"""Semantic memory: facts, policies, domain knowledge for AGI."""

from typing import Any

from fusionagi._logger import logger


class SemanticMemory:
    """Stores facts, policies, domain knowledge. Queryable and updatable."""

    def __init__(self, max_facts: int = 50000) -> None:
        self._facts: dict[str, dict[str, Any]] = {}
        self._by_key: dict[str, list[str]] = {}
        self._max_facts = max_facts

    def add_fact(self, fact_id: str, statement: str, source: str = "", domain: str = "", metadata: dict[str, Any] | None = None) -> None:
        if len(self._facts) >= self._max_facts and fact_id not in self._facts:
            self._evict_one()
        entry = {"statement": statement, "source": source, "domain": domain, "metadata": metadata or {}}
        self._facts[fact_id] = entry
        if domain:
            self._by_key.setdefault(domain, []).append(fact_id)
        logger.debug("Semantic memory: fact added", extra={"fact_id": fact_id, "domain": domain})

    def get_fact(self, fact_id: str) -> dict[str, Any] | None:
        return self._facts.get(fact_id)

    def query(self, domain: str | None = None, limit: int = 100) -> list[dict[str, Any]]:
        if domain:
            ids = self._by_key.get(domain, [])[-limit:]
            return [self._facts[id] for id in ids if id in self._facts]
        return list(self._facts.values())[-limit:]

    def update_fact(self, fact_id: str, **kwargs: Any) -> bool:
        if fact_id not in self._facts:
            return False
        for k, v in kwargs.items():
            if k in self._facts[fact_id]:
                self._facts[fact_id][k] = v
        return True

    def forget(self, fact_id: str) -> bool:
        if fact_id not in self._facts:
            return False
        entry = self._facts.pop(fact_id)
        domain = entry.get("domain", "")
        if domain and fact_id in self._by_key.get(domain, []):
            self._by_key[domain] = [x for x in self._by_key[domain] if x != fact_id]
        return True

    def _evict_one(self) -> None:
        if not self._facts:
            return
        rid = next(iter(self._facts))
        self.forget(rid)