server {
    listen 7860;
    server_name _;

    root /app/frontend/build;
    index index.html;

    # Allow HuggingFace to embed this app in an iframe
    add_header X-Frame-Options "" always;
    add_header Content-Security-Policy "frame-ancestors 'self' https://huggingface.co https://*.hf.space;" always;
    add_header Cross-Origin-Opener-Policy "unsafe-none" always;
    add_header Cross-Origin-Embedder-Policy "unsafe-none" always;

    # Gzip
    gzip on;
    gzip_types text/plain text/css application/json application/javascript text/javascript;

    # Proxy all /api/* requests to the Node.js backend
    location /api/ {
        proxy_pass http://127.0.0.1:5000;
        proxy_http_version 1.1;
        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_read_timeout 60s;
    }

    # Health check pass-through
    location /health {
        proxy_pass http://127.0.0.1:5000/health;
    }

    # React SPA — every unknown route serves index.html
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Cache static assets aggressively
    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
        try_files $uri =404;
    }
}