from __future__ import annotations

from datetime import datetime, timezone
from typing import cast

from sqlalchemy import Table
from sqlalchemy.dialects.postgresql import insert as pg_insert
from sqlmodel import Session

from infrastructure.postgres.property_override_table import PropertyOverrideRow
from repositories.property.property_override_repository import (
    PropertyOverrideInsert,
    PropertyOverrideRepository,
)


class PropertyOverridePostgresRepository(PropertyOverrideRepository):
    """Postgres adapter for ``property_overrides`` (ADR-0006).

    Write-only: the finaliser materialises the fact layer; no reads here.
    """

    def __init__(self, session: Session) -> None:
        self._session = session
        # ``__table__`` is injected at runtime on table=True classes but the
        # stubs don't expose it; pin to ``Table`` so the dialect insert is typed.
        self._table: Table = cast(Table, getattr(PropertyOverrideRow, "__table__"))

    def upsert_all(self, rows: list[PropertyOverrideInsert]) -> int:
        if not rows:
            return 0

        now = datetime.now(timezone.utc)
        values = [
            {
                "property_id": r.property_id,
                "portfolio_id": r.portfolio_id,
                "building_part": r.building_part,
                "override_component": r.override_component,
                "override_value": r.override_value,
                "original_spreadsheet_description": r.original_spreadsheet_description,
                "created_at": now,
                "updated_at": now,
            }
            for r in rows
        ]

        stmt = pg_insert(self._table).values(values)
        # Re-run = recalculate (ADR-0005/0006): refresh the snapshot on conflict,
        # in contrast to ``property``'s on_conflict_do_nothing. When a per-property
        # user-edit path lands (and a ``source`` column with it), this set_ gains a
        # ``WHERE source='classifier'`` guard so hand-edits survive.
        stmt = stmt.on_conflict_do_update(
            index_elements=["property_id", "override_component", "building_part"],
            set_={
                "override_value": stmt.excluded.override_value,
                "original_spreadsheet_description": stmt.excluded.original_spreadsheet_description,
                "updated_at": now,
            },
        )

        # SQLModel re-exports SQLAlchemy's Session.execute; one overload is marked
        # deprecated in the stubs but the upsert path is supported.
        result = self._session.execute(stmt)  # pyright: ignore[reportDeprecated]
        return cast(int, result.rowcount)