"""Project Knowledge Graph service.

第一阶段目标：
1. 构建统一实体/关系/证据写入能力
2. 支持结构化数据（project/task/signal/user）同步
3. 支持代码目录扫描快照
4. 提供图谱概览统计
"""

from __future__ import annotations

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

from sqlalchemy import and_, func, select
from sqlalchemy.ext.asyncio import AsyncSession

from ...models import (
    IngestEvent,
    IngestOffset,
    KGEvidence,
    KGEntity,
    KGRelation,
    KGSyncRun,
    Project,
    FeishuItem,
    Signal,
    SymbolDefinition,
    SymbolReference,
    Task,
    User,
)
from ..context_cache_service import context_cache_service
from ..signal.symbol_index import SymbolIndexService


from ...utils.timezone import now_cn_naive
def _utc_now_naive() -> datetime:
    return now_cn_naive()


DDL_BLOCKED_PREFIXES = [
    "CREATE",
    "ALTER",
    "DROP",
    "TRUNCATE",
    "RENAME",
    "COMMENT",
    "GRANT",
    "REVOKE",
]
DDL_GUARDRAIL_POLICY_KEY = "policy:ddl_via_interface_only"
DDL_GUARDRAIL_POLICY_NAME = "DDL 只能通过受控接口/迁移流程"


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