gahew

server/src/services/healthService/index.js

@@ -0,0 +1,92 @@
+// health Service
+// Purpose: Defines the health Service module and the helpers/state used by this service unit.
+// Scope: Keeps runtime behavior unchanged while isolating responsibilities into a clear module boundary.
+const fsp = require('fs/promises');
+const path = require('path');
+const roverManager = require('../roverManager');
+const { getRoomCameras } = require('../roomCameraService');
+const { getRoomCameraState } = require('../roomCameraSnapshotService');
+const { getReplayHealthSnapshot } = require('../replayEngineV2');
+
+const ROVER_SNAPSHOT_DIR = process.env.ROVER_SNAPSHOT_DIR || '/var/lib/rover-snapshots';
+const HEALTH_INTERVAL_MS = 5000;
+const ROOM_CAMERA_STALE_MS = 5000;
+const ROVER_SNAPSHOT_STALE_MS = 5000;
+
+let latest = {
+  updatedAt: Date.now(),
+  replay: { sources: [], readyCount: 0, totalCount: 0 },
+  snapshots: { rovers: [], rooms: [] },
+};
+
+function collectReplayHealth() {
+  return getReplayHealthSnapshot();
+}
+
+async function collectSnapshotHealth(now) {
+  const rovers = roverManager.getRoster().map((rover) => ({
+    id: String(rover.id),
+    name: rover.name || rover.id,
+  }));
+  const roverSnapshots = [];
+  for (const rover of rovers) {
+    const filePath = path.join(ROVER_SNAPSHOT_DIR, `${rover.id}.jpg`);
+    let exists = false;
+    let size = 0;
+    let updatedAt = null;
+    try {
+      const stat = await fsp.stat(filePath);
+      exists = true;
+      size = stat.size;
+      updatedAt = stat.mtimeMs;
+    } catch {
+      // missing snapshot
+    }
+    const ageMs = updatedAt ? now - updatedAt : null;
+    const stale = ageMs != null ? ageMs > ROVER_SNAPSHOT_STALE_MS : true;
+    roverSnapshots.push({
+      id: rover.id,
+      name: rover.name,
+      exists,
+      size,
+      updatedAt,
+      ageMs,
+      stale,
+    });
+  }
+
+  const roomSnapshots = getRoomCameras().map((camera) => {
+    const state = getRoomCameraState(camera.id);
+    const updatedAt = state?.ts || null;
+    const ageMs = updatedAt ? now - updatedAt : null;
+    const stale = ageMs != null ? ageMs > ROOM_CAMERA_STALE_MS : true;
+    return {
+      id: camera.id,
+      name: camera.name || camera.id,
+      updatedAt,
+      ageMs,
+      error: state?.error || null,
+      stale,
+    };
+  });
+
+  return { rovers: roverSnapshots, rooms: roomSnapshots };
+}
+
+async function refreshHealth() {
+  const now = Date.now();
+  const replay = collectReplayHealth(now);
+  const snapshots = await collectSnapshotHealth(now);
+  latest = { updatedAt: now, replay, snapshots };
+}
+
+refreshHealth();
+setInterval(refreshHealth, HEALTH_INTERVAL_MS);
+
+function getHealthSnapshot() {
+  return latest;
+}
+
+module.exports = {
+  getHealthSnapshot,
+};