var Dialog = {};
Dialog.Box = Class.create();
Object.extend(Dialog.Box.prototype, {
  initialize: function(id) {
    this.createOverlay();

    this.dialog_box = $(id);
    this.dialog_box.show = this.show.bind(this);
    this.dialog_box.hide = this.hide.bind(this);

    this.parent_element = this.dialog_box.parentNode;

    var e_dims = Element.getDimensions(this.dialog_box);
    var b_dims = Element.getDimensions(this.overlay);
    this.dialog_box.style.left = ((b_dims.width/2) - (e_dims.width/2)) + 'px';
    this.dialog_box.style.top = '12px';
  },

  createOverlay: function() {
    if($('dialog_overlay')) {
      this.overlay = $('dialog_overlay');
    } else {
      this.overlay = document.createElement('div');
      this.overlay.id = 'dialog_overlay';
      Object.extend(this.overlay.style, {
      	position: 'absolute',
      	top: 0,
      	left: 0,
      	zIndex: 90,
      	width: '100%',
      	backgroundColor: '#000',
      	display: 'none'
      });
      document.body.insertBefore(this.overlay, document.body.childNodes[0]);
    }
  },

  moveDialogBox: function(where) {
    Element.remove(this.dialog_box);
    if(where == 'back')
      this.dialog_box = this.parent_element.appendChild(this.dialog_box);
    else
      this.dialog_box = this.overlay.parentNode.insertBefore(this.dialog_box, this.overlay);
  },

  show: function() {
    this.overlay.style.height = $('body').getHeight()+'px';
    this.moveDialogBox('out');
    this.overlay.onclick = this.hide.bind(this);
    this.selectBoxes('hide');
    new Effect.Appear(this.overlay, {duration: 0.1, from: 0.0, to: 0.3});
    this.dialog_box.style.display = ''
  },

  hide: function() {
    this.selectBoxes('show');
    new Effect.Fade(this.overlay, {duration: 0.1});
    this.dialog_box.style.display = 'none';
    this.moveDialogBox('back');
    $A(this.dialog_box.getElementsByTagName('input')).each(function(e){if(e.type!='submit')e.value=''});
  },

  selectBoxes: function(what) {
    $A(document.getElementsByTagName('select')).each(function(select) {
      Element[what](select);
    });

    if(what == 'hide')
      $A(this.dialog_box.getElementsByTagName('select')).each(function(select){Element.show(select)})
  }
});