feat: add Eleven Labs Scribe adapter

internal/transcriber/adapter_elevenlabs.go

@@ -0,0 +1,108 @@
+package transcriber
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"mime/multipart"
+	"net/http"
+	"time"
+)
+
+// ElevenLabsAdapter implements TranscriptionAdapter for ElevenLabs Scribe API
+type ElevenLabsAdapter struct {
+	client *http.Client
+	config Config
+}
+
+// ElevenLabsResponse represents the API response
+type ElevenLabsResponse struct {
+	Text string `json:"text"`
+}
+
+// NewElevenLabsAdapter creates a new ElevenLabs adapter
+func NewElevenLabsAdapter(config Config) *ElevenLabsAdapter {
+	return &ElevenLabsAdapter{
+		client: &http.Client{Timeout: 30 * time.Second},
+		config: config,
+	}
+}
+
+// Transcribe sends audio to ElevenLabs API for transcription
+func (a *ElevenLabsAdapter) Transcribe(ctx context.Context, audioData []byte) (string, error) {
+	if len(audioData) == 0 {
+		return "", nil
+	}
+
+	// Convert raw PCM to WAV format
+	wavData, err := convertToWAV(audioData)
+	if err != nil {
+		return "", fmt.Errorf("convert to WAV: %w", err)
+	}
+
+	// Create multipart form body
+	var body bytes.Buffer
+	writer := multipart.NewWriter(&body)
+
+	// Add audio file
+	part, err := writer.CreateFormFile("file", "audio.wav")
+	if err != nil {
+		return "", fmt.Errorf("create form file: %w", err)
+	}
+	if _, err := io.Copy(part, bytes.NewReader(wavData)); err != nil {
+		return "", fmt.Errorf("copy audio data: %w", err)
+	}
+
+	// Add model_id
+	if err := writer.WriteField("model_id", a.config.Model); err != nil {
+		return "", fmt.Errorf("write model_id: %w", err)
+	}
+
+	// Add language_code if specified
+	if a.config.Language != "" {
+		if err := writer.WriteField("language_code", a.config.Language); err != nil {
+			return "", fmt.Errorf("write language_code: %w", err)
+		}
+	}
+
+	if err := writer.Close(); err != nil {
+		return "", fmt.Errorf("close writer: %w", err)
+	}
+
+	// Create HTTP request
+	url := "https://api.elevenlabs.io/v1/speech-to-text"
+	req, err := http.NewRequestWithContext(ctx, "POST", url, &body)
+	if err != nil {
+		return "", fmt.Errorf("create request: %w", err)
+	}
+
+	req.Header.Set("Content-Type", writer.FormDataContentType())
+	req.Header.Set("xi-api-key", a.config.APIKey)
+
+	start := time.Now()
+	resp, err := a.client.Do(req)
+	duration := time.Since(start)
+
+	if err != nil {
+		log.Printf("elevenlabs-adapter: API call failed after %v: %v", duration, err)
+		return "", fmt.Errorf("elevenlabs request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		bodyBytes, _ := io.ReadAll(resp.Body)
+		log.Printf("elevenlabs-adapter: API returned status %d: %s", resp.StatusCode, string(bodyBytes))
+		return "", fmt.Errorf("elevenlabs API status %d: %s", resp.StatusCode, string(bodyBytes))
+	}
+
+	var result ElevenLabsResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return "", fmt.Errorf("decode response: %w", err)
+	}
+
+	log.Printf("elevenlabs-adapter: transcribed %d bytes in %v: %q", len(audioData), duration, result.Text)
+	return result.Text, nil
+}