"""
Alert Rules Router - 告警规则配置接口
API endpoints for alert rule CRUD operations.
"""

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.dependencies import require_write
from app.models import AlertRule
from app.schemas import (
    APIResponse,
    AlertRuleCreate,
    AlertRuleResponse,
    AlertRuleUpdate,
)

router = APIRouter(prefix="/api/alert-rules", tags=["Alert Rules / 告警规则"])


@router.get(
    "",
    response_model=APIResponse[list[AlertRuleResponse]],
    summary="获取告警规则列表 / List alert rules",
)
async def list_rules(db: AsyncSession = Depends(get_db)):
    """获取所有告警规则。"""
    result = await db.execute(select(AlertRule).order_by(AlertRule.id))
    rules = list(result.scalars().all())
    return APIResponse(data=[AlertRuleResponse.model_validate(r) for r in rules])


@router.post(
    "",
    response_model=APIResponse[AlertRuleResponse],
    status_code=201,
    summary="创建告警规则 / Create alert rule",
    dependencies=[Depends(require_write)],
)
async def create_rule(body: AlertRuleCreate, db: AsyncSession = Depends(get_db)):
    """创建新告警规则。"""
    rule = AlertRule(
        name=body.name,
        rule_type=body.rule_type,
        conditions=body.conditions,
        is_active=body.is_active,
        device_ids=body.device_ids,
        group_id=body.group_id,
        description=body.description,
    )
    db.add(rule)
    await db.flush()
    await db.refresh(rule)
    return APIResponse(data=AlertRuleResponse.model_validate(rule))


@router.get(
    "/{rule_id}",
    response_model=APIResponse[AlertRuleResponse],
    summary="获取告警规则详情 / Get alert rule",
)
async def get_rule(rule_id: int, db: AsyncSession = Depends(get_db)):
    """获取告警规则详情。"""
    result = await db.execute(select(AlertRule).where(AlertRule.id == rule_id))
    rule = result.scalar_one_or_none()
    if not rule:
        raise HTTPException(status_code=404, detail=f"规则 {rule_id} 不存在")
    return APIResponse(data=AlertRuleResponse.model_validate(rule))


@router.put(
    "/{rule_id}",
    response_model=APIResponse[AlertRuleResponse],
    summary="更新告警规则 / Update alert rule",
    dependencies=[Depends(require_write)],
)
async def update_rule(
    rule_id: int, body: AlertRuleUpdate, db: AsyncSession = Depends(get_db)
):
    """更新告警规则。"""
    result = await db.execute(select(AlertRule).where(AlertRule.id == rule_id))
    rule = result.scalar_one_or_none()
    if not rule:
        raise HTTPException(status_code=404, detail=f"规则 {rule_id} 不存在")
    update_data = body.model_dump(exclude_unset=True)
    for k, v in update_data.items():
        setattr(rule, k, v)
    await db.flush()
    await db.refresh(rule)
    return APIResponse(data=AlertRuleResponse.model_validate(rule))


@router.delete(
    "/{rule_id}",
    response_model=APIResponse,
    summary="删除告警规则 / Delete alert rule",
    dependencies=[Depends(require_write)],
)
async def delete_rule(rule_id: int, db: AsyncSession = Depends(get_db)):
    """删除告警规则。"""
    result = await db.execute(select(AlertRule).where(AlertRule.id == rule_id))
    rule = result.scalar_one_or_none()
    if not rule:
        raise HTTPException(status_code=404, detail=f"规则 {rule_id} 不存在")
    await db.delete(rule)
    await db.flush()
    return APIResponse(message="规则已删除")