app.py

import os, io, asyncio, tempfile, threading, re, subprocess, shutil, logging, secrets
from fastapi import FastAPI, Form, Request, HTTPException
from fastapi.responses import StreamingResponse, JSONResponse
from fastapi.middleware.gzip import GZipMiddleware

app = FastAPI()
app.add_middleware(GZipMiddleware, minimum_size=1000)

# ══════════════════════════════════════════════════════════════════
# SECURITY — Token check
# Set API_SECRET environment variable in HuggingFace Space settings
# ══════════════════════════════════════════════════════════════════
API_SECRET = os.environ.get("API_SECRET", "")

def verify_token(request: Request):
    if not API_SECRET:
        logging.warning("⚠️ API_SECRET not set — rejecting request")
        raise HTTPException(status_code=503, detail="Server not configured")
    token = request.headers.get("X-API-Token", "")
    if not secrets.compare_digest(token, API_SECRET):
        raise HTTPException(status_code=403, detail="Unauthorized")

# ══════════════════════════════════════════════════════════════════
# PIPER TTS SETUP — Auto download on first run
# ══════════════════════════════════════════════════════════════════
PIPER_DIR = "/tmp/piper"
PIPER_BIN = os.path.join(PIPER_DIR, "piper")
PIPER_MODELS_DIR = "/tmp/piper_models"
PIPER_READY = False

PIPER_VOICES = {
    # English
    "piper:en_US-amy-medium":        ("en_US-amy-medium.onnx",         "en_US-amy-medium.onnx.json"),
    "piper:en_US-joe-medium":        ("en_US-joe-medium.onnx",         "en_US-joe-medium.onnx.json"),
    "piper:en_US-lessac-medium":     ("en_US-lessac-medium.onnx",      "en_US-lessac-medium.onnx.json"),
    "piper:en_US-ryan-high":         ("en_US-ryan-high.onnx",          "en_US-ryan-high.onnx.json"),
    "piper:en_GB-alan-medium":       ("en_GB-alan-medium.onnx",        "en_GB-alan-medium.onnx.json"),
    "piper:en_GB-alba-medium":       ("en_GB-alba-medium.onnx",        "en_GB-alba-medium.onnx.json"),
    # Urdu / Hindi / Arabic
    "piper:ur_PK-fasih-medium":      ("ur_PK-fasih-medium.onnx",       "ur_PK-fasih-medium.onnx.json"),
    "piper:hi_IN-pratham-medium":     ("hi_IN-pratham-medium.onnx",     "hi_IN-pratham-medium.onnx.json"),
    "piper:ar_JO-kareem-medium":     ("ar_JO-kareem-medium.onnx",      "ar_JO-kareem-medium.onnx.json"),
    # Other languages
    "piper:de_DE-thorsten-medium":   ("de_DE-thorsten-medium.onnx",    "de_DE-thorsten-medium.onnx.json"),
    "piper:fr_FR-upmc-medium":       ("fr_FR-upmc-medium.onnx",        "fr_FR-upmc-medium.onnx.json"),
    "piper:ru_RU-irina-medium":      ("ru_RU-irina-medium.onnx",       "ru_RU-irina-medium.onnx.json"),
    "piper:tr_TR-dfki-medium":       ("tr_TR-dfki-medium.onnx",        "tr_TR-dfki-medium.onnx.json"),
    "piper:pt_BR-faber-medium":      ("pt_BR-faber-medium.onnx",       "pt_BR-faber-medium.onnx.json"),
    "piper:nl_NL-mls-medium":        ("nl_NL-mls-medium.onnx",         "nl_NL-mls-medium.onnx.json"),
}

PIPER_BASE_URL = "https://huggingface.co/rhasspy/piper-voices/resolve/main"

def setup_piper():
    global PIPER_READY
    try:
        import platform
        os.makedirs(PIPER_DIR, exist_ok=True)
        os.makedirs(PIPER_MODELS_DIR, exist_ok=True)

        system = platform.system().lower()
        arch   = platform.machine().lower()

        if system == "linux" and "x86" in arch:
            piper_url = "https://github.com/rhasspy/piper/releases/download/2023.11.14-2/piper_linux_x86_64.tar.gz"
        elif system == "linux" and "aarch" in arch:
            piper_url = "https://github.com/rhasspy/piper/releases/download/2023.11.14-2/piper_linux_aarch64.tar.gz"
        else:
            print(f"⚠️ Piper: unsupported platform {system}/{arch}, Piper disabled")
            return

