/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

module.metadata = {
  "stability": "unstable"
};

const { Cc, Ci, Cu } = require("chrome");
const base64 = require("../base64");
const { defer } = require("../core/promise");
const { newURI } = require("../url/utils");

const IOService = Cc["@mozilla.org/network/io-service;1"].
  getService(Ci.nsIIOService);

const { deprecateFunction } = require('../util/deprecate');
const { NetUtil } = Cu.import("resource://gre/modules/NetUtil.jsm");
const FaviconService = Cc["@mozilla.org/browser/favicon-service;1"].
                          getService(Ci.nsIFaviconService);
const AsyncFavicons = FaviconService.QueryInterface(Ci.mozIAsyncFavicons);

const PNG_B64 = "data:image/png;base64,";
const DEF_FAVICON_URI = "chrome://mozapps/skin/places/defaultFavicon.png";
let   DEF_FAVICON = null;

/**
 * Takes URI of the page and returns a promise that resolves
 * to the page's favicon URI.
 * @param {String} uri
 * @param {Function} (callback)
 * @returns {Promise}
 */

exports.getFavicon = function getFavicon(uri, callback) {
  let pageURI = newURI(uri);
  let deferred = defer();
  AsyncFavicons.getFaviconURLForPage(pageURI, function (aURI) {
    if (aURI && aURI.spec)
      deferred.resolve(aURI.spec.toString());
    else
      deferred.reject(null);
  });
  if (callback) deferred.promise.then(callback, callback);
  return deferred.promise;
};

/**
 * Takes URI of the page and returns associated favicon URI.
 * If page under passed uri has no favicon then base64 encoded data URI of
 * default faveicon is returned.
 * @param {String} uri
 * @returns {String}
 */
function getFaviconURIForLocation(uri) {
  let pageURI = NetUtil.newURI(uri);
  try {
    return FaviconService.getFaviconDataAsDataURL(
                  FaviconService.getFaviconForPage(pageURI));
  }
  catch(e) {
    if (!DEF_FAVICON) {
      DEF_FAVICON = PNG_B64 +
                    base64.encode(getChromeURIContent(DEF_FAVICON_URI));
    }
    return DEF_FAVICON;
  }
}
exports.getFaviconURIForLocation = getFaviconURIForLocation;

/**
 * Takes chrome URI and returns content under that URI.
 * @param {String} chromeURI
 * @returns {String}
 */
function getChromeURIContent(chromeURI) {
  let channel = IOService.newChannel(chromeURI, null, null);
  let input = channel.open();
  let stream = Cc["@mozilla.org/binaryinputstream;1"].
                createInstance(Ci.nsIBinaryInputStream);
  stream.setInputStream(input);
  let content = stream.readBytes(input.available());
  stream.close();
  input.close();
  return content;
}
exports.getChromeURIContent = deprecateFunction(getChromeURIContent,
  'getChromeURIContent is deprecated, ' +
  'please use require("sdk/net/url").readURI instead.'
);

/**
 * Creates a base-64 encoded ASCII string from a string of binary data.
 */
exports.base64Encode = deprecateFunction(base64.encode,
  'base64Encode is deprecated, ' +
  'please use require("sdk/base64").encode instead.'
);
/**
 * Decodes a string of data which has been encoded using base-64 encoding.
 */
exports.base64Decode = deprecateFunction(base64.decode,
  'base64Dencode is deprecated, ' +
  'please use require("sdk/base64").decode instead.'
);
