인증 API: JWT + 소셜 로그인 + 미들웨어

1. 로그인 → Supabase Auth Server
2. Access Token (1시간) + Refresh Token (영구) 발급
3. 쿠키에 저장 (httpOnly + secure + sameSite=lax)
4. 매 요청마다 middleware가 토큰 검증·갱신
5. 만료 5분 전 자동 갱신 (refresh)

// src/lib/supabase/server.ts
import { createServerClient } from '@supabase/ssr'
import { cookies } from 'next/headers'

export async function createClient() {
  const cookieStore = await cookies()
  return 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)
          )
        },
      },
    }
  )
}

// src/middleware.ts
import { createServerClient } from '@supabase/ssr'
import { NextResponse, type NextRequest } from 'next/server'

export async function middleware(request: NextRequest) {
  let response = NextResponse.next({ request })

  const supabase = createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        getAll() { return request.cookies.getAll() },
        setAll(cookies) {
          cookies.forEach(({ name, value, options }) => {
            response.cookies.set(name, value, options)
          })
        },
      },
    }
  )

  const { data: { user } } = await supabase.auth.getUser()

  // 인증 필요 페이지 보호
  if (!user && request.nextUrl.pathname.startsWith('/dashboard')) {
    return NextResponse.redirect(new URL('/login', request.url))
  }

  return response
}

export const config = {
  matcher: [
    '/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)',
  ],
}

// src/app/auth/callback/route.ts
import { NextResponse } from 'next/server'
import { createClient } from '@/lib/supabase/server'

export async function GET(request: Request) {
  const { searchParams, origin } = new URL(request.url)
  const code = searchParams.get('code')
  const next = searchParams.get('next') ?? '/dashboard'

  if (code) {
    const supabase = await createClient()
    const { error } = await supabase.auth.exchangeCodeForSession(code)
    if (!error) return NextResponse.redirect(`${origin}${next}`)
  }

  return NextResponse.redirect(`${origin}/login?error=auth_failed`)
}

// src/app/(auth)/logout/route.ts
import { NextResponse } from 'next/server'
import { createClient } from '@/lib/supabase/server'

export async function POST() {
  const supabase = await createClient()
  await supabase.auth.signOut()
  return NextResponse.redirect(new URL('/', process.env.NEXT_PUBLIC_APP_URL!))
}

// src/app/api/generations/route.ts
import { NextResponse } from 'next/server'
import { createClient } from '@/lib/supabase/server'

export async function POST(request: Request) {
  const supabase = await createClient()
  const { data: { user } } = await supabase.auth.getUser()
  if (!user) {
    return NextResponse.json({ error: { code: 'UNAUTHORIZED' } }, { status: 401 })
  }
  // 비즈니스 로직...
}

-- API token 테이블
create table api_tokens (
  id uuid primary key default gen_random_uuid(),
  user_id uuid references users(id) on delete cascade,
  name text,
  token_hash text not null,
  created_at timestamptz default now(),
  last_used_at timestamptz,
  expires_at timestamptz
);

// 검증
import { createHash } from 'crypto'

export async function authenticateApiToken(token: string) {
  const hash = createHash('sha256').update(token).digest('hex')
  const supabase = createServiceClient()  // service role
  const { data } = await supabase
    .from('api_tokens')
    .select('user_id, expires_at')
    .eq('token_hash', hash)
    .single()

  if (!data || (data.expires_at && new Date(data.expires_at) < new Date())) return null
  return data.user_id
}

- Server Action: Next.js가 자동으로 CSRF 토큰 검증
- Route Handler: SameSite=lax 쿠키 + Origin 헤더 체크
- API Token: Bearer 헤더 (CSRF 무관)