From f73ef29c1e1116556095ecc94b7806909162f985 Mon Sep 17 00:00:00 2001
From: Cobra <cobra@192.168.1.42>
Date: Tue, 14 Apr 2026 13:39:37 -0400
Subject: [PATCH] net_alerter: Add Strategy 0 MAC deduplication and fix
 Strategy 3 overwrite bug

Strategy 0 now checks if a MAC already exists in any identity's wifi_macs/ble_macs
sets before creating a new record. Prevents duplicate identity creation on repeated
mDNS/ARP signals.

Strategy 3 now conditionally updates existing records instead of unconditionally
overwriting them. Preserves signal_count and signal_types accumulation needed for
auto-enrollment (2+ signal types).

Fixes issue where devices seen only via mDNS/ARP never reached enrollment threshold.
---
 net_alerter/net_alerter.py | 65 +++++++++++++++++++++++++++++---------
 1 file changed, 50 insertions(+), 15 deletions(-)

diff --git a/net_alerter/net_alerter.py b/net_alerter/net_alerter.py
index 91489d1..13c9431 100644
--- a/net_alerter/net_alerter.py
+++ b/net_alerter/net_alerter.py
@@ -186,6 +186,7 @@ def _correlate_or_create_identity(mac: str, signal_type: str, dhcp_fp: str = "",
     signal_type: "ble", "dhcp", "arp", or "mdns"
 
     Lookup strategy:
+    0. Check if MAC already exists in any identity's MAC sets
     1. If handoff_seq provided, look for matching BLE handoff seq anchor
     2. If dhcp_fp provided, look for matching DHCP fingerprint
     3. If neither, create new provisional identity
@@ -196,6 +197,18 @@ def _correlate_or_create_identity(mac: str, signal_type: str, dhcp_fp: str = "",
         # Determine signal category: 'ble' or 'wifi' (for dhcp/arp/mdns)
         signal_category = 'ble' if signal_type == 'ble' else 'wifi'
 
+        # Strategy 0: Check if MAC already exists in any identity
+        for iid, dev in device_store.items():
+            if mac in dev['wifi_macs'] or mac in dev['ble_macs']:
+                # Found existing identity for this MAC — update instead of creating new
+                dev['last_seen'][mac] = time.time()
+                dev['signal_types'].add(signal_category)
+                logging.debug(f"MAC {mac} already linked to identity {iid}, updated {signal_category} signal")
+                # Check if meets enrollment criteria (2+ signal types)
+                if len(dev['signal_types']) >= 2 and not dev['enrolled']:
+                    _fire_enrollment_callback(iid)
+                return iid
+
         # Strategy 1: Match by BLE Handoff sequence (most stable)
         if handoff_seq is not None:
             for iid, dev in device_store.items():
@@ -232,23 +245,45 @@ def _correlate_or_create_identity(mac: str, signal_type: str, dhcp_fp: str = "",
             # Provisional identity based on first MAC seen
             identity_id = f"prov:{mac}"
 
-        dev = _create_identity_record(identity_id)
-
-        # Add initial signal
-        if signal_type == "ble":
-            dev['ble_macs'].add(mac)
-            if handoff_seq is not None:
-                dev['handoff_seq'] = handoff_seq
-            dev['signal_types'].add('ble')
+        # Check if this identity already exists (e.g., multiple mDNS/ARP signals for same MAC)
+        if identity_id in device_store:
+            dev = device_store[identity_id]
+            # Update existing record instead of overwriting
+            if signal_type == "ble":
+                dev['ble_macs'].add(mac)
+                if handoff_seq is not None:
+                    dev['handoff_seq'] = handoff_seq
+                dev['signal_types'].add('ble')
+            else:
+                dev['wifi_macs'].add(mac)
+                if dhcp_fp:
+                    dev['dhcp_fingerprint'] = dhcp_fp
+                dev['signal_types'].add('wifi')
+            dev['last_seen'][mac] = time.time()
+            # Check if meets enrollment criteria (2+ signal types)
+            if len(dev['signal_types']) >= 2 and not dev['enrolled']:
+                _fire_enrollment_callback(identity_id)
+            logging.debug(f"Updated device identity {identity_id} with {signal_type} signal (MAC: {mac})")
         else:
-            dev['wifi_macs'].add(mac)
-            if dhcp_fp:
-                dev['dhcp_fingerprint'] = dhcp_fp
-            dev['signal_types'].add('wifi')
+            # Create new identity
+            dev = _create_identity_record(identity_id)
+
+            # Add initial signal
+            if signal_type == "ble":
+                dev['ble_macs'].add(mac)
+                if handoff_seq is not None:
+                    dev['handoff_seq'] = handoff_seq
+                dev['signal_types'].add('ble')
+            else:
+                dev['wifi_macs'].add(mac)
+                if dhcp_fp:
+                    dev['dhcp_fingerprint'] = dhcp_fp
+                dev['signal_types'].add('wifi')
+
+            dev['last_seen'][mac] = time.time()
+            device_store[identity_id] = dev
+            logging.debug(f"Created new device identity {identity_id} from {signal_type} signal")
 
-        dev['last_seen'][mac] = time.time()
-        device_store[identity_id] = dev
-        logging.debug(f"Created new device identity {identity_id} from {signal_type} signal")
         return identity_id