        if not os.path.exists(PIPER_BIN):
            print("📥 Piper binary indiriliyor...")
            import urllib.request
            tar_path = "/tmp/piper.tar.gz"
            urllib.request.urlretrieve(piper_url, tar_path)
            import tarfile
            with tarfile.open(tar_path, "r:gz") as tf:
                tf.extractall("/tmp/piper_extract")
            extracted = "/tmp/piper_extract/piper"
            if os.path.isdir(extracted):
                for item in os.listdir(extracted):
                    shutil.move(os.path.join(extracted, item), os.path.join(PIPER_DIR, item))
            else:
                shutil.move(extracted, PIPER_BIN)
            os.chmod(PIPER_BIN, 0o755)
            print("✅ Piper binary ready")

        PIPER_READY = True
        print("✅ Piper TTS ready")
    except Exception as e:
        print(f"⚠️ Piper setup failed (non-critical): {e}")
        PIPER_READY = False

threading.Thread(target=setup_piper, daemon=True).start()


def download_piper_model(voice_code: str) -> tuple:
    """Model yoksa indir, path tuple dondur (onnx, json)"""
    if voice_code not in PIPER_VOICES:
        raise ValueError(f"Unknown Piper voice: {voice_code}")
    onnx_file, json_file = PIPER_VOICES[voice_code]
    onnx_path = os.path.join(PIPER_MODELS_DIR, onnx_file)
    json_path  = os.path.join(PIPER_MODELS_DIR, json_file)

    import urllib.request
    # Build correct HF path: en/en_US/amy/medium/en_US-amy-medium.onnx
    parts = onnx_file.rsplit("-", 2)
    lang_code = parts[0]  # en_US
    voice     = parts[1]  # amy
    quality   = parts[2].replace(".onnx", "")  # medium
    lang_short = lang_code.split("_")[0]  # en
    hf_dir = f"{lang_short}/{lang_code}/{voice}/{quality}"

    for fname, fpath in [(onnx_file, onnx_path), (json_file, json_path)]:
        if not os.path.exists(fpath):
            url = f"{PIPER_BASE_URL}/{hf_dir}/{fname}"
            print(f"📥 Downloading Piper model: {fname}")
            try:
                urllib.request.urlretrieve(url, fpath)
            except Exception:
                url2 = f"{PIPER_BASE_URL}/{lang_short}/{lang_code}/{fname}"
                urllib.request.urlretrieve(url2, fpath)
    return onnx_path, json_path


def download_piper_dynamic(voice_code: str) -> tuple:
    """Dynamic Piper voice download — code format: piper:ar_JO-kareem-low"""
    model_name = voice_code.replace("piper:", "")  # ar_JO-kareem-low
    # Prevent path traversal
    if ".." in model_name or "/" in model_name or "\\" in model_name:
        raise ValueError(f"Invalid voice code: {voice_code}")
    onnx_file = f"{model_name}.onnx"
    json_file = f"{model_name}.onnx.json"
    onnx_path = os.path.join(PIPER_MODELS_DIR, onnx_file)
    json_path = os.path.join(PIPER_MODELS_DIR, json_file)

    if os.path.exists(onnx_path) and os.path.exists(json_path):
        return onnx_path, json_path

    import urllib.request
    # Model format: lang_code-voice_name-quality (e.g., ar_JO-kareem-low)
    # HF path: ar/ar_JO/kareem/low/ar_JO-kareem-low.onnx
    dash_parts = model_name.rsplit("-", 2)  # Split from right: ["ar_JO", "kareem", "low"]
    if len(dash_parts) >= 3:
        lang_code = dash_parts[0]    # ar_JO
        voice = dash_parts[1]        # kareem
        quality = dash_parts[2]      # low
        lang = lang_code.split("_")[0]  # ar
        hf_path = f"{lang}/{lang_code}/{voice}/{quality}"
    else:
        hf_path = f"{model_name}/{model_name}"

    for fname, fpath in [(onnx_file, onnx_path), (json_file, json_path)]:
        if not os.path.exists(fpath):
            url = f"{PIPER_BASE_URL}/{hf_path}/{fname}"
            print(f"📥 Downloading dynamic Piper model: {fname}")
            try:
                urllib.request.urlretrieve(url, fpath)
            except Exception as e:
                print(f"⚠️ Dynamic Piper download failed: {e}")
                raise
    return onnx_path, json_path


