/* 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";

const {classes: Cc, interfaces: Ci, utils: Cu} = Components;

Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/Preferences.jsm");
Cu.import("resource://gre/modules/Log.jsm");

const XPINSTALL_MIMETYPE   = "application/x-xpinstall";

const MSG_INSTALL_ENABLED  = "WebInstallerIsInstallEnabled";
const MSG_INSTALL_ADDON    = "WebInstallerInstallAddonFromWebpage";
const MSG_INSTALL_CALLBACK = "WebInstallerInstallCallback";


var log = Log.repository.getLogger("AddonManager.InstallTrigger");
log.level = Log.Level[Preferences.get("extensions.logging.enabled", false) ? "Warn" : "Trace"];

function CallbackObject(id, callback, mediator) {
  this.id = id;
  this.callback = callback;
  this.callCallback = function(url, status) {
    try {
      this.callback(url, status);
    } catch (e) {
      log.warn("InstallTrigger callback threw an exception: " + e);
    }

    mediator._callbacks.delete(id);
  };
}

function RemoteMediator(window) {
  window.QueryInterface(Ci.nsIInterfaceRequestor);
  let utils = window.getInterface(Ci.nsIDOMWindowUtils);
  this._windowID = utils.currentInnerWindowID;

  this.mm = window
    .getInterface(Ci.nsIDocShell)
    .QueryInterface(Ci.nsIInterfaceRequestor)
    .getInterface(Ci.nsIContentFrameMessageManager);
  this.mm.addWeakMessageListener(MSG_INSTALL_CALLBACK, this);

  this._lastCallbackID = 0;
  this._callbacks = new Map();
}

RemoteMediator.prototype = {
  receiveMessage(message) {
    if (message.name == MSG_INSTALL_CALLBACK) {
      let payload = message.data;
      let callbackHandler = this._callbacks.get(payload.callbackID);
      if (callbackHandler) {
        callbackHandler.callCallback(payload.url, payload.status);
      }
    }
  },

  enabled(url) {
    let params = {
      mimetype: XPINSTALL_MIMETYPE
    };
    return this.mm.sendSyncMessage(MSG_INSTALL_ENABLED, params)[0];
  },

  install(install, principal, callback, window) {
    let callbackID = this._addCallback(callback);

    install.mimetype = XPINSTALL_MIMETYPE;
    install.triggeringPrincipal = principal;
    install.callbackID = callbackID;

    if (Services.appinfo.processType == Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT) {
      // When running in the main process this might be a frame inside an
      // in-content UI page, walk up to find the first frame element in a chrome
      // privileged document
      let element = window.frameElement;
      let ssm = Services.scriptSecurityManager;
      while (element && !ssm.isSystemPrincipal(element.ownerDocument.nodePrincipal))
        element = element.ownerGlobal.frameElement;

      if (element) {
        let listener = Cc["@mozilla.org/addons/integration;1"].
                       getService(Ci.nsIMessageListener);
        return listener.wrappedJSObject.receiveMessage({
          name: MSG_INSTALL_ADDON,
          target: element,
          data: install,
        });
      }
    }

    // Fall back to sending through the message manager
    let messageManager = window.QueryInterface(Ci.nsIInterfaceRequestor)
                               .getInterface(Ci.nsIWebNavigation)
                               .QueryInterface(Ci.nsIDocShell)
                               .QueryInterface(Ci.nsIInterfaceRequestor)
                               .getInterface(Ci.nsIContentFrameMessageManager);

    return messageManager.sendSyncMessage(MSG_INSTALL_ADDON, install)[0];
  },

  _addCallback(callback) {
    if (!callback || typeof callback != "function")
      return -1;

    let callbackID = this._windowID + "-" + ++this._lastCallbackID;
    let callbackObject = new CallbackObject(callbackID, callback, this);
    this._callbacks.set(callbackID, callbackObject);
    return callbackID;
  },

  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference])
};


function InstallTrigger() {
}

InstallTrigger.prototype = {
  // Here be magic. We've declared ourselves as providing the
  // nsIDOMGlobalPropertyInitializer interface, and are registered in the
  // "JavaScript-global-property" category in the XPCOM category manager. This
  // means that for newly created windows, XPCOM will createinstance this
  // object, and then call init, passing in the window for which we need to
  // provide an instance. We then initialize ourselves and return the webidl
  // version of this object using the webidl-provided _create method, which
  // XPCOM will then duly expose as a property value on the window. All this
  // indirection is necessary because webidl does not (yet) support statics
  // (bug 863952). See bug 926712 for more details about this implementation.
  init(window) {
    this._window = window;
    this._principal = window.document.nodePrincipal;
    this._url = window.document.documentURIObject;

    try {
      this._mediator = new RemoteMediator(window);
    } catch (ex) {
      // If we can't set up IPC (e.g., because this is a top-level window
      // or something), then don't expose InstallTrigger.
      return null;
    }

    return window.InstallTriggerImpl._create(window, this);
  },

  enabled() {
    return this._mediator.enabled(this._url.spec);
  },

  updateEnabled() {
    return this.enabled();
  },

  install(installs, callback) {
    let keys = Object.keys(installs);
    if (keys.length > 1) {
      throw new this._window.Error("Only one XPI may be installed at a time");
    }

    let item = installs[keys[0]];

    if (typeof item === "string") {
      item = { URL: item };
    }
    if (!item.URL) {
      throw new this._window.Error("Missing URL property for '" + name + "'");
    }

    let url = this._resolveURL(item.URL);
    if (!this._checkLoadURIFromScript(url)) {
      throw new this._window.Error("Insufficient permissions to install: " + url.spec);
    }

    let iconUrl = null;
    if (item.IconURL) {
      iconUrl = this._resolveURL(item.IconURL);
      if (!this._checkLoadURIFromScript(iconUrl)) {
        iconUrl = null; // If page can't load the icon, just ignore it
      }
    }

    let installData = {
      uri: url.spec,
      hash: item.Hash || null,
      name: item.name,
      icon: iconUrl ? iconUrl.spec : null,
    };

    return this._mediator.install(installData, this._principal, callback, this._window);
  },

  startSoftwareUpdate(url, flags) {
    let filename = Services.io.newURI(url)
                              .QueryInterface(Ci.nsIURL)
                              .filename;
    let args = {};
    args[filename] = { "URL": url };
    return this.install(args);
  },

  installChrome(type, url, skin) {
    return this.startSoftwareUpdate(url);
  },

  _resolveURL(url) {
    return Services.io.newURI(url, null, this._url);
  },

  _checkLoadURIFromScript(uri) {
    let secman = Services.scriptSecurityManager;
    try {
      secman.checkLoadURIWithPrincipal(this._principal,
                                       uri,
                                       secman.DISALLOW_INHERIT_PRINCIPAL);
      return true;
    } catch (e) {
      return false;
    }
  },

  classID: Components.ID("{9df8ef2b-94da-45c9-ab9f-132eb55fddf1}"),
  contractID: "@mozilla.org/addons/installtrigger;1",
  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports, Ci.nsIDOMGlobalPropertyInitializer])
};



this.NSGetFactory = XPCOMUtils.generateNSGetFactory([InstallTrigger]);
