feat: alert detection and dispatch system for real-time mesh alerts

- Add AlertEngine to detect infra down/recovery, battery critical, critical node offline
- Add alert_channel, critical_nodes, alert_cooldown_minutes config options
- Wire alerts to channel broadcast and DM subscribers
- Add TUI options for critical nodes, alert channel, cooldown

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

meshai/alert_engine.py

@@ -0,0 +1,191 @@
+"""Alert engine — detects mesh state changes and dispatches alerts."""
+
+import logging
+import time
+from typing import Optional, TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from .mesh_health import MeshHealthEngine
+    from .mesh_reporter import MeshReporter
+    from .subscriptions import SubscriptionManager
+
+logger = logging.getLogger(__name__)
+
+
+class AlertEngine:
+    """Detects mesh state changes and dispatches alerts."""
+
+    def __init__(
+        self,
+        health_engine: "MeshHealthEngine",
+        reporter: "MeshReporter",
+        subscription_manager: "SubscriptionManager",
+        critical_nodes: list[str] = None,
+        alert_cooldown_minutes: int = 30,
+    ):
+        self._health = health_engine
+        self._reporter = reporter
+        self._subs = subscription_manager
+        self._critical_nodes = set(n.upper() for n in (critical_nodes or []))
+        self._cooldown_seconds = alert_cooldown_minutes * 60
+
+        # Previous state snapshot for change detection
+        self._prev_infra_online: dict[int, bool] = {}  # node_num -> was_online
+        self._prev_battery: dict[int, float] = {}  # node_num -> battery_percent
+
+        # Cooldown tracker: condition_key -> last_alert_time
+        self._cooldowns: dict[str, float] = {}
+
+        # Queued alerts for delivery
+        self._pending_alerts: list[dict] = []
+
+    def check(self) -> list[dict]:
+        """Compare current health to previous state. Returns list of alert dicts.
+
+        Each alert dict: {
+            "type": "infra_offline" | "infra_recovery" | "battery_critical" | "critical_node_down",
+            "node_name": str,
+            "node_short": str,
+            "node_num": int,
+            "region": str,
+            "message": str,
+            "scope_type": "mesh" | "region" | "node",
+            "scope_value": str,
+            "is_critical": bool,
+        }
+        """
+        health = self._health.mesh_health
+        if not health:
+            return []
+
+        now = time.time()
+        alerts = []
+
+        for node in health.nodes.values():
+            if not node.is_infrastructure:
+                continue
+
+            node_num = node.node_num
+            name = node.long_name or node.short_name or str(node_num)
+            short = node.short_name or str(node_num)
+            region = node.region or "Unknown"
+            is_critical = short.upper() in self._critical_nodes
+
+            # --- Infrastructure offline detection ---
+            was_online = self._prev_infra_online.get(node_num)
+            is_online = node.is_online
+
+            if was_online is not None:  # Skip first run (no previous state)
+                if was_online and not is_online:
+                    # Node went OFFLINE
+                    alert_type = "critical_node_down" if is_critical else "infra_offline"
+                    cooldown_key = f"offline_{node_num}"
+
+                    if self._check_cooldown(cooldown_key, now):
+                        emoji = "\U0001F6A8" if is_critical else "\u274C"  # 🚨 or ❌
+                        region_display = self._get_region_display(region)
+
+                        alerts.append({
+                            "type": alert_type,
+                            "node_name": name,
+                            "node_short": short,
+                            "node_num": node_num,
+                            "region": region,
+                            "message": f"{emoji} {name} went offline in {region_display}.",
+                            "scope_type": "region",
+                            "scope_value": region,
+                            "is_critical": is_critical,
+                        })
+                        self._cooldowns[cooldown_key] = now
+
+                elif not was_online and is_online:
+                    # Node came BACK ONLINE
+                    cooldown_key = f"recovery_{node_num}"
+
+                    if self._check_cooldown(cooldown_key, now):
+                        region_display = self._get_region_display(region)
+
+                        alerts.append({
+                            "type": "infra_recovery",
+                            "node_name": name,
+                            "node_short": short,
+                            "node_num": node_num,
+                            "region": region,
+                            "message": f"\u2705 {name} is back online in {region_display}.",  # ✅
+                            "scope_type": "region",
+                            "scope_value": region,
+                            "is_critical": is_critical,
+                        })
+                        self._cooldowns[cooldown_key] = now
+
+            # --- Battery critical detection (infra only) ---
+            if node.battery_percent is not None and 0 < node.battery_percent <= 100:
+                prev_bat = self._prev_battery.get(node_num)
+                current_bat = node.battery_percent
+
+                if current_bat < 10 and (prev_bat is None or prev_bat >= 10):
+                    # Battery just dropped below 10%
+                    cooldown_key = f"battery_{node_num}"
+
+                    if self._check_cooldown(cooldown_key, now):
+                        region_display = self._get_region_display(region)
+
+                        alerts.append({
+                            "type": "battery_critical",
+                            "node_name": name,
+                            "node_short": short,
+                            "node_num": node_num,
+                            "region": region,
+                            "message": f"\U0001F50B {name} battery critical at {current_bat:.0f}% in {region_display}.",  # 🔋
+                            "scope_type": "region",
+                            "scope_value": region,
+                            "is_critical": is_critical,
+                        })
+                        self._cooldowns[cooldown_key] = now
+
+                self._prev_battery[node_num] = current_bat
+
+            # Update state snapshot
+            self._prev_infra_online[node_num] = is_online
+
+        self._pending_alerts = alerts
+        return alerts
+
+    def _get_region_display(self, region: str) -> str:
+        """Get display name for region."""
+        if not self._reporter:
+            return region
+        try:
+            context = self._reporter._region_context(region)
+            if context:
+                return context.split("(")[0].strip()
+        except Exception:
+            pass
+        return region
+
+    def _check_cooldown(self, key: str, now: float) -> bool:
+        """Check if enough time has passed since last alert for this condition."""
+        last = self._cooldowns.get(key, 0)
+        return (now - last) >= self._cooldown_seconds
+
+    def get_pending_alerts(self) -> list[dict]:
+        """Get alerts pending delivery."""
+        return self._pending_alerts
+
+    def clear_pending(self):
+        """Clear pending alerts after delivery."""
+        self._pending_alerts = []
+
+    def get_subscribers_for_alert(self, alert: dict) -> list[dict]:
+        """Find subscribers matching an alert's scope."""
+        if not self._subs:
+            return []
+
+        # Get all alert subscribers
+        # mesh-scope subscribers get everything
+        # region-scope subscribers get alerts for their region
+        # node-scope subscribers get alerts for their specific node
+        return self._subs.get_alert_subscribers(
+            scope_type=alert.get("scope_type"),
+            scope_value=alert.get("scope_value"),
+        )

