性能：看板数据合并为单次请求 + 摄像头名称缓存

- 新增 GET /alert/dashboard 聚合接口，一次返回全部看板数据
- 共用同一个 DB session 执行所有查询，减少连接开销
- 摄像头名称服务增加 5 分钟内存缓存，避免重复查询 WVP
- 设备Top10 和最近告警共用一次批量摄像头名称查询

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/routers/yudao_aiot_alarm.py

@@ -279,6 +279,42 @@ async def delete_alert(
     return YudaoResponse.success(True)
 
 
+@router.get("/alert/dashboard")
+async def get_dashboard(
+    trendDays: int = Query(7, ge=1, le=90, description="趋势天数"),
+    service: AlarmEventService = Depends(get_alarm_event_service),
+    current_user: dict = Depends(get_current_user)
+):
+    """看板数据（一次返回全部，减少请求数）"""
+    data = service.get_dashboard_data(trend_days=trendDays)
+
+    # 批量查询摄像头名称（device-top + recent-alerts 共用）
+    camera_service = get_camera_name_service()
+    device_ids = list(set(
+        [d["deviceId"] for d in data["deviceTop"]] +
+        [a.get("device_id", "") for a in data["recentAlerts"]]
+    ))
+    camera_info_map = {}
+    try:
+        camera_info_map = await camera_service.get_camera_infos_batch(device_ids)
+    except Exception as e:
+        logger.warning(f"批量查询摄像头信息失败: {e}")
+
+    # 填充设备名称
+    for item in data["deviceTop"]:
+        did = item["deviceId"]
+        info = camera_info_map.get(did)
+        item["deviceName"] = camera_service.format_display_name(did, info)
+
+    # 转换最近告警
+    alarm_list = []
+    for a in data["recentAlerts"]:
+        alarm_list.append(await _alarm_to_camel(a, camera_info_map, camera_service))
+    data["recentAlerts"] = alarm_list
+
+    return YudaoResponse.success(data)
+
+
 @router.get("/alert/statistics")
 async def get_statistics(
     service: AlarmEventService = Depends(get_alarm_event_service),

app/services/alarm_event_service.py

@@ -656,6 +656,102 @@ class AlarmEventService:
         finally:
             db.close()
 
