From 7f31812e3cce2157bbb2bf9809ed276eb3b27911 Mon Sep 17 00:00:00 2001
From: Harald Schilly <harald.schilly@gmail.com>
Date: Tue, 7 Jan 2025 14:34:28 +0100
Subject: [PATCH] frontend/admin: set the user UI lang temporarily to the one
 of the admin

---
 .../frontend/admin/users/impersonate.tsx      | 11 +++++++---
 src/packages/server/auth/impersonate.ts       | 20 +++++++++++++------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/src/packages/frontend/admin/users/impersonate.tsx b/src/packages/frontend/admin/users/impersonate.tsx
index 66d7373673..b0d7a3fc38 100644
--- a/src/packages/frontend/admin/users/impersonate.tsx
+++ b/src/packages/frontend/admin/users/impersonate.tsx
@@ -5,11 +5,13 @@
 
 import { Alert, Card } from "antd";
 import { join } from "path";
+
 import { Rendered, useEffect, useState } from "@cocalc/frontend/app-framework";
 import { Icon, Loading } from "@cocalc/frontend/components";
 import { appBasePath } from "@cocalc/frontend/customize/app-base-path";
 import { webapp_client } from "@cocalc/frontend/webapp-client";
 import { CopyToClipBoard } from "@cocalc/frontend/components";
+import { useLocalizationCtx } from "@cocalc/frontend/app/localize";
 
 interface Props {
   account_id: string;
@@ -21,11 +23,13 @@ export function Impersonate({ first_name, last_name, account_id }: Props) {
   const [auth_token, set_auth_token] = useState<string | null>(null);
   const [err, set_err] = useState<string | null>(null);
   const [extraWarning, setExtraWarning] = useState<boolean>(false);
+  const { locale } = useLocalizationCtx();
 
   async function get_token(): Promise<void> {
     try {
-      const auth_token =
-        await webapp_client.admin_client.get_user_auth_token(account_id);
+      const auth_token = await webapp_client.admin_client.get_user_auth_token(
+        account_id,
+      );
       set_auth_token(auth_token);
       set_err(null);
     } catch (err) {
@@ -43,9 +47,10 @@ export function Impersonate({ first_name, last_name, account_id }: Props) {
       return <Loading />;
     }
 
+    // The lang_temp temporarily sets the interface language of the user to impersonate to the one of the admin
     const link = join(
       appBasePath,
-      `auth/impersonate?auth_token=${auth_token}&lang_temp=en`,
+      `auth/impersonate?auth_token=${auth_token}&lang_temp=${locale}`,
     );
 
     const handleClick = (event: React.MouseEvent<HTMLAnchorElement>) => {
diff --git a/src/packages/server/auth/impersonate.ts b/src/packages/server/auth/impersonate.ts
index 0904c0b895..3bfb9372dd 100644
--- a/src/packages/server/auth/impersonate.ts
+++ b/src/packages/server/auth/impersonate.ts
@@ -1,12 +1,14 @@
 /* Sign in using an impersonation auth_token. */
 
-import getPool from "@cocalc/database/pool";
-import { createRememberMeCookie } from "@cocalc/server/auth/remember-me";
 import Cookies from "cookies";
+
 import { REMEMBER_ME_COOKIE_NAME } from "@cocalc/backend/auth/cookie-names";
-import clientSideRedirect from "@cocalc/server/auth/client-side-redirect";
-import { getServerSettings } from "@cocalc/database/settings/server-settings";
 import base_path from "@cocalc/backend/base-path";
+import getPool from "@cocalc/database/pool";
+import { getServerSettings } from "@cocalc/database/settings/server-settings";
+import clientSideRedirect from "@cocalc/server/auth/client-side-redirect";
+import { createRememberMeCookie } from "@cocalc/server/auth/remember-me";
+import { isLocale } from "@cocalc/util/i18n/const";
 
 export async function signInUsingImpersonateToken({ req, res }) {
   try {
@@ -17,7 +19,7 @@ export async function signInUsingImpersonateToken({ req, res }) {
 }
 
 async function doIt({ req, res }) {
-  const { auth_token } = req.query;
+  const { auth_token, lang_temp } = req.query;
   if (!auth_token) {
     throw Error("invalid empty token");
   }
@@ -40,7 +42,13 @@ async function doIt({ req, res }) {
   });
 
   const { dns } = await getServerSettings();
-  const target = `https://${dns}${base_path}`;
+  let target = `https://${dns}${base_path}app`;
+
+  // if lang_temp is a locale, then append it as a query parameter.
+  // This is usally "en" to help admins understanding the UI without changing the user's language preferences.
+  if (isLocale(lang_temp)) {
+    target += `?lang_temp=${encodeURIComponent(lang_temp)}`;
+  }
 
   clientSideRedirect({ res, target });
 }