/*

 * @author Bruno Bornsztein <bruno@missingmethod.com>

 * @copyright 2007 Curbly LLC

 * @package Glider

 * @license MIT

 * @url http://code.google.com/p/missingmethod-projects/wiki/Glider

 * @version 0.0.4

 * @dependencies prototype.js 1.5.1+, effects.js

 */



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({ controlsEvent:'click', 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() {

		this.controls = this.wrapper.getElementsBySelector('.controls a');

		this.controls.invoke('observe', this.options.controlsEvent, this.events.click);

  },	



  click: function(event) {

		this.stop();

    var element = Event.findElement(event, 'a');

    if (this.scrolling) 

        this.scrolling.cancel();

        

	moveToHere = element.href.split("#")[1];

        

    this.moveTo(moveToHere, this.scroller, { duration:this.options.duration });     

    Event.stop(event);



		this.controls.each(function(control){

			if (control == element) {

				control.addClassName("active")

			}else{

				control.removeClassName("active")

			}			

		});

  },



	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;

  }

});