michael@0: // -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; -*-
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 file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = [ "HomeProvider" ];
michael@0: 
michael@0: const { utils: Cu, classes: Cc, interfaces: Ci } = Components;
michael@0: 
michael@0: Cu.import("resource://gre/modules/Messaging.jsm");
michael@0: Cu.import("resource://gre/modules/osfile.jsm");
michael@0: Cu.import("resource://gre/modules/Promise.jsm");
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: Cu.import("resource://gre/modules/Sqlite.jsm");
michael@0: Cu.import("resource://gre/modules/Task.jsm");
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: /*
michael@0:  * SCHEMA_VERSION history:
michael@0:  *   1: Create HomeProvider (bug 942288)
michael@0:  *   2: Add filter column to items table (bug 942295/975841)
michael@0:  */
michael@0: const SCHEMA_VERSION = 2;
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "DB_PATH", function() {
michael@0:   return OS.Path.join(OS.Constants.Path.profileDir, "home.sqlite");
michael@0: });
michael@0: 
michael@0: const PREF_STORAGE_LAST_SYNC_TIME_PREFIX = "home.storage.lastSyncTime.";
michael@0: const PREF_SYNC_UPDATE_MODE = "home.sync.updateMode";
michael@0: const PREF_SYNC_CHECK_INTERVAL_SECS = "home.sync.checkIntervalSecs";
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gSyncCheckIntervalSecs", function() {
michael@0:   return Services.prefs.getIntPref(PREF_SYNC_CHECK_INTERVAL_SECS);
michael@0: });
michael@0: 
michael@0: XPCOMUtils.defineLazyServiceGetter(this,
michael@0:   "gUpdateTimerManager", "@mozilla.org/updates/timer-manager;1", "nsIUpdateTimerManager");
michael@0: 
michael@0: /**
michael@0:  * All SQL statements should be defined here.
michael@0:  */
michael@0: const SQL = {
michael@0:   createItemsTable:
michael@0:     "CREATE TABLE items (" +
michael@0:       "_id INTEGER PRIMARY KEY AUTOINCREMENT, " +
michael@0:       "dataset_id TEXT NOT NULL, " +
michael@0:       "url TEXT," +
michael@0:       "title TEXT," +
michael@0:       "description TEXT," +
michael@0:       "image_url TEXT," +
michael@0:       "filter TEXT," +
michael@0:       "created INTEGER" +
michael@0:     ")",
michael@0: 
michael@0:   dropItemsTable:
michael@0:     "DROP TABLE items",
michael@0: 
michael@0:   insertItem:
michael@0:     "INSERT INTO items (dataset_id, url, title, description, image_url, filter, created) " +
michael@0:       "VALUES (:dataset_id, :url, :title, :description, :image_url, :filter, :created)",
michael@0: 
michael@0:   deleteFromDataset:
michael@0:     "DELETE FROM items WHERE dataset_id = :dataset_id"
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Technically this function checks to see if the user is on a local network,
michael@0:  * but we express this as "wifi" to the user.
michael@0:  */
michael@0: function isUsingWifi() {
michael@0:   let network = Cc["@mozilla.org/network/network-link-service;1"].getService(Ci.nsINetworkLinkService);
michael@0:   return (network.linkType === Ci.nsINetworkLinkService.LINK_TYPE_WIFI || network.linkType === Ci.nsINetworkLinkService.LINK_TYPE_ETHERNET);
michael@0: }
michael@0: 
michael@0: function getNowInSeconds() {
michael@0:   return Math.round(Date.now() / 1000);
michael@0: }
michael@0: 
michael@0: function getLastSyncPrefName(datasetId) {
michael@0:   return PREF_STORAGE_LAST_SYNC_TIME_PREFIX + datasetId;
michael@0: }
michael@0: 
michael@0: // Whether or not we've registered an update timer.
michael@0: var gTimerRegistered = false;
michael@0: 
michael@0: // Map of datasetId -> { interval: <integer>, callback: <function> }
michael@0: var gSyncCallbacks = {};
michael@0: 
michael@0: /**
michael@0:  * nsITimerCallback implementation. Checks to see if it's time to sync any registered datasets.
michael@0:  *
michael@0:  * @param timer The timer which has expired.
michael@0:  */
michael@0: function syncTimerCallback(timer) {
michael@0:   for (let datasetId in gSyncCallbacks) {
michael@0:     let lastSyncTime = 0;
michael@0:     try {
michael@0:       lastSyncTime = Services.prefs.getIntPref(getLastSyncPrefName(datasetId));
michael@0:     } catch(e) { }
michael@0: 
michael@0:     let now = getNowInSeconds();
michael@0:     let { interval: interval, callback: callback } = gSyncCallbacks[datasetId];
michael@0: 
michael@0:     if (lastSyncTime < now - interval) {
michael@0:       let success = HomeProvider.requestSync(datasetId, callback);
michael@0:       if (success) {
michael@0:         Services.prefs.setIntPref(getLastSyncPrefName(datasetId), now);
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: this.HomeStorage = function(datasetId) {
michael@0:   this.datasetId = datasetId;
michael@0: };
michael@0: 
michael@0: this.ValidationError = function(message) {
michael@0:   this.name = "ValidationError";
michael@0:   this.message = message;
michael@0: };
michael@0: ValidationError.prototype = new Error();
michael@0: ValidationError.prototype.constructor = ValidationError;
michael@0: 
michael@0: this.HomeProvider = Object.freeze({
michael@0:   ValidationError: ValidationError,
michael@0: 
michael@0:   /**
michael@0:    * Returns a storage associated with a given dataset identifer.
