"""한국어 우선 TTS 웹 서비스 (MeloTTS 기반).

- 로그인/과금 없이 무제한으로 사용 가능
- 한국어/영어 목소리 모델을 언어별로 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 .tts_engine import engine

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

app = FastAPI(title="한국어 TTS 스튜디오", version="1.0.0")

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


class TTSRequest(BaseModel):
    text: str = Field(..., description="읽을 텍스트")
    language: str = Field("KR", description="언어 코드 (KR / EN)")
    speaker: str | None = Field(None, description="화자 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:
    # 첫 요청 지연을 줄이기 위해 백그라운드가 아닌 즉시 워밍업
    engine.warmup()


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

    return {
        "status": "ok",
        "device": engine.device,
        "cuda": torch.cuda.is_available(),
        "gpu": torch.cuda.get_device_name(0) if torch.cuda.is_available() else None,
    }


@app.get("/api/voices")
def voices() -> dict:
    return {"languages": engine.list_voices()}


@app.post("/api/tts")
def tts(req: TTSRequest) -> Response:
    try:
        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")