ajyy/backend/app/main.py

from contextlib import asynccontextmanager
from pathlib import Path

from fastapi import FastAPI, Request
from fastapi.exceptions import RequestValidationError
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from fastapi.staticfiles import StaticFiles

from app.api.auth import router as auth_router
from app.api.public import router as public_router
from app.core.config import get_settings
from app.core.database import SessionLocal, init_db
from app.core.response import AppHTTPError, error_response, success_response
from app.services.seed import seed_if_empty


settings = get_settings()


@asynccontextmanager
async def lifespan(app: FastAPI):
    init_db()
    db = SessionLocal()
    try:
        seed_if_empty(db)
    finally:
        db.close()
    yield


app = FastAPI(title=settings.APP_NAME, lifespan=lifespan)

_cors_origins = [o.strip() for o in settings.CORS_ORIGINS.split(",") if o.strip()]
if not _cors_origins:
    _cors_origins = ["*"]

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

app.include_router(auth_router, prefix=settings.API_V1_PREFIX)
app.include_router(public_router, prefix=settings.API_V1_PREFIX)

_upload_dir = Path(settings.LOCAL_STORAGE_DIR)
_upload_dir.mkdir(parents=True, exist_ok=True)
app.mount("/uploads", StaticFiles(directory=str(_upload_dir)), name="uploads")


@app.exception_handler(AppHTTPError)
async def app_http_error_handler(_request: Request, exc: AppHTTPError):
    return JSONResponse(
        status_code=exc.status_code,
        content=error_response(exc.status_code, exc.message, exc.data),
    )


@app.exception_handler(RequestValidationError)
async def request_validation_error_handler(
    _request: Request, exc: RequestValidationError
):
    # 全局约定：校验失败统一 HTTP 400 + 信封，避免 FastAPI 默认 422/detail
    msg = "请求参数校验失败"
    errors = exc.errors()
    if errors:
        first = errors[0]
        loc = ".".join(str(x) for x in first.get("loc", ()) if x != "body")
        detail = first.get("msg") or msg
        msg = f"{loc}: {detail}" if loc else str(detail)
    return JSONResponse(
        status_code=400,
        content=error_response(400, msg),
    )


@app.get(f"{settings.API_V1_PREFIX}/health")
def health_check():
    return success_response({"status": "ok"})