*2)-d, b+c/2, c/2, d);
	    },    
	    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;
	    },    
	    easeOutInSine: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutSine(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInSine((t*2)-d, b+c/2, c/2, d);
	    },    
	    easeInExpo: function(t, b, c, d) {
	        return(t==0) ? b : c * Math.pow(2, 10 *(t/d - 1)) + b - c * 0.001;
	    },    
	    easeOutExpo: function(t, b, c, d) {
	        return(t==d) ? b+c : c * 1.001 *(-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 - c * 0.0005;
	        return c/2 * 1.0005 *(-Math.pow(2, -10 * --t) + 2) + b;
	    },    
	    easeOutInExpo: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutExpo(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInExpo((t*2)-d, b+c/2, c/2, d);
	    },    
	    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;
	    },    
	    easeOutInCirc: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutCirc(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInCirc((t*2)-d, b+c/2, c/2, d);
	    },    
	    easeInElastic: function(t, b, c, d, a, p) {
	        var s;
	        if(t==0) return b;  if((t/=d)==1) return b+c;  if(!p) p=d*.3;
	        if(!a || a < Math.abs(c)) { a=c; s=p/4; } else 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, a, p) {
	        var s;
	        if(t==0) return b;  if((t/=d)==1) return b+c;  if(!p) p=d*.3;
	        if(!a || a < Math.abs(c)) { a=c; s=p/4; } else 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, a, p) {
	        var s;
	        if(t==0) return b;  if((t/=d/2)==2) return b+c;  if(!p) p=d*(.3*1.5);
	        if(!a || a < Math.abs(c)) { a=c; s=p/4; }       else s = p/(2*Math.PI) * Math.asin(c/a);
	        if(t < 1) return -.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 )*.5 + c + b;
	    },    
	    easeOutInElastic: function(t, b, c, d, a, p) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutElastic(t*2, b, c/2, d, a, p);
	        return JSTweener.easingFunctions.easeInElastic((t*2)-d, b+c/2, c/2, d, a, p);
	    },    
	    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;
	    },    
	    easeOutInBack: function(t, b, c, d, s) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutBack(t*2, b, c/2, d, s);
	        return JSTweener.easingFunctions.easeInBack((t*2)-d, b+c/2, c/2, d, s);
	    },    
	    easeInBounce: function(t, b, c, d) {
	        return c - JSTweener.easingFunctions.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 + .75) + b;
	        } else if(t <(2.5/2.75)) {
	            return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
	        } else {
	            return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
	        }
	    },    
	    easeInOutBounce: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeInBounce(t*2, 0, c, d) * .5 + b;
	        else return JSTweener.easingFunctions.easeOutBounce(t*2-d, 0, c, d) * .5 + c*.5 + b;
	    },    
	    easeOutInBounce: function(t, b, c, d) {
	        if(t < d/2) return JSTweener.easingFunctions.easeOutBounce(t*2, b, c/2, d);
	        return JSTweener.easingFunctions.easeInBounce((t*2)-d, b+c/2, c/2, d);
	    }
	};
	JSTweener.easingFunctions.linear = JSTweener.easingFunctions.easeNone;

	JSTweener.stopAll = function(){
			this.objects = [];
	}

	return JSTweener;
}