def _piper_synth_chunk(text: str, onnx_path: str, json_path: str, length_scale: float) -> bytes:
    with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as out_f:
        out_path = out_f.name
    try:
        cmd = [
            PIPER_BIN,
            "--model", onnx_path,
            "--config", json_path,
            "--output_file", out_path,
            "--length_scale", str(round(length_scale, 2)),
        ]
        result = subprocess.run(
            cmd,
            input=text.encode("utf-8"),
            capture_output=True,
            timeout=120,
        )
        if result.returncode != 0:
            raise Exception(f"Piper error: {result.stderr.decode()[:200]}")
        with open(out_path, "rb") as f:
            return f.read()
    finally:
        if os.path.exists(out_path):
            os.unlink(out_path)


def _ffmpeg_concat_wav(parts: list) -> bytes:
    """Merge multiple WAV byte chunks using ffmpeg concat (same codec)."""
    if len(parts) == 1:
        return parts[0]
    tmp_files, concat_list, out_path = [], None, None
    try:
        for data in parts:
            fd, path = tempfile.mkstemp(suffix=".wav")
            os.close(fd)
            with open(path, "wb") as f:
                f.write(data)
            tmp_files.append(path)
        fd, concat_list = tempfile.mkstemp(suffix=".txt")
        os.close(fd)
        with open(concat_list, "w") as f:
            for p in tmp_files:
                f.write(f"file '{p}'\n")
        fd, out_path = tempfile.mkstemp(suffix=".wav")
        os.close(fd)
        subprocess.run(["ffmpeg", "-y", "-hide_banner", "-loglevel", "error",
                        "-f", "concat", "-safe", "0", "-i", concat_list,
                        "-c", "copy", out_path], check=True, timeout=60)
        with open(out_path, "rb") as f:
            return f.read()
    except Exception:
        return b"".join(parts)
    finally:
        for p in tmp_files:
            try: os.unlink(p)
            except Exception: pass
        for x in (concat_list, out_path):
            if x:
                try: os.unlink(x)
                except Exception: pass


def synthesize_piper(text: str, voice_code: str, speed: float = 1.0) -> bytes:
    if not PIPER_READY:
        raise Exception("Piper is not available on this system")
    # Pehle PIPER_VOICES dict mein check karo, nahi mila to dynamic download
    if voice_code in PIPER_VOICES:
        onnx_path, json_path = download_piper_model(voice_code)
    else:
        # Dynamic voice — direct HuggingFace se download
        onnx_path, json_path = download_piper_dynamic(voice_code)
    length_scale = 1.0 / max(0.25, min(4.0, speed))
    # Lambi text ko chunk karo (Piper stdin limit + timeout avoid karne ke liye)
    if len(text) > 1400:
        chunks = split_text(text, max_chars=1400)
    else:
        chunks = [text]
    if len(chunks) == 1:
        return _piper_synth_chunk(chunks[0], onnx_path, json_path, length_scale)
    parts = []
    for ch in chunks:
        if ch.strip():
            parts.append(_piper_synth_chunk(ch, onnx_path, json_path, length_scale))
    if not parts:
        raise Exception("Piper: no audio generated")
    return _ffmpeg_concat_wav(parts)


def split_text(text: str, max_chars: int = 1400) -> list:
    """Text ko chunklara bol"""
    text = text.strip()
    if not text:
        return []
    sentence_re = re.compile(
        r'(?:(?<=[.!?\u0964\u06D4\u061F\u2026])\s+)|(?<=[\u3002\uff01\uff1f])'
    )
    chunks, current = [], ""
    for para in re.split(r'\n+', text):
        para = para.strip()
        if not para:
            if current:
                chunks.append(current)
                current = ""
            continue
        for sentence in sentence_re.split(para):
            sentence = sentence.strip()
            if not sentence:
                continue
            if len(sentence) > max_chars:
                words, buf = sentence.split(), ""
                for word in words:
                    add = (" " if buf else "") + word
                    if len(buf) + len(add) <= max_chars:
                        buf += add
                    else:
                        if buf:
                            chunks.append(buf)
                        buf = word
                if buf:
                    chunks.append(buf)
            elif len(current) + len(sentence) + 1 <= max_chars:
                current = (current + " " + sentence).strip()
            else:
                if current:
                    chunks.append(current)
                current = sentence
        if current:
            chunks.append(current)
            current = ""
    if current:
        chunks.append(current)
    return [c for c in chunks if c.strip()]


