(function() {
  
  if (typeof document != 'undefined' && typeof window != 'undefined') {
    return;
  }
  
  var XML = require('o3-xml'),
      URL = require('url'),
      HTTP = require('http'),
      
      Canvas = require('canvas'),
      Image = require('canvas').Image;

  function request(url, encoding, callback) {
    var oURL = URL.parse(url),
        client = HTTP.createClient(80, oURL.hostname),
        request = client.request('GET', oURL.pathname, { 'host': oURL.hostname });

    client.addListener('error', function(err) {
      if (err.errno === process.ECONNREFUSED) {
        fabric.log('ECONNREFUSED: connection refused to ' + client.host + ':' + client.port);
      }
      else {
        fabric.log(err.message);
      }
    });

    request.end();
    request.on('response', function (response) {
      var body = "";
      if (encoding) {
        response.setEncoding(encoding);
      }
      response.on('end', function () {
        callback(body);
      });
      response.on('data', function (chunk) {
        if (response.statusCode == 200) {
          body += chunk;
        }
      });
    });
  }

  fabric.Canvas.prototype.loadImageFromURL = function(url, callback) {
    request(url, 'binary', function(body) {
      var img = new Image();
      img.src = new Buffer(body, 'binary');
      callback(new fabric.Image(img));
    });
  };

  fabric.loadSVGFromURL = function(url, callback) {
    url = url.replace(/^\n\s*/, '').replace(/\?.*$/, '').trim();
    request(url, '', function(body) {
      var doc = XML.parseFromString(body);
      fabric.parseSVGDocument(doc.documentElement, function(results, options) {
        callback(results, options);
      });
    });
  };
  
  fabric.util.getScript = function(url, callback) {
    request(url, '', function(body) {
      eval(body);
      callback && callback();
    });
  };

  fabric.Image.fromObject = function(object, callback) {
    fabric.Canvas.prototype.loadImageFromURL(object.src, function(oImg) {
      oImg._initConfig(object);
      callback(oImg);
    });
  };

  fabric.createCanvasForNode = function(width, height) {
    
    var canvasEl = fabric.document.createElement('canvas'),
        nodeCanvas = new Canvas(width || 600, height || 600);

    // jsdom doesn't create style on canvas element, so here be temp. workaround 
    canvasEl.style = { };

    canvasEl.width = nodeCanvas.width;
    canvasEl.height = nodeCanvas.height;

    var fabricCanvas = new fabric.Canvas(canvasEl);
    fabricCanvas.contextContainer = nodeCanvas.getContext('2d');
    fabricCanvas.nodeCanvas = nodeCanvas;

    return fabricCanvas;
  };
  
  fabric.Canvas.prototype.createPNGStream = function() {
    return this.nodeCanvas.createPNGStream();
  };
  
  var origSetWidth = fabric.Canvas.prototype.setWidth;
  fabric.Canvas.prototype.setWidth = function(width) {
    origSetWidth.call(this);
    this.nodeCanvas.width = width;
    return this;
  };
  
  var origSetHeight = fabric.Canvas.prototype.setHeight;
  fabric.Canvas.prototype.setHeight = function(height) {
    origSetHeight.call(this);
    this.nodeCanvas.height = height;
    return this;
  };
  
})();