"""审核规则自动同步到数据库。

启动时从 _RULE_REGISTRY 提取所有注册规则，同步到 audit_rules 表：
- 新增规则 → INSERT
- 已有规则 → UPDATE severity/config_json/is_enabled（保留用户自定义覆盖）
- 不再存在的规则 → 不删除（保留历史数据）
"""
import json
import logging
from typing import Any, Dict, List

from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

logger = logging.getLogger(__name__)


async def sync_rules_to_db(db: AsyncSession) -> int:
    """将注册表中的规则同步到数据库。返回同步数量。"""
    from app.services.audit_engine_v2 import _RULE_REGISTRY, RuleCategory, Severity

    synced = 0
    for code, (default_rule, _func) in _RULE_REGISTRY.items():
        # 查找已有记录（按 code 或 name）
        from app.models.audit_rule import AuditRule
        stmt = select(AuditRule).where(AuditRule.code == code)
        result = await db.execute(stmt)
        existing = result.scalar_one_or_none()

        if existing is None:
            # 按 name 兼容查找
            stmt2 = select(AuditRule).where(AuditRule.name == default_rule.name)
            result2 = await db.execute(stmt2)
            existing = result2.scalar_one_or_none()

        config_json_str = json.dumps(default_rule.config, ensure_ascii=False) if default_rule.config else None
        category = default_rule.category.value if isinstance(default_rule.category, RuleCategory) else str(default_rule.category)
        severity = default_rule.severity.value if isinstance(default_rule.severity, Severity) else str(default_rule.severity)

        if existing is None:
            # 新增
            new_rule = AuditRule(
                code=code,
                name=default_rule.name,
                description=default_rule.description,
                rule_type=category,
                severity=severity,
                db_type=default_rule.db_type,
                pattern=default_rule.pattern,
                value=None,
                config_json=config_json_str,
                is_enabled=default_rule.is_enabled,
                message=default_rule.message_template,
            )
            db.add(new_rule)
            synced += 1
        else:
            # 已有：更新 code 和 description（保留用户自定义的 severity/enabled/config）
            needs_update = False
            if existing.code is None:
                existing.code = code
                needs_update = True
            if existing.description != default_rule.description and existing.description is None:
                existing.description = default_rule.description
                needs_update = True
            if existing.message != default_rule.message_template and existing.message is None:
                existing.message = default_rule.message_template
                needs_update = True
            # 仅在 config_json 为空时初始化（首次同步）
            if existing.config_json is None and config_json_str:
                existing.config_json = config_json_str
                needs_update = True
            if needs_update:
                synced += 1

    await db.commit()
    if synced > 0:
        logger.info(f"审核规则同步完成: {synced} 条更新")
    return synced