server {
    listen 8080;
    server_name localhost;

    # Set maximum upload size
    client_max_body_size 300M;

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

    # Main location for Grist
    location / {
        proxy_pass http://127.0.0.1:8484;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_read_timeout 90;
        proxy_buffering off;
    }

    # Health check endpoint
    location = /healthz {
        access_log off;
        add_header Content-Type text/plain;
        return 200 'OK';
    }

    # Static file caching
    location ~* \.(jpg|jpeg|png|gif|ico|css|js)$ {
        proxy_pass http://127.0.0.1:8484;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        expires 30d;
        add_header Cache-Control "public, no-transform";
    }

    # Error pages
    error_page 500 502 503 504 /50x.html;
    location = /50x.html {
        root /usr/share/nginx/html;
    }
}