"""Security memory (canon B5). Memory informs; negative memory blocks until cleared (C10)."""

from __future__ import annotations

from dataclasses import dataclass
from typing import Any, Mapping

from emergent_security.model import Request, frozen_mapping


@dataclass(frozen=True)
class MemoryEntry:
    decision_class: str
    scope: Mapping[str, Any]
    polarity: str
    cleared: bool = False

    @classmethod
    def from_dict(cls, data: Mapping[str, Any]) -> MemoryEntry:
        return cls(
            decision_class=str(data["decision_class"]),
            scope=frozen_mapping(data.get("scope")),
            polarity=str(data.get("polarity", "positive")),
            cleared=bool(data.get("cleared", False)),
        )

    def blocks(self, request: Request) -> bool:
        return (
            self.polarity == "negative"
            and not self.cleared
            and self.decision_class == request.decision_class
            and all(request.scope.get(key) == value for key, value in self.scope.items())
        )