package main

import "os"
import "fmt"
import "time"
import "bufio"
import "context"
import "crypto/tls"
import "git.tebibyte.media/sashakoshka/hopp"
import "git.tebibyte.media/sashakoshka/hopp/examples/chat"

func main() {
	name := os.Args[0]
	if len(os.Args) != 3 && len(os.Args) != 4 {
		fmt.Fprintf(os.Stderr, "Usage: %s HOST:PORT ROOM [NICKNAME]\n", name)
		os.Exit(2)
	}
	address := os.Args[1]
	room    := os.Args[2]
	var nickname hopp.Option[string]; if len(os.Args) >= 4 {
		nickname = hopp.O(os.Args[3])
	}
	trans, err := join(address, room, nickname)
	handleErr(1, err)
	go func() {
		reader := bufio.NewReader(os.Stdin)
		for {
			line, err := reader.ReadString('\n')
			if err != nil { break }
			send(trans, line)
		}
	}()
	for {
		message, err := chat.Receive(trans)
		handleErr(1, err)
		switch message := message.(type) {
		case *chat.MessageChat:
			nickname := "Anonymous"
			if value, ok := message.Nickname.Get(); ok {
				nickname = value
			}
			fmt.Fprintf(os.Stdout, "%s: %s\n", nickname, message.Content)
		case *chat.MessageJoinNotify:
			fmt.Fprintf(os.Stdout, "(i) %s joined the room\n", message.Nickname)
		case *chat.MessageLeaveNotify:
			fmt.Fprintf(os.Stdout, "(i) %s left the room\n", message.Nickname)
		}
	}
}

func join(address string, room string, nickname hopp.Option[string]) (hopp.Trans, error) {
	ctx, done := context.WithTimeout(context.Background(), 16 * time.Second)
	defer done()
	dialer := hopp.Dialer {
		TLSConfig: &tls.Config {
			// don't actually do this in real life
			InsecureSkipVerify: true,
		},
	}
	conn, err := dialer.Dial(ctx, "quic", address)
	if err != nil { return nil, err }

	err = updateProfile(conn, nickname)
	if err != nil { return nil, err }
	
	transRoom, err := conn.OpenTrans()
	if err != nil { return nil, err }
	err = chat.Send(transRoom, &chat.MessageJoin {
		Room: room,
	})
	if err != nil { return nil, err }
	return transRoom, nil
}

func send(trans hopp.Trans, content string) error {
	return chat.Send(trans, &chat.MessageChat {
		Content: content,
	})
}

func updateProfile(conn hopp.Conn, nickname hopp.Option[string]) error {
	trans, err := conn.OpenTrans()
	if err != nil { return err }
	defer trans.Close()
	err = chat.Send(trans, &chat.MessageUpdateProfile {
		Nickname: nickname,
	})
	if err != nil { return err }
	message, err := chat.Receive(trans)
	if err != nil { return err }
	switch message := message.(type) {
	case *chat.MessageError: return message
	default:                 return nil
	}
}

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