from uuid import UUID
from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from backend.app.core.dependencies import require_any_permissions, require_permissions
from backend.app.db.session import get_db
from backend.app.models import Department, User
from backend.app.schemas.department import DepartmentCreate, DepartmentResponse, DepartmentUpdate


router = APIRouter(prefix="/departments", tags=["departments"])


def is_limited_scope(user: User) -> bool:
    return user.role and user.role.name not in {"管理员", "排班员"}


@router.get("", response_model=list[DepartmentResponse])
async def list_departments(
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(require_any_permissions(["users.view", "schedule.view"])),
):
    query = select(Department)
    if is_limited_scope(current_user):
        if current_user.dept_id:
            query = query.where(Department.id == current_user.dept_id)
        elif current_user.campus_id:
            query = query.where(Department.campus_id == current_user.campus_id)
        else:
            return []
    result = await db.execute(query.order_by(Department.name))
    return result.scalars().all()


@router.post("", response_model=DepartmentResponse, dependencies=[Depends(require_permissions(["users.edit"]))])
async def create_department(payload: DepartmentCreate, db: AsyncSession = Depends(get_db)):
    dept = Department(campus_id=payload.campus_id, name=payload.name)
    db.add(dept)
    await db.commit()
    await db.refresh(dept)
    return dept


@router.put("/{dept_id}", response_model=DepartmentResponse, dependencies=[Depends(require_permissions(["users.edit"]))])
async def update_department(dept_id: UUID, payload: DepartmentUpdate, db: AsyncSession = Depends(get_db)):
    result = await db.execute(select(Department).where(Department.id == dept_id))
    dept = result.scalar_one_or_none()
    if not dept:
        raise HTTPException(status_code=404, detail="科室不存在")
    dept.campus_id = payload.campus_id
    dept.name = payload.name
    await db.commit()
    await db.refresh(dept)
    return dept


@router.delete("/{dept_id}", dependencies=[Depends(require_permissions(["users.delete"]))])
async def delete_department(dept_id: UUID, db: AsyncSession = Depends(get_db)):
    result = await db.execute(select(Department).where(Department.id == dept_id))
    dept = result.scalar_one_or_none()
    if not dept:
        raise HTTPException(status_code=404, detail="科室不存在")
    await db.delete(dept)
    await db.commit()
    return {"success": True}