channel_requester: Auto-move clients to existing channels

A client can join the channel requester, which creates a channel for this user and moves the client
respectively. However, when the client leaves the channel and joins the channel requester channel
instead while the own channel still exists, the client stays in the channel requester channel. This
change ensures, that either a new channel gets created or that the client gets moved to the already
existing channel.

modules/channel_requester/main.py

@@ -245,6 +245,41 @@ def find_channels_by_prefix(self, channel_name_prefix=None):
 
         return managed_channels_list
 
+    def find_channel_by_name(self, channel_name=None):
+        """
+        Find a channel with a specific name.
+        :param: channel_name: The name of the channel, which you want to search for.
+        :return: dict
+        :type: dict
+        """
+        if channel_name is None:
+            return None
+
+        try:
+            all_channels = self.ts3conn.channellist()
+        except TS3Exception:
+            ChannelRequester.logger.exception("Could not get the current channel list.")
+            raise
+
+        for channel in all_channels:
+            if channel.get("channel_name") == channel_name:
+                return channel
+
+        return None
+
+    def move_client_to_channel_id(self, client, channel_id):
+        """
+        Moves a client into a specific channel.
+        """
+        try:
+            self.ts3conn.clientmove(int(channel_id), int(client.clid))
+        except TS3QueryException:
+            ChannelRequester.logger.exception(
+                "Failed to move the client into his private channel: %s",
+                str(client),
+            )
+            raise
+
     def create_channel(self, client=None):
         """
         Creates a channel and grants a specific client channel admin permissions.
@@ -328,6 +363,17 @@ def create_channel(self, client=None):
             str(main_channel_name),
         )
 
+        existing_user_channel = self.find_channel_by_name(
+            str(client_info.get("client_nickname"))
+        )
+        if existing_user_channel is not None:
+            ChannelRequester.logger.info(
+                "client_nickname=%s has already an existing channel. Moving the client directly.",
+                str(client_info.get("client_nickname")),
+            )
+            self.move_client_to_channel_id(client, existing_user_channel.get("cid"))
+            return
+
         channel_properties = []
         channel_properties.append("channel_flag_semi_permanent=1")
         channel_properties.append(f"cpid={int(main_channel_cid)}")
@@ -449,16 +495,7 @@ def create_channel(self, client=None):
                             )
                             raise
 
-            try:
-                self.ts3conn.clientmove(
-                    int(recently_created_channel.get("cid")), int(client.clid)
-                )
-            except TS3QueryException:
-                ChannelRequester.logger.exception(
-                    "Failed to move the client into his private channel: %s",
-                    str(client),
-                )
-                raise
+            self.move_client_to_channel_id(client, recently_created_channel.get("cid"))
 
             try:
                 self.ts3conn._send(