Implement LIST NEWSGROUPS

lib/nntp/tiny/session.py

@@ -223,8 +223,63 @@ class Session():
 
         return self.end()
 
+    def _newsgroup_summary(self, newsgroup: Newsgroup):
+        sql = """
+            select
+                min(id),
+                max(id)
+            from
+                newsgroup_message
+            where
+                newsgroup_id = ?
+        """
+
+        cr  = self.db.execute(sql, (newsgroup.id,))
+        row = cr.fetchone()
+
+        return {
+            'low':   row[0],
+            'high':  row[1],
+            'perms': 'n'
+        }
+
+
+    def print_newsgroup(self, newsgroup: Newsgroup):
+        summary = self._newsgroup_summary(newsgroup)
+
+        return self.print("%s %d %d %s" % (
+            newsgroup.name,
+            summary['low'],
+            summary['high'],
+            summary['perms']
+        ))
+
+    def _cmd_list_newsgroups(self):
+        self.respond(ResponseCode.NNTP_INFORMATION_FOLLOWS)
+
+        for name in self.server.newsgroups:
+            newsgroup = self.server.newsgroups[name]
+
+            self.print_newsgroup(newsgroup)
+
+        return self.end()
+
+    LIST_SUBCOMMANDS = {
+        'NEWSGROUPS': _cmd_list_newsgroups,
+    }
+
     def _cmd_list(self, *args):
-        pass
+        if len(args) == 0:
+            return self.respond(ResponseCode.NNTP_SYNTAX_ERROR, "No subcommand provided")
+
+        subcmd, *subargs = args
+
+        fn = self.LIST_SUBCOMMANDS.get(subcmd.upper())
+
+        if fn is None:
+            return self.respond(ResponseCode.NNTP_COMMAND_UNKNOWN)
+
+        return fn(self, *subargs)
 
     RE_DATE_SHORT = re.compile(r'^(\d{2})(\d{2})(\d{2})$')
     RE_DATE_LONG  = re.compile(r'^(\d{4})(\d{2})(\d{2})$')
@@ -291,26 +346,6 @@ class Session():
 
         return self.end()
 
-    def _newsgroup_summary(self, newsgroup: Newsgroup):
-        sql = """
-            select
-                min(id),
-                max(id)
-            from
-                newsgroup_message
-            where
-                newsgroup_id = ?
-        """
-
-        cr  = self.db.execute(sql, (newsgroup.id,))
-        row = cr.fetchone()
-
-        return {
-            'min':   row[0],
-            'max':   row[1],
-            'perms': 'n'
-        }
-
     def _cmd_newgroups(self, wildmat, datestr, timestr, *args):
         gmt = False
 
@@ -327,14 +362,8 @@ class Session():
         for name in self.server.newsgroups:
             if fnmatch.fnmatch(name, wildmat):
                 newsgroup = self.server.newsgroups[name]
-                summary   = self._newsgroup_summary(newsgroup)
 
-                self.print("%s %d %d %s" % (
+                self.print_newsgroup(newsgroup)
-                    newsgroup.name,
-                    summary['min'],
-                    summary['max'],
-                    summary['perms']
-                ))
 
         return self.end()