# ══════════════════════════════════════════════════════════════════
# SILERO TTS — v4 model (48kHz, 12 Russian speakers)
# Loaded via torch.package.PackageImporter (requires torch < 2.3)
# ══════════════════════════════════════════════════════════════════
SILERO_READY = False
SILERO_MODELS_DIR = "/tmp/silero_models"
SILERO_SAMPLE_RATE = 48000
SILERO_MODELS = {}
SILERO_LOAD_LOCK = threading.Lock()

SILERO_MODEL_URLS = [
    "https://models.silero.ai/models/tts/ru/v4_ru.pt",
    "https://huggingface.co/Derur/silero-models/resolve/main/tts/ru/ru_v4/v4_ru.pt",
]

SILERO_SPEAKERS_RU = [
    "xenia", "eugene", "baya", "kseniya", "aidar", "kolya",
    "mikhai", "nikita", "pavel", "tatiana", "elena", "irina",
]


def download_silero_model() -> str:
    """Download Silero v4 Russian model. Returns path on success."""
    import urllib.request
    os.makedirs(SILERO_MODELS_DIR, exist_ok=True)
    model_path = os.path.join(SILERO_MODELS_DIR, "v4_ru.pt")
    if os.path.exists(model_path) and os.path.getsize(model_path) > 100000:
        return model_path
    for url in SILERO_MODEL_URLS:
        try:
            print(f"📥 Downloading Silero v4: {url[:80]}...")
            urllib.request.urlretrieve(url, model_path)
            if os.path.getsize(model_path) > 100000:
                print(f"✅ Silero v4 downloaded ({os.path.getsize(model_path)//1024}KB)")
                return model_path
            os.remove(model_path)
        except Exception as e:
            print(f"⚠️ Download failed: {e}")
            try:
                os.remove(model_path)
            except Exception:
                pass
    return ""


def setup_silero():
    global SILERO_READY
    try:
        import torch
        model_path = download_silero_model()
        if model_path:
            model = torch.package.PackageImporter(model_path).load_pickle("tts_models", "model")
            SILERO_MODELS["ru"] = model
            SILERO_READY = True
            print("✅ Silero TTS ready (v4 Russian — 12 speakers)")
        else:
            print("❌ Silero TTS: model download failed")
    except Exception as e:
        print(f"❌ Silero setup failed: {e}")

threading.Thread(target=setup_silero, daemon=True).start()


def synthesize_silero(text: str, voice_code: str) -> bytes:
    """Silero TTS — code: silero:ru_xenia. v4 model via torch.package.
    Model lazily load hota hai (self-heal) agar startup thread fail hua ho."""
    import numpy as np, scipy.io.wavfile as wav
    try:
        import torch
    except ImportError:
        raise Exception("Silero TTS requires torch. Install: pip install torch==2.1.2")

    lang_speaker = voice_code.replace("silero:", "")
    lang = lang_speaker.split("_")[0]
    speaker = lang_speaker.split("_", 1)[1] if "_" in lang_speaker else lang_speaker

    # Validate speaker — only real v4 speakers allowed
    valid_speakers = set(SILERO_SPEAKERS_RU)
    if speaker not in valid_speakers:
        raise Exception(f"Invalid Silero speaker '{speaker}'. Valid: {', '.join(valid_speakers)}")

    # Model on-demand load (self-heals if startup thread failed / was slow)
    if lang not in SILERO_MODELS:
        with SILERO_LOAD_LOCK:
            if lang not in SILERO_MODELS:
                model_path = download_silero_model()
                if not model_path:
                    raise Exception("Silero v4 model could not be downloaded (check network / model URL).")
                model = torch.package.PackageImporter(model_path).load_pickle("tts_models", "model")
                SILERO_MODELS[lang] = model
                global SILERO_READY
                SILERO_READY = True

    model = SILERO_MODELS[lang]
    audio = model.apply_tts(text=text, speaker=speaker, sample_rate=SILERO_SAMPLE_RATE)
    audio_np = audio.numpy() if hasattr(audio, "numpy") else audio.cpu().detach().numpy()

