Method start

tui/run.go:186–239

start spawns `snix start -c CONFIG` and returns a tea.Cmd that pumps the subprocess's output into the model's log viewport.

()

// start spawns `snix start -c CONFIG` and returns a tea.Cmd that pumps the
// subprocess's output into the model's log viewport.
func (m runModel) start() tea.Cmd {
	m.st.mu.Lock()
	if m.st.running {
		m.st.mu.Unlock()
		return setStatus("engine already running")
	}
	ctx, cancel := context.WithCancel(context.Background())
	cmd := exec.CommandContext(ctx, m.app.opts.ExePath, "start", "-c", m.app.opts.ConfigPath)
	stdout, _ := cmd.StdoutPipe()
	stderr, _ := cmd.StderrPipe()

	if err := cmd.Start(); err != nil {
		cancel()
		m.st.mu.Unlock()
		return setStatus("failed to start engine: %v", err)
	}
	m.st.cmd = cmd
	m.st.cancel = cancel
	m.st.running = true
	m.st.started = time.Now()
	ch := make(chan tea.Msg, 64)
	m.st.msgCh = ch
	m.st.mu.Unlock()

	// Owner goroutine: scans stdout+stderr into ch, waits for exit, emits
	// runExitMsg, closes ch. Calling cmd.Wait() exactly once.
	go func() {
		var wg sync.WaitGroup
		feed := func(r io.ReadCloser) {
			defer wg.Done()
			sc := bufio.NewScanner(r)
			sc.Buffer(make([]byte, 64*1024), 1024*1024)
			for sc.Scan() {
				select {
				case ch <- runLogMsg(sc.Text()):
				case <-ctx.Done():
					return
				}
			}
		}
		wg.Add(2)
		go feed(stdout)
		go feed(stderr)
		err := cmd.Wait()
		wg.Wait()
		select {
		case ch <- runExitMsg{err: err}:
		default:
		}
		close(ch)
	}()

	return pumpCmd(ch)
}

// pumpCmd blocks on ch and returns each message. When ch closes, emits a
// sentinel runExitMsg with a nil err so the model clears its state.