feat: persist probe quality and notification outbox

backend/app/models/device.py

@@ -1,8 +1,14 @@
 import enum
+from dataclasses import dataclass
 from datetime import datetime
-from sqlalchemy import Column, Integer, String, Float, Boolean, DateTime, Enum, Text
+from typing import TYPE_CHECKING
+
+from sqlalchemy import Boolean, Column, DateTime, Enum, Float, Integer, String
 from sqlalchemy.orm import DeclarativeBase
 
+if TYPE_CHECKING:
+    from app.config import Settings
+
 
 class Base(DeclarativeBase):
     pass
@@ -16,6 +22,56 @@ class DeviceTypeEnum(str, enum.Enum):
     other = "other"           # 其他
 
 
+@dataclass(frozen=True)
+class DeviceMonitoringPolicy:
+    """Resolved monitoring thresholds for one device.
+
+    Nullable device fields intentionally inherit the runtime defaults so a
+    configuration change can apply to devices that do not need exceptions.
+    """
+
+    probe_packets_per_round: int
+    offline_consecutive_rounds: int
+    degraded_window_rounds: int
+    degraded_loss_percent: float
+    recovery_consecutive_clean_rounds: int
+
+    @classmethod
+    def from_device(
+        cls,
+        device: "Device",
+        settings: "Settings",
+    ) -> "DeviceMonitoringPolicy":
+        """Resolve device overrides without changing the stored device."""
+        return cls(
+            probe_packets_per_round=(
+                device.probe_packets_per_round
+                if device.probe_packets_per_round is not None
+                else settings.probe_packets_per_round
+            ),
+            offline_consecutive_rounds=(
+                device.offline_consecutive_rounds
+                if device.offline_consecutive_rounds is not None
+                else settings.offline_consecutive_rounds
+            ),
+            degraded_window_rounds=(
+                device.degraded_window_rounds
+                if device.degraded_window_rounds is not None
+                else settings.degraded_window_rounds
+            ),
+            degraded_loss_percent=(
+                device.degraded_loss_percent
+                if device.degraded_loss_percent is not None
+                else settings.degraded_loss_percent
+            ),
+            recovery_consecutive_clean_rounds=(
+                device.recovery_consecutive_clean_rounds
+                if device.recovery_consecutive_clean_rounds is not None
+                else settings.recovery_consecutive_clean_rounds
+            ),
+        )
+
+
 class Device(Base):
     __tablename__ = "devices"
 
@@ -32,8 +88,39 @@ class Device(Base):
     alert_threshold = Column(Integer, default=5, comment="连续失败次数判离线")
     is_enabled = Column(Boolean, default=True, comment="是否启用监控")
 
+    # 设备级监测策略覆盖；NULL 时使用运行环境中的全局默认值。
+    probe_packets_per_round = Column(
+        Integer,
+        nullable=True,
+        comment="单轮探测发包数覆盖",
+    )
+    offline_consecutive_rounds = Column(
+        Integer,
+        nullable=True,
+        comment="连续全丢包离线轮数覆盖",
+    )
+    degraded_window_rounds = Column(
+        Integer,
+        nullable=True,
+        comment="故障丢包滑动窗口轮数覆盖",
+    )
+    degraded_loss_percent = Column(
+        Float,
+        nullable=True,
+        comment="故障丢包率阈值覆盖",
+    )
+    recovery_consecutive_clean_rounds = Column(
+        Integer,
+        nullable=True,
+        comment="连续零丢包恢复轮数覆盖",
+    )
+
     # 运行状态
-    current_status = Column(String(16), default="unknown", comment="当前状态: online/offline/unknown")
+    current_status = Column(
+        String(16),
+        default="unknown",
+        comment="当前状态: online/degraded/offline/unknown",
+    )
     consecutive_failures = Column(Integer, default=0, comment="当前连续失败次数")
     last_ping_time = Column(DateTime, nullable=True, comment="最后一次 ping 时间")
     last_online_time = Column(DateTime, nullable=True, comment="最后一次在线时间")