gecko/services/sync/modules/engines/bookmarks.js

/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Bookmarks Sync.
 *
 * The Initial Developer of the Original Code is Mozilla.
 * Portions created by the Initial Developer are Copyright (C) 2007
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Dan Mills <thunder@mozilla.com>
 *  Jono DiCarlo <jdicarlo@mozilla.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

const EXPORTED_SYMBOLS = ['BookmarksEngine'];

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;

// Annotation to use for shared bookmark folders, incoming and outgoing:
const INCOMING_SHARED_ANNO = "weave/shared-incoming";
const OUTGOING_SHARED_ANNO = "weave/shared-outgoing";

Cu.import("resource://weave/log4moz.js");
Cu.import("resource://weave/dav.js");
Cu.import("resource://weave/util.js");
Cu.import("resource://weave/crypto.js");
Cu.import("resource://weave/async.js");
Cu.import("resource://weave/engines.js");
Cu.import("resource://weave/syncCores.js");
Cu.import("resource://weave/stores.js");
Cu.import("resource://weave/trackers.js");

/* LONGTERM TODO: when we start working on the ability to share other types
of data besides bookmarks, the xmppClient instance should be moved to hang
off of Weave.Service instead of hanging off the BookmarksEngine.  But for
now this is the easiest place to deal with it. */
Cu.import("resource://weave/xmpp/xmppClient.js");

Function.prototype.async = Async.sugar;

function BookmarksEngine(pbeId) {
  this._init(pbeId);
}
BookmarksEngine.prototype = {
  get name() { return "bookmarks"; },
  get logName() { return "BmkEngine"; },
  get serverPrefix() { return "user-data/bookmarks/"; },

  __core: null,
  get _core() {
    if (!this.__core)
      this.__core = new BookmarksSyncCore();
    return this.__core;
  },

  __store: null,
  get _store() {
    if (!this.__store)
      this.__store = new BookmarksStore();
    return this.__store;
  },

  __tracker: null,
  get _tracker() {
    if (!this.__tracker)
      this.__tracker = new BookmarksTracker();
    return this.__tracker;
  },

  _init: function BmkEngine__init( pbeId ) {
    this.__proto__.__proto__._init.call( this, pbeId );
    if ( Utils.prefs.getBoolPref( "xmpp.enabled" ) ) {
      dump( "Starting XMPP client for bookmark engine..." );
      // TODO call startXmppClient asynchronously?
      this._startXmppClient();
      // TODO catch errors if connection fails.
    }
  },

  _startXmppClient: function BmkEngine__startXmppClient() {
    // TODO this should probably be called asynchronously as it can take a while.

    // Get serverUrl and realm of the jabber server from preferences:
    let serverUrl = Utils.prefs.getCharPref( "xmpp.server.url" );
    let realm = Utils.prefs.getCharPref( "xmpp.server.realm" );
    
    // TODO once we have ejabberd talking to LDAP, the username/password
    // for xmpp will be the same as the ones for Weave itself, so we can
    // read username/password like this:
    // let clientName = ID.get('WeaveID').username;
    // let clientPassword = ID.get('WeaveID').password;
    // until then get these from preferences as well:
    let clientName = Utils.prefs.getCharPref( "xmpp.client.name" );
    let clientPassword = Utils.prefs.getCharPref( "xmpp.client.password" );

    let transport = new HTTPPollingTransport( serverUrl, false, 15000 );
    let auth = new PlainAuthenticator(); 
    // TODO use MD5Authenticator instead once we get it working -- plain is
    // a security hole.
    this._xmppClient = new XmppClient( clientName,
                                       realm,
                                       clientPassword,
				       transport,
                                       auth );
    let self = this;
    let messageHandler = {
      handle: function ( messageText, from ) {
        /* The callback function for incoming xmpp messages.
           We expect message text to be either:
           "share <dir>"
           (sender offers to share directory dir with us)
           or "stop <dir>"
           (sender has stopped sharing directory dir with us.)
           or "accept <dir>"
           (sharee has accepted our offer to share our dir.)
           or "decline <dir>"
           (sharee has declined our offer to share our dir.)
        */
 	let words = messageText.split(" ");
	let commandWord = words[0];
	let directoryName = words[1];
        if ( commandWord == "share" ) {
	  self._incomingShareOffer( directoryName, from );
	} else if ( commandWord == "stop" ) {
	  self._incomingShareWithdrawn( directoryName, from );
	}
      }
    }
    this._xmppClient.registerMessageHandler( messageHandler );
    this._xmppClient.connect( realm );
  },

  _incomingShareOffer: function BmkEngine__incomingShareOffer( dir, user ) {
    /* Called when we receive an offer from another user to share a 
       directory.  

