function $(id)
{
  return document.getElementById( id);
}

var visor = function()
{
	/* ==== private methods ==== */
	function getElementsByClass(object, tag, className)
	{
		var o = object.getElementsByTagName(tag);
		for ( var i = 0, n = o.length, ret = []; i < n; i++)
		{
			if (o[i].className == className) ret.push(o[i]);
		}

		if (ret.length == 1) ret = ret[0];
		return ret;
	}

	function setOpacity( obj, o)
	{
		if (obj.filters)
		{
		  obj.filters.alpha.opacity = Math.round(o);
		}
		else
		{
		  obj.style.opacity = o / 100;
		}
	}

	/* ==== Slider Constructor ==== */
	function Slider(oCont, speed, iW, iH, oP) {
		this.slides = [];
		this.over   = false;
		this.S      = this.S0 = speed;
		this.iW     = iW;
		this.iH     = iH;
		this.oP     = oP;
		this.oc     = document.getElementById(oCont);
		this.frm    = getElementsByClass(this.oc, 'div', 'frame');
		this.NF     = this.frm.length;
		this.timer  = null;

		this.resize();

		for (var i = 0; i < this.NF; i++)
		{
			this.slides[i] = new Slide(this, i);
		}

		this.oc.parent = this;
		this.view      = this.slides[0];
		this.Z         = this.mx;

	  
		this.startAutoTransitions();
		this.startFirstSlider();
		
		

		/* ==== on mouse out event ==== */
		this.oc.onmouseout = function ()
		{
			this.parent.mouseout();
			return false;
		};
	}

	Slider.prototype = {
		/* ==== animation loop ==== */
		run : function () {
			this.Z += this.over ? (this.mn - this.Z) * .5 : (this.mx - this.Z) * .5;
			this.view.calc();
			var i = this.NF;
			while (i--) this.slides[i].move();
		},

		/* ==== resize  ==== */
		resize : function () {
			this.wh = this.oc.clientWidth;
			this.ht = this.oc.clientHeight;
			this.wr = this.wh * this.iW;
			this.r  = this.ht / this.wr;
			this.mx = this.wh / this.NF;
			this.mn = (this.wh * (1 - this.iW)) / (this.NF - 1);
		},

		/* ==== rest  ==== */
		mouseout: function ()
		{
			this.over      = false;
			setOpacity(this.view.img, this.oP);
			this.startAutoTransitions();
		},

		showFirstSlider: function()
		 {
		      var slider = this.visor.s1;
		      slider.view = slider.slides[0];			  
		      slider.view.over();
		 },
		 
		showImage: function()
		{
		      var slider = this.visor.s1;
		       slider.view = slider.slides[slider.currentSlide];
			  
		      slider.currentSlide = (slider.currentSlide + 1) % slider.NF;
		      slider.view.over();
		      slider.timer = window.setTimeout( slider.showImage, 5000);
	  
		},

		 
		 
		 startFirstSlider: function()
		{


      // Esto es para DEBUGGING
	    //window.lastTime = new Date();
      // Fin del codigo de DEBUGGING

		  // Efectuamos las transiciones cada 1 segundo
      this.timer = window.setTimeout( this.showFirstSlider, 500);
		},
		
		startAutoTransitions: function()
		{
		  this.currentSlide = 0;
	    this.stopAutoTransitions();

      // Esto es para DEBUGGING
	    //window.lastTime = new Date();
      // Fin del codigo de DEBUGGING

		  // Efectuamos las transiciones cada 1 segundo
      this.timer = window.setTimeout( this.showImage, 5000);
		},

		stopAutoTransitions: function()
		{
		  if (this.timer !== null)
		  {
		    window.clearTimeout( this.timer);
		    this.timer = null;
		  }
		}
	};

	/* ==== Slide Constructor ==== */
	Slide = function (parent, N) {
		this.parent = parent;
		this.N      = N;
		this.x0     = this.x1 = N * parent.mx;
		this.v      = 0;
		this.loaded = false;
		this.cpt    = 0;
		this.start  = new Date();
		this.obj    = parent.frm[N];
		this.txt    = getElementsByClass(this.obj, 'div', 'text');
		this.img    = getElementsByClass(this.obj, 'img', 'visorimg');
		this.bkg    = document.createElement('div');
		this.bkg.className = 'bgtext';
		this.obj.insertBefore(this.bkg, this.txt);
		if (N == 0) this.obj.style.borderLeft = 'none';
		this.obj.style.left = Math.floor(this.x0) + 'px';
		setOpacity(this.img, parent.oP);

		/* ==== mouse events ==== */
		this.obj.parent = this;

		this.obj.onmouseover = function()
		{
		  this.parent.parent.stopAutoTransitions();
			this.parent.over();
			return false;
		};
	};

	Slide.prototype = {
		/* ==== target positions ==== */
		calc : function() {
			var that = this.parent;

			// left slides
			for (var i = 0; i <= this.N; i++)
			{
				that.slides[i].x1 = i * that.Z;
			}

			// right slides
			for (i = this.N + 1; i < that.NF; i++)
			{
				that.slides[i].x1 = that.wh - (that.NF - i) * that.Z;
			}
		},

		/* ==== HTML animation : move slides ==== */
		move : function() {
			var that = this.parent;
			var s = (this.x1 - this.x0) / that.S;
			/* ==== lateral slide ==== */
			if (this.N && Math.abs(s) > .5) {
				this.obj.style.left = Math.floor(this.x0 += s) + 'px';
			}
			/* ==== vertical text ==== */
			var v = (this.N < that.NF - 1) ? that.slides[this.N + 1].x0 - this.x0 : that.wh - this.x0;
			if (Math.abs(v - this.v) > .5) {
				this.bkg.style.top = this.txt.style.top = Math.floor(2 + that.ht - (v - that.Z) * that.iH * that.r) +
				  'px';
				this.v = v;
				this.cpt++;
			} else {
				if (!this.pro) {
					/* ==== adjust speed ==== */
					this.pro = true;
					var tps = new Date().getTime() - this.start.getTime();
					if(this.cpt > 1) {
						that.S = Math.max(2, (28 / (tps / this.cpt)) * that.S0);
					}
				}
			}
			if (!this.loaded) {
				if (this.img.complete) {
					this.img.style.visibility = 'visible';
					this.loaded = true;
				}
			}
		},

		/* ==== light ==== */
		over : function ()
		{
			this.parent.resize();
			this.parent.over = true;

			setOpacity(this.parent.view.img, this.parent.oP);
			this.parent.view = this;
			this.start = new Date();
			this.cpt = 0;
			this.pro = false;
			this.calc();

			setOpacity(this.img, 100);
		}
	};

	/* ==== public method - script initialization ==== */
	return {
		init : function() {
			// create instances of sliders here
			// parameters : HTMLcontainer name, speed (2 fast - 20 slow), Horizontal ratio, vertical text ratio, opacity
			//this.s1 = new Slider("visor", 12, 1.84/3, 1/3.2, 70);
			this.s1 = new Slider("visor", 12, (1.72 / 3), (1 / 3.2), 70);

			setInterval("visor.s1.run();", 16);
		}
	}
}();