"""AI Steward 上下文缓存服务（Redis）与失效钩子。"""

from __future__ import annotations

import json
import os
import re
from datetime import datetime, timezone
from pathlib import Path
from typing import Any, Optional

from sqlalchemy import and_, case, event, func, inspect, or_, select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import Session

from ...models import Project, ProjectSignalLink, Signal, Task, User, UserProject, UserWorkload

from ...utils.timezone import now_cn_aware
try:
    import redis.asyncio as redis_async
    from redis import Redis as RedisSync

    REDIS_AVAILABLE = True
except Exception:  # pragma: no cover
    REDIS_AVAILABLE = False
    redis_async = None
    RedisSync = None


SYSTEM_SNAPSHOT_SCHEMA_VERSION = "2026-04-07.context-v2"
SYSTEM_TTL_SECONDS = 30 * 60
USER_TTL_SECONDS = 5 * 60
SESSION_TTL_SECONDS = 60 * 60
PROJECT_LIST_TTL_SECONDS = 10 * 60
SIGNAL_PENDING_TTL_SECONDS = 5 * 60
SESSION_MAX_MESSAGES = 20
DONE_TASK_STATUSES = {"done", "completed", "closed", "resolved", "archived"}
PENDING_SIGNAL_STATUSES = {"pending", "todo", "open", "待处理"}


def _safe_int(value: Any, fallback: int = 0) -> int:
    try:
        return int(value)
    except Exception:
        return fallback


def _json_loads(raw: Optional[str], default: Any) -> Any:
    if not raw:
        return default
    try:
        return json.loads(raw)
    except Exception:
        return default


__all__ = [name for name in globals() if not name.startswith("__")]