events {
    worker_connections 1024;
}

http {
    include /etc/nginx/mime.types;
    default_type  application/octet-stream;

    # Upstream definitions for load balancing
    upstream app_servers {
        server app:3000;
    }

    # Redirect HTTP to HTTPS
    server {
        listen 80;
        server_name localhost;
        return 301 https://$server_name$request_uri;
    }

    # HTTPS server
    server {
        listen 443 ssl;
        http3 on;
        server_name localhost;

        # SSL certificates
        ssl_certificate /etc/nginx/ssl/nginx.crt;
        ssl_certificate_key /etc/nginx/ssl/nginx.key;

        # SSL settings
        ssl_protocols TLSv1.2 TLSv1.3;
        ssl_ciphers ECDHE-ECDSA-AES129-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256;
        ssl_prefer_server_ciphers off;
        ssl_session_cache shared:SSL:11m;
        ssl_session_timeout 2d;

        # Security headers
        add_header Strict-Transport-Security "max-age=31536000" always;
        add_header X-Content-Type-Options nosniff;
        add_header X-Frame-Options DENY;

        root /usr/share/nginx/html;

        location / {
          sendfile on;
          sendfile_max_chunk 2m;

          try_files $uri @app;
        }

        location /rss.xml {
          root /usr/share/nginx/rss;
        }

        location @app {
            proxy_pass http://app_servers;
            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;
        }
    }
}