From 0222eca381d1a92e3f01808dd00a116adc42280a Mon Sep 17 00:00:00 2001
From: gahusb <bgg8988@gmail.com>
Date: Thu, 19 Mar 2026 23:44:54 +0900
Subject: [PATCH] =?UTF-8?q?fix:=20Google=20OAuth=20=EB=A1=9C=EA=B7=B8?=
 =?UTF-8?q?=EC=9D=B8=20=EC=8B=9C=20localhost:3000=20=EB=A6=AC=EB=8B=A4?=
 =?UTF-8?q?=EC=9D=B4=EB=A0=89=ED=8A=B8=20=EB=AC=B8=EC=A0=9C=20=EC=88=98?=
 =?UTF-8?q?=EC=A0=95?=
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- app/auth/callback/route.ts: NEXT_PUBLIC_SITE_URL 우선, x-forwarded-host 폴백
  Vercel 내부 라우팅에서 request.url의 origin이 localhost로 잡히는 경우 대응
- app/login/page.tsx: signInWithOAuth redirectTo를 NEXT_PUBLIC_SITE_URL 기준으로 변경
  window.location.origin 대신 명시적 환경변수 사용으로 안정성 확보

Vercel 환경변수에 NEXT_PUBLIC_SITE_URL=https://<도메인> 추가 필요

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 app/auth/callback/route.ts | 22 ++++++++++++----------
 app/login/page.tsx         |  4 +++-
 2 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/app/auth/callback/route.ts b/app/auth/callback/route.ts
index 27401f8..718a862 100644
--- a/app/auth/callback/route.ts
+++ b/app/auth/callback/route.ts
@@ -6,21 +6,23 @@ export async function GET(request: Request) {
   const code = searchParams.get('code');
   const next = searchParams.get('next') ?? '/mypage';
 
+  // 프로덕션 기준 URL 결정
+  // 우선순위: NEXT_PUBLIC_SITE_URL > x-forwarded-host > origin
+  const siteUrl = process.env.NEXT_PUBLIC_SITE_URL;
+  const forwardedHost = request.headers.get('x-forwarded-host');
+  const baseUrl =
+    siteUrl ??
+    (process.env.NODE_ENV !== 'development' && forwardedHost
+      ? `https://${forwardedHost}`
+      : origin);
+
   if (code) {
     const supabase = await createClient();
     const { error } = await supabase.auth.exchangeCodeForSession(code);
     if (!error) {
-      const forwardedHost = request.headers.get('x-forwarded-host');
-      const isLocalEnv = process.env.NODE_ENV === 'development';
-      if (isLocalEnv) {
-        return NextResponse.redirect(`${origin}${next}`);
-      } else if (forwardedHost) {
-        return NextResponse.redirect(`https://${forwardedHost}${next}`);
-      } else {
-        return NextResponse.redirect(`${origin}${next}`);
-      }
+      return NextResponse.redirect(`${baseUrl}${next}`);
     }
   }
 
-  return NextResponse.redirect(`${origin}/login?error=auth-callback-error`);
+  return NextResponse.redirect(`${baseUrl}/login?error=auth-callback-error`);
 }
diff --git a/app/login/page.tsx b/app/login/page.tsx
index 7f1b9da..477c90c 100644
--- a/app/login/page.tsx
+++ b/app/login/page.tsx
@@ -60,9 +60,11 @@ function LoginForm() {
   };
 
   const handleGoogleLogin = async () => {
+    // NEXT_PUBLIC_SITE_URL 이 설정되어 있으면 우선 사용 (localhost 리다이렉트 방지)
+    const base = process.env.NEXT_PUBLIC_SITE_URL ?? window.location.origin;
     const { error } = await supabase.auth.signInWithOAuth({
       provider: 'google',
-      options: { redirectTo: `${window.location.origin}/auth/callback` },
+      options: { redirectTo: `${base}/auth/callback` },
     });
     if (error) setMessage('Google 로그인 오류: ' + error.message);
   };