messages: Implement logic to display TODO widgets.

Author: rsashank

zulipterminal/ui_tools/messages.py

@@ -33,6 +33,7 @@
 from zulipterminal.server_url import near_message_url
 from zulipterminal.ui_tools.tables import render_table
 from zulipterminal.urwid_types import urwid_MarkupTuple, urwid_Size
+from zulipterminal.widget import find_widget_type, process_todo_widget
 
 
 if typing.TYPE_CHECKING:
@@ -729,6 +730,31 @@ def main_view(self) -> List[Any]:
                 "/me", f"<strong>{self.message['sender_full_name']}</strong>", 1
             )
 
+        if self.message.get("submessages"):
+            widget_type = find_widget_type(self.message.get("submessages", []))
+
+            if widget_type == "todo":
+                title, tasks = process_todo_widget(self.message.get("submessages", []))
+
+                todo_widget = "<strong>To-do</strong>\n" + f"<strong>{title}</strong>"
+
+                if tasks:
+                    for task_id, task_info in tasks.items():
+                        task_status = "[✔]" if task_info["completed"] else "[ ]"
+                        task_name = task_info["task"]
+                        task_description = task_info["desc"]
+
+                        todo_widget += f"\n{task_status} <strong>{task_name}</strong>"
+
+                        if task_description:
+                            todo_widget += f": {task_description}"
+
+                # Update the message content with the latest todo_widget,
+                # generated from submessages to reflect the current state.
+                # The original raw content can be fetched if needed,
+                # though it's not very useful.
+                self.message["content"] = todo_widget
+
         # Transform raw message content into markup (As needed by urwid.Text)
         content, self.message_links, self.time_mentions = self.transform_content(
             self.message["content"], self.model.server_url