michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = ["UserAgentUpdates"];
michael@0: 
michael@0: const Ci = Components.interfaces;
michael@0: const Cc = Components.classes;
michael@0: const Cu = Components.utils;
michael@0: 
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(
michael@0:   this, "FileUtils", "resource://gre/modules/FileUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(
michael@0:   this, "OS", "resource://gre/modules/osfile.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(
michael@0:   this, "UpdateChannel", "resource://gre/modules/UpdateChannel.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(
michael@0:   this, "gUpdateTimer", "@mozilla.org/updates/timer-manager;1", "nsIUpdateTimerManager");
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gApp",
michael@0:   function() Cc["@mozilla.org/xre/app-info;1"]
michael@0:     .getService(Ci.nsIXULAppInfo).QueryInterface(Ci.nsIXULRuntime)
michael@0: );
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gDecoder",
michael@0:   function() new TextDecoder()
michael@0: );
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gEncoder",
michael@0:   function() new TextEncoder()
michael@0: );
michael@0: 
michael@0: const TIMER_ID = "user-agent-updates-timer";
michael@0: 
michael@0: const PREF_UPDATES = "general.useragent.updates.";
michael@0: const PREF_UPDATES_ENABLED = PREF_UPDATES + "enabled";
michael@0: const PREF_UPDATES_URL = PREF_UPDATES + "url";
michael@0: const PREF_UPDATES_INTERVAL = PREF_UPDATES + "interval";
michael@0: const PREF_UPDATES_RETRY = PREF_UPDATES + "retry";
michael@0: const PREF_UPDATES_TIMEOUT = PREF_UPDATES + "timeout";
michael@0: const PREF_UPDATES_LASTUPDATED = PREF_UPDATES + "lastupdated";
michael@0: 
michael@0: const KEY_PREFDIR = "PrefD";
michael@0: const KEY_APPDIR = "XCurProcD";
michael@0: const FILE_UPDATES = "ua-update.json";
michael@0: 
michael@0: const PREF_APP_DISTRIBUTION = "distribution.id";
michael@0: const PREF_APP_DISTRIBUTION_VERSION = "distribution.version";
michael@0: 
michael@0: var gInitialized = false;
michael@0: 
michael@0: this.UserAgentUpdates = {
michael@0:   init: function(callback) {
michael@0:     if (gInitialized) {
michael@0:       return;
michael@0:     }
michael@0:     gInitialized = true;
michael@0: 
michael@0:     this._callback = callback;
michael@0:     this._lastUpdated = 0;
michael@0:     this._applySavedUpdate();
michael@0: 
michael@0:     Services.prefs.addObserver(PREF_UPDATES, this, false);
michael@0:   },
michael@0: 
michael@0:   uninit: function() {
michael@0:     if (!gInitialized) {
michael@0:       return;
michael@0:     }
michael@0:     gInitialized = false;
michael@0:     Services.prefs.removeObserver(PREF_UPDATES, this);
michael@0:   },
michael@0: 
michael@0:   _applyUpdate: function(update) {
michael@0:     // Check pref again in case it has changed
michael@0:     if (update && this._getPref(PREF_UPDATES_ENABLED, false)) {
michael@0:       this._callback(update);
michael@0:     } else {
michael@0:       this._callback(null);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   _applySavedUpdate: function() {
michael@0:     if (!this._getPref(PREF_UPDATES_ENABLED, false)) {
michael@0:       // remove previous overrides
michael@0:       this._applyUpdate(null);
michael@0:       return;
michael@0:     }
michael@0:     // try loading from profile dir, then from app dir
michael@0:     let dirs = [KEY_PREFDIR, KEY_APPDIR];
michael@0:     dirs.reduce((prevLoad, dir) => {
michael@0:       let file = FileUtils.getFile(dir, [FILE_UPDATES], true).path;
michael@0:       // tryNext returns promise to read file under dir and parse it
michael@0:       let tryNext = () => OS.File.read(file).then(
michael@0:         (bytes) => {
michael@0:           let update = JSON.parse(gDecoder.decode(bytes));
michael@0:           if (!update) {
michael@0:             throw new Error("invalid update");
michael@0:           }
michael@0:           return update;
michael@0:         }
michael@0:       );
michael@0:       // try to load next one if the previous load failed
michael@0:       return prevLoad ? prevLoad.then(null, tryNext) : tryNext();
michael@0:     }, null).then(
michael@0:       // apply update if loading was successful
michael@0:       (update) => this._applyUpdate(update)
michael@0:     );
michael@0:     this._scheduleUpdate();
michael@0:   },
michael@0: 
michael@0:   _saveToFile: function(update) {
michael@0:     let file = FileUtils.getFile(KEY_PREFDIR, [FILE_UPDATES], true);
michael@0:     let path = file.path;
michael@0:     let bytes = gEncoder.encode(JSON.stringify(update));
michael@0:     OS.File.writeAtomic(path, bytes, {tmpPath: path + ".tmp"}).then(
michael@0:       () => {
michael@0:         this._lastUpdated = Date.now();
michael@0:         Services.prefs.setCharPref(
michael@0:           PREF_UPDATES_LASTUPDATED, this._lastUpdated.toString());
