/* ***** 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 Weave
 *
 * The Initial Developer of the Original Code is Mozilla.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Dan Mills <thunder@mozilla.com>
 *  Philipp von Weitershausen <philipp@weitershausen.de>
 *
 * 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 = ["Clients", "ClientsRec"];

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

Cu.import("resource://services-sync/constants.js");
Cu.import("resource://services-sync/engines.js");
Cu.import("resource://services-sync/ext/StringBundle.js");
Cu.import("resource://services-sync/record.js");
Cu.import("resource://services-sync/resource.js");
Cu.import("resource://services-sync/util.js");

const CLIENTS_TTL = 1814400; // 21 days
const CLIENTS_TTL_REFRESH = 604800; // 7 days

function ClientsRec(collection, id) {
  CryptoWrapper.call(this, collection, id);
}
ClientsRec.prototype = {
  __proto__: CryptoWrapper.prototype,
  _logName: "Record.Clients",
  ttl: CLIENTS_TTL
};

Utils.deferGetSet(ClientsRec, "cleartext", ["name", "type", "commands"]);


XPCOMUtils.defineLazyGetter(this, "Clients", function () {
  return new ClientEngine();
});

function ClientEngine() {
  SyncEngine.call(this, "Clients");

  // Reset the client on every startup so that we fetch recent clients
  this._resetClient();
}
ClientEngine.prototype = {
  __proto__: SyncEngine.prototype,
  _storeObj: ClientStore,
  _recordObj: ClientsRec,

  // Always sync client data as it controls other sync behavior
  get enabled() true,

  get lastRecordUpload() {
    return Svc.Prefs.get(this.name + ".lastRecordUpload", 0);
  },
  set lastRecordUpload(value) {
    Svc.Prefs.set(this.name + ".lastRecordUpload", Math.floor(value));
  },

  // Aggregate some stats on the composition of clients on this account
  get stats() {
    let stats = {
      hasMobile: this.localType == "mobile",
      names: [this.localName],
      numClients: 1,
    };

    for each (let {name, type} in this._store._remoteClients) {
      stats.hasMobile = stats.hasMobile || type == "mobile";
      stats.names.push(name);
      stats.numClients++;
    }

    return stats;
  },

  // Remove any commands for the local client and mark it for upload
  clearCommands: function clearCommands() {
    delete this.localCommands;
    this._tracker.addChangedID(this.localID);
  },

  // Send a command+args pair to each remote client
  sendCommand: function sendCommand(command, args) {
    // Helper to determine if the client already has this command
    let notDupe = function(other) other.command != command ||
      JSON.stringify(other.args) != JSON.stringify(args);

    // Package the command/args pair into an object
    let action = {
      command: command,
      args: args,
    };

    // Send the command to each remote client
    for (let [id, client] in Iterator(this._store._remoteClients)) {
      // Set the action to be a new commands array if none exists
      if (client.commands == null)
        client.commands = [action];
      // Add the new action if there are no duplicates
      else if (client.commands.every(notDupe))
        client.commands.push(action);
      // Must have been a dupe.. skip!
      else
        continue;

      this._log.trace("Client " + id + " got a new action: " + [command, args]);
      this._tracker.addChangedID(id);
    }
  },

  get localID() {
    // Generate a random GUID id we don't have one
    let localID = Svc.Prefs.get("client.GUID", "");
    return localID == "" ? this.localID = Utils.makeGUID() : localID;
  },
  set localID(value) Svc.Prefs.set("client.GUID", value),

  get localName() {
    let localName = Svc.Prefs.get("client.name", "");
    if (localName != "")
      return localName;

    // Generate a client name if we don't have a useful one yet
    let env = Cc["@mozilla.org/process/environment;1"]
                .getService(Ci.nsIEnvironment);
    let user = env.get("USER") || env.get("USERNAME") ||
               Svc.Prefs.get("account") || Svc.Prefs.get("username");
    let brand = new StringBundle("chrome://branding/locale/brand.properties");
    let app = brand.get("brandShortName");

    let system = Cc["@mozilla.org/system-info;1"]
                   .getService(Ci.nsIPropertyBag2).get("device") ||
                 Cc["@mozilla.org/network/protocol;1?name=http"]
                   .getService(Ci.nsIHttpProtocolHandler).oscpu;

    return this.localName = Str.sync.get("client.name2", [user, app, system]);
  },
  set localName(value) Svc.Prefs.set("client.name", value),

  get localType() Svc.Prefs.get("client.type", "desktop"),
  set localType(value) Svc.Prefs.set("client.type", value),

  isMobile: function isMobile(id) {
    if (this._store._remoteClients[id])
      return this._store._remoteClients[id].type == "mobile";
    return false;
  },

  _syncStartup: function _syncStartup() {
    // Reupload new client record periodically.
    if (Date.now() / 1000 - this.lastRecordUpload > CLIENTS_TTL_REFRESH) {
      this._tracker.addChangedID(this.localID);
      this.lastRecordUpload = Date.now() / 1000;
    }
    SyncEngine.prototype._syncStartup.call(this);
  },

  // Always process incoming items because they might have commands
  _reconcile: function _reconcile() {
    return true;
  },

  // Treat reset the same as wiping for locally cached clients
  _resetClient: function _resetClient() this._wipeClient(),

  _wipeClient: function _wipeClient() {
    SyncEngine.prototype._resetClient.call(this);
    this._store.wipe();
  },

  removeClientData: function removeClientData() {
    let res = new Resource(this.engineURL + "/" + this.localID);
    res.delete();
  },

  // Override the default behavior to delete bad records from the server.
  handleHMACMismatch: function handleHMACMismatch(item, mayRetry) {
    this._log.debug("Handling HMAC mismatch for " + item.id);
    
    let base = SyncEngine.prototype.handleHMACMismatch.call(this, item, mayRetry);
    if (base != SyncEngine.kRecoveryStrategy.error)
      return base;

    // It's a bad client record. Save it to be deleted at the end of the sync.
    this._log.debug("Bad client record detected. Scheduling for deletion.");
    this._deleteId(item.id);

    // Neither try again nor error; we're going to delete it.
    return SyncEngine.kRecoveryStrategy.ignore;
  }
};

function ClientStore(name) {
  Store.call(this, name);
}
ClientStore.prototype = {
  __proto__: Store.prototype,

  create: function create(record) this.update(record),

  update: function update(record) {
    // Only grab commands from the server; local name/type always wins
    if (record.id == Clients.localID)
      Clients.localCommands = record.commands;
    else
      this._remoteClients[record.id] = record.cleartext;
  },

  createRecord: function createRecord(id, collection) {
    let record = new ClientsRec(collection, id);

    // Package the individual components into a record for the local client
    if (id == Clients.localID) {
      record.name = Clients.localName;
      record.type = Clients.localType;
      record.commands = Clients.localCommands;
    }
    else
      record.cleartext = this._remoteClients[id];

    return record;
  },

  itemExists: function itemExists(id) id in this.getAllIDs(),

  getAllIDs: function getAllIDs() {
    let ids = {};
    ids[Clients.localID] = true;
    for (let id in this._remoteClients)
      ids[id] = true;
    return ids;
  },

  wipe: function wipe() {
    this._remoteClients = {};
  },
};