michael@0:    *
michael@0:    * @param datasetId
michael@0:    *        (string) Unique identifier for the dataset.
michael@0:    *
michael@0:    * @return HomeStorage
michael@0:    */
michael@0:   getStorage: function(datasetId) {
michael@0:     return new HomeStorage(datasetId);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Checks to see if it's an appropriate time to sync.
michael@0:    *
michael@0:    * @param datasetId Unique identifier for the dataset to sync.
michael@0:    * @param callback Function to call when it's time to sync, called with datasetId as a parameter.
michael@0:    *
michael@0:    * @return boolean Whether or not we were able to sync.
michael@0:    */
michael@0:   requestSync: function(datasetId, callback) {
michael@0:     // Make sure it's a good time to sync.
michael@0:     if ((Services.prefs.getIntPref(PREF_SYNC_UPDATE_MODE) === 1) && !isUsingWifi()) {
michael@0:       Cu.reportError("HomeProvider: Failed to sync because device is not on a local network");
michael@0:       return false;
michael@0:     }
michael@0: 
michael@0:     callback(datasetId);
michael@0:     return true;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Specifies that a sync should be requested for the given dataset and update interval.
michael@0:    *
michael@0:    * @param datasetId Unique identifier for the dataset to sync.
michael@0:    * @param interval Update interval in seconds. By default, this is throttled to 3600 seconds (1 hour).
michael@0:    * @param callback Function to call when it's time to sync, called with datasetId as a parameter.
michael@0:    */
michael@0:   addPeriodicSync: function(datasetId, interval, callback) {
michael@0:     // Warn developers if they're expecting more frequent notifications that we allow.
michael@0:     if (interval < gSyncCheckIntervalSecs) {
michael@0:       Cu.reportError("HomeProvider: Warning for dataset " + datasetId +
michael@0:         " : Sync notifications are throttled to " + gSyncCheckIntervalSecs + " seconds");
michael@0:     }
michael@0: 
michael@0:     gSyncCallbacks[datasetId] = {
michael@0:       interval: interval,
michael@0:       callback: callback
michael@0:     };
michael@0: 
michael@0:     if (!gTimerRegistered) {
michael@0:       gUpdateTimerManager.registerTimer("home-provider-sync-timer", syncTimerCallback, gSyncCheckIntervalSecs);
michael@0:       gTimerRegistered = true;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Removes a periodic sync timer.
michael@0:    *
michael@0:    * @param datasetId Dataset to sync.
michael@0:    */
michael@0:   removePeriodicSync: function(datasetId) {
michael@0:     delete gSyncCallbacks[datasetId];
michael@0:     Services.prefs.clearUserPref(getLastSyncPrefName(datasetId));
michael@0:     // You can't unregister a update timer, so we don't try to do that.
michael@0:   }
michael@0: });
michael@0: 
michael@0: var gDatabaseEnsured = false;
michael@0: 
michael@0: /**
michael@0:  * Creates the database schema.
michael@0:  */
michael@0: function createDatabase(db) {
michael@0:   return Task.spawn(function create_database_task() {
michael@0:     yield db.execute(SQL.createItemsTable);
michael@0:   });
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Migrates the database schema to a new version.
michael@0:  */
michael@0: function upgradeDatabase(db, oldVersion, newVersion) {
michael@0:   return Task.spawn(function upgrade_database_task() {
michael@0:     for (let v = oldVersion + 1; v <= newVersion; v++) {
michael@0:       switch(v) {
michael@0:         case 2:
michael@0:           // Recreate the items table discarding any
michael@0:           // existing data.
michael@0:           yield db.execute(SQL.dropItemsTable);
michael@0:           yield db.execute(SQL.createItemsTable);
michael@0:           break;
michael@0:       }
michael@0:     }
michael@0:   });
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Opens a database connection and makes sure that the database schema version
michael@0:  * is correct, performing migrations if necessary. Consumers should be sure
michael@0:  * to close any database connections they open.
michael@0:  *
michael@0:  * @return Promise
michael@0:  * @resolves Handle on an opened SQLite database.
michael@0:  */
michael@0: function getDatabaseConnection() {
michael@0:   return Task.spawn(function get_database_connection_task() {
michael@0:     let db = yield Sqlite.openConnection({ path: DB_PATH });
michael@0:     if (gDatabaseEnsured) {
michael@0:       throw new Task.Result(db);
michael@0:     }
michael@0: 
michael@0:     try {
michael@0:       // Check to see if we need to perform any migrations.
michael@0:       let dbVersion = parseInt(yield db.getSchemaVersion());
michael@0: 
michael@0:       // getSchemaVersion() returns a 0 int if the schema
michael@0:       // version is undefined.
