Indication support multi language

src/Infrastructure/BotSharp.Abstraction/Conversations/IIndicationLocalizer.cs

@@ -0,0 +1,14 @@
+namespace BotSharp.Abstraction.Conversations;
+
+/// <summary>
+/// Puts an indication into the conversation's language before it is pushed. Indications skip
+/// TranslationResponseHook -- they go out ahead of the function, where an LLM translation would
+/// hold up the very line meant to say "working on it" -- so the host supplies fixed wording instead.
+/// Optional: with none registered, indications go out as the function wrote them.
+/// </summary>
+public interface IIndicationLocalizer
+{
+    /// <param name="language">The conversation's <c>StateConst.LANGUAGE</c>, e.g. <c>LanguageType.CHINESE</c>.</param>
+    /// <returns>The wording for <paramref name="language"/>, or <paramref name="indication"/> unchanged when there is none.</returns>
+    string Localize(string indication, string language);
+}

src/Infrastructure/BotSharp.Core/MessageHub/ConversationHub.cs

@@ -8,11 +8,14 @@ namespace BotSharp.Core.MessageHub;
 public sealed class ConversationHub
 {
     private readonly MessageHub<HubObserveData<RoleDialogModel>> _hub;
+    private readonly Func<string, string>? _localize;
 
-    internal ConversationHub(MessageHub<HubObserveData<RoleDialogModel>> hub, string? conversationId)
+    internal ConversationHub(MessageHub<HubObserveData<RoleDialogModel>> hub, string? conversationId,
+        Func<string, string>? localize = null)
     {
         _hub = hub;
         ConversationId = conversationId;
+        _localize = localize;
     }
 
     /// <summary>Where every push goes; null when taken outside a conversation.</summary>
@@ -30,7 +33,7 @@ public void PushIndication(RoleDialogModel message, string? indication)
             return;
         }
 
-        message.Indication = indication;
+        message.Indication = _localize?.Invoke(indication) ?? indication;
 
         _hub.Push(new()
         {

src/Infrastructure/BotSharp.Core/MessageHub/MessageHubExtensions.cs

@@ -1,3 +1,5 @@
+using BotSharp.Abstraction.Infrastructures.Enums;
+
 namespace BotSharp.Core.MessageHub;
 
 public static class MessageHubExtensions
@@ -9,6 +11,12 @@ public static ConversationHub GetHub(this IServiceProvider services)
     {
         var conv = services.GetRequiredService<IConversationService>();
         var hub = services.GetRequiredService<MessageHub<HubObserveData<RoleDialogModel>>>();
-        return new ConversationHub(hub, conv.ConversationId);
+
+        // Resolved now, not at push time: a hub may be kept and pushed from a transport's own thread.
+        var localizer = services.GetService<IIndicationLocalizer>();
+        var language = conv.States.GetState(StateConst.LANGUAGE, LanguageType.ENGLISH);
+        Func<string, string>? localize = localizer == null ? null : text => localizer.Localize(text, language);
+
+        return new ConversationHub(hub, conv.ConversationId, localize);
     }
 }