package main

import (
	"fmt"

	"hamlog/internal/applog"
	"hamlog/internal/audio"
	"hamlog/internal/cwdecode"

	wruntime "github.com/wailsapp/wails/v2/pkg/runtime"
)

// CW decoder: taps the RX audio device (the same "From radio" capture the DVK
// and QSO recorder use) and streams decoded Morse text to the UI. It is started
// only by the frontend, and only while the entry mode is CW.

// StartCWDecoder begins decoding CW from the configured RX audio device. The
// frontend calls this when the decoder toggle is on AND the mode is CW. Safe to
// call repeatedly; a second call is a no-op while already running.
func (a *App) StartCWDecoder() error {
	a.cwMu.Lock()
	defer a.cwMu.Unlock()
	if a.cwStop != nil {
		return nil // already running
	}
	dev := ""
	if a.settings != nil {
		dev, _ = a.settings.Get(a.ctx, keyAudioFromRadio)
	}
	if dev == "" {
		return fmt.Errorf("no RX audio device configured (set \"From radio\" in Audio settings)")
	}

	dec := cwdecode.New(audio.SampleRate,
		func(text string) {
			if a.ctx != nil {
				wruntime.EventsEmit(a.ctx, "cw:text", text)
			}
		},
		func(st cwdecode.Status) {
			if a.ctx != nil {
				wruntime.EventsEmit(a.ctx, "cw:status", st)
			}
		},
	)

	stop := make(chan struct{})
	a.cwStop = stop
	go func() {
		if err := audio.StreamCapture(dev, stop, dec.Process); err != nil {
			applog.Printf("cw: capture failed: %v", err)
			if a.ctx != nil {
				wruntime.EventsEmit(a.ctx, "cw:error", err.Error())
			}
		}
		// Capture ended (stopped or errored) — clear state so a restart works.
		a.cwMu.Lock()
		if a.cwStop == stop {
			a.cwStop = nil
		}
		a.cwMu.Unlock()
	}()
	return nil
}

// StopCWDecoder halts the CW decoder if running.
func (a *App) StopCWDecoder() {
	a.cwMu.Lock()
	stop := a.cwStop
	a.cwStop = nil
	a.cwMu.Unlock()
	if stop != nil {
		close(stop)
	}
}

// CWDecoderRunning reports whether the decoder is currently capturing.
func (a *App) CWDecoderRunning() bool {
	a.cwMu.Lock()
	defer a.cwMu.Unlock()
	return a.cwStop != nil
}