package vpn

import (
	"github.com/qdm12/gluetun/internal/configuration/settings"
	"github.com/qdm12/gluetun/internal/constants/vpn"
	"github.com/qdm12/gluetun/internal/netlink"
)

func (l *Loop) isIPv6Used(settings settings.VPN) bool {
	if !l.ipv6SupportLevel.IsSupported() {
		return false
	}
	switch settings.Type {
	case vpn.AmneziaWg:
		for _, prefix := range settings.AmneziaWg.Wireguard.Addresses {
			if prefix.Addr().Is6() {
				return true
			}
		}
		return false
	case vpn.OpenVPN:
		link, err := l.netLinker.LinkByName(settings.OpenVPN.Interface)
		if err != nil {
			l.logger.Warnf("assuming IPv6 is not supported, cannot get OpenVPN link by name: %v", err)
			return false
		}
		ipv6Prefixes, err := l.netLinker.AddrList(link.Index, netlink.FamilyV6)
		if err != nil {
			l.logger.Warnf("assuming IPv6 is not supported, cannot list OpenVPN link addresses: %v", err)
			return false
		}
		for _, prefix := range ipv6Prefixes {
			if prefix.Addr().IsGlobalUnicast() && !prefix.Addr().IsPrivate() {
				return true
			}
		}
		return false
	case vpn.Wireguard:
		for _, prefix := range settings.Wireguard.Addresses {
			if prefix.Addr().Is6() {
				return true
			}
		}
		return false
	default:
		panic("vpn type not implemented: " + settings.Type)
	}
}