From 1f6789b9cf7f68abd373c758536e76f23d895474 Mon Sep 17 00:00:00 2001
From: Eddy de Vink <github@eddydev.ink>
Date: Thu, 24 Sep 2026 22:44:10 +0200
Subject: [PATCH] =?UTF-8?q?feat(ack):=20activity-driven=20check=20loop=20+?=
 =?UTF-8?q?=20prune=20=E2=80=94=20geen=2030s-polling=20in=20rust?=
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Content-Transfer-Encoding: 8bit

---
 .env.example      |  3 ++-
 src/ackTracker.js | 44 ++++++++++++++++++++++++++++++++++++++++----
 src/index.js      | 18 +++++++++++++++++-
 3 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/.env.example b/.env.example
index 5eca407..21102fb 100644
--- a/.env.example
+++ b/.env.example
@@ -23,7 +23,8 @@ MAX_REQUESTS_PER_DAY=5
 
 # Ack tracking (ghost-send detectie; vereist message_ack aangezet in wwebjs-api .env)
 ACK_STUCK_TIMEOUT_MS=300000      # 5 min zonder ack 2 = stuck
-ACK_CHECK_INTERVAL_MS=30000      # checkinterval
+ACK_PRUNED_AFTER_MS=1800000      # 30 min: stale trackings opruimen (loop stopt dan)
+ACK_CHECK_INTERVAL_MS=30000      # checkinterval (alleen actief als er iets pending is)
 
 # Admin notifications
 ADMIN_NUMBER=31612345678@c.us
diff --git a/src/ackTracker.js b/src/ackTracker.js
index 0c0d372..d02bf55 100644
--- a/src/ackTracker.js
+++ b/src/ackTracker.js
@@ -6,17 +6,31 @@
 // Findings (2026-09-24): an ack-1 hang is a bestand×ontvanger interaction, NOT
 // the session. The same file hung (ack 1) for one recipient yet delivered
 // (ack 3) to another in the same fresh session. A session restart does NOT fix
-// an ack-1 hang (the same file kept hanging after restart) and needlessly
-// disrupts production — so we deliberately do NOT auto-restart here. We only
-// detect + notify + name the file, so it can be re-rendered and re-tested.
+// an ack-1 hang and needlessly disrupts production — so we deliberately do NOT
+// auto-restart here. We only detect + notify + name the file, so it can be
+// re-rendered and re-tested.
+//
+// Activity-driven: the caller (index.js) is notified via the pending listener
+// when the tracked set becomes non-empty, and starts a check loop only then.
+// No polling when nothing is tracked.
 //
 // Requires the bridge (wwebjs-api) to emit message_ack: remove 'message_ack'
 // from DISABLED_CALLBACKS in the wwebjs-api .env and restart the container.
 
 const STUCK_TIMEOUT_MS = parseInt(process.env.ACK_STUCK_TIMEOUT_MS, 10) || 5 * 60 * 1000
+const PRUNE_AFTER_MS = parseInt(process.env.ACK_PRUNED_AFTER_MS, 10) || 30 * 60 * 1000
 
 // messageId -> { chatId, filename, sentAt, ack, notifiedStuck }
 const sends = new Map()
+let pendingListener = null
+
+function setPendingListener(fn) {
+  pendingListener = typeof fn === 'function' ? fn : null
+}
+
+function notifyPendingChange() {
+  if (pendingListener) pendingListener(sends.size)
+}
 
 function registerSend(messageId, chatId, filename) {
   if (!messageId) return
@@ -28,6 +42,7 @@ function registerSend(messageId, chatId, filename) {
     notifiedStuck: false
   })
   console.log(`[ack] track ${messageId} (${filename} → ${chatId})`)
+  notifyPendingChange()
 }
 
 function handleAck(messageId, ack) {
@@ -38,6 +53,25 @@ function handleAck(messageId, ack) {
   if (ack >= 2) {
     sends.delete(messageId) // delivered; nothing left to track
     console.log(`[ack] delivered ack=${ack} ${messageId} (${entry.filename})`)
+    notifyPendingChange()
+  }
+}
+
+// Remove stale entries (older than PRUNE_AFTER_MS). Stuck entries were notified
+// once around STUCK_TIMEOUT_MS; keeping them longer only leaks memory and keeps
+// the check-loop alive, so they are dropped here.
+function prune() {
+  const now = Date.now()
+  let removed = 0
+  for (const [id, entry] of sends) {
+    if (now - entry.sentAt > PRUNE_AFTER_MS) {
+      sends.delete(id)
+      removed++
+    }
+  }
+  if (removed > 0) {
+    console.log(`[ack] pruned ${removed} stale entr${removed === 1 ? 'y' : 'ies'} (leeftijd > ${Math.round(PRUNE_AFTER_MS / 60000)} min)`)
+    notifyPendingChange()
   }
 }
 
@@ -65,6 +99,8 @@ module.exports = {
   registerSend,
   handleAck,
   stuckEntries,
+  prune,
   markNotified,
-  pendingCount
+  pendingCount,
+  setPendingListener
 }
\ No newline at end of file
diff --git a/src/index.js b/src/index.js
index bb3f395..162da5c 100644
--- a/src/index.js
+++ b/src/index.js
@@ -116,6 +116,7 @@ async function startServer() {
 }
 
 async function checkStuckAcks() {
+  ackTracker.prune()
   const stuck = ackTracker.stuckEntries()
   if (stuck.length === 0) return
   for (const s of stuck) {
@@ -130,7 +131,22 @@ async function checkStuckAcks() {
   }
 }
 
+// Lazy, activity-driven check loop: only runs while there is a tracked send
+// pending, and stops as soon as the tracked set is empty. No 30s polling in
+// idle. Re-arms itself after every tick while pendingCount() > 0.
 const ackCheckIntervalMs = parseInt(process.env.ACK_CHECK_INTERVAL_MS, 10) || 30000
-setInterval(checkStuckAcks, ackCheckIntervalMs)
+let ackTimer = null
+
+function scheduleAckCheck() {
+  if (ackTimer) return
+  if (ackTracker.pendingCount() === 0) return
+  ackTimer = setTimeout(() => {
+    ackTimer = null
+    checkStuckAcks()
+    if (ackTracker.pendingCount() > 0) scheduleAckCheck()
+  }, ackCheckIntervalMs)
+}
+
+ackTracker.setPendingListener(() => scheduleAckCheck())
 
 startServer()
\ No newline at end of file