/**
 * @author Bruno Bornsztein 
 * @copyright 2007 Curbly LLC
 * @package Slider
 * @license MIT
 * @url http://www.missingmethod.com/projects/slider/
 * @version 0.0.1
 * @dependencies prototype.js, effects.js
 */

var ViewMaster = Class.create();
ViewMaster.prototype = {
  initialize: function(wrapper, options){
    this.scrolling  = false;
    this.wrapper    = $(wrapper);
    this.scroller   = this.wrapper.down('div.scroller');
    this.sections   = this.wrapper.getElementsBySelector('div.selection');
    this.options    = Object.extend({ duration: 1.0 }, options || {});

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

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

    this.addObservers();
  },

  addObservers: function() {
    var controls = this.wrapper.getElementsBySelector('div.controls a');
    controls.invoke('observe', 'click', this.events.click);
  },

  click: function(event) {
    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;

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

    this.scrolling  = new Effect.HorizontalScroll(container, {
      duration: this.options.duration, 
      x: (element[0] - container[0]), y:(element[1] - container[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
    });
  }
};

Effect.HorizontalScroll = Class.create();
Object.extend(Object.extend(Effect.Scroll.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;
  }
});