"""Calendar plugin contract — public interface for cross-plugin access."""

from __future__ import annotations

from typing import Any

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.plugins.builtins.calendar.models import Calendar, CalendarEntry, CalendarEntryLink
from app.plugins.builtins.contracts import get_contract_registry


class CalendarContract:
    """Public contract for the calendar plugin."""

    contract_name = "calendar"

    Calendar = Calendar
    CalendarEntry = CalendarEntry
    CalendarEntryLink = CalendarEntryLink

    @staticmethod
    async def dsar_collect(
        db: AsyncSession, tenant_id: Any, user_id: Any
    ) -> dict[str, Any]:
        """GDPR Art. 15: collect calendar entries owned by the user."""
        cal_entries = (
            await db.execute(
                select(CalendarEntry).where(
                    CalendarEntry.tenant_id == tenant_id,
                    CalendarEntry.owner_id == user_id,
                    CalendarEntry.deleted_at.is_(None),
                ).limit(1000)
            )
        ).scalars().all()
        return {
            "calendar_entries": [
                {
                    "id": str(e.id),
                    "title": e.title,
                    "entry_type": e.entry_type,
                    "start_at": e.start_at.isoformat() if e.start_at else None,
                    "end_at": e.end_at.isoformat() if e.end_at else None,
                }
                for e in cal_entries
            ]
        }

    @classmethod
    def get_function(cls, name: str):
        """Return a callable exposed by this contract, or None if absent."""
        return getattr(cls, name, None)


# ─── self-registration ───

_contract = CalendarContract()
get_contract_registry().register("calendar", _contract)

# Backward-compatible local accessor
_contract_instance: CalendarContract | None = None


def get_contract() -> CalendarContract:
    global _contract_instance
    if _contract_instance is None:
        _contract_instance = CalendarContract()
    return _contract_instance


__all__ = ["CalendarContract", "Calendar", "CalendarEntry", "CalendarEntryLink"]