events {
    worker_connections 1024;
}

http {
    upstream tournament_backend {
        server tournament-app:4000;
    }

    server {
        listen 80;
        server_name localhost;

        # Security headers
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header X-XSS-Protection "1; mode=block" always;
        add_header X-Content-Type-Options "nosniff" always;
        add_header Referrer-Policy "no-referrer-when-downgrade" always;
        add_header Content-Security-Policy "default-src 'self' http: https: data: blob: 'unsafe-inline'" always;

        # API routes
        location /api/ {
            proxy_pass http://tournament_backend;
            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_cache_bypass $http_upgrade;
        }

        # WebSocket support for Socket.IO
        location /socket.io/ {
            proxy_pass http://tournament_backend;
            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;
        }

        # Serve static files (React build)
        location / {
            root /usr/share/nginx/html;
            try_files $uri $uri/ /index.html;
            
            # Cache static assets
            location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg)$ {
                expires 1y;
                add_header Cache-Control "public, immutable";
            }
        }

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

    # HTTPS configuration (uncomment and configure SSL certificates)
    # server {
    #     listen 443 ssl http2;
    #     server_name localhost;
    #
    #     ssl_certificate /etc/nginx/ssl/cert.pem;
    #     ssl_certificate_key /etc/nginx/ssl/key.pem;
    #
    #     # SSL configuration
    #     ssl_protocols TLSv1.2 TLSv1.3;
    #     ssl_ciphers ECDHE-RSA-AES256-GCM-SHA512:DHE-RSA-AES256-GCM-SHA512:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384;
    #     ssl_prefer_server_ciphers off;
    #
    #     # Same location blocks as above
    #     location /api/ {
    #         proxy_pass http://tournament_backend;
    #         # ... same proxy settings
    #     }
    # }
}