package middleware

import (
	"net/http"

	"github.com/klauspost/compress/gzhttp"
)

// Compress returns gzip/zstd response compression using klauspost/compress,
// which is considerably faster than compress/gzip. Responses that already
// carry a Content-Encoding (e.g. precompressed frontend assets) are passed
// through untouched.
//
// Request-body decompression is left disabled on purpose (decompression bombs).
//
// Do not apply this to the WebSocket route.
func Compress() (func(http.Handler) http.Handler, error) {
	wrap, err := gzhttp.NewWrapper(
		gzhttp.MinSize(1000),
		gzhttp.CompressionLevel(5),
		gzhttp.EnableZstd(true),
	)
	if err != nil {
		return nil, err
	}
	return func(next http.Handler) http.Handler {
		return wrap(next)
	}, nil
}