    buf = io.BytesIO()
    wav.write(buf, SILERO_SAMPLE_RATE, (audio_np * 32767).astype(np.int16))
    buf.seek(0)
    return buf.read()


def _ffmpeg_concat_mp3(parts: list) -> bytes:
    """Merge multiple MP3 byte chunks using ffmpeg concat."""
    if len(parts) == 1:
        return parts[0]
    tmp_files = []
    concat_list = None
    out_path = None
    try:
        for data in parts:
            fd, path = tempfile.mkstemp(suffix=".mp3")
            os.close(fd)
            with open(path, "wb") as f:
                f.write(data)
            tmp_files.append(path)
        fd, concat_list = tempfile.mkstemp(suffix=".txt")
        os.close(fd)
        with open(concat_list, "w") as f:
            for p in tmp_files:
                f.write(f"file '{p}'\n")
        fd, out_path = tempfile.mkstemp(suffix=".mp3")
        os.close(fd)
        subprocess.run(["ffmpeg", "-y", "-hide_banner", "-loglevel", "error",
                        "-f", "concat", "-safe", "0", "-i", concat_list,
                        "-c", "copy", out_path], check=True, timeout=60)
        with open(out_path, "rb") as f:
            return f.read()
    except Exception:
        return b"".join(parts)
    finally:
        for p in tmp_files:
            try: os.unlink(p)
            except Exception: pass
        if concat_list:
            try: os.unlink(concat_list)
            except Exception: pass
        if out_path:
            try: os.unlink(out_path)
            except Exception: pass


async def synthesize_edge(
    text: str,
    voice: str,
    rate: str = "+0%",
    volume: str = "+0%",
    pitch: str = "+0Hz",
    style: str = None,
    styledegree: str = None,
) -> bytes:
    import edge_tts
    chunks = split_text(text)
    audio_parts = []
    kwargs = {"rate": rate, "volume": volume, "pitch": pitch}
    if style and style != "Default" and style != "General":
        kwargs["style"] = style
    if styledegree is not None:
        try:
            sd = float(styledegree)
            if 0.0 <= sd <= 2.0:
                kwargs["styledegree"] = styledegree
        except Exception:
            pass
    for chunk in chunks:
        final_data = None
        for attempt in range(3):
            data = bytearray()
            try:
                comm = edge_tts.Communicate(chunk, voice, **kwargs)
                async for packet in comm.stream():
                    if packet["type"] == "audio" and packet.get("data"):
                        data.extend(packet["data"])
                if data:
                    final_data = bytes(data)
                    break
            except Exception as e:
                if attempt == 2:
                    raise
                await asyncio.sleep(1 + attempt)
        audio_parts.append(final_data if final_data else b"")
    if len(audio_parts) == 1:
        return audio_parts[0]
    return _ffmpeg_concat_mp3(audio_parts)


@app.get("/")
def root():
    return {"status": "VoiceCraft TTS Server OK", "engines": ["edge", "piper", "silero"]}


@app.get("/health")
@app.head("/health")
def health():
    return {
        "status": "ok",
        "piper_ready": PIPER_READY,
        "silero_ready": SILERO_READY,
        "silero_speakers": SILERO_SPEAKERS_RU,
        "engines": ["edge", "piper", "silero"],
    }


@app.get("/all_voices")
async def all_voices_list():
    """All voices — Edge (400+) + Piper (900+) + Silero (12 RU)"""
    result = {"edge": {}, "piper": {}, "silero": {}}

    # Edge TTS — 400+ voices (complete list, clean naming)
    try:
        import edge_tts
        voices = await edge_tts.list_voices()
        for v in voices:
            short = v.get("ShortName", "")
            friendly = v.get("FriendlyName", "") or short
            name = friendly
            for remove in ["Microsoft Server Speech Text to Speech Voice", "Microsoft", "Online", "(Natural)", "(Neural)", "(Standard)", "(Multilingual)", "(Expressive)"]:
                name = name.replace(remove, "")
            if "," in name:
                name = name.split(",")[-1]
            # Clean dash pattern: " - " or "  -  " → single " - "
            name = re.sub(r'\s*-\s*', ' - ', name)
            # Collapse all whitespace to single space
            name = re.sub(r'\s+', ' ', name)
            name = name.strip(" -").strip()
            region = short.split("-")[0] + "-" + short.split("-")[1] if "-" in short else ""
            result["edge"][f"{name} [{region}]"] = short
    except Exception as e:
        print(f"Edge voices error: {e}")

