urgent: revert the backend message

Author: Junyi-99

internal/api/chat/create_conversation_message_stream.go

@@ -1,8 +1,12 @@
 package chat
 
 import (
-	"errors"
+	"paperdebugger/internal/api/mapper"
+	"paperdebugger/internal/models"
+	"paperdebugger/internal/services"
 	chatv1 "paperdebugger/pkg/gen/api/chat/v1"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
 )
 
 func (s *ChatServer) sendStreamError(stream chatv1.ChatService_CreateConversationMessageStreamServer, err error) error {
@@ -19,5 +23,60 @@ func (s *ChatServer) CreateConversationMessageStream(
 	req *chatv1.CreateConversationMessageStreamRequest,
 	stream chatv1.ChatService_CreateConversationMessageStreamServer,
 ) error {
-	return s.sendStreamError(stream, errors.New("Due to some technical problem from LLM providers, we are trying to bring the service back. Please retry later."))
+	ctx := stream.Context()
+	ctx, conversation, err := s.prepare(
+		ctx,
+		req.GetProjectId(),
+		req.GetConversationId(),
+		req.GetUserMessage(),
+		req.GetUserSelectedText(),
+		models.LanguageModel(req.GetLanguageModel()),
+		req.GetConversationType(),
+	)
+	if err != nil {
+		return s.sendStreamError(stream, err)
+	}
+
+	// 用法跟 ChatCompletion 一样，只是传递了 stream 参数
+	openaiChatHistory, inappChatHistory, err := s.aiClient.ChatCompletionStream(ctx, stream, conversation.ID.Hex(), conversation.LanguageModel, conversation.OpenaiChatHistory)
+	if err != nil {
+		return s.sendStreamError(stream, err)
+	}
+
+	// 附加消息到对话
+	bsonMessages := make([]bson.M, len(inappChatHistory))
+	for i := range inappChatHistory {
+		bsonMsg, err := convertToBSON(&inappChatHistory[i])
+		if err != nil {
+			return s.sendStreamError(stream, err)
+		}
+		bsonMessages[i] = bsonMsg
+	}
+	conversation.InappChatHistory = append(conversation.InappChatHistory, bsonMessages...)
+	conversation.OpenaiChatHistory = openaiChatHistory
+	if err := s.chatService.UpdateConversation(conversation); err != nil {
+		return s.sendStreamError(stream, err)
+	}
+
+	if conversation.Title == services.DefaultConversationTitle {
+		go func() {
+			protoMessages := make([]*chatv1.Message, len(conversation.InappChatHistory))
+			for i, bsonMsg := range conversation.InappChatHistory {
+				protoMessages[i] = mapper.BSONToChatMessage(bsonMsg)
+			}
+			title, err := s.aiClient.GetConversationTitle(ctx, protoMessages)
+			if err != nil {
+				s.logger.Error("Failed to get conversation title", "error", err, "conversationID", conversation.ID.Hex())
+				return
+			}
+			conversation.Title = title
+			if err := s.chatService.UpdateConversation(conversation); err != nil {
+				s.logger.Error("Failed to update conversation with new title", "error", err, "conversationID", conversation.ID.Hex())
+				return
+			}
+		}()
+	}
+
+	// The final conversation object is NOT returned
+	return nil
 }