feat(webhooks): add polling optimization and fallback when webhooks are active (Phase 5)

server/utils/cache.js

@@ -72,4 +72,64 @@ class MemoryCache {
 
 const cache = new MemoryCache();
 
+// Webhook metrics for polling optimization
+// These are stored separately from regular cache entries
+const webhookMetrics = {
+  // Per-instance metrics: key = instance URL, value = { lastWebhookTimestamp, eventsReceived, pollsSkipped }
+  instances: new Map(),
+  // Global metrics
+  lastGlobalWebhookTimestamp: null,
+  totalWebhookEventsReceived: 0
+};
+
+function getWebhookMetrics(instanceUrl) {
+  if (!instanceUrl) return null;
+  return webhookMetrics.instances.get(instanceUrl) || {
+    lastWebhookTimestamp: null,
+    eventsReceived: 0,
+    pollsSkipped: 0
+  };
+}
+
+function updateWebhookMetrics(instanceUrl) {
+  const now = Date.now();
+  webhookMetrics.lastGlobalWebhookTimestamp = now;
+  webhookMetrics.totalWebhookEventsReceived++;
+  
+  if (instanceUrl) {
+    const metrics = webhookMetrics.instances.get(instanceUrl) || {
+      lastWebhookTimestamp: null,
+      eventsReceived: 0,
+      pollsSkipped: 0
+    };
+    metrics.lastWebhookTimestamp = now;
+    metrics.eventsReceived++;
+    webhookMetrics.instances.set(instanceUrl, metrics);
+  }
+}
+
+function incrementPollsSkipped(instanceUrl) {
+  if (instanceUrl) {
+    const metrics = webhookMetrics.instances.get(instanceUrl) || {
+      lastWebhookTimestamp: null,
+      eventsReceived: 0,
+      pollsSkipped: 0
+    };
+    metrics.pollsSkipped++;
+    webhookMetrics.instances.set(instanceUrl, metrics);
+  }
+}
+
+function getGlobalWebhookMetrics() {
+  return {
+    lastGlobalWebhookTimestamp: webhookMetrics.lastGlobalWebhookTimestamp,
+    totalWebhookEventsReceived: webhookMetrics.totalWebhookEventsReceived,
+    instances: Object.fromEntries(webhookMetrics.instances)
+  };
+}
+
 module.exports = cache;
+module.exports.getWebhookMetrics = getWebhookMetrics;
+module.exports.updateWebhookMetrics = updateWebhookMetrics;
+module.exports.incrementPollsSkipped = incrementPollsSkipped;
+module.exports.getGlobalWebhookMetrics = getGlobalWebhookMetrics;