Self-repairing message counter

ts/sql/Server.ts

@@ -268,6 +268,8 @@ const dataInterface: ServerInterface = {
   processGroupCallRingCancelation,
   cleanExpiredGroupCallRings,
 
+  getMaxMessageCounter,
+
   getStatisticsForLogging,
 
   // Server-only
@@ -6493,6 +6495,25 @@ async function cleanExpiredGroupCallRings(): Promise<void> {
   });
 }
 
+async function getMaxMessageCounter(): Promise<number | undefined> {
+  const db = getInstance();
+
+  return db
+    .prepare<EmptyQuery>(
+      `
+    SELECT MAX(counter)
+    FROM
+      (
+        SELECT MAX(received_at) AS counter FROM messages
+        UNION
+        SELECT MAX(timestamp) AS counter FROM unprocessed
+      )
+    `
+    )
+    .pluck()
+    .get();
+}
+
 async function getStatisticsForLogging(): Promise<Record<string, string>> {
   const counts = await pProps({
     messageCount: getMessageCount(),