"""한국어 우선 다중 엔진 TTS 웹 서비스.

- 로그인/과금 없이 무제한 사용
- 엔진(MeloTTS, Coqui GlowTTS-KSS 등) 선택 → 언어/목소리 선택
- 속도 / 피치 조절
- GPU 자동 사용
"""
from __future__ import annotations

import os

from fastapi import FastAPI, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse, Response
from fastapi.staticfiles import StaticFiles
from pydantic import BaseModel, Field

from .engines import (
    default_engine_id,
    get_engine,
    list_engines,
    warmup_all,
)

FRONTEND_DIR = os.path.join(os.path.dirname(os.path.dirname(__file__)), "frontend")

app = FastAPI(title="한국어 TTS 스튜디오", version="2.0.0")

app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_methods=["*"],
    allow_headers=["*"],
)


class TTSRequest(BaseModel):
    text: str = Field(..., description="읽을 텍스트")
    engine: str | None = Field(None, description="엔진 ID (melo / coqui-kss 등)")
    language: str = Field("KR", description="언어 코드")
    speaker: str | None = Field(None, description="화자/모델 ID")
    speed: float = Field(1.0, ge=0.5, le=2.0, description="말하기 속도")
    pitch: float = Field(0.0, ge=-12.0, le=12.0, description="피치(반음)")


@app.on_event("startup")
def _startup() -> None:
    warmup_all()


@app.get("/api/health")
def health() -> dict:
    import torch

    return {
        "status": "ok",
        "cuda": torch.cuda.is_available(),
        "gpu": torch.cuda.get_device_name(0) if torch.cuda.is_available() else None,
        "engines": [e.id for e in list_engines()],
        "default_engine": default_engine_id(),
    }


@app.get("/api/engines")
def engines() -> dict:
    return {
        "default": default_engine_id(),
        "engines": [e.describe() for e in list_engines()],
    }


@app.post("/api/tts")
def tts(req: TTSRequest) -> Response:
    engine_id = req.engine or default_engine_id()
    try:
        engine = get_engine(engine_id)
        wav = engine.synth_wav(
            text=req.text,
            language=req.language,
            speaker=req.speaker,
            speed=req.speed,
            pitch=req.pitch,
        )
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc))
    except Exception as exc:  # pragma: no cover
        raise HTTPException(status_code=500, detail=f"합성 실패: {exc}")

    return Response(
        content=wav,
        media_type="audio/wav",
        headers={"Content-Disposition": 'inline; filename="tts.wav"'},
    )


@app.get("/")
def index() -> FileResponse:
    return FileResponse(os.path.join(FRONTEND_DIR, "index.html"))


app.mount("/static", StaticFiles(directory=FRONTEND_DIR), name="static")