"""Routing decision storage.

Stores every routing decision with the full feature snapshot for audit,
recalibration, and explainability. Backed by the v3_routing_decisions table.
"""

from __future__ import annotations

from dataclasses import dataclass, field
from uuid import UUID

from services.intelligence_pipeline_v3.routing.router import RoutingDecision


@dataclass
class RoutingDecisionStore:
    """In-memory store for routing decisions.

    In production, this would be backed by the ``v3_routing_decisions`` table.
    This implementation provides the storage interface for use in the pipeline
    orchestrator and for testing.

    The store is append-only — decisions are immutable once stored.
    """

    _decisions: list[RoutingDecision] = field(default_factory=list)
    _by_pipeline_run: dict[UUID, list[RoutingDecision]] = field(default_factory=dict)

    def store(self, decision: RoutingDecision) -> None:
        """Store a routing decision.

        Parameters
        ----------
        decision:
            The routing decision to persist. Must have a unique id.
        """
        self._decisions.append(decision)
        run_decisions = self._by_pipeline_run.setdefault(
            decision.pipeline_run_id, []
        )
        run_decisions.append(decision)

    def get_by_pipeline_run(self, run_id: UUID) -> list[RoutingDecision]:
        """Retrieve all routing decisions for a pipeline run.

        Parameters
        ----------
        run_id:
            The pipeline run identifier.

        Returns
        -------
        list[RoutingDecision]
            All decisions for the given run, in insertion order.
            Returns empty list if no decisions exist for the run.
        """
        return list(self._by_pipeline_run.get(run_id, []))

    def get_all(self) -> list[RoutingDecision]:
        """Retrieve all stored decisions in insertion order."""
        return list(self._decisions)

    def count(self) -> int:
        """Return the total number of stored decisions."""
        return len(self._decisions)