feat: Replace Delete Chat button with Retry Generation button

AI.NET/Resources/Strings/Strings.resx

@@ -120,8 +120,8 @@
   <data name="About" xml:space="preserve">
     <value>About</value>
   </data>
-  <data name="DeleteChat" xml:space="preserve">
-    <value>Delete Current Chat (Ctrl+D)</value>
+  <data name="RetryGeneration" xml:space="preserve">
+    <value>Retry Last AI Response (Ctrl+R)</value>
   </data>
   <data name="Mem0ServerUrl" xml:space="preserve">
     <value>Mem0 Server URL</value>

AI.NET/Resources/Strings/Strings.zh-CHS.resx

@@ -120,8 +120,8 @@
   <data name="About" xml:space="preserve">
     <value>关于</value>
   </data>
-  <data name="DeleteChat" xml:space="preserve">
-    <value>删除当前聊天 (Ctrl+D)</value>
+  <data name="RetryGeneration" xml:space="preserve">
+    <value>重新生成 AI 回复 (Ctrl+R)</value>
   </data>
   <data name="Mem0ServerUrl" xml:space="preserve">
     <value>Mem0 服务器地址</value>

AI.NET/Resources/Strings/Strings.zh-CN.resx

@@ -123,8 +123,8 @@
   <data name="About" xml:space="preserve">
     <value>关于</value>
   </data>
-  <data name="DeleteChat" xml:space="preserve">
-    <value>删除当前聊天 (Ctrl+D)</value>
+  <data name="RetryGeneration" xml:space="preserve">
+    <value>重新生成 AI 回复 (Ctrl+R)</value>
   </data>
   <data name="Mem0ServerUrl" xml:space="preserve">
     <value>Mem0 服务器地址</value>

AI.NET/Service/AI.cs

@@ -40,11 +40,53 @@ public static async Task RequestAIAsync(string message, MarkdownScrollViewer out
             TopicsHelper.SaveTopicsAsync(Topics);
         }
         /// <summary>
-        /// Delete a chat session
+        /// Retry generating the last AI response
         /// </summary>
-        public static void DeleteMessages()
+        /// <param name="outputBox">The UI element to update</param>
+        public static async Task RetryLastResponseAsync(MarkdownScrollViewer outputBox)
         {
-            Topics.RemoveAt(Topics.CurrentTopicIndex);
+            var messages = Topics.CurrentTopic.MessageList;
+
+            // Find the last user message and remove any subsequent AI/system messages
+            int lastUserIndex = -1;
+            for (int i = messages.Count - 1; i >= 0; i--)
+            {
+                if (messages[i].Role == ChatMessageRole.User)
+                {
+                    lastUserIndex = i;
+                    break;
+                }
+            }
+
+            if (lastUserIndex == -1)
+            {
+                return; // No user message found to retry
+            }
+
+            // Remove all messages after the last user message
+            while (messages.Count > lastUserIndex + 1)
+            {
+                messages.RemoveAt(messages.Count - 1);
+            }
+
+            string lastUserMessage = messages[lastUserIndex].Content;
+
+            // Update the output box to show we're retrying
+            string currentMarkdown = await Topics.CurrentTopic.GetMarkdownAsync();
+            outputBox.Markdown = currentMarkdown + "AI:";
+
+            // Handle memory if enabled
+            if (Mem0.IsEnabled)
+                await HandleMemoryAsync(lastUserMessage);
+
+            // Generate new AI response
+            Topics.CurrentTopic.Add(new Chat()
+            {
+                Content = await OpenAI.GenerateReplyAsync(outputBox),
+                Role = ChatMessageRole.Assistant
+            });
+
+            // Save topics to file
             TopicsHelper.SaveTopicsAsync(Topics);
         }
         public static void NewChat(Data.SystemPrompt prompt)

AI.NET/Windows/MainWindow.xaml

@@ -64,8 +64,8 @@
                 <Button x:Name="newButton" Click="NewChatButton_Click" Margin="10,0,0,0" ToolTip="{x:Static strings:Strings.NewChat}">
                     <ic:FluentIcon Icon="CommentAdd" IconVariant="Regular"/>
                 </Button>
-                <Button x:Name="deleteChatButton" Click="DeleteChatButton_Click" Margin="10,0,0,0" ToolTip="{x:Static strings:Strings.DeleteChat}">
-                    <ic:FluentIcon Icon="Delete" IconVariant="Filled" Foreground="Red"/>
+                <Button x:Name="retryButton" Click="RetryButton_Click" Margin="10,0,0,0" ToolTip="{x:Static strings:Strings.RetryGeneration}">
+                    <ic:FluentIcon Icon="ArrowClockwise" IconVariant="Filled" Foreground="Orange"/>
                 </Button>
             </StackPanel>
         </Grid>

AI.NET/Windows/MainWindow.xaml.cs

@@ -87,7 +87,7 @@ private void SetBusyState(bool isBusy)
             sendButton.IsChecked = isBusy;
             sendButton.IsEnabled = !isBusy;
             newButton.IsEnabled = !isBusy;
-            deleteChatButton.IsEnabled = !isBusy;
+            retryButton.IsEnabled = !isBusy;
         }
         private void NewChatButton_Click(object sender, RoutedEventArgs e)
         {
@@ -98,14 +98,25 @@ private void NewChatButton_Click(object sender, RoutedEventArgs e)
             topicBox.SelectedIndex = Service.AI.Topics.TopicList.Count - 1;
         }
 
-        private void DeleteChatButton_Click(object sender, RoutedEventArgs e)
+        private async void RetryButton_Click(object sender, RoutedEventArgs e)
         {
             if (topicBox.SelectedIndex >= 0 && topicBox.Items.Count > 0)
             {
-                outputBox.Markdown = string.Empty;
-                int index = topicBox.SelectedIndex;
-                Service.AI.DeleteMessages();
-                topicBox.SelectedIndex = index - 1;
+                SetBusyState(true);
+                try
+                {
+                    await Service.AI.RetryLastResponseAsync(outputBox);
+                }
+                catch (Exception ex)
+                {
+                    Growl.Error(new() { StaysOpen = true, Message = ex.Message });
+                    Log.Error("Error when retrying AI response", ex);
+                }
+                finally
+                {
+                    outputBox.Markdown += markdownNewLine;
+                    SetBusyState(false);
+                }
             }
         }
 
@@ -165,8 +176,8 @@ private void Window_KeyDown(object sender, KeyEventArgs e)
                     NewChatButton_Click(sender, e);
                 else if (e.Key == Key.Enter)
                     SendButton_Click(sender, e);
-                else if (e.Key == Key.D)
-                    DeleteChatButton_Click(sender, e);
+                else if (e.Key == Key.R)
+                    RetryButton_Click(sender, e);
             }
         }