/**
 * @author Bruno Bornsztein <bruno@missingmethod.com>
 * @copyright 2007 Curbly LLC
 * @package Glider
 * @license MIT
 * @url http://www.missingmethod.com/projects/glider/
 * @version 0.0.4
 * @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;
		this.sections   = this.wrapper.select('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
			mark = this.options.initialSection;
		}else{
			mark = this.wrapper.down('div.scroller').firstDescendant().id;
		}
		if(this.options.autoGlide) this.start();
		this.controls.each(function(control){
			if (control.href.split('#')[1] == mark) {
				if(control.down('img')){
					control.down('img').addClassName("active");
				}else{
					control.addClassName('active');
				}
			}else{
				if(control.down('img')){
					control.down('img').removeClassName("active");
				}else{
					control.removeClassName('active');
				}
			}			
		});

	},
	
	addObservers: function() {
		var obj = this;                      
		this.controls = $$('.controls a').findAll(function(elm){ 
			return obj.wrapper.select('div.section').find(function(e){ 
				return e.id == elm.href.split('#')[1]
			})
		});
		//		this.controls = this.wrapper.select('.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();

		var myTarget = $(element.href.split("#")[1])
		//	var myTarget = this.wrapper.down('#'+element.href.split("#")[1])
		this.moveTo(myTarget, this.scroller, { duration:this.options.duration });     
		Event.stop(event);

		this.controls.each(function(control){
			if (control == element) {
				if(control.down('img')){
					control.down('img').addClassName("active");
				}else{
					control.addClassName('active');
				}
			}else{
				if(control.down('img')){
					control.down('img').removeClassName("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])});
			this.controls.each(function(control){
				if (control.href.split('#')[1] == element.id) {
					if(control.down('img')){
						control.down('img').addClassName("active");
					}else{
						control.addClassName('active');
					}
				}else{
					if(control.down('img')){
						control.down('img').removeClassName("active");
					}else{
						control.removeClassName('active');
					}
				}
			});
			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;
  }
});