events {
    worker_connections 1024;
}

http {
    upstream k8s_lb {
        # Alaska deliveries LoadBalancer NodePort (8201 service -> 30662 node port)
        server host.docker.internal:30662;
        server 66.116.226.234:30662 backup;
    }

    server {
        listen 8201;
        server_name _;

        location / {
            # Handle OPTIONS preflight requests BEFORE proxying
            if ($request_method = 'OPTIONS') {
                add_header 'Access-Control-Allow-Origin' '*' always;
                add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS' always;
                add_header 'Access-Control-Allow-Headers' 'DNT,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization' always;
                add_header 'Access-Control-Max-Age' 1728000 always;
                add_header 'Content-Type' 'text/plain; charset=utf-8' always;
                add_header 'Content-Length' 0 always;
                return 204;
            }

            # Add CORS headers to all responses
            add_header 'Access-Control-Allow-Origin' '*' always;
            add_header 'Access-Control-Allow-Methods' 'GET, POST, PUT, PATCH, DELETE, OPTIONS' always;
            add_header 'Access-Control-Allow-Headers' '*' always;
            add_header 'Access-Control-Max-Age' '600' always;
            add_header 'Vary' 'Origin' always;

            # Proxy to Kubernetes LoadBalancer
            proxy_pass http://k8s_lb;
            
            # Hide upstream CORS headers to avoid duplicates with Nginx headers
            proxy_hide_header 'Access-Control-Allow-Origin';
            proxy_hide_header 'Access-Control-Allow-Methods';
            proxy_hide_header 'Access-Control-Allow-Headers';
            proxy_hide_header 'Access-Control-Max-Age';

            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;
        }
    }
}