add mistra voxtral

internal/transcriber/adapter_mistral.go

@@ -0,0 +1,60 @@
+package transcriber
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/sashabaranov/go-openai"
+)
+
+// MistralAdapter implements TranscriptionAdapter for Mistral Voxtral API
+type MistralAdapter struct {
+	client *openai.Client
+	config Config
+}
+
+func NewMistralAdapter(config Config) *MistralAdapter {
+	clientConfig := openai.DefaultConfig(config.APIKey)
+	clientConfig.BaseURL = "https://api.mistral.ai/v1"
+	client := openai.NewClientWithConfig(clientConfig)
+
+	return &MistralAdapter{
+		client: client,
+		config: config,
+	}
+}
+
+func (a *MistralAdapter) 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 transcription request
+	req := openai.AudioRequest{
+		Model:    a.config.Model,
+		Reader:   bytes.NewReader(wavData),
+		FilePath: "audio.wav",
+		Language: a.config.Language,
+	}
+
+	start := time.Now()
+	resp, err := a.client.CreateTranscription(ctx, req)
+	duration := time.Since(start)
+
+	if err != nil {
+		log.Printf("mistral-adapter: API call failed after %v: %v", duration, err)
+		return "", fmt.Errorf("mistral transcription: %w", err)
+	}
+
+	log.Printf("mistral-adapter: transcribed %d bytes in %v: %q", len(audioData), duration, resp.Text)
+	return resp.Text, nil
+}