1 files changed, 110 insertions, 0 deletions
diff --git a/toolkit/components/passwordmgr/LoginRelatedRealms.sys.mjs b/toolkit/components/passwordmgr/LoginRelatedRealms.sys.mjs
new file mode 100644
index 0000000000..bcfd675b4b
--- /dev/null
+++ b/toolkit/components/passwordmgr/LoginRelatedRealms.sys.mjs
@@ -0,0 +1,110 @@
+/* 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/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  LoginHelper: "resource://gre/modules/LoginHelper.sys.mjs",
+  RemoteSettings: "resource://services-settings/remote-settings.sys.mjs",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "log", () => {
+  let logger = lazy.LoginHelper.createLogger("LoginRelatedRealms");
+  return logger;
+});
+
+export class LoginRelatedRealmsParent extends JSWindowActorParent {
+  /**
+   * @type RemoteSettingsClient
+   *
+   * @memberof LoginRelatedRealmsParent
+   */
+  _sharedCredentialsClient = null;
+  /**
+   * @type string[][]
+   *
+   * @memberof LoginRelatedRealmsParent
+   */
+  _relatedDomainsList = [[]];
+
+  /**
+   * Handles the Remote Settings sync event
+   *
+   * @param {Object} aEvent
+   * @param {Array} aEvent.current Records that are currently in the collection after the sync event
+   * @param {Array} aEvent.created Records that were created
+   * @param {Array} aEvent.updated Records that were updated
+   * @param {Array} aEvent.deleted Records that were deleted
+   * @memberof LoginRelatedRealmsParent
+   */
+  onRemoteSettingsSync(aEvent) {
+    let {
+      data: { current },
+    } = aEvent;
+    this._relatedDomainsList = current;
+  }
+
+  async getSharedCredentialsCollection() {
+    if (!this._sharedCredentialsClient) {
+      this._sharedCredentialsClient = lazy.RemoteSettings(
+        lazy.LoginHelper.relatedRealmsCollection
+      );
+      this._sharedCredentialsClient.on("sync", event =>
+        this.onRemoteSettingsSync(event)
+      );
+      this._relatedDomainsList = await this._sharedCredentialsClient.get();
+    }
+    return this._relatedDomainsList;
+  }
+
+  /**
+   * Determine if there are any related realms of this `formOrigin` using the related realms collection
+   * @param {string} formOrigin A form origin
+   * @return {string[]} filteredRealms An array of domains related to the `formOrigin`
+   * @async
+   * @memberof LoginRelatedRealmsParent
+   */
+  async findRelatedRealms(formOrigin) {
+    try {
+      let formOriginURI = Services.io.newURI(formOrigin);
+      let originDomain = formOriginURI.host;
+      let [{ relatedRealms } = {}] =
+        await this.getSharedCredentialsCollection();
+      if (!relatedRealms) {
+        return [];
+      }
+      let filterOriginIndex;
+      let shouldInclude = false;
+      let filteredRealms = relatedRealms.filter(_realms => {
+        for (let relatedOrigin of _realms) {
+          // We can't have an origin that matches multiple entries in our related realms collection
+          // so we exit the loop early
+          if (shouldInclude) {
+            return false;
+          }
+          if (Services.eTLD.hasRootDomain(originDomain, relatedOrigin)) {
+            shouldInclude = true;
+            break;
+          }
+        }
+        return shouldInclude;
+      });
+      // * Filtered realms is a nested array due to its structure in Remote Settings
+      filteredRealms = filteredRealms.flat();
+
+      filterOriginIndex = filteredRealms.indexOf(originDomain);
+      // Removing the current formOrigin match if it exists in the related realms
+      // so that we don't return duplicates when we search for logins
+      if (filterOriginIndex !== -1) {
+        filteredRealms.splice(filterOriginIndex, 1);
+      }
+      return filteredRealms;
+    } catch (e) {
+      lazy.log.error(e);
+      return [];
+    }
+  }
+}