       TODO what should happen is that we add a notification to the queue
       telling that the incoming share has been offered; when the offer
       is accepted we will call createIncomingShare and then
       updateIncomingShare.

       But since we don't have notification in place yet, I'm going to skip
       right ahead to creating the incoming share.
    */

  },

  _incomingShareWithdrawn: function BmkEngine__incomingShareStop( dir, user ) {
    /* Called when we receive a message telling us that a user who has
       already shared a directory with us has chosen to stop sharing
       the directory.
       
       TODO Find the incomingShare in our bookmark tree that corresponds
       to the shared directory, and delete it; add a notification to
       the queue telling us what has happened.
    */
  },

  _sync: function BmkEngine__sync() {
    /* After syncing, also call syncMounts to get the
       incoming shared bookmark folder contents. */
    let self = yield;
    this.__proto__.__proto__._sync.async(this, self.cb );
    yield;
    this.updateAllIncomingShares(self.cb);
    yield;
    self.done();
  },

  _share: function BmkEngine__share( selectedFolder, username ) {
    // Return true if success, false if failure.
    let ret = false;
    let ans = Cc["@mozilla.org/browser/annotation-service;1"].
      getService(Ci.nsIAnnotationService);
    let self = yield;

    /* TODO What should the behavior be if i'm already sharing it with user
       A and I ask to share it with user B?  (This should be prevented by
       the UI. */

    // Create the outgoing share folder on the server
    // TODO do I need to call these asynchronously?
    this._createOutgoingShare.async( this, selectedFolder, username );
    this._updateOutgoingShare.async( this, selectedFolder, username );

    /* Set the annotation on the folder so we know
       it's an outgoing share: */
    let folderItemId = selectedFolder.node.itemId;
    let folderName = selectedFolder.getAttribute( "label" );
    ans.setItemAnnotation(folderItemId, OUTGOING_SHARED_ANNO, username, 0,
                            ans.EXPIRE_NEVER);
    // TODO: does this clobber existing annotations?

    // Send an xmpp message to the share-ee
    if ( this._xmppClient ) {
      let msgText = "share " + folderName;
      this._xmppClient.sendMessage( username, msgText );
    }

    /* LONGTERM TODO: in the future when we allow sharing one folder
       with many people, the value of the annotation can be a whole list
       of usernames instead of just one. */

    dump( "Bookmark engine shared " +folderName + " with " + username );
    ret = true;
    self.done( ret );
  },

  updateAllIncomingShares: function BmkEngine_updateAllIncoming(onComplete) {
    this._updateAllIncomingShares.async(this, onComplete);
  },
  _updateAllIncomingShares: function BmkEngine__updateAllIncoming() {
    /* For every bookmark folder in my tree that has the annotation
       marking it as an incoming shared folder, pull down its latest
       contents from its owner's account on the server.  (This is
       a one-way data transfer because I can't modify bookmarks that
       are owned by someone else but shared to me; any changes I make
       to the folder contents are simply wiped out by the latest
       server contents.) */
    let self = yield;
    let mounts = this._store.findIncomingShares();

    for (i = 0; i < mounts.length; i++) {
      try {
        this._updateIncomingShare.async(this, self.cb, mounts[i]);
        yield;
      } catch (e) {
        this._log.warn("Could not sync shared folder from " + mounts[i].userid);
        this._log.trace(Utils.stackTrace(e));
      }
    }
  },

  _createOutgoingShare: function BmkEngine__createOutgoing(folder, username) {
    let self = yield;
    let prefix = DAV.defaultPrefix;

    this._log.debug("Sharing bookmarks from " + guid + " with " + username);

    this._getSymKey.async(this, self.cb);
    yield;

    // copied from getSymKey
    DAV.GET(this.keysFile, self.cb);
    let ret = yield;
    Utils.ensureStatus(ret.status, "Could not get keys file.");
    // note: this._json is just an encoder/decoder, no state.
    let keys = this._json.decode(ret.responseText);

