"""Business logic for vacation days.

The service owns rules; the repository only persists. Routers call services, not
repositories directly. This is the REFERENCE service — keep services thin and
free of HTTP/DB details.
"""

from datetime import datetime
from uuid import UUID, uuid4

from app.entities.vacation_days import VacationDays
from app.repositories.vacation_days_repository import VacationDaysRepository
from app.utils.errors import NotFoundError, ValidationError


class VacationDaysService:
    def __init__(self, repo: VacationDaysRepository) -> None:
        self._repo = repo

    async def upsert(
        self,
        personal_data_uuid: UUID,
        workspace_id: UUID,
        year: int,
        total_days: int,
        saved_days_in: int = 0,
    ) -> VacationDays:
        """Create or update the (parent, year) vacation entry.

        Raises ValidationError on negative inputs (schema also guards this, but a
        service should not trust its caller).
        """
        if total_days < 0 or saved_days_in < 0:
            raise ValidationError("Vacation day counts cannot be negative")

        existing = await self._repo.get_by_parent_year(personal_data_uuid, year)
        if existing is not None:
            existing.total_days = total_days
            existing.saved_days_in = saved_days_in
            return await self._repo.update(existing.id, existing)

        entity = VacationDays(
            id=uuid4(),
            personal_data_uuid=personal_data_uuid,
            workspace_id=workspace_id,
            year=year,
            total_days=total_days,
            saved_days_in=saved_days_in,
            created_at=datetime.now(),
            updated_at=datetime.now(),
        )
        return await self._repo.create(entity)

    async def get(self, vacation_days_id: UUID, workspace_id: UUID | None = None) -> VacationDays:
        entity = await self._repo.get_by_id(vacation_days_id)
        if entity is None or (workspace_id is not None and entity.workspace_id != workspace_id):
            raise NotFoundError(f"VacationDays {vacation_days_id} not found")
        return entity

    async def list_for_workspace(self, workspace_id: UUID) -> list[VacationDays]:
        return await self._repo.list(workspace_id=workspace_id)