package main

import (
	"flag"
	"log"
	"net"

	"omnisocketgo/cmd/internal/server"
	"omnisocketgo/cmd/internal/transport"
)

func main() {
	listenAddr := flag.String("listen", ":9003", "UDP relay listen address (downstream, for KCP peer to connect)")
	upstreamAddr := flag.String("upstream", "127.0.0.1:9002", "upstream KCP server address (server D)")
	flag.Parse()

	upstreamUDPAddr, err := net.ResolveUDPAddr("udp", *upstreamAddr)
	if err != nil {
		log.Fatalf("resolve upstream address %s: %v", *upstreamAddr, err)
	}

	listenNetwork, udpListenAddr, err := transport.ResolveUDPListenConfig(*listenAddr)
	if err != nil {
		log.Fatalf("resolve udp relay listen address %s: %v", *listenAddr, err)
	}

	conn, err := net.ListenPacket(listenNetwork, udpListenAddr.String())
	if err != nil {
		log.Fatalf("listen %s on %s: %v", listenNetwork, udpListenAddr, err)
	}

	relay, err := server.NewUDPRelay(conn, upstreamUDPAddr)
	if err != nil {
		_ = conn.Close()
		log.Fatalf("create udp relay: %v", err)
	}

	log.Printf("udp relay listening on %s %s, upstream %s", listenNetwork, conn.LocalAddr(), *upstreamAddr)

	if err := relay.Serve(); err != nil {
		log.Fatalf("udp relay serve: %v", err)
	}
}