from uuid import UUID

from fastapi import APIRouter, Depends
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.core.database import get_db
from app.core.dependencies import CurrentUser, require_role
from app.models import Company
from app.models.department import Department
from app.models.user import User, UserRole
from app.schemas.company import (
    CompanyOut,
    CompanyUpdate,
    DepartmentCreate,
    DepartmentOut,
    DepartmentUpdate,
)

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

_admin_roles = (UserRole.COMPANY_ADMIN, UserRole.SUPER_ADMIN)


@router.get("/me", response_model=CompanyOut)
async def get_my_company(current_user: CurrentUser, db: AsyncSession = Depends(get_db)):
    company = await db.get(Company, current_user.company_id)
    return CompanyOut.model_validate(company)


@router.patch("/me", response_model=CompanyOut)
async def update_my_company(
    data: CompanyUpdate,
    current_user: User = require_role(*_admin_roles),
    db: AsyncSession = Depends(get_db),
):
    company = await db.get(Company, current_user.company_id)
    for field, value in data.model_dump(exclude_none=True).items():
        setattr(company, field, value)
    return CompanyOut.model_validate(company)


# ── Departments ──────────────────────────────────────────────────────────────

@router.get("/me/departments", response_model=list[DepartmentOut])
async def list_departments(current_user: CurrentUser, db: AsyncSession = Depends(get_db)):
    depts = await db.scalars(
        select(Department).where(Department.company_id == current_user.company_id)
    )
    return [DepartmentOut.model_validate(d) for d in depts.all()]


@router.post("/me/departments", response_model=DepartmentOut, status_code=201)
async def create_department(
    data: DepartmentCreate,
    current_user: User = require_role(*_admin_roles),
    db: AsyncSession = Depends(get_db),
):
    dept = Department(company_id=current_user.company_id, **data.model_dump())
    db.add(dept)
    await db.flush()
    return DepartmentOut.model_validate(dept)


@router.patch("/me/departments/{dept_id}", response_model=DepartmentOut)
async def update_department(
    dept_id: UUID,
    data: DepartmentUpdate,
    current_user: User = require_role(*_admin_roles),
    db: AsyncSession = Depends(get_db),
):
    dept = await db.get(Department, dept_id)
    if not dept or dept.company_id != current_user.company_id:
        from fastapi import HTTPException
        raise HTTPException(status_code=404, detail="Department not found")
    for field, value in data.model_dump(exclude_none=True).items():
        setattr(dept, field, value)
    return DepartmentOut.model_validate(dept)


@router.delete("/me/departments/{dept_id}", status_code=204)
async def delete_department(
    dept_id: UUID,
    current_user: User = require_role(*_admin_roles),
    db: AsyncSession = Depends(get_db),
):
    dept = await db.get(Department, dept_id)
    if not dept or dept.company_id != current_user.company_id:
        from fastapi import HTTPException
        raise HTTPException(status_code=404, detail="Department not found")
    await db.delete(dept)