    // get the other user's pubkey
    let serverURL = Utils.prefs.getCharPref("serverURL");

    try {
      DAV.defaultPrefix = "user/" + username + "/";
      DAV.GET("public/pubkey", self.cb);
      ret = yield;
    }
    catch (e) { throw e; }
    finally { DAV.defaultPrefix = prefix; }

    Utils.ensureStatus(ret.status, "Could not get public key for " + username);

    let id = new Identity();
    id.pubkey = ret.responseText;

    // now encrypt the symkey with their pubkey and upload the new keyring
    Crypto.RSAencrypt.async(Crypto, self.cb, this._engineId.password, id);
    let enckey = yield;
    if (!enckey)
      throw "Could not encrypt symmetric encryption key";

    keys.ring[username] = enckey;
    DAV.PUT(this.keysFile, this._json.encode(keys), self.cb);
    ret = yield;
    Utils.ensureStatus(ret.status, "Could not upload keyring file.");

    this._log.debug("All done sharing!");

    // Call Atul's js api for setting htaccess:
    let api = new Sharing.Api( DAV );
    api.shareWithUsers( directory, [username], self.cb );
    let result = yield;

    self.done(true);
  },

  _updateOutgoingShare: function BmkEngine__updateOutgoing(guid, username) {
    /* TODO this needs to have the logic to break the shared bookmark
       subtree out of the store and put it in a separate file...*/
  },

  _stopOutgoingShare: function BmkEngine__stopOutgoingShare( guid, username ) {
    /* TODO implement this... */
  },

  _createIncomingShare: function BookmarkEngine__createShare(guid, id, title) {

    /* TODO This used to be called just _createShare, but its semantics
       have changed slightly -- its purpose now is to create a new empty
       incoming shared bookmark folder.  To do this is mostly the same code,
       but it will need a few tweaks.
    */
    let bms = Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
      getService(Ci.nsINavBookmarksService);
    let ans = Cc["@mozilla.org/browser/annotation-service;1"].
      getService(Ci.nsIAnnotationService);

    let root;
    let a = ans.getItemsWithAnnotation("weave/mounted-shares-folder", {});
    if (a.length == 1)
      root = a[0];

    if (!root) {
      root = bms.createFolder(bms.toolbarFolder, "Shared Folders",
                              bms.DEFAULT_INDEX);
      ans.setItemAnnotation(root, "weave/mounted-shares-folder", true, 0,
                            ans.EXPIRE_NEVER);
    }

    let item;
    a = ans.getItemsWithAnnotation("weave/mounted-share-id", {});
    for (let i = 0; i < a.length; i++) {
      if (ans.getItemAnnotation(a[i], "weave/mounted-share-id") == id) {
        item = a[i];
        break;
      }
    }

    if (!item) {
      let newId = bms.createFolder(root, title, bms.DEFAULT_INDEX);
      ans.setItemAnnotation(newId, "weave/mounted-share-id", id, 0,
                            ans.EXPIRE_NEVER);
    }
  },


  _updateIncomingShare: function BmkEngine__updateIncomingShare(mountData) {
    /* Pull down bookmarks from the server for a single incoming
       shared folder. */

    /* TODO modify this: the old implementation assumes we want to copy
       everything that the other user has, by pulling down snapshot and
       diffs and applying the diffs to the snapshot.  Instead, now we just
       want to get a single subfolder and its children, which will be in
       a separate file. */

    let self = yield;
    let user = mountData.userid;
    let prefix = DAV.defaultPrefix;
    let serverURL = Utils.prefs.getCharPref("serverURL");
    let snap = new SnapshotStore();

    this._log.debug("Syncing shared folder from user " + user);

    try {
      DAV.defaultPrefix = "user/" + user + "/";

      this._getSymKey.async(this, self.cb);
      yield;

      this._log.trace("Getting status file for " + user);
      DAV.GET(this.statusFile, self.cb);
      let resp = yield;
      Utils.ensureStatus(resp.status, "Could not download status file.");
      let status = this._json.decode(resp.responseText);

      this._log.trace("Downloading server snapshot for " + user);
      DAV.GET(this.snapshotFile, self.cb);
      resp = yield;
      Utils.ensureStatus(resp.status, "Could not download snapshot.");
      Crypto.PBEdecrypt.async(Crypto, self.cb, resp.responseText,
    			        this._engineId, status.snapEncryption);
      let data = yield;
      snap.data = this._json.decode(data);

      this._log.trace("Downloading server deltas for " + user);
      DAV.GET(this.deltasFile, self.cb);
      resp = yield;
      Utils.ensureStatus(resp.status, "Could not download deltas.");
      Crypto.PBEdecrypt.async(Crypto, self.cb, resp.responseText,
    			        this._engineId, status.deltasEncryption);
      data = yield;
      deltas = this._json.decode(data);
    }
    catch (e) { throw e; }
    finally { DAV.defaultPrefix = prefix; }

