/**
 * @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();
      // initialSection should be the id of the section you want to show up on load
     if(this.options.initialSection) {
       //スタイルシート-カレントクラスのクリア
       this.clearClass();
       
       this.moveTo(this.options.initialSection, this.scroller, { duration:this.options.duration });
       
       //スタイルシート-カレントクラスの追加
       //debug
       //$("debug").innerHTML=this.options.initialSection;
       var initialTab = "tab"+this.options.initialSection.split("section")[1];
       //debug
       //$("debug").innerHTML=initialTab
       Element.addClassName(initialTab, "current");
     }
     if(this.options.autoGlide) this.start();
   },
 
  addObservers: function() {
    var controls = this.wrapper.getElementsBySelector('#controls a');
    controls.invoke('observe', 'click', this.events.click);
  }, 

  click: function(event) {
  //スタイルシート-カレントクラスのクリア
  this.clearClass();
  var element = Event.findElement(event, 'a');
  this.stop();
  if (this.scrolling) this.scrolling.cancel();
  this.moveTo(element.href.split("#")[1], this.scroller, { duration:this.options.duration });
    //スタイルシート-カレントクラスの追加
    Element.addClassName(element, 'current');
    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(){
    //スタイルシート-カレントクラスのクリア
    this.clearClass();
    if (this.current) {
      var currentIndex = this.current._index;
      var nextIndex = (this.sections.length - 1 == currentIndex) ? 0 : currentIndex + 1;      
    } else var nextIndex = 1;

    $$('#controls ul').each(function(element) {
      var descendants = element.descendants();

      descendants = descendants.map(function (descendant) {
        return $(descendant);
      });
  
      for (var i = 0, length = descendants.length;length > i;i++) {
        var elem = descendants[i];

        if (elem.tagName.match('A')) {
          if ("section" + (nextIndex + 1) == elem.href.split("#")[1]) {
            Element.addClassName(elem, 'current');
            //elem.href = 'javascript:void(0);';
            break;
          }
        }
      }
    })


    this.moveTo(this.sections[nextIndex], this.scroller, { 
      duration: this.options.duration
    });
  },
 
  previous: function(){
    //スタイルシート-カレントクラスのクリア
    this.clearClass();
    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;

    $$('#controls ul').each(function(element) {
      var descendants = element.descendants();

      descendants = descendants.map(function (descendant) {
        return $(descendant);
      });
  
      for (var i = 0, length = descendants.length;length > i;i++) {
        var elem = descendants[i];

        if (elem.tagName.match('A')) {
          if ("section" + (prevIndex + 1) == elem.href.split("#")[1]) {
            Element.addClassName(elem, 'current');
            //elem.href = 'javascript:void(0);';
            break;
          }
        }
      }
    })

    
    this.moveTo(this.sections[prevIndex], this.scroller, { 
      duration: this.options.duration
    });
  },

 stop: function()
 {
  clearTimeout(this.timer);
 },
 
 start: function()
 {
  this.periodicallyUpdate();
 },
  
 
 //スタイルシートカレントクラスのクリアメソッド
 clearClass: function()
 {
  $$(".current").each(function(obj){
    obj.className = "";
  });
 },

 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;
  }
});