Autocomplete.hash = {};
Autocomplete.generator = 0;
function Autocomplete(source,type,callback) {
  this.id = Autocomplete.generator++;          
  this.source = source;
  this.type = type;
  this.index = -1;
  this.guesses = [];
  this.visible = false;
  this.callback = callback;
  var scopedThis = this;
  
  this.display = document.createElement('div');
  this.display.style.position = 'absolute';
  this.display.style.display = 'none';
  this.display.className = 'autocompleter';
  this.display.style.backgroundColor = 'white';
  this.display.style.border = '1px solid #42619C';
  this.display.style.zIndex = 10;
  this.display.style.overflow = 'hidden';
  this.display.onmouseout = function(event) {
    scopedThis.clearIndex();
  }
  
  this.source.onkeydown = function(event) {
    event = event || window.event;
    switch(event.keyCode) {
      case 38: //up
        scopedThis.setIndex(scopedThis.index-1);
        return false;
      case 40: //down
        scopedThis.setIndex(scopedThis.index+1);
        return false;
      case 13: //enter
      case 9: //tab
        if(scopedThis.visible) {
          if(scopedThis.index == -1) {
            scopedThis.setIndex(0);
          }
          if(scopedThis.index != -1) {
            scopedThis.accept();
            if(event.keyCode != 9) {
              return false;
            }
          }
        }
        break;
    }
  }
  this.source.onkeyup = function(event) {
    if(scopedThis.source.value != scopedThis.previous) {
      scopedThis.setGuesses(scopedThis.guesses);
    }
    scopedThis.request();
  }
  this.source.onblur = function(event) {
    scopedThis.cancel(true);
  }
  
  Autocomplete.hash[this.id] = this;
}
Autocomplete.prototype = {
  accept: function() {
    if(this.index != -1) {
      var app = this.guesses[this.index];
      this.source.value = app.display;
      //this.source.appId = app.value;
      this.previous = this.source.value;
      this.cancel(true);
      if(this.callback) {
        this.callback(app);
      }
    }
  },
  cancel: function(clear) {
    if(this.ajax) {
      this.ajax.cancel();
      this.ajax = null;
    }
    if(clear) {
      this.setGuesses([]);
    }
  },
  request: function() {
    if(this.source.value == '') {
      this.previous = '';
      this.setGuesses([]);
    }
    else if(this.source.value != this.previous) {
      this.previous = this.source.value;      
      var scopedThis = this;
      this.cancel();
      var ajax = new Ajax("/ajax/autocomplete.php",{
        method:'get',
        data:'type='+encodeURIComponent(this.type)+'&text='+encodeURIComponent(this.source.value),
        onComplete:function(response){
          scopedThis.ajax = null;
          try {
            eval("var guesses = "+response);
            scopedThis.setGuesses(guesses);
          }
          catch(E){alert(E.name + ": "+E.message)}
        }
      });
      ajax.request();
      this.ajax = ajax;
    }
  },
  setGuesses: function(guesses) {
    if(guesses.length > 0) {
      this.guesses = guesses;
    }
    this.index = -1;
    var scopedThis = this;
    var coords = $(this.source).getCoordinates();
    this.display.style.left = coords.left + 'px';
    this.display.style.top = coords.bottom + 'px';
    this.display.style.width = Math.round(coords.width * 1.5) + 'px';
    this.display.innerHTML = '';
    var displayed = 0;
    for(var i = 0 ; i < guesses.length ; i++) {
      var app = guesses[i];
      var div = document.createElement('div');
      div.style.position = 'relative';
      div.style.overflow = 'hidden';
      div.style.cursor = 'pointer';
      div.style.whiteSpace = 'nowrap';
      div.style.width = '100%';
      div.innerHTML = '';
      if(app.icon){
        div.innerHTML += "<img style='margin-left:2px;margin-top:2px;' height=16 width=16 src='"+app.icon+"'/> ";
      }
      else {
        div.innerHTML += "<img style='margin-left:2px;margin-top:2px;height:16px;width:1px;' height=16 width=1 src='/blank.gif'/> ";
      }
      div.innerHTML += "<span style='position:relative;top:-4px;'>"+app.display+"</span>";
      eval("div.onmouseover = function(event) {scopedThis.setIndex("+displayed+");};");
      eval("div.onmousedown = function(event) {scopedThis.setIndex("+displayed+");scopedThis.accept();};");
      div.title = app.display;
      app.dom = div;
      this.display.appendChild(div);
      displayed++;
    }
    this.visible = displayed>0;
    this.display.style.display = this.visible?'':'none';
    if(this.display.parentNode != document.body) {
      document.body.appendChild(this.display);
    }
  },
  clearIndex: function() {
    if(this.index != -1) {
      this.guesses[this.index].dom.style.backgroundColor = '';
    }
    this.index = -1;
  },
  setIndex: function(index) {
    if(index < 0) {
      index = 0;
    }
    if(index >= this.guesses.length) {
      index = this.guesses.length - 1;
    }
    if(this.index != index) {
      if(this.index != -1) {
        this.guesses[this.index].dom.style.backgroundColor = '';
      }
      this.index = index;
      this.guesses[index].dom.style.backgroundColor = '#DEDFEF';
    }
  }
};