1 files changed, 120 insertions, 0 deletions
diff --git a/browser/components/newtab/lib/ASRouterNewTabHook.jsm b/browser/components/newtab/lib/ASRouterNewTabHook.jsm
new file mode 100644
index 0000000000..78eb465725
--- /dev/null
+++ b/browser/components/newtab/lib/ASRouterNewTabHook.jsm
@@ -0,0 +1,120 @@
+/* vim: set ts=2 sw=2 sts=2 et tw=80: */
+/* 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/. */
+"use strict";
+
+const EXPORTED_SYMBOLS = ["ASRouterNewTabHook"];
+
+class ASRouterNewTabHookInstance {
+  constructor() {
+    this._newTabMessageHandler = null;
+    this._parentProcessMessageHandler = null;
+    this._router = null;
+    this._clearChildMessages = (...params) =>
+      this._newTabMessageHandler === null
+        ? Promise.resolve()
+        : this._newTabMessageHandler.clearChildMessages(...params);
+    this._clearChildProviders = (...params) =>
+      this._newTabMessageHandler === null
+        ? Promise.resolve()
+        : this._newTabMessageHandler.clearChildProviders(...params);
+    this._updateAdminState = (...params) =>
+      this._newTabMessageHandler === null
+        ? Promise.resolve()
+        : this._newTabMessageHandler.updateAdminState(...params);
+  }
+
+  /**
+   * Params:
+   *    object - {
+   *      messageHandler: message handler for parent process messages
+   *      {
+   *        handleCFRAction: Responds to CFR action and returns a Promise
+   *        handleTelemetry: Logs telemetry events and returns nothing
+   *      },
+   *      router: ASRouter instance
+   *      createStorage: function to create DB storage for ASRouter
+   *   }
+   */
+  async initialize({ messageHandler, router, createStorage }) {
+    this._parentProcessMessageHandler = messageHandler;
+    this._router = router;
+    if (!this._router.initialized) {
+      const storage = await createStorage();
+      await this._router.init({
+        storage,
+        sendTelemetry: this._parentProcessMessageHandler.handleTelemetry,
+        dispatchCFRAction: this._parentProcessMessageHandler.handleCFRAction,
+        clearChildMessages: this._clearChildMessages,
+        clearChildProviders: this._clearChildProviders,
+        updateAdminState: this._updateAdminState,
+      });
+    }
+  }
+
+  destroy() {
+    if (this._router?.initialized) {
+      this.disconnect();
+      this._router.uninit();
+    }
+  }
+
+  /**
+   * Connects new tab message handler to hook.
+   * Note: Should only ever be called on an initialized instance
+   * Params:
+   *    newTabMessageHandler - {
+   *      clearChildMessages: clears child messages and returns Promise
+   *      clearChildProviders: clears child providers and returns Promise.
+   *      updateAdminState: updates admin state and returns Promise
+   *   }
+   * Returns: parentProcessMessageHandler
+   */
+  connect(newTabMessageHandler) {
+    this._newTabMessageHandler = newTabMessageHandler;
+    return this._parentProcessMessageHandler;
+  }
+
+  /**
+   * Disconnects new tab message handler from hook.
+   */
+  disconnect() {
+    this._newTabMessageHandler = null;
+  }
+}
+
+class AwaitSingleton {
+  constructor() {
+    this.instance = null;
+    const initialized = new Promise(resolve => {
+      this.setInstance = instance => {
+        this.setInstance = () => {};
+        this.instance = instance;
+        resolve(instance);
+      };
+    });
+    this.getInstance = () => initialized;
+  }
+}
+
+const ASRouterNewTabHook = (() => {
+  const singleton = new AwaitSingleton();
+  const instance = new ASRouterNewTabHookInstance();
+  return {
+    getInstance: singleton.getInstance,
+
+    /**
+     * Param:
+     *    params - see ASRouterNewTabHookInstance.init
+     */
+    createInstance: async params => {
+      await instance.initialize(params);
+      singleton.setInstance(instance);
+    },
+
+    destroy: () => {
+      instance.destroy();
+    },
+  };
+})();