✨ Basic message sending and listing

lib/screens/chat.dart

@@ -6,6 +6,7 @@ import 'package:provider/provider.dart';
 import 'package:surface/providers/channel.dart';
 import 'package:surface/types/chat.dart';
 import 'package:surface/widgets/account/account_image.dart';
+import 'package:surface/widgets/dialog.dart';
 import 'package:surface/widgets/loading_indicator.dart';
 
 class ChatScreen extends StatefulWidget {
@@ -27,10 +28,13 @@ class _ChatScreenState extends State<ChatScreen> {
     chan.fetchChannels().listen((channels) {
       if (mounted) setState(() => _channels = channels);
     })
-      ..onError((_) {
+      ..onError((err) {
+        if (!mounted) return;
+        context.showErrorDialog(err);
         setState(() => _isBusy = false);
       })
       ..onDone(() {
+        if (!mounted) return;
         setState(() => _isBusy = false);
       });
   }
@@ -67,6 +71,15 @@ class _ChatScreenState extends State<ChatScreen> {
                     content: null,
                     fallbackWidget: const Icon(Symbols.chat, size: 20),
                   ),
+                  onTap: () {
+                    GoRouter.of(context).pushNamed(
+                      'chatRoom',
+                      pathParameters: {
+                        'scope': channel.realm?.alias ?? 'global',
+                        'alias': channel.alias,
+                      },
+                    );
+                  },
                 );
               },
             ),

lib/screens/chat/room.dart

@@ -0,0 +1,102 @@
+import 'package:easy_localization/easy_localization.dart';
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:styled_widget/styled_widget.dart';
+import 'package:surface/controllers/chat_message_controller.dart';
+import 'package:surface/providers/channel.dart';
+import 'package:surface/types/chat.dart';
+import 'package:surface/widgets/chat/chat_message.dart';
+import 'package:surface/widgets/chat/chat_message_input.dart';
+import 'package:surface/widgets/dialog.dart';
+import 'package:surface/widgets/loading_indicator.dart';
+import 'package:very_good_infinite_list/very_good_infinite_list.dart';
+
+class ChatRoomScreen extends StatefulWidget {
+  final String scope;
+  final String alias;
+  const ChatRoomScreen({super.key, required this.scope, required this.alias});
+
+  @override
+  State<ChatRoomScreen> createState() => _ChatRoomScreenState();
+}
+
+class _ChatRoomScreenState extends State<ChatRoomScreen> {
+  bool _isBusy = false;
+
+  SnChannel? _channel;
+
+  late final ChatMessageController _messageController;
+
+  Future<void> _fetchChannel() async {
+    setState(() => _isBusy = true);
+
+    try {
+      final chan = context.read<ChatChannelProvider>();
+      _channel = await chan.getChannel('${widget.scope}:${widget.alias}');
+    } catch (err) {
+      if (!mounted) return;
+      context.showErrorDialog(err);
+    } finally {
+      setState(() => _isBusy = false);
+    }
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    _messageController = ChatMessageController(context);
+    _fetchChannel().then((_) async {
+      await _messageController.initialize(_channel!);
+      await _messageController.checkUpdate();
+    });
+  }
+
+  @override
+  void dispose() {
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(_channel?.name ?? 'loading'.tr()),
+      ),
+      body: ListenableBuilder(
+        listenable: _messageController,
+        builder: (context, _) {
+          return Column(
+            children: [
+              LoadingIndicator(isActive: _isBusy),
+              if (_messageController.isPending)
+                Expanded(
+                  child: const CircularProgressIndicator().center(),
+                ),
+              if (!_messageController.isPending)
+                Expanded(
+                  child: InfiniteList(
+                    hasReachedMax: _messageController.isAllLoaded,
+                    itemCount: _messageController.messages.length,
+                    isLoading: _messageController.isLoading,
+                    onFetchData: () {
+                      _messageController.loadMessages();
+                    },
+                    itemBuilder: (context, idx) {
+                      final message = _messageController.messages[idx];
+                      return ChatMessage(data: message);
+                    },
+                  ),
+                ),
+              if (!_messageController.isPending)
+                Material(
+                  elevation: 2,
+                  child: ChatMessageInput(controller: _messageController)
+                      .padding(bottom: MediaQuery.of(context).padding.bottom),
+                ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+}