events {
    worker_connections 1024;
}

http {
    upstream markdown-editor {
        server markdown-editor:3000;
    }

    # Rate limiting
    limit_req_zone $binary_remote_addr zone=api:10m rate=10r/s;

    server {
        listen 80;
        server_name localhost;

        # Security headers
        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;

        # Gzip compression
        gzip on;
        gzip_vary on;
        gzip_min_length 1024;
        gzip_proxied any;
        gzip_comp_level 6;
        gzip_types
            text/plain
            text/css
            text/xml
            text/javascript
            application/json
            application/javascript
            application/xml+rss
            application/atom+xml
            image/svg+xml;

        # Static files caching
        location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
            expires 1y;
            add_header Cache-Control "public, immutable";
            proxy_pass http://markdown-editor;
            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;
        }

        # API routes with rate limiting
        location /api/ {
            limit_req zone=api burst=20 nodelay;
            proxy_pass http://markdown-editor;
            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;
        }

        # Main application
        location / {
            proxy_pass http://markdown-editor;
            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;
            
            # WebSocket support (if needed)
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

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

    # HTTPS configuration (uncomment and configure for production)
    # server {
    #     listen 443 ssl http2;
    #     server_name your-domain.com;
    #     
    #     ssl_certificate /etc/nginx/ssl/cert.pem;
    #     ssl_certificate_key /etc/nginx/ssl/key.pem;
    #     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
    # }
}