import os
import subprocess
import tempfile
import shutil
import edge_tts

# TTS_ENGINE: "edge" (default) or "piper"
TTS_ENGINE = os.getenv("TTS_ENGINE", "edge")

# --- Edge TTS config ---
# Romanian voices: ro-RO-EmilNeural (male), ro-RO-AlinaNeural (female)
EDGE_VOICE = os.getenv("TTS_VOICE", "ro-RO-EmilNeural")

# --- Piper TTS config ---
PIPER_VOICE_MODEL = None


def _find_piper_exe():
    piper_path = shutil.which("piper")
    if piper_path:
        return piper_path
    venv_piper = os.path.join(os.path.dirname(os.path.dirname(__file__)), "venv", "Scripts", "piper.exe")
    if os.path.exists(venv_piper):
        return venv_piper
    return "piper"


PIPER_EXE = _find_piper_exe()


def set_voice(model_path: str):
    """Set Piper voice model path (called from main.py startup)."""
    global PIPER_VOICE_MODEL
    PIPER_VOICE_MODEL = model_path


async def synthesize(text: str) -> bytes:
    if TTS_ENGINE == "piper":
        return _synthesize_piper(text)
    else:
        return await _synthesize_edge(text)


# --- Edge TTS ---

async def _synthesize_edge(text: str) -> bytes:
    with tempfile.NamedTemporaryFile(suffix=".mp3", delete=False) as f:
        tmp_path = f.name
    try:
        communicate = edge_tts.Communicate(text, EDGE_VOICE)
        await communicate.save(tmp_path)
        with open(tmp_path, "rb") as f:
            return f.read()
    finally:
        if os.path.exists(tmp_path):
            os.unlink(tmp_path)


# --- Piper TTS ---

def _synthesize_piper(text: str) -> bytes:
    if PIPER_VOICE_MODEL is None:
        raise RuntimeError("No Piper voice model configured. Place .onnx files in backend/voices/")

    with tempfile.NamedTemporaryFile(suffix=".wav", delete=False) as f:
        out_path = f.name
    try:
        process = subprocess.run(
            [PIPER_EXE, "--model", PIPER_VOICE_MODEL, "--output_file", out_path],
            input=text.encode("utf-8"),
            capture_output=True,
            timeout=30,
        )
        if process.returncode != 0:
            raise RuntimeError(f"Piper TTS failed: {process.stderr.decode()}")
        with open(out_path, "rb") as f:
            return f.read()
    finally:
        if os.path.exists(out_path):
            os.unlink(out_path)