import json
import os
import sys
from pathlib import Path

from melo.api import TTS


LANGUAGE = os.getenv("TTS_LANGUAGE", "KR")
SPEAKER = os.getenv("TTS_SPEAKER", "KR")
DEVICE = os.getenv("TTS_DEVICE", "cpu")
SPEED = float(os.getenv("TTS_SPEED", "1.18"))
SDP_RATIO = float(os.getenv("TTS_SDP_RATIO", "0.22"))
NOISE_SCALE = float(os.getenv("TTS_NOISE_SCALE", "0.55"))
NOISE_SCALE_W = float(os.getenv("TTS_NOISE_SCALE_W", "0.75"))

_MODEL = None
_SPEAKER_ID = None


def load_model():
    global _MODEL
    global _SPEAKER_ID

    if _MODEL is not None and _SPEAKER_ID is not None:
        return _MODEL, _SPEAKER_ID

    model = TTS(language=LANGUAGE, device=DEVICE)
    speaker_ids = model.hps.data.spk2id

    if SPEAKER not in speaker_ids:
        supported = ", ".join(sorted(speaker_ids.keys()))
        raise RuntimeError(f"지원하지 않는 speaker 입니다: {SPEAKER}. 사용 가능: {supported}")

    _MODEL = model
    _SPEAKER_ID = speaker_ids[SPEAKER]
    return _MODEL, _SPEAKER_ID


def handle_ping():
    model, speaker_id = load_model()
    return {
        "language": LANGUAGE,
        "speaker": SPEAKER,
        "speaker_id": speaker_id,
        "device": DEVICE,
        "speed": SPEED,
        "sdp_ratio": SDP_RATIO,
        "noise_scale": NOISE_SCALE,
        "noise_scale_w": NOISE_SCALE_W,
        "speaker_count": len(model.hps.data.spk2id),
    }


def handle_synthesize(params):
    text = str(params["text"]).strip()
    output_path = Path(str(params["output_path"]))
    output_path.parent.mkdir(parents=True, exist_ok=True)

    model, speaker_id = load_model()
    model.tts_to_file(
        text,
        speaker_id,
        str(output_path),
        speed=SPEED,
        sdp_ratio=SDP_RATIO,
        noise_scale=NOISE_SCALE,
        noise_scale_w=NOISE_SCALE_W,
    )

    return {
        "output_path": str(output_path),
        "text_length": len(text),
    }


def main():
    for raw_line in sys.stdin:
        line = raw_line.strip()
        if not line:
            continue

        try:
            payload = json.loads(line)
            request_id = str(payload["id"])
            method = payload["method"]
            params = payload.get("params", {})

            if method == "ping":
                result = handle_ping()
            elif method == "synthesize":
                result = handle_synthesize(params)
            else:
                raise RuntimeError(f"알 수 없는 method 입니다: {method}")

            sys.stdout.write(json.dumps({"id": request_id, "result": result}, ensure_ascii=False) + "\n")
            sys.stdout.flush()
        except Exception as error:
            request_id = "unknown"
            try:
                request_id = str(payload.get("id", "unknown"))
            except Exception:
                pass

            sys.stdout.write(json.dumps({"id": request_id, "error": str(error)}, ensure_ascii=False) + "\n")
            sys.stdout.flush()


if __name__ == "__main__":
    main()