package node

import "net"

type LuxDnsServer struct {
	node     *LuxNode
	stopChan chan bool
}

func NewLuxDnsServer(node *LuxNode) LuxDnsServer {
	return LuxDnsServer{
		node:     node,
		stopChan: make(chan bool),
	}
}

func (sv *LuxDnsServer) HandleRequest(req []byte) []byte {
	return nil
}

func (sv *LuxDnsServer) CreateFrontend(udpListen string) error {
	listenAddr, err := net.ResolveUDPAddr("udp", udpListen)
	if err != nil {
		return err
	}

	conn, err := net.ListenUDP("udp", listenAddr)
	if err != nil {
		return err
	}

	go func(sv *LuxDnsServer) {
		defer conn.Close()

		buf := make([]byte, 512)

		for {
			select {
			case <-sv.stopChan:
				return
			default:
				n, addr, err := conn.ReadFromUDP(buf)
				if err != nil {
					log.Debugf("failed to recv dns udp: %v\n", err)
				}

				res := sv.HandleRequest(buf[:n])
				if len(res) > 0 {
					_, err := conn.WriteToUDP(res, addr)
					if err != nil {
						log.Debugf("failed to send dns reply: %v\n", err)
					}
				}
			}
		}
	}(sv)

	return nil
}

func (sv *LuxDnsServer) Stop() {
	sv.stopChan <- true
}