/* vim:set ts=2 sw=2 sts=2 expandtab */
/* 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/. */

// @see http://mxr.mozilla.org/mozilla-central/source/js/src/xpconnect/loader/mozJSComponentLoader.cpp

'use strict';

// IMPORTANT: Avoid adding any initialization tasks here, if you need to do
// something before add-on is loaded consider addon/runner module instead!

const { classes: Cc, Constructor: CC, interfaces: Ci, utils: Cu,
        results: Cr, manager: Cm } = Components;
const ioService = Cc['@mozilla.org/network/io-service;1'].
                  getService(Ci.nsIIOService);
const resourceHandler = ioService.getProtocolHandler('resource').
                        QueryInterface(Ci.nsIResProtocolHandler);
const systemPrincipal = CC('@mozilla.org/systemprincipal;1', 'nsIPrincipal')();
const scriptLoader = Cc['@mozilla.org/moz/jssubscript-loader;1'].
                     getService(Ci.mozIJSSubScriptLoader);

const REASON = [ 'unknown', 'startup', 'shutdown', 'enable', 'disable',
                 'install', 'uninstall', 'upgrade', 'downgrade' ];

let loader = null;
let unload = null;
let cuddlefishSandbox = null;
let nukeTimer = null;

// Utility function that synchronously reads local resource from the given
// `uri` and returns content string.
function readURI(uri) {
  let ioservice = Cc['@mozilla.org/network/io-service;1'].
    getService(Ci.nsIIOService);
  let channel = ioservice.newChannel(uri, 'UTF-8', null);
  let stream = channel.open();

  let cstream = Cc['@mozilla.org/intl/converter-input-stream;1'].
    createInstance(Ci.nsIConverterInputStream);
  cstream.init(stream, 'UTF-8', 0, 0);

  let str = {};
  let data = '';
  let read = 0;
  do {
    read = cstream.readString(0xffffffff, str);
    data += str.value;
  } while (read != 0);

  cstream.close();

  return data;
}

// Utility function that converts cfx-py generated paths to a
// module ids.
function path2id(path) {
  // Strips out `/lib` and `.js` from package/lib/path.js
  return path.replace(/([^\/]*)\/lib/, '$1').replace(/.js$/, '');
}
// Utility function that takes old manifest format and creates a manifest
// in a new format: https://github.com/mozilla/addon-sdk/wiki/JEP-Linker
function manifestV2(manifest) {
  return Object.keys(manifest).reduce(function(result, path) {
    let entry = manifest[path];
    let id = path2id(path);
    let requirements = entry.requirements || {};
    result[id] = {
      requirements: Object.keys(requirements).reduce(function(result, path) {
        result[path] = path2id(requirements[path].path);
        return result;
      }, {})
    };
    return result
  }, {});
}

// We don't do anything on install & uninstall yet, but in a future
// we should allow add-ons to cleanup after uninstall.
function install(data, reason) {}
function uninstall(data, reason) {}

function startup(data, reasonCode) {
  try {
    let reason = REASON[reasonCode];
    // URI for the root of the XPI file.
    // 'jar:' URI if the addon is packed, 'file:' URI otherwise.
    // (Used by l10n module in order to fetch `locale` folder)
    let rootURI = data.resourceURI.spec;

    // TODO: Maybe we should perform read harness-options.json asynchronously,
    // since we can't do anything until 'sessionstore-windows-restored' anyway.
    let options = JSON.parse(readURI(rootURI + './harness-options.json'));

    let id = options.jetpackID;
    let name = options.name;
    // Register a new resource 'domain' for this addon which is mapping to
    // XPI's `resources` folder.
    // Generate the domain name by using jetpack ID, which is the extension ID
    // by stripping common characters that doesn't work as a domain name:
    let uuidRe =
      /^\{([0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\}$/;

    let domain = id.
      toLowerCase().
      replace(/@/g, '-at-').
      replace(/\./g, '-dot-').
      replace(uuidRe, '$1');

    let prefixURI = 'resource://' + domain + '/';
    let resourcesURI = ioService.newURI(rootURI + '/resources/', null, null);
    resourceHandler.setSubstitution(domain, resourcesURI);

    // Create path to URLs mapping supported by loader.
    let paths = Object.keys(options.metadata).reduce(function(result, name) {
      result[name + '/'] = prefixURI + name + '/lib/'
      result[name + '/tests/'] = prefixURI + name + '/tests/'
      return result
    }, {
      // Relative modules resolve to add-on package lib
      './': prefixURI + name + '/lib/',
      'toolkit/': 'resource://gre/modules/toolkit/',
      '': 'resources:///modules/'
    });

