Fix Google OAuth: add /auth/callback route, redirect to / instead of /login

frontend/src/app/auth/callback/route.ts

@@ -0,0 +1,36 @@
+import { createServerClient } from "@supabase/ssr";
+import { cookies } from "next/headers";
+import { NextResponse, type NextRequest } from "next/server";
+
+export async function GET(request: NextRequest) {
+  const { searchParams, origin } = new URL(request.url);
+  const code = searchParams.get("code");
+  const next = searchParams.get("next") ?? "/dashboard";
+
+  if (code) {
+    const cookieStore = await cookies();
+    const supabase = createServerClient(
+      process.env.NEXT_PUBLIC_SUPABASE_URL!,
+      process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
+      {
+        cookies: {
+          getAll() {
+            return cookieStore.getAll();
+          },
+          setAll(cookiesToSet) {
+            cookiesToSet.forEach(({ name, value, options }) =>
+              cookieStore.set(name, value, options)
+            );
+          },
+        },
+      }
+    );
+
+    const { error } = await supabase.auth.exchangeCodeForSession(code);
+    if (!error) {
+      return NextResponse.redirect(`${origin}${next}`);
+    }
+  }
+
+  return NextResponse.redirect(`${origin}/?error=auth`);
+}

frontend/src/components/auth-provider.tsx

@@ -72,7 +72,7 @@ export function AuthProvider({ children }: { children: ReactNode }) {
     const { error } = await supabase.auth.signInWithOAuth({
       provider: "google",
       options: {
-        redirectTo: `${window.location.origin}/dashboard`,
+        redirectTo: `${window.location.origin}/auth/callback?next=/dashboard`,
       },
     });
     if (error) throw error;

frontend/src/middleware.ts

@@ -47,9 +47,9 @@ export async function middleware(request: NextRequest) {
 
   // Redirect unauthenticated users away from protected routes
   if (isProtectedRoute && !user) {
-    const loginUrl = new URL("/login", request.url);
-    loginUrl.searchParams.set("redirectTo", pathname);
-    return NextResponse.redirect(loginUrl);
+    const homeUrl = new URL("/", request.url);
+    homeUrl.searchParams.set("redirectTo", pathname);
+    return NextResponse.redirect(homeUrl);
   }
 
   // Redirect authenticated users away from auth pages