From b1e3e71b68e776a987916170b30c15af2eb28446 Mon Sep 17 00:00:00 2001
From: Jack Kingsman <jack.kingsman@gmail.com>
Date: Mon, 9 Mar 2026 17:03:07 -0700
Subject: [PATCH] extract dm ack tracker service

---
 app/event_handlers.py          | 31 +++++++-----------------
 app/services/dm_ack_tracker.py | 43 ++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 23 deletions(-)
 create mode 100644 app/services/dm_ack_tracker.py

diff --git a/app/event_handlers.py b/app/event_handlers.py
index 0e1db4b..526e8fb 100644
--- a/app/event_handlers.py
+++ b/app/event_handlers.py
@@ -12,6 +12,7 @@ from app.repository import (
     ContactRepository,
     MessageRepository,
 )
+from app.services import dm_ack_tracker
 from app.services.messages import create_fallback_direct_message, increment_ack_and_broadcast
 from app.websocket import broadcast_event
 
@@ -23,33 +24,17 @@ logger = logging.getLogger(__name__)
 # Track active subscriptions so we can unsubscribe before re-registering
 # This prevents handler duplication after reconnects
 _active_subscriptions: list["Subscription"] = []
-
-
-# Track pending ACKs: expected_ack_code -> (message_id, timestamp, timeout_ms)
-_pending_acks: dict[str, tuple[int, float, int]] = {}
+_pending_acks = dm_ack_tracker._pending_acks
 
 
 def track_pending_ack(expected_ack: str, message_id: int, timeout_ms: int) -> None:
-    """Track a pending ACK for a direct message."""
-    _pending_acks[expected_ack] = (message_id, time.time(), timeout_ms)
-    logger.debug(
-        "Tracking pending ACK %s for message %d (timeout %dms)",
-        expected_ack,
-        message_id,
-        timeout_ms,
-    )
+    """Compatibility wrapper for pending DM ACK tracking."""
+    dm_ack_tracker.track_pending_ack(expected_ack, message_id, timeout_ms)
 
 
 def cleanup_expired_acks() -> None:
-    """Remove expired pending ACKs."""
-    now = time.time()
-    expired = []
-    for code, (_msg_id, created_at, timeout_ms) in _pending_acks.items():
-        if now - created_at > (timeout_ms / 1000) * 2:  # 2x timeout as buffer
-            expired.append(code)
-    for code in expired:
-        del _pending_acks[code]
-        logger.debug("Expired pending ACK %s", code)
+    """Compatibility wrapper for expiring stale DM ACK entries."""
+    dm_ack_tracker.cleanup_expired_acks()
 
 
 async def on_contact_message(event: "Event") -> None:
@@ -280,8 +265,8 @@ async def on_ack(event: "Event") -> None:
 
     cleanup_expired_acks()
 
-    if ack_code in _pending_acks:
-        message_id, _, _ = _pending_acks.pop(ack_code)
+    message_id = dm_ack_tracker.pop_pending_ack(ack_code)
+    if message_id is not None:
         logger.info("ACK received for message %d", message_id)
         # DM ACKs don't carry path data, so paths is intentionally omitted.
         # The frontend's mergePendingAck handles the missing field correctly,
diff --git a/app/services/dm_ack_tracker.py b/app/services/dm_ack_tracker.py
new file mode 100644
index 0000000..b882073
--- /dev/null
+++ b/app/services/dm_ack_tracker.py
@@ -0,0 +1,43 @@
+"""Shared pending ACK tracking for outgoing direct messages."""
+
+import logging
+import time
+
+logger = logging.getLogger(__name__)
+
+PendingAck = tuple[int, float, int]
+
+_pending_acks: dict[str, PendingAck] = {}
+
+
+def track_pending_ack(expected_ack: str, message_id: int, timeout_ms: int) -> None:
+    """Track an expected ACK code for an outgoing direct message."""
+    _pending_acks[expected_ack] = (message_id, time.time(), timeout_ms)
+    logger.debug(
+        "Tracking pending ACK %s for message %d (timeout %dms)",
+        expected_ack,
+        message_id,
+        timeout_ms,
+    )
+
+
+def cleanup_expired_acks() -> None:
+    """Remove stale pending ACK entries."""
+    now = time.time()
+    expired_codes = [
+        code
+        for code, (_message_id, created_at, timeout_ms) in _pending_acks.items()
+        if now - created_at > (timeout_ms / 1000) * 2
+    ]
+    for code in expired_codes:
+        del _pending_acks[code]
+        logger.debug("Expired pending ACK %s", code)
+
+
+def pop_pending_ack(ack_code: str) -> int | None:
+    """Claim the tracked message ID for an ACK code if present."""
+    pending = _pending_acks.pop(ack_code, None)
+    if pending is None:
+        return None
+    message_id, _, _ = pending
+    return message_id