server {
    listen 80;
    root /usr/share/nginx/html;
    index index.html;

    # SPA fallback
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Proxy API requests to backend (including WebSocket for chat)
    location /api/ {
        proxy_pass http://backend:3100;
        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
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_read_timeout 86400;
    }

    location /health {
        proxy_pass http://backend:3100;
    }
}