Effect = {}
Effect2 = Effect; // deprecated


Effect.Transitions = {
  linear: Prototype.K,
  sinoidal: function(pos) {
    return (-Math.cos(pos*Math.PI)/2) + 0.5;
  },
  reverse: function(pos) {
    return 1-pos;
  },
  flicker: function(pos) {
    return ((-Math.cos(pos*Math.PI)/4) + 0.75) + Math.random()/4;
  },
  wobble: function(pos) {
    return (-Math.cos(pos*Math.PI*(9*pos))/2) + 0.5;
  },
  pulse: function(pos, pulses) { 
    pulses = pulses || 5; 
    return (
      Math.round((pos % (1/pulses)) * pulses) == 0 ? 
            ((pos * pulses * 2) - Math.floor(pos * pulses * 2)) : 
        1 - ((pos * pulses * 2) - Math.floor(pos * pulses * 2))
      );
  },
  none: function(pos) {
    return 0;
  },
  full: function(pos) {
    return 1;
  }
};

/* ------------- core effects ------------- */

Effect.ScopedQueue = Class.create();
Object.extend(Object.extend(Effect.ScopedQueue.prototype, Enumerable), {
  initialize: function() {
    this.effects  = [];
    this.interval = null;
  },
  _each: function(iterator) {
    this.effects._each(iterator);
  },
  add: function(effect) {
    var timestamp = new Date().getTime();
    
    var position = (typeof effect.options.queue == 'string') ? 
      effect.options.queue : effect.options.queue.position;
    
    switch(position) {
      case 'front':
        // move unstarted effects after this effect  
        this.effects.findAll(function(e){ return e.state=='idle' }).each( function(e) {
            e.startOn  += effect.finishOn;
            e.finishOn += effect.finishOn;
          });
        break;
      case 'with-last':
        timestamp = this.effects.pluck('startOn').max() || timestamp;
        break;
      case 'end':
        // start effect after last queued effect has finished
        timestamp = this.effects.pluck('finishOn').max() || timestamp;
        break;
    }
    
    effect.startOn  += timestamp;
    effect.finishOn += timestamp;

    if(!effect.options.queue.limit || (this.effects.length < effect.options.queue.limit))
      this.effects.push(effect);
    
    if(!this.interval) 
      this.interval = setInterval(this.loop.bind(this), 40);
  },
  remove: function(effect) {
    this.effects = this.effects.reject(function(e) { return e==effect });
    if(this.effects.length == 0) {
      clearInterval(this.interval);
      this.interval = null;
    }
  },
  loop: function() {
    var timePos = new Date().getTime();
    this.effects.invoke('loop', timePos);
  }
});

Effect.Queues = {
  instances: $H(),
  get: function(queueName) {
    if(typeof queueName != 'string') return queueName;
    
    if(!this.instances[queueName])
      this.instances[queueName] = new Effect.ScopedQueue();
      
    return this.instances[queueName];
  }
}
Effect.Queue = Effect.Queues.get('global');

Effect.DefaultOptions = {
  transition: Effect.Transitions.sinoidal,
  duration:   1.0,   // seconds
  fps:        25.0,  // max. 25fps due to Effect.Queue implementation
  sync:       false, // true for combining
  from:       0.0,
  to:         1.0,
  delay:      0.0,
  queue:      'parallel'
}