    // apply deltas to get current snapshot
    for (var i = 0; i < deltas.length; i++) {
      snap.applyCommands.async(snap, self.cb, deltas[i]);
      yield;
    }

    // prune tree / get what we want
    for (let guid in snap.data) {
      if (snap.data[guid].type != "bookmark")
        delete snap.data[guid];
      else
        snap.data[guid].parentGUID = mountData.rootGUID;
    }

    this._log.trace("Got bookmarks fror " + user + ", comparing with local copy");
    this._core.detectUpdates(self.cb, mountData.snapshot, snap.data);
    let diff = yield;

    // FIXME: should make sure all GUIDs here live under the mountpoint
    this._log.trace("Applying changes to folder from " + user);
    this._store.applyCommands.async(this._store, self.cb, diff);
    yield;

    this._log.trace("Shared folder from " + user + " successfully synced!");
  }
};
BookmarksEngine.prototype.__proto__ = new Engine();

function BookmarksSyncCore() {
  this._init();
}
BookmarksSyncCore.prototype = {
  _logName: "BMSync",

  __bms: null,
  get _bms() {
    if (!this.__bms)
      this.__bms = Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
                   getService(Ci.nsINavBookmarksService);
    return this.__bms;
  },

  _itemExists: function BSC__itemExists(GUID) {
    return this._bms.getItemIdForGUID(GUID) >= 0;
  },

  _getEdits: function BSC__getEdits(a, b) {
    // NOTE: we do not increment ret.numProps, as that would cause
    // edit commands to always get generated
    let ret = SyncCore.prototype._getEdits.call(this, a, b);
    ret.props.type = a.type;
    return ret;
  },

  // compares properties
  // returns true if the property is not set in either object
  // returns true if the property is set and equal in both objects
  // returns false otherwise
  _comp: function BSC__comp(a, b, prop) {
    return (!a.data[prop] && !b.data[prop]) ||
      (a.data[prop] && b.data[prop] && (a.data[prop] == b.data[prop]));
  },

  _commandLike: function BSC__commandLike(a, b) {
    // Check that neither command is null, that their actions, types,
    // and parents are the same, and that they don't have the same
    // GUID.
    // * Items with the same GUID do not qualify for 'likeness' because
    //   we already consider them to be the same object, and therefore
    //   we need to process any edits.
    // * Remove or edit commands don't qualify for likeness either,
    //   since remove or edit commands with different GUIDs are
    //   guaranteed to refer to two different items
    // * The parent GUID check works because reconcile() fixes up the
    //   parent GUIDs as it runs, and the command list is sorted by
    //   depth
    if (!a || !b ||
        a.action != b.action ||
        a.action != "create" ||
        a.data.type != b.data.type ||
        a.data.parentGUID != b.data.parentGUID ||
        a.GUID == b.GUID)
      return false;

    // Bookmarks and folders are allowed to be in a different index as long as
    // they are in the same folder.  Separators must be at
    // the same index to qualify for 'likeness'.
    switch (a.data.type) {
    case "bookmark":
      if (this._comp(a, b, 'URI') &&
          this._comp(a, b, 'title'))
        return true;
      return false;
    case "query":
      if (this._comp(a, b, 'URI') &&
          this._comp(a, b, 'title'))
        return true;
      return false;
    case "microsummary":
      if (this._comp(a, b, 'URI') &&
          this._comp(a, b, 'generatorURI'))
        return true;
      return false;
    case "folder":
      if (this._comp(a, b, 'title'))
        return true;
      return false;
    case "livemark":
      if (this._comp(a, b, 'title') &&
          this._comp(a, b, 'siteURI') &&
          this._comp(a, b, 'feedURI'))
        return true;
      return false;
    case "separator":
      if (this._comp(a, b, 'index'))
        return true;
      return false;
    default:
      let json = Cc["@mozilla.org/dom/json;1"].createInstance(Ci.nsIJSON);
      this._log.error("commandLike: Unknown item type: " + json.encode(a));
      return false;
    }
  }
};
BookmarksSyncCore.prototype.__proto__ = new SyncCore();

function BookmarksStore() {
  this._init();
}
BookmarksStore.prototype = {
  _logName: "BStore",

