Login with Google — client UI (#4028) (#4279)

Resolves #4028 (client half — backend is openfrontio/infra#368, which
must be deployed first).

## Description:

Adds "Login with Google" to the client, alongside the existing Discord
login. Companion to the backend PR (openfrontio/infra#368).

- `Auth.ts` — `googleLogin()` (full-page redirect to
`/auth/login/google?redirect_uri=…`, mirrors `discordLogin()`).
- `ApiSchemas.ts` — `GoogleUserSchema` + optional `user.google` on
`UserMeResponseSchema`.
- `AccountModal.ts` — a "Login with Google" button (Google brand
guidelines: white surface, dark text, the multicolor "G" mark) in the
login options, and the logged-in view now renders a Google-authenticated
user's email (also added `google` to `isLinkedAccount()`).
- `en.json` — `main.login_google`.
- `resources/images/GoogleLogo.svg` — the Google "G" mark.

> **Draft.** Depends on infra#368 being deployed (the button hits the
live `/auth/login/google`).

## Please complete the following:

- [x] I have added screenshots for all UI updates <!-- TODO: add
screenshot of the Google button -->
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory <!-- no client
tests exist for AccountModal/Auth; verified via tsc --noEmit + eslint.
Backend behaviour is covered in infra#368 -->

## Please put your Discord username so you can be contacted if a bug or
regression is found:

jish

src/client/AccountModal.ts

@@ -9,7 +9,13 @@ import {
 import { assetUrl } from "../core/AssetUrls";
 import { Cosmetics } from "../core/CosmeticSchemas";
 import { fetchPlayerById, getUserMe } from "./Api";
-import { discordLogin, logOut, sendMagicLink } from "./Auth";
+import {
+  discordLogin,
+  googleLogin,
+  linkGoogle,
+  logOut,
+  sendMagicLink,
+} from "./Auth";
 import "./components/baseComponents/stats/DiscordUserHeader";
 import "./components/baseComponents/stats/GameList";
 import "./components/baseComponents/stats/PlayerStatsTable";
@@ -96,7 +102,7 @@ export class AccountModal extends BaseModal {
 
   private isLinkedAccount(): boolean {
     const me = this.userMeResponse?.user;
-    return !!(me?.discord ?? me?.email);
+    return !!(me?.discord ?? me?.google ?? me?.email);
   }
 
   protected modalConfig() {
@@ -252,6 +258,18 @@ export class AccountModal extends BaseModal {
     if (me?.discord) {
       return html`
         <div class="flex flex-col items-center gap-3 w-full">
+          ${this.renderCurrency()} ${this.renderLinkGoogleButton()}
+          ${this.renderLogoutButton()}
+        </div>
+      `;
+    } else if (me?.google) {
+      return html`
+        <div class="flex flex-col items-center gap-3 w-full">
+          <div class="text-white text-lg font-medium">
+            ${translateText("account_modal.linked_account", {
+              account_name: me.google.email,
+            })}
+          </div>
           ${this.renderCurrency()} ${this.renderLogoutButton()}
         </div>
       `;
@@ -263,13 +281,35 @@ export class AccountModal extends BaseModal {
               account_name: me.email,
             })}
           </div>
-          ${this.renderCurrency()} ${this.renderLogoutButton()}
+          ${this.renderCurrency()} ${this.renderLinkGoogleButton()}
+          ${this.renderLogoutButton()}
         </div>
       `;
     }
     return html``;
   }
 
+  // Shown when logged in without a Google identity yet. Lets the user attach
+  // Google to their existing account (we never auto-merge by email).
+  private renderLinkGoogleButton(): TemplateResult {
+    if (this.userMeResponse?.user?.google) return html``;
+    return html`
+      <button
+        @click=${this.handleLinkGoogle}
+        class="w-full px-6 py-3 text-[#1f1f1f] bg-white hover:bg-[#f7f8f8] border border-[#dadce0] rounded-xl focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-[#4285F4] transition-colors duration-200 flex items-center justify-center gap-3 shadow-lg"
+      >
+        <img
+          src=${assetUrl("images/GoogleLogo.svg")}
+          alt=${translateText("account_modal.google_alt")}
+          class="w-5 h-5"
+        />
+        <span class="font-bold tracking-wide"
+          >${translateText("account_modal.link_google")}</span
+        >
+      </button>
+    `;
+  }
+
   private async viewGame(gameId: string): Promise<void> {
     this.close();
     const encodedGameId = encodeURIComponent(gameId);
@@ -340,6 +380,22 @@ export class AccountModal extends BaseModal {
               >
             </button>
 
+            <!-- Google Login Button (Google brand guidelines: white surface,
+                 dark text, the multicolor "G" mark) -->
+            <button
+              @click="${this.handleGoogleLogin}"
+              class="w-full px-6 py-4 text-[#1f1f1f] bg-white hover:bg-[#f7f8f8] border border-[#dadce0] rounded-xl focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-[#4285F4] transition-colors duration-200 flex items-center justify-center gap-3 group relative overflow-hidden shadow-lg"
+            >
+              <img
+                src=${assetUrl("images/GoogleLogo.svg")}
+                alt="Google"
+                class="w-6 h-6 relative z-10"
+              />
+              <span class="font-bold relative z-10 tracking-wide"
+                >${translateText("main.login_google")}</span
+              >
+            </button>
+
             <!-- Divider -->
             <div class="flex items-center gap-4 py-2">
               <div class="h-px bg-white/10 flex-1"></div>
@@ -417,8 +473,60 @@ export class AccountModal extends BaseModal {
     discordLogin();
   }
 
