from fastapi import FastAPI
from fastapi import Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse

from backend.app.api.router import api_router
from backend.app.core.config import get_settings
from backend.app.core.exceptions import AppException

settings = get_settings()

app = FastAPI(title=settings.app_name)

app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.cors_origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


@app.exception_handler(AppException)
async def app_exception_handler(_: Request, exc: AppException) -> JSONResponse:
    # 统一业务异常返回格式，避免每个接口重复构造错误响应。
    return JSONResponse(
        status_code=exc.status_code,
        content={
            "code": exc.code,
            "message": exc.message,
            "data": {},
        },
    )


app.include_router(api_router)