// proxyWriter is used to track final status and size of the
// response sent to the client
type proxyWriter struct {
	http.ResponseWriter
	status int
	size   int
}

func (r *proxyWriter) Header() http.Header {
	return r.ResponseWriter.Header()
}

func (r *proxyWriter) Write(b []byte) (int, error) {
	if r.status == 0 {
		// default if WriteHeader has not been called yet
		r.status = http.StatusOK
	}
	size, err := r.ResponseWriter.Write(b)
	r.size += size
	return size, err
}

func (r *proxyWriter) WriteHeader(status int) {
	r.status = status
	r.ResponseWriter.WriteHeader(status)
}

func (r *proxyWriter) Status() int {
	return r.status
}

func (r *proxyWriter) Size() int {
	return r.size
}