1 files changed, 214 insertions, 0 deletions
diff --git a/extra/tts.go b/extra/tts.go
new file mode 100644
index 0000000..b8dd0d0
--- /dev/null
+++ b/extra/tts.go
@@ -0,0 +1,214 @@
+package extra
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"gf-lt/config"
+	"gf-lt/models"
+	"io"
+	"log/slog"
+	"net/http"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/gopxl/beep/v2"
+	"github.com/gopxl/beep/v2/mp3"
+	"github.com/gopxl/beep/v2/speaker"
+	"github.com/neurosnap/sentences/english"
+)
+
+var (
+	TTSTextChan         = make(chan string, 10000)
+	TTSFlushChan        = make(chan bool, 1)
+	TTSDoneChan         = make(chan bool, 1)
+	endsWithPunctuation = regexp.MustCompile(`[;.!?]$`)
+)
+
+type Orator interface {
+	Speak(text string) error
+	Stop()
+	// pause and resume?
+	GetLogger() *slog.Logger
+}
+
+// impl https://github.com/remsky/Kokoro-FastAPI
+type KokoroOrator struct {
+	logger        *slog.Logger
+	URL           string
+	Format        models.AudioFormat
+	Stream        bool
+	Speed         float32
+	Language      string
+	Voice         string
+	currentStream *beep.Ctrl // Added for playback control
+	textBuffer    strings.Builder
+	// textBuffer bytes.Buffer
+}
+
+func (o *KokoroOrator) stoproutine() {
+	<-TTSDoneChan
+	o.logger.Info("orator got done signal")
+	o.Stop()
+	// drain the channel
+	for len(TTSTextChan) > 0 {
+		<-TTSTextChan
+	}
+}
+
+func (o *KokoroOrator) readroutine() {
+	tokenizer, _ := english.NewSentenceTokenizer(nil)
+	// var sentenceBuf bytes.Buffer
+	// var remainder strings.Builder
+	for {
+		select {
+		case chunk := <-TTSTextChan:
+			// sentenceBuf.WriteString(chunk)
+			// text := sentenceBuf.String()
+			_, err := o.textBuffer.WriteString(chunk)
+			if err != nil {
+				o.logger.Warn("failed to write to stringbuilder", "error", err)
+				continue
+			}
+			text := o.textBuffer.String()
+			sentences := tokenizer.Tokenize(text)
+			o.logger.Info("adding chunk", "chunk", chunk, "text", text, "sen-len", len(sentences))
+			for i, sentence := range sentences {
+				if i == len(sentences)-1 {
+					o.textBuffer.Reset()
+					_, err := o.textBuffer.WriteString(sentence.Text)
+					if err != nil {
+						o.logger.Warn("failed to write to stringbuilder", "error", err)
+						continue
+					}
+					continue // if only one (often incomplete) sentence; wait for next chunk
+				}
+				o.logger.Info("calling Speak with sentence", "sent", sentence.Text)
+				if err := o.Speak(sentence.Text); err != nil {
+					o.logger.Error("tts failed", "sentence", sentence.Text, "error", err)
+				}
+			}
+		case <-TTSFlushChan:
+			o.logger.Info("got flushchan signal start")
+			// lln is done get the whole message out
+			if len(TTSTextChan) > 0 { // otherwise might get stuck
+				for chunk := range TTSTextChan {
+					_, err := o.textBuffer.WriteString(chunk)
+					if err != nil {
+						o.logger.Warn("failed to write to stringbuilder", "error", err)
+						continue
+					}
+					if len(TTSTextChan) == 0 {
+						break
+					}
+				}
+			}
+			// INFO: if there is a lot of text it will take some time to make with tts at once
+			// to avoid this pause, it might be better to keep splitting on sentences
+			// but keepinig in mind that remainder could be ommited by tokenizer
+			// Flush remaining text
+			remaining := o.textBuffer.String()
+			o.logger.Info("got flushchan signal", "rem", remaining)
+			defer o.textBuffer.Reset()
+			if remaining != "" {
+				o.logger.Info("calling Speak with remainder", "rem", remaining)
+				if err := o.Speak(remaining); err != nil {
+					o.logger.Error("tts failed", "sentence", remaining, "error", err)
+				}
+			}
+		}
+	}
+}
+
+func NewOrator(log *slog.Logger, cfg *config.Config) Orator {
+	orator := &KokoroOrator{
+		logger:   log,
+		URL:      cfg.TTS_URL,
+		Format:   models.AFMP3,
+		Stream:   false,
+		Speed:    cfg.TTS_SPEED,
+		Language: "a",
+		Voice:    "af_bella(1)+af_sky(1)",
+	}
+	go orator.readroutine()
+	go orator.stoproutine()
+	return orator
+}
+
+func (o *KokoroOrator) GetLogger() *slog.Logger {
+	return o.logger
+}
+
+func (o *KokoroOrator) requestSound(text string) (io.ReadCloser, error) {
+	payload := map[string]interface{}{
+		"input":           text,
+		"voice":           o.Voice,
+		"response_format": o.Format,
+		"download_format": o.Format,
+		"stream":          o.Stream,
+		"speed":           o.Speed,
+		// "return_download_link": true,
+		"lang_code": o.Language,
+	}
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return nil, fmt.Errorf("failed to marshal payload: %w", err)
+	}
+	req, err := http.NewRequest("POST", o.URL, bytes.NewBuffer(payloadBytes)) //nolint:noctx
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("accept", "application/json")
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("request failed: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		defer resp.Body.Close()
+		return nil, fmt.Errorf("unexpected status code: %d", resp.StatusCode)
+	}
+	return resp.Body, nil
+}
+
+func (o *KokoroOrator) Speak(text string) error {
+	o.logger.Info("fn: Speak is called", "text-len", len(text))
+	body, err := o.requestSound(text)
+	if err != nil {
+		o.logger.Error("request failed", "error", err)
+		return fmt.Errorf("request failed: %w", err)
+	}
+	defer body.Close()
+	// Decode the mp3 audio from response body
+	streamer, format, err := mp3.Decode(body)
+	if err != nil {
+		o.logger.Error("mp3 decode failed", "error", err)
+		return fmt.Errorf("mp3 decode failed: %w", err)
+	}
+	defer streamer.Close()
+	// here it spams with errors that speaker cannot be initialized more than once, but how would we deal with many audio records then?
+	if err := speaker.Init(format.SampleRate, format.SampleRate.N(time.Second/10)); err != nil {
+		o.logger.Debug("failed to init speaker", "error", err)
+	}
+	done := make(chan bool)
+	// Create controllable stream and store reference
+	o.currentStream = &beep.Ctrl{Streamer: beep.Seq(streamer, beep.Callback(func() {
+		close(done)
+		o.currentStream = nil
+	})), Paused: false}
+	speaker.Play(o.currentStream)
+	<-done // we hang in this routine;
+	return nil
+}
+
+func (o *KokoroOrator) Stop() {
+	// speaker.Clear()
+	o.logger.Info("attempted to stop orator", "orator", o)
+	speaker.Lock()
+	defer speaker.Unlock()
+	if o.currentStream != nil {
+		// o.currentStream.Paused = true
+		o.currentStream.Streamer = nil
+	}
+}