package xmpp

import (
	"encoding/xml"
	"errors"
	"io"
	"log"
)

type encoderDecoder struct {
	session    *session
	tx         *xml.Encoder
	rx         *xml.Decoder
	terminator chan bool
}

func newEncoderDecoder(s *session) encoderDecoder {
	ed := encoderDecoder{}

	ed.session = s

	lw := logger{"TX: "}
	w := io.MultiWriter(s.transport, lw)
	ed.tx = xml.NewEncoder(w)
	ed.tx.Indent("", "    ")

	lr := logger{"RX: "}
	r := io.TeeReader(s.transport, lr)
	ed.rx = xml.NewDecoder(r)

	return ed
}

func (ed *encoderDecoder) encodeToken(t xml.Token) error {
	var err error
	defer func() {
		if err != nil {
			log.Println(err)
		}
	}()

	err = ed.tx.EncodeToken(t)
	if err != nil {
		return err
	}
	err = ed.tx.Flush()
	if err != nil {
		return err
	}

	return nil
}

func (ed *encoderDecoder) run() {
	for {
		select {
		case <-ed.terminator:
			return
		default:
			t, err := ed.rx.Token()
			if t != nil && err == nil {
				c := xml.CopyToken(t)
				ed.session.rx <- c
			}
			if err != nil {
				if errors.Is(err, io.EOF) {
					return
				}
				log.Println(err) // FIXME terminate session on error
				return
			}
		}
	}
}