map $http_x_forwarded_proto $real_scheme {
    default $scheme;
    https https;
}

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

    # Security headers
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    add_header X-XSS-Protection "1; mode=block" always;

    # Gzip
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml text/javascript image/svg+xml;
    gzip_min_length 256;

    # Cache static assets
    location ~* \.(css|js|png|jpg|jpeg|gif|ico|svg|woff|woff2)$ {
        expires 30d;
        add_header Cache-Control "public, immutable";
    }

    # Cache HTML with short TTL for freshness
    location ~* \.html$ {
        expires 1h;
        add_header Cache-Control "public, must-revalidate";
    }

    # Health check endpoint
    location /health {
        access_log off;
        return 200 "ok";
        add_header Content-Type text/plain;
    }

    # Redirect unprefixed paths to /en/
    location ~ "^/(?!en/|de/|fr/|css/|js/|data/|fonts/|img/|favicon|android|apple|site|llms|health|robots|index\.xml|BingSiteAuth|[0-9a-f]{32}\.txt)" {
        return 302 $real_scheme://$host/en$request_uri;
    }

    # Clean URLs
    location / {
        try_files $uri $uri/ $uri.html =404;
    }

    # Custom 404
    error_page 404 /404.html;
}