Effect.Base = function() {};
Effect.Base.prototype = {
  position: null,
  start: function(options) {
    this.options      = Object.extend(Object.extend({},Effect.DefaultOptions), options || {});
    this.currentFrame = 0;
    this.state        = 'idle';
    this.startOn      = this.options.delay*1000;
    this.finishOn     = this.startOn + (this.options.duration*1000);
    this.event('beforeStart');
    if(!this.options.sync)
      Effect.Queues.get(typeof this.options.queue == 'string' ? 
        'global' : this.options.queue.scope).add(this);
  },
  loop: function(timePos) {
    if(timePos >= this.startOn) {
      if(timePos >= this.finishOn) {
        this.render(1.0);
        this.cancel();
        this.event('beforeFinish');
        if(this.finish) this.finish(); 
        this.event('afterFinish');
        return;  
      }
      var pos   = (timePos - this.startOn) / (this.finishOn - this.startOn);
      var frame = Math.round(pos * this.options.fps * this.options.duration);
      if(frame > this.currentFrame) {
        this.render(pos);
        this.currentFrame = frame;
      }
    }
  },
  render: function(pos) {
    if(this.state == 'idle') {
      this.state = 'running';
      this.event('beforeSetup');
      if(this.setup) this.setup();
      this.event('afterSetup');
    }
    if(this.state == 'running') {
      if(this.options.transition) pos = this.options.transition(pos);
      pos *= (this.options.to-this.options.from);
      pos += this.options.from;
      this.position = pos;
      this.event('beforeUpdate');
      if(this.update) this.update(pos);
      this.event('afterUpdate');
    }
  },
  cancel: function() {
    if(!this.options.sync)
      Effect.Queues.get(typeof this.options.queue == 'string' ? 
        'global' : this.options.queue.scope).remove(this);
    this.state = 'finished';
  },
  event: function(eventName) {
    if(this.options[eventName + 'Internal']) this.options[eventName + 'Internal'](this);
    if(this.options[eventName]) this.options[eventName](this);
  },
  inspect: function() {
    return '#<Effect:' + $H(this).inspect() + ',options:' + $H(this.options).inspect() + '>';
  }
}

 
 

Effect.Move = Class.create();
Object.extend(Object.extend(Effect.Move.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    if(!this.element) throw(Effect._elementDoesNotExistError);
    var options = Object.extend({
      x:    0,
      y:    0,
      mode: 'relative'
    }, arguments[1] || {});
    this.start(options);
  },
  setup: function() {
    // Bug in Opera: Opera returns the "real" position of a static element or
    // relative element that does not have top/left explicitly set.
    // ==> Always set top and left for position relative elements in your stylesheets 
    // (to 0 if you do not need them) 
    this.element.makePositioned();
    this.originalLeft = parseFloat(this.element.getStyle('left') || '0');
    this.originalTop  = parseFloat(this.element.getStyle('top')  || '0');
    if(this.options.mode == 'absolute') {
      // absolute movement, so we need to calc deltaX and deltaY
      this.options.x = this.options.x - this.originalLeft;
      this.options.y = this.options.y - this.originalTop;
    }
  },
  update: function(position) {
    this.element.setStyle({
      left: Math.round(this.options.x  * position + this.originalLeft) + 'px',
      top:  Math.round(this.options.y  * position + this.originalTop)  + 'px'
    });
  }
});
 
 
 
 
var Fader = {
  _assets: $H({}),
  _checkInterval: null,
  _options: {},
  _update: function() {
    var allFaded = true;
    Fader._assets.each(function(a){
      if(!a[1].complete && a[1].image.complete) {
        a[1].complete = true;
        a[1].completed_at = new Date().getTime();;
        if(a[1].options.onComplete) a[1].options.onComplete(a[0]);
      }
      if(!a[1].complete && !a[1].image.complete) allFaded = false;
    });
    if(allFaded) {
      clearInterval(Fader._checkInterval);
      Fader._checkInterval = null;
      if(Fader._options && Fader._options.onComplete) Fader._options.onComplete();
      Fader._options = null;
    }
  },
  initialize: function() {
    var options = arguments[0] || {};
    Fader._options = options;
  },
   load: function(url) {
    if(Fader._assets[url]) return;
    var options = arguments[1] || {};
    var a = {};
    a.image = new Image();
    a.image.src = url;
    a.complete = false;
    a.options  = options;
    a.loaded_at = new Date().getTime();
    Event.observe(a.image, 'error', function(){ Fader.error(url) });
    Fader._assets[url] = a;
    if(!Fader._checkInterval) Fader._checkInterval = setInterval(Fader._update,10);
  },
  error: function(url) {
    var asset = Fader._assets[url];
    asset.complete = true;
    if(asset.options.onComplete) asset.options.onComplete('../webimages/blank.gif');
  },
  stats: function(url) {
    return (Fader._assets[url]._complete ?
      (Fader._assets[url]._completed_at - Fader._assets[url]._loaded_at) : null);
  },
  isQueued: function(url) {
    return !!(Fader._assets[url]);
  },
  isLoaded: function(url) {
    return (Fader._assets[url] && Fader._assets[url].complete);
  },
  reset: function() {
    Fader._assets = $H({});
  }
};