Design

elevenlabs.go

@@ -0,0 +1,115 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+
+	tgbot "github.com/go-telegram/bot"
+)
+
+const (
+	elevenLabsTTSURL = "https://api.elevenlabs.io/v1/text-to-speech/"
+	elevenLabsSTTURL = "https://api.elevenlabs.io/v1/speech-to-text"
+	elevenLabsDefaultModel = "eleven_multilingual_v2"
+)
+
+// generateSpeech converts text to an mp3 audio stream via ElevenLabs TTS.
+func (b *Bot) generateSpeech(ctx context.Context, text string) (io.Reader, error) {
+	model := b.config.ElevenLabsModel
+	if model == "" {
+		model = elevenLabsDefaultModel
+	}
+	body, err := json.Marshal(map[string]string{
+		"text":     text,
+		"model_id": model,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("elevenlabs TTS marshal error: %w", err)
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		elevenLabsTTSURL+b.config.ElevenLabsVoiceID, bytes.NewReader(body))
+	if err != nil {
+		return nil, fmt.Errorf("elevenlabs TTS request error: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("xi-api-key", b.config.ElevenLabsAPIKey)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("elevenlabs TTS error: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		defer resp.Body.Close()
+		errBody, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("elevenlabs TTS error: status %d: %s", resp.StatusCode, errBody)
+	}
+	return resp.Body, nil
+}
+
+// transcribeVoice downloads a Telegram voice file and transcribes it via ElevenLabs STT.
+// Uses a direct multipart HTTP call instead of the SDK wrapper to avoid a bug in the
+// ogen-generated encoder: AdditionalFormats (nil slice) is always written as an empty
+// string with Content-Type: application/json, which ElevenLabs rejects with 400.
+func (b *Bot) transcribeVoice(ctx context.Context, fileID string) (string, error) {
+	// 1. Resolve and download the voice file from Telegram.
+	fileInfo, err := b.tgBot.GetFile(ctx, &tgbot.GetFileParams{FileID: fileID})
+	if err != nil {
+		return "", fmt.Errorf("telegram GetFile error: %w", err)
+	}
+	downloadURL := b.tgBot.FileDownloadLink(fileInfo)
+	audioResp, err := http.Get(downloadURL) //nolint:noctx
+	if err != nil {
+		return "", fmt.Errorf("voice download error: %w", err)
+	}
+	defer audioResp.Body.Close()
+
+	// 2. Build multipart body with binary audio — bypasses SDK encoding issues.
+	var buf bytes.Buffer
+	mw := multipart.NewWriter(&buf)
+	if err := mw.WriteField("model_id", "scribe_v1"); err != nil {
+		return "", fmt.Errorf("multipart write error: %w", err)
+	}
+	part, err := mw.CreateFormFile("file", "audio.ogg")
+	if err != nil {
+		return "", fmt.Errorf("multipart create file error: %w", err)
+	}
+	if _, err := io.Copy(part, audioResp.Body); err != nil {
+		return "", fmt.Errorf("multipart copy error: %w", err)
+	}
+	if err := mw.Close(); err != nil {
+		return "", fmt.Errorf("multipart close error: %w", err)
+	}
+
+	// 3. POST to ElevenLabs STT.
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost,
+		elevenLabsSTTURL, &buf)
+	if err != nil {
+		return "", fmt.Errorf("create STT request error: %w", err)
+	}
+	req.Header.Set("Content-Type", mw.FormDataContentType())
+	req.Header.Set("xi-api-key", b.config.ElevenLabsAPIKey)
+
+	sttResp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("elevenlabs STT request error: %w", err)
+	}
+	defer sttResp.Body.Close()
+
+	if sttResp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(sttResp.Body)
+		return "", fmt.Errorf("elevenlabs STT error: status %d: %s", sttResp.StatusCode, body)
+	}
+
+	var result struct {
+		Text string `json:"text"`
+	}
+	if err := json.NewDecoder(sttResp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("elevenlabs STT decode error: %w", err)
+	}
+	return result.Text, nil
+}