From a4873493df86c4ab5f31c8980960cf2042f2974d Mon Sep 17 00:00:00 2001
From: Sudo-Ivan <ivan@quad4.io>
Date: Fri, 2 Jan 2026 17:28:27 -0600
Subject: [PATCH] feat(MessageHandler): optimize conversation fetching using
 window functions for improved performance and add unread message filtering
 capability

---
 meshchatx/src/backend/message_handler.py | 47 +++++++++++++++++-------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/meshchatx/src/backend/message_handler.py b/meshchatx/src/backend/message_handler.py
index 38199b6..2bdd495 100644
--- a/meshchatx/src/backend/message_handler.py
+++ b/meshchatx/src/backend/message_handler.py
@@ -57,33 +57,52 @@ class MessageHandler:
         return self.db.provider.fetchall(query, params)
 
     def get_conversations(self, local_hash, filter_unread=False):
-        # Implementation moved from get_conversations DAO but with local_hash filter
+        # Implementation using window functions for better performance
+        # This requires SQLite 3.25+
         query = """
-            SELECT m1.* FROM lxmf_messages m1
-            JOIN (
-                SELECT 
-                    CASE WHEN source_hash = ? THEN destination_hash ELSE source_hash END as peer_hash,
-                    MAX(timestamp) as max_ts
+            WITH RankedMessages AS (
+                SELECT *,
+                       CASE WHEN source_hash = ? THEN destination_hash ELSE source_hash END as peer_hash,
+                       ROW_NUMBER() OVER (
+                           PARTITION BY CASE WHEN source_hash = ? THEN destination_hash ELSE source_hash END 
+                           ORDER BY timestamp DESC
+                       ) as rn
                 FROM lxmf_messages
                 WHERE source_hash = ? OR destination_hash = ?
-                GROUP BY peer_hash
-            ) m2 ON (CASE WHEN m1.source_hash = ? THEN m1.destination_hash ELSE m1.source_hash END = m2.peer_hash 
-                     AND m1.timestamp = m2.max_ts)
-            WHERE (m1.source_hash = ? OR m1.destination_hash = ?)
+            )
+            SELECT * FROM RankedMessages WHERE rn = 1
         """
         params = [
             local_hash,
             local_hash,
             local_hash,
             local_hash,
-            local_hash,
-            local_hash,
         ]
 
         if filter_unread:
-            query += " AND EXISTS (SELECT 1 FROM lxmf_messages m3 WHERE (m3.source_hash = m2.peer_hash AND m3.destination_hash = ?) AND m3.state = 'received' AND m3.is_incoming = 1)"
+            # For filtering unread, we need to check if there are any received messages from that peer
+            query = """
+                WITH RankedMessages AS (
+                    SELECT *,
+                           CASE WHEN source_hash = ? THEN destination_hash ELSE source_hash END as peer_hash,
+                           ROW_NUMBER() OVER (
+                               PARTITION BY CASE WHEN source_hash = ? THEN destination_hash ELSE source_hash END 
+                               ORDER BY timestamp DESC
+                           ) as rn
+                    FROM lxmf_messages
+                    WHERE source_hash = ? OR destination_hash = ?
+                )
+                SELECT * FROM RankedMessages WHERE rn = 1
+                AND EXISTS (
+                    SELECT 1 FROM lxmf_messages m3 
+                    WHERE m3.source_hash = peer_hash 
+                    AND m3.destination_hash = ? 
+                    AND m3.state = 'received' 
+                    AND m3.is_incoming = 1
+                )
+            """
             params.append(local_hash)
 
-        query += " ORDER BY m1.timestamp DESC"
+        query += " ORDER BY timestamp DESC"
 
         return self.db.provider.fetchall(query, params)