package main

import "io"
import "os"
import "fmt"
import "log"
import "errors"
import "git.tebibyte.media/sashakoshka/hopp"
// import "git.tebibyte.media/sashakoshka/hopp/examples/ping"

var network = "tcp"
var addr    = "localhost:7959"

func main() {
	name := os.Args[0]
	if len(os.Args) != 2 {
		fmt.Fprintf(os.Stderr, "Usage: %s HOST:PORT\n", name)
		os.Exit(2)
	}
	address  := os.Args[1]
	err := listen(address)
	handleErr(1, err)
}

func listen(addr string) error {
	defer log.Println("(i) closing")
	
	listener, err := hopp.Listen(network, addr, nil)
	if err != nil { return err }
	log.Printf("(i) hosting on %s", addr)
	for {
		conn, err := listener.Accept()
		if err != nil { return err }
		go run(conn)
	}
}

func run(conn hopp.Conn) {
	log.Printf("-=E %v connected", conn.RemoteAddr())
	defer log.Printf("X=- %v disconnected", conn.RemoteAddr())
	defer conn.Close()
	
	for {
		trans, err := conn.AcceptTrans()
		if err != nil {
			if !errors.Is(err, io.EOF) {
				log.Printf("XXX %v failed: %v", conn.RemoteAddr(), err)
			}
			return
		}
		go runTrans(conn, trans)
	}
}

func runTrans(conn hopp.Conn, trans hopp.Trans) {
	defer trans.Close()

	for {
		// message, _, err := ping.Receive(trans)
		// if err != nil {
		// 	if !errors.Is(err, io.EOF) {
		// 		log.Printf("XXX failed to receive message: %v", err)
		// 	}
		// 	return
		// }
		// switch message := message.(type) {
		// case *ping.MessagePing:
		// 	log.Printf("--> ping (%d) from %v", message, conn.RemoteAddr())
		// 	response := ping.MessagePong(*message)
		// 	_, err := ping.Send(trans, &response)
		// 	if err != nil {
		// 		log.Printf("XXX failed to send message: %v", err)
		// 		return
		// 	}
		// }
		method, reader, err := trans.ReceiveReader()
		if err != nil { log.Println("SERVER", err); return }
		data, err := io.ReadAll(reader)
		if err != nil { log.Println("SERVER", err); return }
		log.Println("SERVER got", method, data)
		log.Println("SERVER send", method, data)
		func (){
			writer, err := trans.SendWriter(1)
			if err != nil { log.Println("SERVER", err); return }
			defer writer.Close()
			_, err = writer.Write(data[:])
			if err != nil { log.Println("SERVER", err); return }
		}()
	}
}

func handleErr(code int, err error) {
	if err != nil {
		fmt.Fprintf(os.Stderr, "%s: %v\n", os.Args[0], err)
		os.Exit(code)
	}
}