michael@0:       },
michael@0:       Cu.reportError
michael@0:     );
michael@0:   },
michael@0: 
michael@0:   _getPref: function(name, def) {
michael@0:     try {
michael@0:       switch (typeof def) {
michael@0:         case "number": return Services.prefs.getIntPref(name);
michael@0:         case "boolean": return Services.prefs.getBoolPref(name);
michael@0:       }
michael@0:       return Services.prefs.getCharPref(name);
michael@0:     } catch (e) {
michael@0:       return def;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   _getParameters: function() ({
michael@0:     "%DATE%": function() Date.now().toString(),
michael@0:     "%PRODUCT%": function() gApp.name,
michael@0:     "%APP_ID%": function() gApp.ID,
michael@0:     "%APP_VERSION%": function() gApp.version,
michael@0:     "%BUILD_ID%": function() gApp.appBuildID,
michael@0:     "%OS%": function() gApp.OS,
michael@0:     "%CHANNEL%": function() UpdateChannel.get(),
michael@0:     "%DISTRIBUTION%": function() this._getPref(PREF_APP_DISTRIBUTION, ""),
michael@0:     "%DISTRIBUTION_VERSION%": function() this._getPref(PREF_APP_DISTRIBUTION_VERSION, ""),
michael@0:   }),
michael@0: 
michael@0:   _getUpdateURL: function() {
michael@0:     let url = this._getPref(PREF_UPDATES_URL, "");
michael@0:     let params = this._getParameters();
michael@0:     return url.replace(/%[A-Z_]+%/g, function(match) {
michael@0:       let param = params[match];
michael@0:       // preserve the %FOO% string (e.g. as an encoding) if it's not a valid parameter
michael@0:       return param ? encodeURIComponent(param()) : match;
michael@0:     });
michael@0:   },
michael@0: 
michael@0:   _fetchUpdate: function(url, success, error) {
michael@0:     let request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
michael@0:                     .createInstance(Ci.nsIXMLHttpRequest);
michael@0:     request.mozBackgroundRequest = true;
michael@0:     request.timeout = this._getPref(PREF_UPDATES_TIMEOUT, 60000);
michael@0:     request.open("GET", url, true);
michael@0:     request.overrideMimeType("application/json");
michael@0:     request.responseType = "json";
michael@0: 
michael@0:     request.addEventListener("load", function() {
michael@0:       let response = request.response;
michael@0:       response ? success(response) : error();
michael@0:     });
michael@0:     request.addEventListener("error", error);
michael@0:     request.send();
michael@0:   },
michael@0: 
michael@0:   _update: function() {
michael@0:     let url = this._getUpdateURL();
michael@0:     url && this._fetchUpdate(url,
michael@0:       (function(response) { // success
michael@0:         // apply update and save overrides to profile
michael@0:         this._applyUpdate(response);
michael@0:         this._saveToFile(response);
michael@0:         this._scheduleUpdate(); // cancel any retries
michael@0:       }).bind(this),
michael@0:       (function(response) { // error
michael@0:         this._scheduleUpdate(true /* retry */);
michael@0:       }).bind(this));
michael@0:   },
michael@0: 
michael@0:   _scheduleUpdate: function(retry) {
michael@0:     // only schedule updates in the main process
michael@0:     if (gApp.processType !== Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT) {
michael@0:       return;
michael@0:     }
michael@0:     let interval = this._getPref(PREF_UPDATES_INTERVAL, 604800 /* 1 week */);
michael@0:     if (retry) {
michael@0:       interval = this._getPref(PREF_UPDATES_RETRY, interval);
michael@0:     }
michael@0:     gUpdateTimer.registerTimer(TIMER_ID, this, Math.max(1, interval));
michael@0:   },
michael@0: 
michael@0:   notify: function(timer) {
michael@0:     // timer notification
michael@0:     if (this._getPref(PREF_UPDATES_ENABLED, false)) {
michael@0:       this._update();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   observe: function(subject, topic, data) {
michael@0:     switch (topic) {
michael@0:       case "nsPref:changed":
michael@0:         if (data === PREF_UPDATES_ENABLED) {
michael@0:           this._applySavedUpdate();
michael@0:         } else if (data === PREF_UPDATES_INTERVAL) {
michael@0:           this._scheduleUpdate();
michael@0:         } else if (data === PREF_UPDATES_LASTUPDATED) {
michael@0:           // reload from file if there has been an update
michael@0:           let lastUpdated = parseInt(
michael@0:             this._getPref(PREF_UPDATES_LASTUPDATED, "0"), 0);
michael@0:           if (lastUpdated > this._lastUpdated) {
michael@0:             this._applySavedUpdate();
michael@0:             this._lastUpdated = lastUpdated;
michael@0:           }
michael@0:         }
michael@0:         break;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   QueryInterface: XPCOMUtils.generateQI([
michael@0:     Ci.nsIObserver,
michael@0:     Ci.nsITimerCallback,
michael@0:   ]),
michael@0: };