events {
    worker_connections 1024;
}

http {
    upstream portfolio_backend {
        # Health check enabled upstream
        server portfolio-app-1:3000 max_fails=3 fail_timeout=30s;
        server portfolio-app-2:3000 max_fails=3 fail_timeout=30s;
    }
    
    # Resolver for dynamic upstream resolution
    resolver 127.0.0.11 valid=10s;

    # Main server
    server {
        listen 80;
        server_name _;

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

        # Main location
        location / {
            proxy_pass http://portfolio_backend;
            
            # Proxy settings
            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;

            # Timeout settings
            proxy_connect_timeout 5s;
            proxy_send_timeout 60s;
            proxy_read_timeout 60s;

            # Buffer settings
            proxy_buffering on;
            proxy_buffer_size 4k;
            proxy_buffers 8 4k;
            
            # Health check for upstream
            proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
            proxy_next_upstream_tries 2;
            proxy_next_upstream_timeout 10s;
        }

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