-  protected onOpen(): void {
+  private handleGoogleLogin() {
+    googleLogin();
+  }
+
+  private async handleLinkGoogle(): Promise<void> {
+    // On success linkGoogle navigates to Google; the result comes back as a
+    // `link=...` router arg handled in handleLinkResult. A false return means we
+    // couldn't start it.
+    const started = await linkGoogle();
+    if (!started) {
+      alert(translateText("account_modal.link_google_failed"));
+    }
+  }
+
+  // The Google link callback returns us to #modal=account&link=<result>, so the
+  // router reopens this modal with a `link` arg. Surface the outcome, then strip
+  // the one-shot param from the URL so a refresh/re-open doesn't replay it.
+  private handleLinkResult(args?: Record<string, unknown>): void {
+    const link = typeof args?.link === "string" ? args.link : undefined;
+    if (link === undefined) return;
+
+    // replaceState doesn't fire hashchange, so removing the param won't re-route.
+    const params = new URLSearchParams(window.location.hash.slice(1));
+    params.delete("link");
+    const rest = params.toString();
+    history.replaceState(
+      null,
+      "",
+      rest ? `#${rest}` : window.location.pathname + window.location.search,
+    );
+
+    // Defer so the modal paints before the (blocking) alert. "cancel" needs no
+    // feedback — the user chose to back out.
+    if (link === "google") {
+      setTimeout(
+        () => alert(translateText("account_modal.link_google_success")),
+        0,
+      );
+    } else if (link === "already_linked") {
+      setTimeout(
+        () => alert(translateText("account_modal.link_google_already_linked")),
+        0,
+      );
+    } else if (link === "error") {
+      setTimeout(
+        () => alert(translateText("account_modal.link_google_error")),
+        0,
+      );
+    }
+  }
+
+  protected onOpen(args?: Record<string, unknown>): void {
     this.isLoadingUser = true;
+    this.handleLinkResult(args);
 
     if (SUBSCRIPTIONS_ENABLED) {
       void fetchCosmetics().then((cosmetics) => {

src/client/Api.ts

@@ -282,13 +282,14 @@ export function getAudience() {
   return domainname;
 }
 
-// Check if the user's account is linked to a Discord or email account.
+// Check if the user's account is linked to a Discord, Google, or email account.
 export function hasLinkedAccount(
   userMeResponse: UserMeResponse | false,
 ): boolean {
   return (
     userMeResponse !== false &&
     (userMeResponse.user?.discord !== undefined ||
+      userMeResponse.user?.google !== undefined ||
       userMeResponse.user?.email !== undefined)
   );
 }

src/client/Auth.ts

@@ -19,6 +19,41 @@ export function discordLogin() {
   window.location.href = `${getApiBase()}/auth/login/discord?redirect_uri=${redirectUri}`;
 }
 
+export function googleLogin() {
+  const redirectUri = encodeURIComponent(window.location.href);
+  window.location.href = `${getApiBase()}/auth/login/google?redirect_uri=${redirectUri}`;
+}
+
+// Link a Google account to the currently logged-in player. Unlike login this is
+// an authenticated request, so we fetch the Google authorize URL with the
+// Bearer token (a top-level navigation can't carry it) and then navigate to it.
+// Returns false if the user isn't logged in or the request fails.
+export async function linkGoogle(): Promise<boolean> {
+  const authHeader = await getAuthHeader();
+  if (authHeader === "") return false;
+  const redirectUri = encodeURIComponent(window.location.href);
+  try {
+    const response = await fetch(
+      `${getApiBase()}/auth/link/google?redirect_uri=${redirectUri}`,
+      {
+        headers: { Authorization: authHeader },
+        credentials: "include",
+      },
+    );
+    if (!response.ok) {
+      console.error("Failed to start Google link", response);
+      return false;
+    }
+    const { url } = await response.json();
+    if (typeof url !== "string") return false;
+    window.location.href = url;
+    return true;
+  } catch (e) {
+    console.error("Failed to start Google link", e);
+    return false;
+  }
+}
+
 export async function tempTokenLogin(token: string): Promise<string | null> {
   const response = await fetch(
     `${getApiBase()}/auth/login/token?login-token=${token}`,

src/client/Main.ts

@@ -162,6 +162,14 @@ function updateAccountNavButton(userMeResponse: UserMeResponse | false) {
     return;
   }
 
+  // Google logins have no avatar; show the same person/email badge as magic-link.
+  const google =
+    userMeResponse !== false ? userMeResponse.user.google : undefined;
+  if (google) {
+    showEmailLoggedIn();
+    return;
+  }
+
   showSignIn();
 }
 

src/client/Matchmaking.ts

@@ -122,7 +122,9 @@ export class MatchmakingModal extends BaseModal {
     const isLoggedIn =
       userMe &&
       userMe.user &&
-      (userMe.user.discord !== undefined || userMe.user.email !== undefined);
+      (userMe.user.discord !== undefined ||
+        userMe.user.google !== undefined ||
+        userMe.user.email !== undefined);
     if (!isLoggedIn) {
       window.dispatchEvent(
         new CustomEvent("show-message", {