from __future__ import annotations

from abc import ABC, abstractmethod
from dataclasses import dataclass

from domain.modelling.plan import Plan


@dataclass(frozen=True)
class PlanSaveRequest:
    """Bundles the five fields the plan repository needs to persist one Plan.

    Mirrors ``EpcSaveRequest`` in shape — used by ``PlanRepository.save_batch()``
    to accumulate write intent before the batch is flushed in one Unit of Work."""

    plan: Plan
    property_id: int
    scenario_id: int
    portfolio_id: int
    is_default: bool


class PlanRepository(ABC):
    """Persists a Plan (and its Plan Measures) for a Property + Scenario.

    A re-run INSERTs a fresh Plan and keeps the prior one as history rather than
    deleting it. When the new Plan is the default, prior default Plans for the
    same (Property, Scenario) are demoted to `is_default=False`, so the current
    Plan is the one with `is_default=True` (ADR-0012 / ADR-0017). `portfolio_id`
    and `is_default` are supplied by the orchestrator (the former from the
    trigger, the latter from the Scenario).
    """

    @abstractmethod
    def save(
        self,
        plan: Plan,
        *,
        property_id: int,
        scenario_id: int,
        portfolio_id: int,
        is_default: bool,
    ) -> int:
        """Persist ``plan`` and return its Plan id. Keeps prior Plans for
        ``(property_id, scenario_id)`` as history; when ``is_default`` is True,
        demotes those prior Plans to ``is_default=False``."""
        ...

    @abstractmethod
    def save_batch(self, requests: list[PlanSaveRequest]) -> list[int]:
        """Persist a batch of Plans in three statements regardless of batch size.

        Returns one plan id per request in input order. Fires a single demote
        UPDATE only when at least one request has ``is_default=True``. Keeps
        prior Plans as history (ADR-0017)."""
        ...