  __bms: null,
  get _bms() {
    if (!this.__bms)
      this.__bms = Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
                   getService(Ci.nsINavBookmarksService);
    return this.__bms;
  },

  __hsvc: null,
  get _hsvc() {
    if (!this.__hsvc)
      this.__hsvc = Cc["@mozilla.org/browser/nav-history-service;1"].
                    getService(Ci.nsINavHistoryService);
    return this.__hsvc;
  },

  __ls: null,
  get _ls() {
    if (!this.__ls)
      this.__ls = Cc["@mozilla.org/browser/livemark-service;2"].
        getService(Ci.nsILivemarkService);
    return this.__ls;
  },

  __ms: null,
  get _ms() {
    if (!this.__ms)
      this.__ms = Cc["@mozilla.org/microsummary/service;1"].
        getService(Ci.nsIMicrosummaryService);
    return this.__ms;
  },

  __ts: null,
  get _ts() {
    if (!this.__ts)
      this.__ts = Cc["@mozilla.org/browser/tagging-service;1"].
                  getService(Ci.nsITaggingService);
    return this.__ts;
  },

  __ans: null,
  get _ans() {
    if (!this.__ans)
      this.__ans = Cc["@mozilla.org/browser/annotation-service;1"].
                   getService(Ci.nsIAnnotationService);
    return this.__ans;
  },

  _getItemIdForGUID: function BStore__getItemIdForGUID(GUID) {
    switch (GUID) {
    case "menu":
      return this._bms.bookmarksMenuFolder;
    case "toolbar":
      return this._bms.toolbarFolder;
    case "unfiled":
      return this._bms.unfiledBookmarksFolder;
    default:
      return this._bms.getItemIdForGUID(GUID);
    }
    return null;
  },

  _createCommand: function BStore__createCommand(command) {
    let newId;
    let parentId = this._getItemIdForGUID(command.data.parentGUID);

    if (parentId < 0) {
      this._log.warn("Creating node with unknown parent -> reparenting to root");
      parentId = this._bms.bookmarksMenuFolder;
    }

    switch (command.data.type) {
    case "query":
    case "bookmark":
    case "microsummary": {
      this._log.debug(" -> creating bookmark \"" + command.data.title + "\"");
      let URI = Utils.makeURI(command.data.URI);
      newId = this._bms.insertBookmark(parentId,
                                       URI,
                                       command.data.index,
                                       command.data.title);
      this._ts.untagURI(URI, null);
      this._ts.tagURI(URI, command.data.tags);
      this._bms.setKeywordForBookmark(newId, command.data.keyword);
      if (command.data.description) {
        this._ans.setItemAnnotation(newId, "bookmarkProperties/description",
                                    command.data.description, 0,
                                    this._ans.EXPIRE_NEVER);
      }

      if (command.data.type == "microsummary") {
        this._log.debug("   \-> is a microsummary");
        this._ans.setItemAnnotation(newId, "bookmarks/staticTitle",
                                    command.data.staticTitle || "", 0, this._ans.EXPIRE_NEVER);
        let genURI = Utils.makeURI(command.data.generatorURI);
        try {
          let micsum = this._ms.createMicrosummary(URI, genURI);
          this._ms.setMicrosummary(newId, micsum);
        }
        catch(ex) { /* ignore "missing local generator" exceptions */ }
      }
    } break;
    case "folder":
      this._log.debug(" -> creating folder \"" + command.data.title + "\"");
      newId = this._bms.createFolder(parentId,
                                     command.data.title,
                                     command.data.index);
      break;
    case "livemark":
      this._log.debug(" -> creating livemark \"" + command.data.title + "\"");
      newId = this._ls.createLivemark(parentId,
                                      command.data.title,
                                      Utils.makeURI(command.data.siteURI),
                                      Utils.makeURI(command.data.feedURI),
                                      command.data.index);
      break;
    case "mounted-share":
    // TODO this is to create the shared-items folder on another machine
    // to duplicate the one that's on the first machine; we don't need that
    // anymore.  OR is it to create the folder on the sharee's computer?
      this._log.debug(" -> creating share mountpoint \"" + command.data.title + "\"");
      newId = this._bms.createFolder(parentId,
                                     command.data.title,
                                     command.data.index);

