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

    # allow large asset uploads (wordcloud SVG/PNG can be several MB)
    client_max_body_size 100M;

    # gzip compression
    gzip on;
    gzip_vary on;
    gzip_min_length 1024;
    gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript image/svg+xml;

    # Proxy all /api requests to the backend service
    location /api/ {
        proxy_pass http://backend:8000/api/;
        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;

        # SSE / long-running endpoints
        proxy_buffering off;
        proxy_cache off;
        proxy_read_timeout 3600s;
        proxy_send_timeout 3600s;
    }

    # Serve static files, fallback to index.html for SPA routes
    location / {
        try_files $uri $uri/ /index.html;
    }
}