// Copyright (c) 2005 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
// See scriptaculous.js for full license.  
Array.prototype.call = function() {
  var args = arguments;
  this.each(function(f){ f.apply(this, args) });
}
/*--------------------------------------------------------------------------*/
var Effect = {
  _elementDoesNotExistError: {
    name: 'ElementDoesNotExistError',
    message: 'The specified DOM element does not exist, but is required for this effect to operate'
  }
};
var Effect2 = Effect; // deprecated
/* ------------- transitions ------------- */
Effect.Transitions = {}
Effect.Transitions.sinoidal = function(pos) { return (-Math.cos(pos*Math.PI)/2) + 0.5; }
/* ------------- 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 '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.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;
  }
});
Element.addMethods();