      this._ans.setItemAnnotation(newId, "weave/mounted-share-id",
                                  command.data.mountId, 0, this._ans.EXPIRE_NEVER);
      break;
    case "separator":
      this._log.debug(" -> creating separator");
      newId = this._bms.insertSeparator(parentId, command.data.index);
      break;
    default:
      this._log.error("_createCommand: Unknown item type: " + command.data.type);
      break;
    }
    if (newId)
      this._bms.setItemGUID(newId, command.GUID);
  },

  _removeCommand: function BStore__removeCommand(command) {
    if (command.GUID == "menu" ||
        command.GUID == "toolbar" ||
        command.GUID == "unfiled") {
      this._log.warn("Attempted to remove root node (" + command.GUID +
                     ").  Skipping command.");
      return;
    }

    var itemId = this._bms.getItemIdForGUID(command.GUID);
    if (itemId < 0) {
      this._log.warn("Attempted to remove item " + command.GUID +
                     ", but it does not exist.  Skipping.");
      return;
    }
    var type = this._bms.getItemType(itemId);

    switch (type) {
    case this._bms.TYPE_BOOKMARK:
      this._log.debug("  -> removing bookmark " + command.GUID);
      this._bms.removeItem(itemId);
      break;
    case this._bms.TYPE_FOLDER:
      this._log.debug("  -> removing folder " + command.GUID);
      this._bms.removeFolder(itemId);
      break;
    case this._bms.TYPE_SEPARATOR:
      this._log.debug("  -> removing separator " + command.GUID);
      this._bms.removeItem(itemId);
      break;
    default:
      this._log.error("removeCommand: Unknown item type: " + type);
      break;
    }
  },

  _editCommand: function BStore__editCommand(command) {
    if (command.GUID == "menu" ||
        command.GUID == "toolbar" ||
        command.GUID == "unfiled") {
      this._log.warn("Attempted to edit root node (" + command.GUID +
                     ").  Skipping command.");
      return;
    }

    var itemId = this._bms.getItemIdForGUID(command.GUID);
    if (itemId < 0) {
      this._log.warn("Item for GUID " + command.GUID + " not found.  Skipping.");
      return;
    }

    for (let key in command.data) {
      switch (key) {
      case "type":
        // all commands have this to help in reconciliation, but it makes
        // no sense to edit it
        break;
      case "GUID":
        var existing = this._getItemIdForGUID(command.data.GUID);
        if (existing < 0)
          this._bms.setItemGUID(itemId, command.data.GUID);
        else
          this._log.warn("Can't change GUID " + command.GUID +
                         " to " + command.data.GUID + ": GUID already exists.");
        break;
      case "title":
        this._bms.setItemTitle(itemId, command.data.title);
        break;
      case "URI":
        this._bms.changeBookmarkURI(itemId, Utils.makeURI(command.data.URI));
        break;
      case "index":
        this._bms.moveItem(itemId, this._bms.getFolderIdForItem(itemId),
                           command.data.index);
        break;
      case "parentGUID": {
        let index = -1;
        if (command.data.index && command.data.index >= 0)
          index = command.data.index;
        this._bms.moveItem(
          itemId, this._getItemIdForGUID(command.data.parentGUID), index);
      } break;
      case "tags": {
        let tagsURI = this._bms.getBookmarkURI(itemId);
        this._ts.untagURI(tagsURI, null);
        this._ts.tagURI(tagsURI, command.data.tags);
      } break;
      case "keyword":
        this._bms.setKeywordForBookmark(itemId, command.data.keyword);
        break;
      case "description":
        if (command.data.description) {
          this._ans.setItemAnnotation(itemId, "bookmarkProperties/description",
                                      command.data.description, 0,
                                      this._ans.EXPIRE_NEVER);
        }
        break;
      case "generatorURI": {
        let micsumURI = Utils.makeURI(this._bms.getBookmarkURI(itemId));
        let genURI = Utils.makeURI(command.data.generatorURI);
        let micsum = this._ms.createMicrosummary(micsumURI, genURI);
        this._ms.setMicrosummary(itemId, micsum);
      } break;
      case "siteURI":
        this._ls.setSiteURI(itemId, Utils.makeURI(command.data.siteURI));
        break;
      case "feedURI":
        this._ls.setFeedURI(itemId, Utils.makeURI(command.data.feedURI));
        break;
      default:
        this._log.warn("Can't change item property: " + key);
        break;
      }
    }
  },

