/*
 Copyright 2007-2009 WebDriver committers
 Copyright 2007-2009 Google Inc.

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */


function Screenshooter() {
}


Screenshooter.grab = function(window) {
  var document = window.document;
  var documentElement = document.documentElement;
  var canvas = document.getElementById('fxdriver-screenshot-canvas');
  if (canvas == null) {
    canvas = document.createElement('canvas');
    canvas.id = 'fxdriver-screenshot-canvas';
    canvas.style.display = 'none';
    documentElement.appendChild(canvas);
  }
  var width =
      Math.max(documentElement.scrollWidth, document.body.scrollWidth);
  var height =
      Math.max(documentElement.scrollHeight, document.body.scrollHeight);
  canvas.width = width;
  canvas.height = height;
  var context = canvas.getContext('2d');
  context.drawWindow(window, 0, 0, width, height, 'rgb(0,0,0)');
  return canvas;
};


Screenshooter.toBase64 = function(canvas) {
  var dataUrl = canvas.toDataURL('image/png');
  var index = dataUrl.indexOf('base64,');
  if (index == -1) {
    // No base64 data marker.
    throw new Error("Invalid base64 data: " + dataUrl);
  }
  return dataUrl.substring(index + 'base64,'.length);
};


Screenshooter.save = function(canvas, filepath) {
  var cc = Components.classes;
  var ci = Components.interfaces;
  var dataUrl = canvas.toDataURL('image/png');
  var ioService = cc['@mozilla.org/network/io-service;1'].
      getService(ci.nsIIOService);
  var dataUri = ioService.newURI(dataUrl, 'UTF-8', null);
  var channel = ioService.newChannelFromURI(dataUri);
  var file = cc['@mozilla.org/file/local;1'].createInstance(ci.nsILocalFile);
  file.initWithPath(filepath);
  var inputStream = channel.open();
  var binaryInputStream = cc['@mozilla.org/binaryinputstream;1'].
      createInstance(ci.nsIBinaryInputStream);
  binaryInputStream.setInputStream(inputStream);
  var fileOutputStream = cc['@mozilla.org/network/safe-file-output-stream;1'].
      createInstance(ci.nsIFileOutputStream);
  fileOutputStream.init(file, -1, -1, null);
  var n = binaryInputStream.available();
  var bytes = binaryInputStream.readBytes(n);
  fileOutputStream.write(bytes, n);
  if (fileOutputStream instanceof ci.nsISafeOutputStream) {
    fileOutputStream.finish();
  } else {
    fileOutputStream.close();
  }
};