function focusShift() {};

function registerSpace(instance) 
{
  var spaceName = instance.attributes.name;
  var spaceDir = 'spaces/' + spaceName + '/';

  if (!instance.attributes.icon) 
  {
    var icon = installed[spaceName].replace('.js', '.png');
    instance.attributes.icon = icon;
  } 
  else if (instance.attributes.icon.indexOf('/') == -1) 
  {
    var icon = spaceDir + instance.attributes.icon;
    instance.attributes.icon = icon;
  }

  // if a css file is defined in the attributes load the style
  if (instance.attributes.css) 
  {
    if (instance.attributes.css.indexOf('/') == -1) 
    {
      var css = spaceDir + instance.attributes.css;
      instance.attributes.css = css;
    }
    loadStyle(instance.attributes.css, instance.onCssLoad.bind(instance));
  }

  // This exposes each space instance to the console
  ShiftSpace[instance.attributes.name + 'Space'] = instance;
}

function loadFile(url, callback) 
{
  // If the URL doesn't start with "http://", assume it's on our server
  if (url.substr(0, 7) != 'http://' &&
      url.substr(0, 8) != 'https://') 
  {
    url = __server__ + url;
  }

  // Load the URL then execute the callback
  //log('Loading ' + url + ' from network');
  GM_xmlhttpRequest({
    'method': 'GET',
    'url': url,
    'onload': function(response) 
    {
      if (typeof callback == 'function') 
      {
        callback(response);
      }
    }
  });
  return true;
}

function loadStyle(url, callback, frame) 
{
  // TODO: check to see if the domain is different, if so don't mess with the url - David
  var dir = url.split('/');
  dir.pop();
  dir = dir.join('/');
  if (dir.substr(0, 7) != 'http://') 
{
    dir = __server__ + dir;
  }

  loadFile(url, function(rx) {
    var css = rx.responseText;
    css = css.replace(/url\(([^)]+)\)/g, 'url(' + dir + '/$1)');
    
    // if it's a frame load it into the frame
    if(frame)
    {
      var doc = frame.contentDocument;

      if( doc.getElementsByTagName('head').length != 0 )
      {
        var head = doc.getElementsByTagName('head')[0];
      }
      else
      {
        // In Safari iframes don't get the head element by default - David
        // Mootools-ize body
        $(doc.body);
        var head = new Element( 'head' );
        head.injectBefore( doc.body );
      }

      var style = new Element('style', {
        type: 'text/css'
      });

      style.appendText(css); // You can not use setHTML on style elements in Safari - David
      style.injectInside(head);
    }
    else
    {
      GM_addStyle(css);
    }
    
    if (typeof callback == 'function') 
    {
      callback();
    } 

  });
}

// stores direct references to the shift objects
function pinElement(element, pinRef)
{
  var targetNode = $(ShiftSpace.Pin.toNode(pinRef));
  
  // pinRef has become active set targetElement and element properties
  $extend(pinRef, {
    'element': element,
    'targetElement': targetNode
  });
  
  switch(pinRef.action)
  {
    case 'before':
      element.injectBefore(targetNode);
    break;
    
    case 'replace':
      targetNode.replaceWith(element);
      //pinRef.targetStyles = targetNode.getStyles('float', 'width', 'height', 'position', 'display');
      //element.setStyles(pinRef.targetStyles);
    break;
    
    case 'after':
      element.injectAfter(targetNode);
    break;
    
    case 'relative':
      var elPos = element.getPosition();
      var tgPos = targetNode.getPosition();
    
      // if no offset set it now
      if(!pinRef.offset)
      {
        var elpos = element.getPosition();
        var tpos = targetNode.getPosition();
        pinRef.offset = {x: elpos.x - tpos.x, y: elpos.y - tpos.y};
        pinRef.originalOffset = {x: elpos.x, y: elpos.y};
      }
      
      // hide the element while we do some node magic
      element.addClass('SSDisplayNone');
    
      // wrap the target node
      var wrapper = new Element('div', {
        'class': 'SSImageWrapper SSPositionRelative'
      });
      targetNode.replaceWith(wrapper);
      targetNode.injectInside(wrapper);
      
      // if the target node is an image we
      // want the wrapper node to display inline
      if(targetNode.getTag() == 'img')
      {
        wrapper.setStyle('display', 'inline');
      }
      var styles = targetNode.getStyles('width', 'height');
    
      // set the dimensions of the wrapper
      if( styles.width && styles.height != 'auto' )
      {
        wrapper.setStyle('width', styles.width);
      }
      else
      {
        wrapper.setStyle('width', targetNode.getSize().size.x);
      }
      
      if( styles.height && styles.height != 'auto' )
      {
        wrapper.setStyle('height', styles.height);
      }
      else
      {
        wrapper.setStyle('height', targetNode.getSize().size.y);
      }
    
      // override clicks in case the wrapper is inside of a link
      wrapper.addEvent('click', function(_evt) {
        var evt = new Event(_evt);
        evt.stop();
      });
      // store a reference to the wrapper
      pinRef.wrapper = wrapper;

      targetNode = wrapper;
    
      // inject it inside the parent of the target node
      element.injectInside(targetNode);
    
      // position absolute now
      if(element.getStyle('position') != 'absolute')
      {
        pinRef.cssPosition = element.getStyle('position');
        element.setStyle('position', 'absolute');
      }

      // set the position
      element.setStyles({
        left: pinRef.offset.x,
        top: pinRef.offset.y
      });
      
      // we're done show the element
      element.removeClass('SSDisplayNone');
    break;

    default:
    break;
  }
}