from pathlib import Path
from threading import Lock

from fastapi import FastAPI
from pydantic import BaseModel, Field

app = FastAPI(title="Emotion Museum TTS")

_model = None
_speaker_ids = None
_model_lock = Lock()


class SynthesizeRequest(BaseModel):
    text: str = Field(min_length=1, max_length=5000)
    voice: str = "default_zh_female"
    outputPath: str


def get_model():
    global _model, _speaker_ids
    with _model_lock:
        if _model is None:
            from melo.api import TTS

            _model = TTS(language="ZH", device="cpu")
            _speaker_ids = _model.hps.data.spk2id
        return _model, _speaker_ids


@app.get("/health")
def health():
    return {"status": "ok"}


@app.post("/synthesize")
def synthesize(request: SynthesizeRequest):
    output = Path(request.outputPath)
    output.parent.mkdir(parents=True, exist_ok=True)

    try:
        model, speaker_ids = get_model()
        speaker_id = speaker_ids.get("ZH")
        model.tts_to_file(request.text, speaker_id, str(output), speed=1.0)
    except Exception as exc:
        return {
            "success": False,
            "audioPath": None,
            "durationMs": None,
            "engine": "melotts",
            "errorMessage": str(exc),
        }

    return {
        "success": True,
        "audioPath": str(output),
        "durationMs": None,
        "engine": "melotts",
    }