Implement LIST ACTIVE

lib/nntp/tiny/session.py

@@ -263,8 +263,41 @@ class Session():
 
         return self.end()
 
+    def _newsgroup_last_active(self, newsgroup: Newsgroup):
+        sql = """
+            select
+                max(created_on)
+            from
+                newsgroup_message
+            where
+                newsgroup_id = ?
+        """
+
+        cr  = self.db.execute(sql, (newsgroup.id,))
+        row = cr.fetchone()
+
+        if row is None:
+            return
+
+        return datetime.datetime.fromisoformat(row[0])
+
+    def _cmd_list_active(self):
+        now = datetime.datetime.now(datetime.UTC)
+
+        self.respond(ResponseCode.NNTP_INFORMATION_FOLLOWS)
+
+        for name in self.server.newsgroups:
+            newsgroup   = self.server.newsgroups[name]
+            last_active = self._newsgroup_last_active(newsgroup)
+
+            if now - last_active < datetime.timedelta(days=1):
+                self.print_newsgroup(newsgroup)
+
+        return self.end()
+
     LIST_SUBCOMMANDS = {
         'NEWSGROUPS': _cmd_list_newsgroups,
+        'ACTIVE':     _cmd_list_active,
     }
 
     def _cmd_list(self, *args):