Refactor DashBot

lib/dashbot/models/chat_state.dart

@@ -0,0 +1,35 @@
+import '../error/chat_failure.dart';
+import 'chat_message.dart';
+
+class ChatState {
+  final Map<String, List<ChatMessage>> chatSessions; // requestId -> messages
+  final bool isGenerating;
+  final String currentStreamingResponse;
+  final String? currentRequestId;
+  final ChatFailure? lastError;
+
+  const ChatState({
+    this.chatSessions = const {},
+    this.isGenerating = false,
+    this.currentStreamingResponse = '',
+    this.currentRequestId,
+    this.lastError,
+  });
+
+  ChatState copyWith({
+    Map<String, List<ChatMessage>>? chatSessions,
+    bool? isGenerating,
+    String? currentStreamingResponse,
+    String? currentRequestId,
+    ChatFailure? lastError,
+  }) {
+    return ChatState(
+      chatSessions: chatSessions ?? this.chatSessions,
+      isGenerating: isGenerating ?? this.isGenerating,
+      currentStreamingResponse:
+          currentStreamingResponse ?? this.currentStreamingResponse,
+      currentRequestId: currentRequestId ?? this.currentRequestId,
+      lastError: lastError ?? this.lastError,
+    );
+  }
+}