    # Piper TTS — all voices (clean naming, no engine hints)
    try:
        import urllib.request, json as _json
        api_url = "https://huggingface.co/api/models/rhasspy/piper-voices"
        req = urllib.request.Request(api_url, headers={"User-Agent": "VoiceCraft/2.0"})
        with urllib.request.urlopen(req, timeout=60) as resp:
            data = _json.loads(resp.read())
        siblings = data.get("siblings", [])
        for s in siblings:
            rfn = s.get("rfilename", s.get("rfn", ""))
            if not rfn.endswith(".onnx") or ".json" in rfn or "samples" in rfn:
                continue
            parts = rfn.split("/")
            if len(parts) < 2:
                continue
            model_name = parts[-1].replace(".onnx", "")
            dash_parts = model_name.rsplit("-", 2)
            if len(dash_parts) >= 3:
                lang_code = dash_parts[0].replace("_", "-")
                voice = dash_parts[1].replace("_", " ").title()
                quality = dash_parts[2]
                if quality in ("low", "x_low"):
                    continue
                quality_map = {"high": " +", "medium": "", "low": " -", "x_low": " --"}
                qs = quality_map.get(quality, " -")
                display = f"{voice} [{lang_code}]{qs}"
            else:
                display = model_name.replace("_", " ").title()
            full_code = f"piper:{model_name}"
            result["piper"][display] = full_code
    except Exception as e:
        print(f"Piper dynamic fetch error: {e}")
        for key in PIPER_VOICES:
            result["piper"][key] = key  # voice code as string, not tuple

    # Silero v4 — Russian (12 speakers)
    silero_ru_speakers = {
        "xenia": "Xenia", "eugene": "Eugene", "baya": "Baya", "kseniya": "Kseniya",
        "aidar": "Aidar", "kolya": "Kolya", "mikhai": "Mikhai", "nikita": "Nikita",
        "pavel": "Pavel", "tatiana": "Tatiana", "elena": "Elena", "irina": "Irina",
    }
    for speaker_code, display_name in silero_ru_speakers.items():
        result["silero"][f"{display_name} \u2022 Russian [RU]"] = f"silero:ru_{speaker_code}"

    total = len(result["edge"]) + len(result["piper"]) + len(result.get("silero", {}))
    return {"voices": result, "total": total}


@app.post("/tts")
async def tts_endpoint(
    request: Request,
    engine:  str = Form(...),   # "edge" | "piper" | "silero"
    text:    str = Form(...),
    voice:   str = Form("en-US-AvaNeural"),   # edge voice code OR piper/silero code
    rate:    str = Form("+0%"),               # edge only
    volume:  str = Form("+0%"),               # edge only
    pitch:   str = Form("+0Hz"),              # edge only
    speed:   float = Form(1.0),              # piper only
    style:   str = Form(None),               # edge style (emotion)
    styledegree: str = Form(None),           # edge style degree 0-2
):
    verify_token(request)

    if not text or not text.strip():
        return JSONResponse(status_code=400, content={"error": "Text is empty"})

    text = text.strip()

    try:
        if engine == "edge":
            audio = await synthesize_edge(text, voice, rate=rate, volume=volume, pitch=pitch, style=style, styledegree=styledegree)
            media = "audio/mpeg"
            fname = "tts_edge.mp3"

        elif engine == "piper":
            audio = synthesize_piper(text, voice, speed=speed)
            media = "audio/wav"
            fname = "tts_piper.wav"

        elif engine == "silero":
            audio = synthesize_silero(text, voice)
            media = "audio/wav"
            fname = "tts_silero.wav"

        else:
            return JSONResponse(status_code=400, content={"error": f"Unknown engine: {engine}"})

        return StreamingResponse(
            io.BytesIO(audio),
            media_type=media,
            headers={"Content-Disposition": f"attachment; filename={fname}"},
        )

    except Exception as e:
        logging.error(f"TTS error: {e}", exc_info=True)
        return JSONResponse(
            status_code=500,
            content={"error": f"Synthesis failed: {str(e)[:240]}"},
        )