"""
FastAPI 入口。启动：

    python -m uvicorn server.main:app --host 0.0.0.0 --port 8000

或在 python/ 目录下：

    uvicorn server.main:app --host 0.0.0.0 --port 8000
"""

from __future__ import annotations

from pathlib import Path

from fastapi import FastAPI, File, Form, HTTPException, UploadFile
from fastapi.responses import JSONResponse, Response

from .face_renderer import (
    EffectNotFoundError,
    FaceRenderer,
    NoFaceError,
    RendererPaths,
)

# 路径相对本文件，避免 cwd 不同时找不到资源
_SERVER_DIR = Path(__file__).resolve().parent
_PATHS = RendererPaths(
    obj_path=_SERVER_DIR / "assets" / "face_picture_3dmax.obj",
    effects_dir=_SERVER_DIR / "effects",
)

app = FastAPI(title="Face SDK Web", version="0.1.0")
renderer = FaceRenderer(_PATHS)


@app.get("/health")
def health() -> dict:
    return {"ok": True}


@app.get("/effects")
def list_effects() -> dict:
    return {"effects": renderer.list_effect_ids()}


@app.post("/render")
async def render(
    image: UploadFile = File(...),
    effect_id: int = Form(...),
) -> Response:
    image_bytes = await image.read()
    if not image_bytes:
        raise HTTPException(status_code=400, detail="empty image")
    try:
        png_bytes = renderer.render(image_bytes, effect_id)
    except NoFaceError:
        return JSONResponse(status_code=400, content={"error": "no_face"})
    except EffectNotFoundError as e:
        raise HTTPException(status_code=404, detail=str(e))
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    return Response(content=png_bytes, media_type="image/png")