package main

import (
	"flag"
	"log"
	"strings"

	kcp "github.com/xtaci/kcp-go/v5"

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

func main() {
	listenAddr := flag.String("listen", ":9002", "KCP server listen address")
	bindDevice := flag.String("bind-device", "", "optional Linux network device used when listening")
	logPath := flag.String("latency-log", "", "optional JSONL file path for latency timestamp logs")
	kcpTimestampDebugLogPath := flag.String("kcp-ts-debug-log", "", "optional JSONL file path for KCP packet kernel timestamp debug records")
	flag.Parse()

	hubOptions := make([]server.KCPOption, 0, 1)
	if *logPath != "" {
		logger, err := latencylog.NewJSONLLogger(*logPath)
		if err != nil {
			log.Fatalf("create latency logger %s: %v", *logPath, err)
		}
		defer logger.Close()
		hubOptions = append(hubOptions, server.WithKCPLogger(logger))
	}

	var packetLogger transport.KCPPacketDebugLogger
	if *kcpTimestampDebugLogPath != "" {
		logger, err := transport.NewJSONLKCPPacketDebugLogger(*kcpTimestampDebugLogPath)
		if err != nil {
			log.Fatalf("create kcp packet debug logger %s: %v", *kcpTimestampDebugLogPath, err)
		}
		defer logger.Close()
		packetLogger = logger
	}

	listener, packetConn, err := transport.ListenKCPSessions(*listenAddr, *bindDevice, packetLogger, latencylog.NodeRoleServer, "hub")
	if err != nil {
		log.Fatalf("listen kcp on %s: %v", *listenAddr, err)
	}
	defer packetConn.Close()
	defer listener.Close()

	hub := server.NewKCPHub(hubOptions...)
	log.Printf("kcp server listening on %s", listener.Addr())

	for {
		session, err := listener.AcceptKCP()
		if err != nil {
			if strings.Contains(err.Error(), "closed") {
				return
			}
			log.Printf("accept kcp session: %v", err)
			continue
		}

		go func(sess *kcp.UDPSession) {
			if serveErr := hub.ServeSession(sess); serveErr != nil {
				log.Printf("kcp session closed: %v", serveErr)
			}
		}(session)
	}
}