func handleWinEvents(win *acme.Win) {
	for ev := range win.EventChan() {
		if ev.C2 == 'x' || ev.C2 == 'X' {
			if ev.Flag&2 != 0 {
				ev.Q0 = ev.OrigQ0
				ev.Q1 = ev.OrigQ1
			}
			win.WriteEvent(ev)
			if fs := strings.Fields(string(ev.Text)); len(fs) > 0 && fs[0] == "Del" {
				os.Exit(0)
			}
		}
	}
}

// We would use win.ReadAll except for a bug in acme
// where it crashes when reading trying to read more
// than the negotiated 9P message size.
func readBody(win *acme.Win) ([]byte, error) {
	var body []byte
	buf := make([]byte, 8000)
	for {
		n, err := win.Read("body", buf)
		if err == io.EOF {
			break
		}
		if err != nil {
			return nil, err
		}
		body = append(body, buf[0:n]...)
	}
	return body, nil
}

func showCal(win *acme.Win) {
	cmd := exec.Command("9", "cal")
	out, err := cmd.StdoutPipe()
	if err != nil {
		panic(err)
	}
	go cmd.Start()
	if _, err := io.Copy(dataWriter{win}, out); err != nil {
		panic(err)
	}
	if err := cmd.Wait(); err != nil {
		panic(err)
	}
	win.Ctl("clean")
}

// We would use io.Copy except for a bug in acme
// where it crashes when reading trying to read more
// than the negotiated 9P message size.
func copyBody(w io.Writer, win *acme.Win) error {
	buf := make([]byte, 8000)
	for {
		n, err := win.Read("body", buf)
		if err == io.EOF {
			break
		}
		if err != nil {
			return err
		}
		if _, err := w.Write(buf[0:n]); err != nil {
			return fmt.Errorf("write error: %v", err)
		}
	}
	return nil
}

func writeData(win *acme.Win, data []byte) error {
	if len(data) == 0 {
		_, err := win.Write("data", nil)
		return err
	}
	for len(data) > 0 {
		d := data
		if len(d) > 8000 {
			d = trimIncompleteRune(d[0:8000])
		}
		n, err := win.Write("data", d)
		if err != nil {
			return err
		}
		data = data[n:]
	}
	return nil
}

func events(w *acme.Win) <-chan string {
	c := make(chan string, 10)
	go func() {
		for e := range w.EventChan() {
			switch e.C2 {
			case 'x', 'X': // execute
				if string(e.Text) == "Del" {
					w.Ctl("delete")
				}
				w.WriteEvent(e)
			case 'l', 'L': // look
				w.Ctl("clean")
				c <- string(e.Text)
			}
		}
		w.CloseFiles()
		close(c)
	}()
	return c
}

func blinker(w *acme.Win) chan bool {
	c := make(chan bool)
	go func() {
		t := time.NewTicker(300 * time.Millisecond)
		defer t.Stop()
		dirty := false
		for {
			select {
			case <-t.C:
				dirty = !dirty
				if dirty {
					w.Ctl("dirty")
				} else {
					w.Ctl("clean")
				}
			case <-c:
				if dirty {
					w.Ctl("clean")
				}
				return
			}
		}
	}()
	return c
}

func main() {
	log.SetFlags(0)
	log.SetPrefix("Run: ")

	file := os.Getenv("samfile")
	if file == "" {
		log.Fatal("not running in acme")
	}
	id, _ := strconv.Atoi(os.Getenv("winid"))
	wfile, err := acme.Open(id, nil)
	if err != nil {
		log.Fatal(err)
	}
	wfile.Ctl("put")
	wfile.CloseFiles()

	wname := "/go/run/" + strings.TrimSuffix(path.Base(file), ".go")
	windows, _ := acme.Windows()
	var w *acme.Win
	for _, info := range windows {
		if info.Name == wname {
			ww, err := acme.Open(info.ID, nil)
			if err != nil {
				log.Fatal(err)
			}
			ww.Addr(",")
			ww.Write("data", nil)
			w = ww
			break
		}
	}
	if w == nil {
		ww, err := acme.New()
		if err != nil {
			log.Fatal(err)
		}
		ww.Name(wname)
		w = ww
	}
	w.Ctl("clean")
	defer w.Ctl("clean")

	cmd := exec.Command("go", append([]string{"run", os.Getenv("samfile")}, os.Args[1:]...)...)
	cmd.Stdout = bodyWriter{w}
	cmd.Stderr = cmd.Stdout
	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
	err = cmd.Start()
	if err != nil {
		w.Fprintf("body", "error starting command: %v\n", err)
		return
	}

	//stop := blinker(w)
	w.Ctl("cleartag")
	w.Fprintf("tag", " Kill Stack")

	done := make(chan bool)
	go func() {
		err := cmd.Wait()
		if err != nil {
			w.Fprintf("body", "\nerror running command: %v\n", err)
		}
		//stop <- true
		done <- true
	}()

	deleted := make(chan bool, 1)
	go func() {
		for e := range w.EventChan() {
			if e.C2 == 'x' || e.C2 == 'X' {
				switch string(e.Text) {
				case "Del":
					select {
					case deleted <- true:
					default:
					}
					syscall.Kill(-cmd.Process.Pid, 2)
					continue
				case "Kill":
					syscall.Kill(-cmd.Process.Pid, 2)
					continue
				case "Stack":
					syscall.Kill(-cmd.Process.Pid, 3)
					continue
				}
				w.WriteEvent(e)
			}
		}
	}()

	<-done
	w.Ctl("cleartag")

	select {
	case <-deleted:
		w.Ctl("delete")
	default:
	}
}

func clear(win *acme.Win) {
	win.Addr("0,$")
	if _, err := win.Write("data", []byte{}); err != nil {
		panic(err)
	}
}