michael@0:       if (dbVersion === 0) {
michael@0:         yield createDatabase(db);
michael@0:       } else if (dbVersion < SCHEMA_VERSION) {
michael@0:         yield upgradeDatabase(db, dbVersion, SCHEMA_VERSION);
michael@0:       }
michael@0: 
michael@0:       yield db.setSchemaVersion(SCHEMA_VERSION);
michael@0:     } catch(e) {
michael@0:       // Close the DB connection before passing the exception to the consumer.
michael@0:       yield db.close();
michael@0:       throw e;
michael@0:     }
michael@0: 
michael@0:     gDatabaseEnsured = true;
michael@0:     throw new Task.Result(db);
michael@0:   });
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Validates an item to be saved to the DB.
michael@0:  *
michael@0:  * @param item
michael@0:  *        (object) item object to be validated.
michael@0:  */
michael@0: function validateItem(datasetId, item) {
michael@0:   if (!item.url) {
michael@0:     throw new ValidationError('HomeStorage: All rows must have an URL: datasetId = ' +
michael@0:                               datasetId);
michael@0:   }
michael@0: 
michael@0:   if (!item.image_url && !item.title && !item.description) {
michael@0:     throw new ValidationError('HomeStorage: All rows must have at least an image URL, ' +
michael@0:                               'or a title or a description: datasetId = ' + datasetId);
michael@0:   }
michael@0: }
michael@0: 
michael@0: var gRefreshTimers = {};
michael@0: 
michael@0: /**
michael@0:  * Sends a message to Java to refresh the given dataset. Delays sending
michael@0:  * messages to avoid successive refreshes, which can result in flashing views.
michael@0:  */
michael@0: function refreshDataset(datasetId) {
michael@0:   // Bail if there's already a refresh timer waiting to fire
michael@0:   if (gRefreshTimers[datasetId]) {
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
michael@0:   timer.initWithCallback(function(timer) {
michael@0:     delete gRefreshTimers[datasetId];
michael@0: 
michael@0:     sendMessageToJava({
michael@0:       type: "HomePanels:RefreshDataset",
michael@0:       datasetId: datasetId
michael@0:     });
michael@0:   }, 100, Ci.nsITimer.TYPE_ONE_SHOT);
michael@0: 
michael@0:   gRefreshTimers[datasetId] = timer;
michael@0: }
michael@0: 
michael@0: HomeStorage.prototype = {
michael@0:   /**
michael@0:    * Saves data rows to the DB.
michael@0:    *
michael@0:    * @param data
michael@0:    *        An array of JS objects represnting row items to save.
michael@0:    *        Each object may have the following properties:
michael@0:    *        - url (string)
michael@0:    *        - title (string)
michael@0:    *        - description (string)
michael@0:    *        - image_url (string)
michael@0:    *        - filter (string)
michael@0:    * @param options
michael@0:    *        A JS object holding additional cofiguration properties.
michael@0:    *        The following properties are currently supported:
michael@0:    *        - replace (boolean): Whether or not to replace existing items.
michael@0:    *
michael@0:    * @return Promise
michael@0:    * @resolves When the operation has completed.
michael@0:    */
michael@0:   save: function(data, options) {
michael@0:     return Task.spawn(function save_task() {
michael@0:       let db = yield getDatabaseConnection();
michael@0:       try {
michael@0:         yield db.executeTransaction(function save_transaction() {
michael@0:           if (options && options.replace) {
michael@0:             yield db.executeCached(SQL.deleteFromDataset, { dataset_id: this.datasetId });
michael@0:           }
michael@0: 
michael@0:           // Insert data into DB.
michael@0:           for (let item of data) {
michael@0:             validateItem(this.datasetId, item);
michael@0: 
michael@0:             // XXX: Directly pass item as params? More validation for item?
michael@0:             let params = {
michael@0:               dataset_id: this.datasetId,
michael@0:               url: item.url,
michael@0:               title: item.title,
michael@0:               description: item.description,
michael@0:               image_url: item.image_url,
michael@0:               filter: item.filter,
michael@0:               created: Date.now()
michael@0:             };
michael@0:             yield db.executeCached(SQL.insertItem, params);
michael@0:           }
michael@0:         }.bind(this));
michael@0:       } finally {
michael@0:         yield db.close();
michael@0:       }
michael@0: 
michael@0:       refreshDataset(this.datasetId);
michael@0:     }.bind(this));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Deletes all rows associated with this storage.
michael@0:    *
michael@0:    * @return Promise
michael@0:    * @resolves When the operation has completed.
michael@0:    */
michael@0:   deleteAll: function() {
michael@0:     return Task.spawn(function delete_all_task() {
michael@0:       let db = yield getDatabaseConnection();
michael@0:       try {
michael@0:         let params = { dataset_id: this.datasetId };
michael@0:         yield db.executeCached(SQL.deleteFromDataset, params);
michael@0:       } finally {
michael@0:         yield db.close();
michael@0:       }
michael@0: 
michael@0:       refreshDataset(this.datasetId);
michael@0:     }.bind(this));
michael@0:   }
michael@0: };