/*
Author:
  luistar15, <leo020588 [at] gmail.com>
License:
  MIT License

Class
  viewer v0.9 (rev.08-12-08)

Arguments:
  items: dom collection | required
  parameters - see Parameters below

Parameters:
  sizes: obj | item sizes (px) | default: {w:480,h:240}
  mode: string OR array | 'rand','top','right','bottom','left','alpha' | default: 'rand'
  modes: array | default: ['top','right','bottom','left','alpha']
  fxOptions: object | Fx.Tween options | default: {duration:500}
  interval: int | for periodical | default: 5000

Methods:
  previous(manual): walk to previous item
    manual: bolean | default:false
  next(manual): walk to next item
    manual: bolean | default:false
  play(wait): auto walk items
    wait: boolean | required
  stop(): stop auto walk
  walk(item,manual): walk to item
    item: int | required
    manual: bolean | default:false

Requires:
  mootools 1.2 core
*/

var viewer = new Class({

  mode: 'rand',
  modes: ['top','right','bottom','left','alpha'],
  sizes: {w:485,h:380},
  fxOptions: {duration:500},
  interval: 5000,

  initialize: function(items,options){
    if(options) for(var o in options) this[o]=options[o];
    //
    if(this.buttons){
      this.buttons.previous.addEvent('click',this.previous.bind(this,[true]));
      this.buttons.next.addEvent('click',this.next.bind(this,[true]));
    }
    this.__current = 0;
    this.__previous = null;
    this.items = items.setStyle('display','none');
    this.items[this.__current].setStyle('display','block');
    this.disabled = false;
    this.attrs = {
      left: ['left',-this.sizes.w,0,'px'],
      top: ['top',-this.sizes.h,0,'px'],
      right: ['left',this.sizes.w,0,'px'],
      bottom: ['top',this.sizes.h,0,'px'],
      alpha: ['opacity',0,1,'']
    };
    this.rand = this.mode=='rand';
    this.sequence = typeof(this.mode)=='object' ? this.mode : false;
    this.curseq = 0;
    this.timer = null;
  },

  walk: function(n,manual){
    if(this.__current!==n && !this.disabled){
      this.disabled = true;
      if(manual){
        this.stop();
    	}
      if(this.rand){
        this.mode = this.modes.getRandom();
      }else if(this.sequence){
        this.mode = this.sequence[this.curseq];
        this.curseq += this.curseq+1<this.sequence.length ? 1 : -this.curseq;
    	}
      this.__previous = this.__current;
      this.__current = n;
      var a = this.attrs[this.mode].associate(['p','f','t','u']);
      for(var i=0;i<this.items.length;i++){
        if(this.__current===i){
          this.items[i].setStyles($extend({'display':'block','z-index':'2'},JSON.decode('{"'+a.p+'":"'+a.f+a.u+'"}')));
        }else if(this.__previous===i){
          this.items[i].setStyles({'z-index':'1'});
        }else{
          this.items[i].setStyles({'display':'none','z-index':'0'});
      	}
    	}
      this.items[n].set('tween',$merge(this.fxOptions,{onComplete:this.onComplete.bind(this)})).tween(a.p,a.f,a.t);
    }
  },

  play: function(wait){
    this.stop();
    if(!wait){
      this.next();
    }
    this.timer = this.next.periodical(this.interval,this,[false]);
  },

  stop: function(){
    $clear(this.timer);
  },

  next: function(manual){
    this.walk(this.__current+1<this.items.length ? this.__current+1 : 0,manual);
  },

  previous: function(manual){
    this.walk(this.__current>0 ? this.__current-1 : this.items.length-1,manual);
  },

  onComplete: function(){
    this.disabled = false;
    this.items[this.__previous].setStyle('display','none');
    if(this.onWalk) this.onWalk(this.__current);
  }
});