server {
    listen 80;
    server_name localhost;
    root /usr/share/nginx/html;
    index index.html;

    # ── 보안 헤더 ────────────────────────────────────────────────────────────
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://cdnjs.cloudflare.com; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; connect-src 'self' ws: wss:; font-src 'self';" always;
    add_header Permissions-Policy "camera=(), microphone=(), geolocation=()" always;

    # Gzip 압축 설정
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;

    # index.html — 항상 최신 버전 제공 (Vite 해시 파일은 별도 캐시)
    location = /index.html {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Pragma "no-cache";
    }

    # SPA 라우팅 지원
    location / {
        try_files $uri $uri/ /index.html;
    }

    # API 프록시 (선택사항)
    location /api {
        proxy_pass http://backend:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
    }

    # WebSocket 프록시
    location /ws {
        proxy_pass http://backend:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "Upgrade";
        proxy_set_header Host $host;
        proxy_read_timeout 86400s;   # 24시간 (장중 끊김 방지)
        proxy_send_timeout 86400s;
    }

    # 캐시 설정
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
}