Cyrene_v2/backend/services/voice/providers.go

package voice

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"
)

// --- Cloud TTS (OpenAI-compatible /audio/speech, e.g. Alibaba Bailian compatible mode) ---

type cloudTTS struct {
	baseURL, apiKey, model, defaultVoice string
	client                               *http.Client
}

func (p *cloudTTS) Name() string { return "cloud" }

func (p *cloudTTS) Synthesize(ctx context.Context, text string, voice string) ([]byte, error) {
	if voice == "" {
		voice = p.defaultVoice
	}
	body, _ := json.Marshal(map[string]any{
		"model": p.model,
		"voice": voice,
		"input": text,
	})
	req, err := http.NewRequestWithContext(ctx, "POST", p.baseURL+"/audio/speech", bytes.NewReader(body))
	if err != nil {
		return nil, err
	}
	req.Header.Set("Authorization", "Bearer "+p.apiKey)
	req.Header.Set("Content-Type", "application/json")

	resp, err := p.client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("cloud tts: %w", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		msg, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
		return nil, fmt.Errorf("cloud tts %d: %s", resp.StatusCode, msg)
	}
	return io.ReadAll(resp.Body)
}

// --- Local TTS (self-hosted HTTP TTS server, e.g. GPT-SoVITS / edge-tts-server / OpenTTS) ---

type localTTS struct {
	url    string // POST endpoint accepting {"text","voice"} and returning audio bytes
	client *http.Client
}

func (p *localTTS) Name() string { return "local" }

func (p *localTTS) Synthesize(ctx context.Context, text string, voice string) ([]byte, error) {
	body, _ := json.Marshal(map[string]any{"text": text, "voice": voice})
	req, err := http.NewRequestWithContext(ctx, "POST", p.url, bytes.NewReader(body))
	if err != nil {
		return nil, err
	}
	req.Header.Set("Content-Type", "application/json")

	resp, err := p.client.Do(req)
	if err != nil {
		return nil, fmt.Errorf("local tts: %w", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		return nil, fmt.Errorf("local tts %d", resp.StatusCode)
	}
	return io.ReadAll(resp.Body)
}

// --- edge-tts CLI ---

type edgeTTS struct{ bin string }

// newEdgeTTS locates the edge-tts binary: EDGETTS_BIN env, PATH, then ./.venv.
func newEdgeTTS() *edgeTTS {
	if bin := os.Getenv("EDGETTS_BIN"); bin != "" {
		return &edgeTTS{bin: bin}
	}
	if bin, err := exec.LookPath("edge-tts"); err == nil {
		return &edgeTTS{bin: bin}
	}
	if _, err := os.Stat(".venv/bin/edge-tts"); err == nil {
		abs, _ := filepath.Abs(".venv/bin/edge-tts")
		return &edgeTTS{bin: abs}
	}
	return &edgeTTS{}
}

func (p *edgeTTS) Name() string { return "edge-tts" }

func (p *edgeTTS) available() bool { return p.bin != "" }

func (p *edgeTTS) Synthesize(ctx context.Context, text string, voice string) ([]byte, error) {
	if !p.available() {
		return nil, fmt.Errorf("edge-tts binary not found")
	}
	if voice == "" {
		voice = "zh-CN-XiaoxiaoNeural"
	}
	out := filepath.Join(os.TempDir(), fmt.Sprintf("cyrene-tts-%d.mp3", time.Now().UnixNano()))
	defer os.Remove(out)

	cmd := exec.CommandContext(ctx, p.bin, "--voice", voice, "--text", text, "--write-media", out)
	if combined, err := cmd.CombinedOutput(); err != nil {
		return nil, fmt.Errorf("edge-tts: %w: %s", err, strings.TrimSpace(string(combined)))
	}
	return os.ReadFile(out)
}

// --- espeak CLI ---

type espeakTTS struct{ bin string }

func newEspeakTTS() *espeakTTS {
	for _, name := range []string{"espeak-ng", "espeak"} {
		if bin, err := exec.LookPath(name); err == nil {
			return &espeakTTS{bin: bin}
		}
	}
	return &espeakTTS{}
}

func (p *espeakTTS) Name() string { return "espeak" }

func (p *espeakTTS) Synthesize(ctx context.Context, text string, _ string) ([]byte, error) {
	if p.bin == "" {
		return nil, fmt.Errorf("espeak binary not found")
	}
	cmd := exec.CommandContext(ctx, p.bin, "-v", "zh", "--stdout", text)
	return cmd.Output()
}

// --- Whisper-compatible STT (OpenAI /audio/transcriptions; local servers like faster-whisper too) ---

type whisperSTT struct {
	baseURL, apiKey, model string
	client                 *http.Client
}

func (p *whisperSTT) Name() string { return "whisper-api" }

func (p *whisperSTT) Recognize(ctx context.Context, audioData []byte) (string, error) {
	var buf bytes.Buffer
	w := multipart.NewWriter(&buf)
	fw, err := w.CreateFormFile("file", "audio.wav")
	if err != nil {
		return "", err
	}
	if _, err := fw.Write(audioData); err != nil {
		return "", err
	}
	w.WriteField("model", p.model)
	w.Close()

	req, err := http.NewRequestWithContext(ctx, "POST", p.baseURL+"/audio/transcriptions", &buf)
	if err != nil {
		return "", err
	}
	req.Header.Set("Authorization", "Bearer "+p.apiKey)
	req.Header.Set("Content-Type", w.FormDataContentType())

	resp, err := p.client.Do(req)
	if err != nil {
		return "", fmt.Errorf("stt: %w", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		msg, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
		return "", fmt.Errorf("stt %d: %s", resp.StatusCode, msg)
	}

	var result struct {
		Text string `json:"text"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return "", fmt.Errorf("parse stt: %w", err)
	}
	return result.Text, nil
}