    // Make version 2 of the manifest
    let manifest = manifestV2(options.manifest);

    // Import `cuddlefish.js` module using a Sandbox and bootstrap loader.
    let cuddlefishURI = prefixURI + options.loader;
    cuddlefishSandbox = loadSandbox(cuddlefishURI);
    let cuddlefish = cuddlefishSandbox.exports;

    // Normalize `options.mainPath` so that it looks like one that will come
    // in a new version of linker.
    let main = path2id(options.mainPath);

    unload = cuddlefish.unload;
    loader = cuddlefish.Loader({
      paths: paths,
      // modules manifest.
      manifest: manifest,

      // Add-on ID used by different APIs as a unique identifier.
      id: id,
      // Add-on name.
      name: name,
      // Add-on version.
      version: options.metadata[name].version,
      // Add-on package descriptor.
      metadata: options.metadata[name],
      // Add-on load reason.
      loadReason: reason,

      prefixURI: prefixURI,
      // Add-on URI.
      rootURI: rootURI,
      // options used by system module.
      // File to write 'OK' or 'FAIL' (exit code emulation).
      resultFile: options.resultFile,
      // File to write stdout.
      logFile: options.logFile,
      // Arguments passed as --static-args
      staticArgs: options.staticArgs,

      // Arguments related to test runner.
      modules: {
        '@test/options': {
          allTestModules: options.allTestModules,
          iterations: options.iterations,
          filter: options.filter,
          profileMemory: options.profileMemory,
          stopOnError: options.stopOnError,
          verbose: options.verbose,
        }
      }
    });

    let module = cuddlefish.Module('api-utils/cuddlefish', cuddlefishURI);
    let require = cuddlefish.Require(loader, module);

    require('api-utils/addon/runner').startup(reason, {
      loader: loader,
      main: main,
      prefsURI: rootURI + 'defaults/preferences/prefs.js'
    });
  } catch (error) {
    dump('Bootstrap error: ' + error.message + '\n' +
         (error.stack || error.fileName + ': ' + error.lineNumber) + '\n');
    throw error;
  }
};

function loadSandbox(uri) {
  let proto = {
    sandboxPrototype: {
      loadSandbox: loadSandbox,
      ChromeWorker: ChromeWorker
    }
  };
  let sandbox = Cu.Sandbox(systemPrincipal, proto);
  // Create a fake commonjs environnement just to enable loading loader.js
  // correctly
  sandbox.exports = {};
  sandbox.module = { uri: uri, exports: sandbox.exports };
  sandbox.require = function () {
    throw new Error("Bootstrap sandbox `require` method isn't implemented.");
  };
  scriptLoader.loadSubScript(uri, sandbox, 'UTF-8');
  return sandbox;
}

function unloadSandbox(sandbox) {
  if ("nukeSandbox" in Cu)
    Cu.nukeSandbox(sandbox);
}

function setTimeout(callback, delay) {
  let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
  timer.initWithCallback({ notify: callback }, delay,
                         Ci.nsITimer.TYPE_ONE_SHOT);
  return timer;
}

function shutdown(data, reasonCode) {
  let reason = REASON[reasonCode];
  if (loader) {
    unload(loader, reason);
    unload = null;
    // Avoid leaking all modules when something goes wrong with one particular
    // module. Do not clean it up immediatly in order to allow executing some
    // actions on addon disabling.
    // We need to keep a reference to the timer, otherwise it is collected
    // and won't ever fire.
    nukeTimer = setTimeout(nukeModules, 1000);
  }
};

function nukeModules() {
  nukeTimer = null;
  // module objects store `exports` which comes from sandboxes
  // We should avoid keeping link to these object to avoid leaking sandboxes
  for (let key in loader.modules) {
    delete loader.modules[key];
  }
  // Direct links to sandboxes should be removed too
  for (let key in loader.sandboxes) {
    let sandbox = loader.sandboxes[key];
    delete loader.sandboxes[key];
    // Bug 775067: From FF17 we can kill all CCW from a given sandbox
    unloadSandbox(sandbox);
  }
  loader = null;

  // Unload sandbox used to evaluate loader.js
  unloadSandbox(cuddlefishSandbox.loaderSandbox);
  // Bug 764840: We need to unload cuddlefish otherwise it will stay alive
  // and keep a reference to this compartment.
  unloadSandbox(cuddlefishSandbox);
  cuddlefishSandbox = null;
}