  _getNode: function BSS__getNode(folder) {
    let query = this._hsvc.getNewQuery();
    query.setFolders([folder], 1);
    return this._hsvc.executeQuery(query, this._hsvc.getNewQueryOptions()).root;
  },

  __wrap: function BSS___wrap(node, items, parentGUID, index, guidOverride) {
    let GUID, item;

    // we override the guid for the root items, "menu", "toolbar", etc.
    if (guidOverride) {
      GUID = guidOverride;
      item = {};
    } else {
      GUID = this._bms.getItemGUID(node.itemId);
      item = {parentGUID: parentGUID, index: index};
    }

    if (node.type == node.RESULT_TYPE_FOLDER) {
      if (this._ls.isLivemark(node.itemId)) {
        item.type = "livemark";
        let siteURI = this._ls.getSiteURI(node.itemId);
        let feedURI = this._ls.getFeedURI(node.itemId);
        item.siteURI = siteURI? siteURI.spec : "";
        item.feedURI = feedURI? feedURI.spec : "";

      } else if (this._ans.itemHasAnnotation(node.itemId,
                                             "weave/mounted-share-id")) {
	/* TODO this is for wrapping the special shared folder created by
	   the old-style share command. */
        item.type = "mounted-share";
        item.title = node.title;
        item.mountId = this._ans.getItemAnnotation(node.itemId,
                                                   "weave/mounted-share-id");

      } else {
        item.type = "folder";
        node.QueryInterface(Ci.nsINavHistoryQueryResultNode);
        node.containerOpen = true;
        for (var i = 0; i < node.childCount; i++) {
          this.__wrap(node.getChild(i), items, GUID, i);
        }
      }
      if (!guidOverride)
        item.title = node.title; // no titles for root nodes

    } else if (node.type == node.RESULT_TYPE_URI ||
               node.type == node.RESULT_TYPE_QUERY) {
      if (this._ms.hasMicrosummary(node.itemId)) {
        item.type = "microsummary";
        let micsum = this._ms.getMicrosummary(node.itemId);
        item.generatorURI = micsum.generator.uri.spec; // breaks local generators
        item.staticTitle = this._ans.getItemAnnotation(node.itemId, "bookmarks/staticTitle");
      } else if (node.type == node.RESULT_TYPE_QUERY) {
        item.type = "query";
        item.title = node.title;
      } else {
        item.type = "bookmark";
        item.title = node.title;
      }

      try {
        item.description =
          this._ans.getItemAnnotation(node.itemId, "bookmarkProperties/description");
      } catch (e) {
        item.description = undefined;
      }

      item.URI = node.uri;

      // This will throw if makeURI can't make an nsIURI object out of the
      // node.uri string (or return null if node.uri is null), in which case
      // we won't be able to get tags for the bookmark (but we'll still sync
      // the rest of the record).
      let uri;
      try {
        uri = Utils.makeURI(node.uri);
      }
      catch(e) {
        this._log.error("error parsing URI string <" + node.uri + "> " +
                        "for item " + node.itemId + " (" + node.title + "): " +
                        e);
      }

      if (uri)
        item.tags = this._ts.getTagsForURI(uri, {});

      item.keyword = this._bms.getKeywordForBookmark(node.itemId);

    } else if (node.type == node.RESULT_TYPE_SEPARATOR) {
      item.type = "separator";

    } else {
      this._log.warn("Warning: unknown item type, cannot serialize: " + node.type);
      return;
    }

    items[GUID] = item;
  },

  // helper
  _wrap: function BStore__wrap(node, items, rootName) {
    return this.__wrap(node, items, null, null, rootName);
  },

  _wrapMount: function BStore__wrapMount(node, id) {
    if (node.type != node.RESULT_TYPE_FOLDER)
      throw "Trying to wrap a non-folder mounted share";

    let GUID = this._bms.getItemGUID(node.itemId);
    let ret = {rootGUID: GUID, userid: id, snapshot: {}};

    node.QueryInterface(Ci.nsINavHistoryQueryResultNode);
    node.containerOpen = true;
    for (var i = 0; i < node.childCount; i++) {
      this.__wrap(node.getChild(i), ret.snapshot, GUID, i);
    }

