package resolver

import (
	"errors"
	"net"
	"strings"
)

func ClassifyDNSError(err error) string {
	if err == nil {
		return "other"
	}
	var dnsErr *net.DNSError
	if errors.As(err, &dnsErr) {
		if dnsErr.IsNotFound {
			return "nxdomain"
		}
		if dnsErr.IsTimeout {
			return "timeout"
		}
		if dnsErr.IsTemporary {
			return "temporary"
		}
	}
	msg := strings.ToLower(err.Error())
	switch {
	case strings.Contains(msg, "no such host"), strings.Contains(msg, "nxdomain"):
		return "nxdomain"
	case strings.Contains(msg, "i/o timeout"), strings.Contains(msg, "timeout"):
		return "timeout"
	case strings.Contains(msg, "temporary"):
		return "temporary"
	default:
		return "other"
	}
}

func SplitDNS(dns string) (string, string) {
	if strings.Contains(dns, "#") {
		parts := strings.SplitN(dns, "#", 2)
		host := strings.TrimSpace(parts[0])
		port := strings.TrimSpace(parts[1])
		if host == "" {
			host = "127.0.0.1"
		}
		if port == "" {
			port = "53"
		}
		return host, port
	}
	return strings.TrimSpace(dns), ""
}