import uuid

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.deps import get_db_session, require_roles
from app.schemas.common import PaginatedResponse
from app.crud import user as user_crud
from app.utils.pagination import paginate
from app.schemas.user import UserCreate, UserRead, UserUpdate

router = APIRouter()


@router.get("/", response_model=PaginatedResponse[UserRead], summary="用户列表", description="仅 ADMIN 可用，支持 skip/limit。")
async def list_users(
    skip: int = 0,
    limit: int = 100,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(require_roles(["ADMIN"])),
) -> PaginatedResponse[UserRead]:
    users = await user_crud.list_users(db, skip=skip, limit=limit)
    total_users = await user_crud.list_users(db, skip=0, limit=10_000_000)
    return paginate(list(users), total=len(total_users))


@router.post("/", response_model=UserRead, status_code=status.HTTP_201_CREATED)
async def create_user(
    user_in: UserCreate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(require_roles(["ADMIN"])),
) -> UserRead:
    existing = await user_crud.get_by_username(db, user_in.username)
    if existing:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Username already exists",
        )
    user = await user_crud.create_user(db, user_in)
    return user


@router.patch("/{user_id}", response_model=UserRead)
async def update_user(
    user_id: uuid.UUID,
    user_in: UserUpdate,
    db: AsyncSession = Depends(get_db_session),
    current_user=Depends(require_roles(["ADMIN"])),
) -> UserRead:
    db_user = await user_crud.get_by_id(db, user_id)
    if not db_user:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="User not found")
    user = await user_crud.update_user(db, db_user, user_in)
    return user