/**
 * @author Bruno Bornsztein <bruno@missingmethod.com>
 * @copyright 2007 Curbly LLC
 * @package Glider
 * @license MIT
 * @url http://www.missingmethod.com/projects/glider/
 * @version 0.0.3
 * @dependencies prototype.js 1.5.1+, effects.js
 */

/*  Thanks to Andrew Dupont for refactoring help and code cleanup - http://andrewdupont.net/  */

Glider = Class.create();
Object.extend(Object.extend(Glider.prototype, Abstract.prototype), {
	initialize: function(wrapper, options){
	    this.scrolling  = false;
	    this.wrapper    = $(wrapper);
	    this.scroller   = this.wrapper.down('div.scroller');
	    this.sections   = this.wrapper.getElementsBySelector('div.section');
	    this.options    = Object.extend({ duration: 1.0, frequency: 3 }, options || {});

	    this.sections.each( function(section, index) {
	      section._index = index;
	    });    

	    this.events = {
	      click: this.click.bind(this)
	    };

	    this.addObservers();
			if(this.options.initialSection) this.moveTo(this.options.initialSection, this.scroller, { duration:this.options.duration });  // initialSection should be the id of the section you want to show up on load
			if(this.options.autoGlide) this.start();
	  },
	
  addObservers: function() {
    var controls = this.wrapper.getElementsBySelector('div.controls a');
    controls.invoke('observe', 'click', this.events.click);
  },	

  click: function(event) {
		this.stop();
    var element = Event.findElement(event, 'a');
    if (this.scrolling) this.scrolling.cancel();
    
    this.moveTo(element.href.split("#")[1], this.scroller, { duration:this.options.duration });     
    Event.stop(event);
  },

	moveTo: function(element, container, options){
			this.current = $(element);

			Position.prepare();
	    var containerOffset = Position.cumulativeOffset(container),
	     elementOffset = Position.cumulativeOffset($(element));

		  this.scrolling 	= new Effect.SmoothScroll(container, 
				{duration:options.duration, x:(elementOffset[0]-containerOffset[0]), y:(elementOffset[1]-containerOffset[1])});
		  return false;
		},
		
  next: function(){
    if (this.current) {
      var currentIndex = this.current._index;
      var nextIndex = (this.sections.length - 1 == currentIndex) ? 0 : currentIndex + 1;      
    } else var nextIndex = 1;

    this.moveTo(this.sections[nextIndex], this.scroller, { 
      duration: this.options.duration
    });
  },
	
  previous: function(){
    if (this.current) {
      var currentIndex = this.current._index;
      var prevIndex = (currentIndex == 0) ? this.sections.length - 1 : 
       currentIndex - 1;
    } else var prevIndex = this.sections.length - 1;
    
    this.moveTo(this.sections[prevIndex], this.scroller, { 
      duration: this.options.duration
    });
  },

	stop: function()
	{
		clearTimeout(this.timer);
	},
	
	start: function()
	{
		this.periodicallyUpdate();
	},
		
	periodicallyUpdate: function()
	{ 
		if (this.timer != null) {
			clearTimeout(this.timer);
			this.next();
		}
		this.timer = setTimeout(this.periodicallyUpdate.bind(this), this.options.frequency*1000);
	}

});

Effect.SmoothScroll = Class.create();
Object.extend(Object.extend(Effect.SmoothScroll.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    var options = Object.extend({
      x:    0,
      y:    0,
      mode: 'absolute'
    } , arguments[1] || {}  );
    this.start(options);
  },
  setup: function() {
    if (this.options.continuous && !this.element._ext ) {
      this.element.cleanWhitespace();
      this.element._ext=true;
      this.element.appendChild(this.element.firstChild);
    }
   
    this.originalLeft=this.element.scrollLeft;
    this.originalTop=this.element.scrollTop;
   
    if(this.options.mode == 'absolute') {
      this.options.x -= this.originalLeft;
      this.options.y -= this.originalTop;
    } 
  },
  update: function(position) {   
    this.element.scrollLeft = this.options.x * position + this.originalLeft;
    this.element.scrollTop  = this.options.y * position + this.originalTop;
  }
});

function hideShowPlayBut(spId)
	{
		var spBox = document.getElementById(spId);
		if(spBox.style.visibility=='hidden') {spBox.style.visibility='visible';return;}
		else spBox.style.visibility='hidden';
	}
	
function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_swapImage() { //v3.0
  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)
   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}
}