+    def get_dashboard_data(self, trend_days: int = 7) -> Dict:
+        """一次查询返回看板所有数据（共用一个 DB session，减少连接开销）"""
+        db = get_session()
+        try:
+            now = beijing_now()
+            today_start = now.replace(hour=0, minute=0, second=0, microsecond=0)
+            yesterday_start = today_start - timedelta(days=1)
+            trend_start = (now - timedelta(days=trend_days)).replace(hour=0, minute=0, second=0, microsecond=0)
+            week_start = (now - timedelta(days=7)).replace(hour=0, minute=0, second=0, microsecond=0)
+
+            # === 统计概览 ===
+            total = db.query(AlarmEvent).count()
+            today_count = db.query(AlarmEvent).filter(AlarmEvent.event_time >= today_start).count()
+            yesterday_count = db.query(AlarmEvent).filter(
+                AlarmEvent.event_time >= yesterday_start, AlarmEvent.event_time < today_start
+            ).count()
+            pending_count = db.query(AlarmEvent).filter(AlarmEvent.handle_status == "UNHANDLED").count()
+            handled_count = db.query(AlarmEvent).filter(AlarmEvent.handle_status.in_(["DONE", "IGNORED"])).count()
+
+            from sqlalchemy.sql.expression import literal_column
+            avg_response = db.query(
+                func.avg(func.timestampdiff(literal_column("MINUTE"), AlarmEvent.event_time, AlarmEvent.handled_at))
+            ).filter(AlarmEvent.handled_at.isnot(None), AlarmEvent.handled_at > AlarmEvent.event_time).scalar()
+
+            by_type = {}
+            for r in db.query(AlarmEvent.alarm_type, func.count(AlarmEvent.alarm_id)).group_by(AlarmEvent.alarm_type).all():
+                by_type[r[0]] = r[1]
+
+            by_level = {}
+            for r in db.query(AlarmEvent.alarm_level, func.count(AlarmEvent.alarm_id)).group_by(AlarmEvent.alarm_level).all():
+                by_level[r[0]] = r[1]
+
+            # === 趋势 ===
+            trend_rows = db.query(
+                func.date(AlarmEvent.event_time).label("date"),
+                AlarmEvent.alarm_type,
+                func.count(AlarmEvent.alarm_id).label("cnt"),
+            ).filter(AlarmEvent.event_time >= trend_start).group_by(
+                func.date(AlarmEvent.event_time), AlarmEvent.alarm_type
+            ).all()
+
+            date_map: Dict[str, Dict[str, int]] = {}
+            for r in trend_rows:
+                d = str(r.date)
+                if d not in date_map:
+                    date_map[d] = {}
+                date_map[d][r.alarm_type] = r.cnt
+
+            trend = []
+            for i in range(trend_days):
+                d = (trend_start + timedelta(days=i)).strftime("%Y-%m-%d")
+                tc = date_map.get(d, {})
+                trend.append({"date": d, "total": sum(tc.values()), **tc})
+
+            # === 设备 Top10（近7天） ===
+            device_rows = db.query(
+                AlarmEvent.device_id, func.count(AlarmEvent.alarm_id).label("cnt")
+            ).filter(AlarmEvent.event_time >= week_start).group_by(
+                AlarmEvent.device_id
+            ).order_by(func.count(AlarmEvent.alarm_id).desc()).limit(10).all()
+
+            device_top = [{"deviceId": r.device_id, "count": r.cnt} for r in device_rows]
+
+            # === 24h 分布（近7天） ===
+            hour_rows = db.query(
+                func.hour(AlarmEvent.event_time).label("h"),
+                func.count(AlarmEvent.alarm_id).label("cnt"),
+            ).filter(AlarmEvent.event_time >= week_start).group_by(
+                func.hour(AlarmEvent.event_time)
+            ).all()
+            hour_map = {r.h: r.cnt for r in hour_rows}
+            hour_dist = [{"hour": h, "count": hour_map.get(h, 0)} for h in range(24)]
+
+            # === 最近10条告警 ===
+            recent = db.query(AlarmEvent).order_by(AlarmEvent.event_time.desc()).limit(10).all()
+            recent_list = [a.to_dict() for a in recent]
+
+            return {
+                "statistics": {
+                    "total": total,
+                    "todayCount": today_count,
+                    "yesterdayCount": yesterday_count,
+                    "pendingCount": pending_count,
+                    "handledCount": handled_count,
+                    "avgResponseMinutes": round(float(avg_response), 1) if avg_response else None,
+                    "byType": by_type,
+                    "byLevel": by_level,
+                },
+                "trend": trend,
+                "deviceTop": device_top,
+                "hourDistribution": hour_dist,
+                "recentAlerts": recent_list,
+            }
+        finally:
+            db.close()
+
     def get_device_summary(
         self,
         page: int = 1,

app/services/camera_name_service.py

@@ -16,44 +16,40 @@
 """
 
 from typing import Optional, Dict, List
+import time
 import httpx
 from app.config import CameraNameConfig
 from app.utils.logger import logger
 
 
 class CameraNameService:
-    """摄像头名称服务"""
+    """摄像头名称服务（带内存缓存）"""
+
+    # 缓存 TTL（秒）
+    CACHE_TTL = 300  # 5 分钟
 
     def __init__(self, config: CameraNameConfig):
-        """
-        初始化服务
-
-        Args:
-            config: 摄像头名称配置
-        """
         self.config = config
+        self._cache: Dict[str, tuple] = {}  # {device_id: (info, expire_time)}
 
     async def get_camera_info(self, device_id: str) -> Optional[Dict]:
-        """
-        从 WVP 查询摄像头信息
+        """从 WVP 查询摄像头信息（带缓存）"""
+        # 检查缓存
+        cached = self._cache.get(device_id)
+        if cached and cached[1] > time.time():
+            return cached[0]
 
-        Args:
-            device_id: 设备ID，支持两种格式：
-                - camera_code 格式：cam_xxxxxxxxxxxx
-                - app/stream 格式：大堂吧台3/012
-
-        Returns:
-            摄像头信息字典，查询失败返回 None
-        """
+        info = None
         # camera_code 格式（推荐）
         if device_id.startswith("cam_"):
-            return await self._query_by_camera_code(device_id)
-
+            info = await self._query_by_camera_code(device_id)
         # app/stream 格式（遗留格式，直接解析）
         elif "/" in device_id:
-            return self._parse_app_stream_format(device_id)
+            info = self._parse_app_stream_format(device_id)
 
-        return None
+        # 写入缓存（包括 None 结果，避免反复查询不存在的设备）
+        self._cache[device_id] = (info, time.time() + self.CACHE_TTL)
+        return info
 
     def _parse_app_stream_format(self, device_id: str) -> Optional[Dict]:
         """