1 files changed, 76 insertions, 0 deletions
diff --git a/services/sync/modules/stages/declined.js b/services/sync/modules/stages/declined.js
new file mode 100644
index 000000000..ff8a14181
--- /dev/null
+++ b/services/sync/modules/stages/declined.js
@@ -0,0 +1,76 @@
+/* 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/. */
+
+/**
+ * This file contains code for maintaining the set of declined engines,
+ * in conjunction with EngineManager.
+ */
+
+"use strict";
+
+this.EXPORTED_SYMBOLS = ["DeclinedEngines"];
+
+var {utils: Cu} = Components;
+
+Cu.import("resource://services-sync/constants.js");
+Cu.import("resource://gre/modules/Log.jsm");
+Cu.import("resource://services-common/utils.js");
+Cu.import("resource://services-common/observers.js");
+Cu.import("resource://gre/modules/Preferences.jsm");
+
+
+
+this.DeclinedEngines = function (service) {
+  this._log = Log.repository.getLogger("Sync.Declined");
+  this._log.level = Log.Level[new Preferences(PREFS_BRANCH).get("log.logger.declined")];
+
+  this.service = service;
+}
+this.DeclinedEngines.prototype = {
+  updateDeclined: function (meta, engineManager=this.service.engineManager) {
+    let enabled = new Set(engineManager.getEnabled().map(e => e.name));
+    let known = new Set(engineManager.getAll().map(e => e.name));
+    let remoteDeclined = new Set(meta.payload.declined || []);
+    let localDeclined = new Set(engineManager.getDeclined());
+
+    this._log.debug("Handling remote declined: " + JSON.stringify([...remoteDeclined]));
+    this._log.debug("Handling local declined: " + JSON.stringify([...localDeclined]));
+
+    // Any engines that are locally enabled should be removed from the remote
+    // declined list.
+    //
+    // Any engines that are locally declined should be added to the remote
+    // declined list.
+    let newDeclined = CommonUtils.union(localDeclined, CommonUtils.difference(remoteDeclined, enabled));
+
+    // If our declined set has changed, put it into the meta object and mark
+    // it as changed.
+    let declinedChanged = !CommonUtils.setEqual(newDeclined, remoteDeclined);
+    this._log.debug("Declined changed? " + declinedChanged);
+    if (declinedChanged) {
+      meta.changed = true;
+      meta.payload.declined = [...newDeclined];
+    }
+
+    // Update the engine manager regardless.
+    engineManager.setDeclined(newDeclined);
+
+    // Any engines that are locally known, locally disabled, and not remotely
+    // or locally declined, are candidates for enablement.
+    let undecided = CommonUtils.difference(CommonUtils.difference(known, enabled), newDeclined);
+    if (undecided.size) {
+      let subject = {
+        declined: newDeclined,
+        enabled: enabled,
+        known: known,
+        undecided: undecided,
+      };
+      CommonUtils.nextTick(() => {
+        Observers.notify("weave:engines:notdeclined", subject);
+      });
+    }
+
+    return declinedChanged;
+  },
+};