meshai/config.py

@@ -198,6 +198,11 @@ class MeshIntelligenceConfig:
     packet_threshold: int = 500  # Non-text packets per 24h to flag
     battery_warning_percent: int = 20  # Battery level for warnings
 
+    # Alert settings
+    critical_nodes: list[str] = field(default_factory=list)  # Short names of critical nodes (e.g., ["MHR", "HPR"])
+    alert_channel: int = -1  # Channel to broadcast alerts on. -1 = disabled, 0+ = channel index
+    alert_cooldown_minutes: int = 30  # Min minutes between repeated alerts for same condition
+
 
 @dataclass
 class Config:

meshai/main.py

@@ -43,6 +43,7 @@ class MeshAI:
         self.health_engine = None
         self.mesh_reporter = None
         self.subscription_manager = None
+        self.alert_engine = None
         self._last_sub_check: float = 0.0
         self.router: Optional[MessageRouter] = None
         self.responder: Optional[Responder] = None
@@ -93,6 +94,12 @@ class MeshAI:
                     self.health_engine.compute(self.data_store)
                     self._last_health_compute = time.time()
 
+                    # Check for alertable conditions
+                    if self.alert_engine:
+                        alerts = self.alert_engine.check()
+                        if alerts:
+                            await self._dispatch_alerts(alerts)
+
             # Check scheduled subscriptions (every 60 seconds)
             if self.subscription_manager and self.mesh_reporter:
                 if time.time() - self._last_sub_check >= 60:
@@ -264,6 +271,19 @@ class MeshAI:
         else:
             self.subscription_manager = None
 
+        # Alert engine (needs health engine, reporter, and subscription manager)
+        if self.health_engine and self.mesh_reporter and self.subscription_manager:
+            from .alert_engine import AlertEngine
+            mi = self.config.mesh_intelligence
+            self.alert_engine = AlertEngine(
+                health_engine=self.health_engine,
+                reporter=self.mesh_reporter,
+                subscription_manager=self.subscription_manager,
+                critical_nodes=getattr(mi, 'critical_nodes', []),
+                alert_cooldown_minutes=getattr(mi, 'alert_cooldown_minutes', 30),
+            )
+            logger.info(f"Alert engine initialized (critical nodes: {getattr(mi, 'critical_nodes', [])})")
+
         # Knowledge base (optional - gracefully degrade if deps missing)
         kb_cfg = self.config.knowledge
         if kb_cfg.enabled and kb_cfg.db_path:
@@ -420,6 +440,40 @@ class MeshAI:
         if pid_file.exists():
             pid_file.unlink()
 
+    async def _dispatch_alerts(self, alerts: list[dict]) -> None:
+        """Dispatch alerts to subscribers and alert channel."""
+        mi = self.config.mesh_intelligence
+        alert_channel = getattr(mi, 'alert_channel', -1)
+
+        for alert in alerts:
+            message = alert["message"]
+            logger.info(f"ALERT: {message}")
+
+            # Send to alert channel if configured
+            if alert_channel >= 0 and self.connector:
+                try:
+                    self.connector.send_message(
+                        text=message,
+                        destination=None,  # Broadcast
+                        channel=alert_channel,
+                    )
+                    logger.info(f"Alert sent to channel {alert_channel}")
+                except Exception as e:
+                    logger.error(f"Failed to send channel alert: {e}")
+
+            # Send DMs to matching subscribers
+            if self.alert_engine and self.subscription_manager:
+                subscribers = self.alert_engine.get_subscribers_for_alert(alert)
+                for sub in subscribers:
+                    user_id = sub["user_id"]
+                    try:
+                        await self._send_sub_dm(user_id, message)
+                        logger.info(f"Alert DM sent to {user_id}: {alert['type']}")
+                    except Exception as e:
+                        logger.error(f"Failed to send alert DM to {user_id}: {e}")
+
+        self.alert_engine.clear_pending()
+
     async def _check_scheduled_subs(self) -> None:
         """Check for and deliver due scheduled reports."""
         from datetime import datetime