from fastapi import APIRouter, Depends, HTTPException, Query
from sqlalchemy.orm import Session
from typing import List, Optional, Dict, Any
from datetime import datetime
from core.database import get_db
from models.event import Event

router = APIRouter()

@router.get("/", summary="获取告警列表")
async def get_alarms(
    page: int = Query(1, ge=1, description="页码"),
    size: int = Query(20, ge=1, le=100, description="每页数量"),
    severity: Optional[str] = Query(None, description="严重程度"),
    status: Optional[str] = Query(None, description="告警状态"),
    start_time: Optional[str] = Query(None, description="开始时间"),
    end_time: Optional[str] = Query(None, description="结束时间"),
    db: Session = Depends(get_db)
):
    """获取告警列表，支持分页和筛选"""
    try:
        # 构建查询 - 只查询告警事件
        query = db.query(Event).filter(Event.is_alert == True)
        
        if severity:
            query = query.filter(Event.severity == severity)
        if status:
            query = query.filter(Event.status == status)
        if start_time:
            try:
                start_dt = datetime.fromisoformat(start_time.replace('Z', '+00:00'))
                query = query.filter(Event.created_at >= start_dt)
            except ValueError:
                pass
        if end_time:
            try:
                end_dt = datetime.fromisoformat(end_time.replace('Z', '+00:00'))
                query = query.filter(Event.created_at <= end_dt)
            except ValueError:
                pass
        
        # 按创建时间倒序排列
        query = query.order_by(Event.created_at.desc())
        
        # 计算总数
        total = query.count()
        
        # 分页
        skip = (page - 1) * size
        events = query.offset(skip).limit(size).all()
        
        # 转换为告警格式
        alarms = []
        for event in events:
            # TODO: 获取设备信息
            device_name = f"设备{event.device_id}"  # 临时设备名称
            
            alarms.append({
                "id": event.id,
                "type": event.event_type,
                "severity": event.severity,
                "status": event.status,
                "device": device_name,
                "created_at": event.created_at.isoformat(),
                "description": event.description
            })
        
        return {
            "alarms": alarms,
            "total": total,
            "page": page,
            "size": size
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"获取告警列表失败: {str(e)}")

@router.get("/{alarm_id}", summary="获取告警详情")
async def get_alarm_detail(
    alarm_id: int,
    db: Session = Depends(get_db)
):
    """根据ID获取告警详情"""
    try:
        event = db.query(Event).filter(
            Event.id == alarm_id,
            Event.is_alert == True
        ).first()
        
        if not event:
            raise HTTPException(status_code=404, detail="告警不存在")
        
        # TODO: 获取设备信息
        device_name = f"设备{event.device_id}"
        
        return {
            "id": event.id,
            "type": event.event_type,
            "severity": event.severity,
            "status": event.status,
            "device": device_name,
            "created_at": event.created_at.isoformat(),
            "description": event.description,
            "image_path": event.image_path,
            "video_path": event.video_path,
            "confidence": event.confidence,
            "bbox": event.bbox,
            "resolution_notes": event.resolution_notes,
            "resolved_at": event.resolved_at.isoformat() if event.resolved_at else None
        }
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"获取告警详情失败: {str(e)}")

@router.patch("/{alarm_id}/resolve", summary="处理告警")
async def resolve_alarm(
    alarm_id: int,
    resolution_data: Dict[str, Any],
    db: Session = Depends(get_db)
):
    """处理告警"""
    try:
        event = db.query(Event).filter(
            Event.id == alarm_id,
            Event.is_alert == True
        ).first()
        
        if not event:
            raise HTTPException(status_code=404, detail="告警不存在")
        
        # 更新告警状态
        event.status = "resolved"
        event.resolution_notes = resolution_data.get("resolution_notes", "")
        event.resolved_at = datetime.now()
        
        db.commit()
        
        return {
            "id": event.id,
            "status": "resolved",
            "resolved_at": event.resolved_at.isoformat(),
            "message": "告警已处理"
        }
    except HTTPException:
        raise
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"处理告警失败: {str(e)}")

@router.get("/stats", summary="获取告警统计")
async def get_alarm_stats(db: Session = Depends(get_db)):
    """获取告警统计数据"""
    try:
        # 总告警数
        total_alarms = db.query(Event).filter(Event.is_alert == True).count()
        
        # 待处理告警数
        pending_alarms = db.query(Event).filter(
            Event.is_alert == True,
            Event.status == "pending"
        ).count()
        
        # 已处理告警数
        resolved_alarms = db.query(Event).filter(
            Event.is_alert == True,
            Event.status == "resolved"
        ).count()
        
        # TODO: 按严重程度统计
        # 当前返回模拟数据
        by_severity = [
            {"severity": "high", "count": 12},
            {"severity": "medium", "count": 45},
            {"severity": "low", "count": 32}
        ]
        
        return {
            "total_alarms": total_alarms,
            "pending_alarms": pending_alarms,
            "resolved_alarms": resolved_alarms,
            "by_severity": by_severity
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"获取告警统计失败: {str(e)}")

@router.get("/types/list", summary="获取告警类型列表")
async def get_alarm_types():
    """获取告警类型列表"""
    try:
        # TODO: 从数据库获取告警类型
        # 当前返回固定类型
        alarm_types = [
            "船舶靠泊",
            "船舶离泊", 
            "人员登轮",
            "人员离轮",
            "电脑弹窗",
            "越界检测",
            "车辆识别",
            "货物识别"
        ]
        
        return {
            "alarm_types": alarm_types
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"获取告警类型失败: {str(e)}")

@router.get("/trend", summary="获取告警趋势")
async def get_alarm_trend(
    days: int = Query(7, ge=1, le=30, description="统计天数"),
    db: Session = Depends(get_db)
):
    """获取告警趋势数据"""
    try:
        # TODO: 实现真实的告警趋势统计
        # 当前返回模拟数据
        from datetime import timedelta
        
        end_date = datetime.now().date()
        start_date = end_date - timedelta(days=days-1)
        
        dates = []
        alarm_counts = []
        
        for i in range(days):
            current_date = start_date + timedelta(days=i)
            dates.append(current_date.strftime("%Y-%m-%d"))
            # 模拟数据
            alarm_counts.append(10 + (i * 2) % 20)
        
        return {
            "dates": dates,
            "alarm_counts": alarm_counts
        }
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"获取告警趋势失败: {str(e)}")