boxes/model: Order mentions typeahead by subscribers for stream msgs.

Update recipient_user_ids in WriteBox for stream messages which is used
to order mentions typeahead. The logic for doing this ordering has
already been implemented in WriteBox.autocomplete_mentions().

stream_id is passed to WriteBox instead of using stream names to look-up
subscriber data to avoid bugs due to duplicate stream names.

zulipterminal/model.py

@@ -461,6 +461,12 @@ def _update_initial_data(self) -> None:
             ]
             raise ServerConnectionFailure(", ".join(failure_text))
 
+    def get_other_subscribers_in_stream(self, stream_id: int) -> List[int]:
+        assert stream_id in self.stream_dict
+
+        return [sub for sub in self.stream_dict[stream_id]['subscribers']
+                if sub != self.user_id]
+
     def get_all_users(self) -> List[Dict[str, Any]]:
         # Dict which stores the active/idle status of users (by email)
         presences = self.initial_data['presences']

zulipterminal/ui_tools/boxes.py

@@ -62,8 +62,11 @@ def private_box_view(self, button: Any=None, email: str='',
         ]
         self.focus_position = 1
 
-    def stream_box_view(self, caption: str='', title: str='') -> None:
+    def stream_box_view(self, stream_id: int, caption: str='', title: str='',
+                        ) -> None:
         self.set_editor_mode()
+        self.recipient_user_ids = self.model.get_other_subscribers_in_stream(
+                                            stream_id)
         self.to_write_box = None
         self.msg_write_box = ReadlineEdit(multiline=True)
         self.msg_write_box.enable_autocomplete(
@@ -899,7 +902,8 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
             elif self.message['type'] == 'stream':
                 self.model.controller.view.write_box.stream_box_view(
                     caption=self.message['display_recipient'],
-                    title=self.message['subject']
+                    title=self.message['subject'],
+                    stream_id=self.stream_id,
                 )
         elif is_command_key('STREAM_MESSAGE', key):
             if self.message['type'] == 'private':
@@ -909,7 +913,8 @@ def keypress(self, size: urwid_Size, key: str) -> Optional[str]:
                 )
             elif self.message['type'] == 'stream':
                 self.model.controller.view.write_box.stream_box_view(
-                    caption=self.message['display_recipient']
+                    caption=self.message['display_recipient'],
+                    stream_id=self.stream_id,
                 )
         elif is_command_key('STREAM_NARROW', key):
             if self.message['type'] == 'private':