    // remove any share mountpoints
    for (let guid in ret.snapshot) {
      // TODO decide what to do with this...
      if (ret.snapshot[guid].type == "mounted-share")
        delete ret.snapshot[guid];
    }

    return ret;
  },

  _resetGUIDs: function BSS__resetGUIDs(node) {
    if (this._ans.itemHasAnnotation(node.itemId, "placesInternal/GUID"))
      this._ans.removeItemAnnotation(node.itemId, "placesInternal/GUID");

    if (node.type == node.RESULT_TYPE_FOLDER &&
        !this._ls.isLivemark(node.itemId)) {
      node.QueryInterface(Ci.nsINavHistoryQueryResultNode);
      node.containerOpen = true;
      for (var i = 0; i < node.childCount; i++) {
        this._resetGUIDs(node.getChild(i));
      }
    }
  },

  findIncomingShares: function BStore_findIncomingShares() {
    /* Returns list of mount data structures, each of which
       represents one incoming shared-bookmark folder. */
    let ret = [];
    let a = this._ans.getItemsWithAnnotation(INCOMING_SHARED_ANNO, {});
    for (let i = 0; i < a.length; i++) {
      /* The value of the incoming-shared annotation is the id of the
       person who has shared it with us.  Get that value: */
      let id = this._ans.getItemAnnotation(a[i], INCOMING_SHARED_ANNO);
      ret.push(this._wrapMount(this._getNode(a[i]), id));
    }
    return ret;
  },

  wrap: function BStore_wrap() {
    var items = {};
    this._wrap(this._getNode(this._bms.bookmarksMenuFolder), items, "menu");
    this._wrap(this._getNode(this._bms.toolbarFolder), items, "toolbar");
    this._wrap(this._getNode(this._bms.unfiledBookmarksFolder), items, "unfiled");
    return items;
  },

  wipe: function BStore_wipe() {
    this._bms.removeFolderChildren(this._bms.bookmarksMenuFolder);
    this._bms.removeFolderChildren(this._bms.toolbarFolder);
    this._bms.removeFolderChildren(this._bms.unfiledBookmarksFolder);
  },

  resetGUIDs: function BStore_resetGUIDs() {
    this._resetGUIDs(this._getNode(this._bms.bookmarksMenuFolder));
    this._resetGUIDs(this._getNode(this._bms.toolbarFolder));
    this._resetGUIDs(this._getNode(this._bms.unfiledBookmarksFolder));
  }
};
BookmarksStore.prototype.__proto__ = new Store();

/*
 * Tracker objects for each engine may need to subclass the
 * getScore routine, which returns the current 'score' for that
 * engine. How the engine decides to set the score is upto it,
 * as long as the value between 0 and 100 actually corresponds
 * to its urgency to sync.
 *
 * Here's an example BookmarksTracker. We don't subclass getScore
 * because the observer methods take care of updating _score which
 * getScore returns by default.
 */
function BookmarksTracker() {
  this._init();
}
BookmarksTracker.prototype = {
  _logName: "BMTracker",

  /* We don't care about the first three */
  onBeginUpdateBatch: function BMT_onBeginUpdateBatch() {

  },
  onEndUpdateBatch: function BMT_onEndUpdateBatch() {

  },
  onItemVisited: function BMT_onItemVisited() {

  },

  /* Every add or remove is worth 4 points,
   * on the basis that adding or removing 20 bookmarks
   * means its time to sync?
   */
  onItemAdded: function BMT_onEndUpdateBatch() {
    this._score += 4;
  },
  onItemRemoved: function BMT_onItemRemoved() {
    this._score += 4;
  },
  /* Changes are worth 2 points? */
  onItemChanged: function BMT_onItemChanged() {
    this._score += 2;
  },

  _init: function BMT__init() {
    this._log = Log4Moz.Service.getLogger("Service." + this._logName);
    this._score = 0;

    Cc["@mozilla.org/browser/nav-bookmarks-service;1"].
    getService(Ci.nsINavBookmarksService).
    addObserver(this, false);
  }
}
BookmarksTracker.prototype.__proto__ = new Tracker();