Implement ChatView with Agent and User Message Tiles

This commit introduces the ChatView widget, a central component of the application that manages the chat interface. It's responsible for displaying both agent and user messages and includes the following features:

- Fetching chats for a specific task upon initialization.
- A reverse ListView to display chats with the most recent messages at the bottom.
- Dynamic rendering of UserMessageTile and AgentMessageTile widgets based on message type.
- Integration with the ChatInputField for inputting user messages.
- Placeholder logic for handling send action, to be implemented later.

This implementation lays the groundwork for a fully functional chat interface within the application, allowing for a seamless interaction between users and agents.

lib/views/chat/chat_view.dart

@@ -0,0 +1,63 @@
+import 'package:auto_gpt_flutter_client/models/message_type.dart';
+import 'package:auto_gpt_flutter_client/views/chat/agent_message_tile.dart';
+import 'package:auto_gpt_flutter_client/views/chat/chat_input_field.dart';
+import 'package:auto_gpt_flutter_client/views/chat/user_message_tile.dart';
+import 'package:flutter/material.dart';
+import 'package:auto_gpt_flutter_client/viewmodels/chat_viewmodel.dart';
+
+class ChatView extends StatefulWidget {
+  final ChatViewModel viewModel;
+
+  const ChatView({Key? key, required this.viewModel}) : super(key: key);
+
+  @override
+  _ChatViewState createState() => _ChatViewState();
+}
+
+class _ChatViewState extends State<ChatView> {
+  @override
+  void initState() {
+    super.initState();
+
+    // Schedule the fetchTasks call for after the initial build
+    WidgetsBinding.instance.addPostFrameCallback((_) {
+      // TODO: Update to actual task id
+      widget.viewModel.fetchChatsForTask(1);
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: Column(
+        children: [
+          // Chat messages list
+          Expanded(
+            child: ListView.builder(
+              reverse: true,
+              itemCount: widget.viewModel.chats.length,
+              itemBuilder: (context, index) {
+                final reversedChats = widget.viewModel.chats.reversed.toList();
+                final chat = reversedChats[index];
+                if (chat.messageType == MessageType.user) {
+                  return UserMessageTile(message: chat.message);
+                } else {
+                  return AgentMessageTile(message: chat.message);
+                }
+              },
+            ),
+          ),
+          // Input area
+          Padding(
+            padding: const EdgeInsets.all(8.0),
+            child: ChatInputField(
+              onSendPressed: () {
+                // TODO: Implement passing the message back up
+              },
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/views/chat_view.dart

@@ -1,18 +0,0 @@
-import 'package:flutter/material.dart';
-
-class ChatView extends StatelessWidget {
-  const ChatView({super.key});
-
-  @override
-  Widget build(BuildContext context) {
-    return Container(
-      color: Colors.green,
-      child: const Center(
-        child: Text(
-          'Chat',
-          style: TextStyle(fontSize: 24, color: Colors.white),
-        ),
-      ),
-    );
-  }
-}