MoviePilot/app/db/adapters/recall.py

"""
只读导出升级前的 Agent 快照，新会话消息不写入此适配器。
"""

from collections.abc import Callable
from datetime import datetime

from sqlalchemy import select
from sqlalchemy.orm import Session

from app.application.messaging.recall import RecallLegacyRecord, RecallSession
from app.db.models.agentchat import AgentChat


class LegacyRecallRepository:
    """
    通过短会话导出有限旧快照，独立消息库保存可恢复的搬迁游标。
    """

    def __init__(self, session_factory: Callable[[], Session]) -> None:
        """
        注入主库工厂，只在尚未完成的历史搬迁时使用。
        """
        self._factory = session_factory

    def page(self, user_id: str, after: int, limit: int) -> tuple[RecallLegacyRecord, ...]:
        """
        仅按 user_id 导出，时间沿用旧记录，不能伪装成升级时新发生的会话。
        """
        with self._factory() as session:
            rows = session.scalars(select(AgentChat).where(AgentChat.user_id == user_id, AgentChat.id > after)
                                   .order_by(AgentChat.id).limit(limit)).all()
            return tuple(RecallLegacyRecord(
                row.id, RecallSession(row.session_id, source=row.source or 'chat', title=row.title or '',
                                      started_at=self._timestamp(row.created_at), last_active=self._timestamp(row.updated_at)),
                tuple(row.agent_messages or []),
            ) for row in rows)

    @staticmethod
    def _timestamp(value: str | None) -> float:
        """
        旧主库时间是宿主本地时间，无可用值时明确保留未知。
        """
        if not value:
            return 0
        try:
            return datetime.fromisoformat(value).timestamp()
        except ValueError:
            return 0