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

    gzip on;
    gzip_types text/css application/javascript application/json image/svg+xml;
    gzip_min_length 1024;

    # index.html – never cache so SW updates are picked up immediately
    location = /index.html {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
    }

    # Static assets – long-term cache (cache busted by SW version)
    location ~* \.(css|js)$ {
        add_header Cache-Control "public, max-age=31536000, immutable";
    }

    # Service worker – no cache so browser always gets the latest version
    location = /sw.js {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Service-Worker-Allowed "/";
    }

    # Runtime config – never cache so NAVIDROME_URL changes are picked up
    location = /config.js {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
    }

    # Manifest – short cache so icon/name updates roll out quickly
    location = /manifest.json {
        add_header Cache-Control "no-cache, no-store, must-revalidate";
        add_header Access-Control-Allow-Origin "*";
    }

    # /app/ alias so the reverse proxy prefix resolves static assets correctly
    location /app/ {
        alias /usr/share/nginx/html/;
        try_files $uri /index.html;
    }

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