Version: 0.4.4.dev.260307

feat: 🚀 增强会话管理与缓存机制

* 会话 ID 空值兜底，若 `conversation_id` 为空时自动生成 UUID
* 在响应头写入 `X-Conversation-ID`，供前端使用，保持同一会话状态

perf: ⚡ 会话状态缓存优化

* 当缓存未命中但 DB 已确认/创建会话后，调用 `SetConversationStatus` 回写 Redis
* 缓存写回失败时记录日志，不中断聊天主流程，确保业务流畅性

fix: 🐛 修复历史消息顺序问题与编译错误

* 修复历史消息顺序问题，保证返回的 N 条历史消息按时间正序喂给模型

  * 通过反转 `created_at desc` 查询结果的切片，确保模型输入顺序正确
* 修复 `fmt.Errorf` 参数不匹配问题，修正编译错误
* 整理 `agent-cache.go` 为标准 UTF-8 编码，避免 Go 编译报错 `invalid UTF-8 encoding`

feat: 🛠️ 独立构建 MCP 服务器

* 使用 `Codex` 构建独立于后端的 MCP 服务器，简化与 Codex 的协作
* 通过该服务器方便 Codex 直接测试和查看 Redis 与 MySQL 中的数据

backend/api/agent.go

@@ -3,11 +3,13 @@ package api
 import (
 	"io"
 	"net/http"
+	"strings"
 
 	"github.com/LoveLosita/smartflow/backend/model"
 	"github.com/LoveLosita/smartflow/backend/respond"
 	"github.com/LoveLosita/smartflow/backend/service"
 	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
 )
 
 type AgentHandler struct {
@@ -33,9 +35,18 @@ func (api *AgentHandler) ChatAgent(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, respond.WrongParamType)
 		return
 	}
+
+	// 兼容：如果前端没传会话 ID，后端兜底创建一个
+	conversationID := strings.TrimSpace(req.ConversationID)
+	if conversationID == "" {
+		conversationID = uuid.NewString()
+	}
+	// 把最终生效的会话 ID 回传给前端，方便后续继续同一会话
+	c.Writer.Header().Set("X-Conversation-ID", conversationID)
+
 	userID := c.GetInt("user_id") // 从上下文中获取用户 ID
 	// 3. 调用 Service 层的聊天方法，获取输出通道和错误通道
-	outChan, errChan := api.svc.AgentChat(c.Request.Context(), req.Message, req.Thinking, userID, req.ConversationID)
+	outChan, errChan := api.svc.AgentChat(c.Request.Context(), req.Message, req.Thinking, userID, conversationID)
 	// 4. 循环转发消息/错误
 	c.Stream(func(w io.Writer) bool {
 		select {

backend/dao/agent-cache.go

@@ -95,7 +95,7 @@ func (m *AgentCache) BackfillHistory(ctx context.Context, sessionID string, mess
 	for i, msg := range messages {
 		data, err := json.Marshal(msg)
 		if err != nil {
-			return fmt.Errorf("marshal failed at index %d: %w", err)
+			return fmt.Errorf("marshal failed at index %d: %w", i, err)
 		}
 		values[i] = data
 	}

backend/dao/agent.go

@@ -44,10 +44,18 @@ func (a *AgentDAO) CreateNewChat(userID int, chatID string) (int64, error) {
 
 func (a *AgentDAO) GetUserChatHistories(ctx context.Context, userID, limit int, chatID string) ([]model.ChatHistory, error) {
 	var histories []model.ChatHistory
-	err := a.db.WithContext(ctx).Where("user_id = ? AND chat_id = ?", userID, chatID).Order("created_at desc").Limit(limit).Find(&histories).Error
+	err := a.db.WithContext(ctx).
+		Where("user_id = ? AND chat_id = ?", userID, chatID).
+		Order("created_at desc").
+		Limit(limit).
+		Find(&histories).Error
 	if err != nil {
 		return nil, err
 	}
+	// 保留“最近 N 条”的前提下，反转为时间正序，便于模型消费
+	for i, j := 0, len(histories)-1; i < j; i, j = i+1, j-1 {
+		histories[i], histories[j] = histories[j], histories[i]
+	}
 	return histories, nil
 }
 

backend/service/agent.go

@@ -3,12 +3,14 @@ package service
 import (
 	"context"
 	"log"
+	"strings"
 
 	"github.com/LoveLosita/smartflow/backend/agent"
 	"github.com/LoveLosita/smartflow/backend/conv"
 	"github.com/LoveLosita/smartflow/backend/dao"
 	"github.com/LoveLosita/smartflow/backend/inits"
 	"github.com/cloudwego/eino/schema"
+	"github.com/google/uuid"
 )
 
 type AgentService struct {
@@ -25,10 +27,21 @@ func NewAgentService(aiHub *inits.AIHub, repo *dao.AgentDAO, agentRedis *dao.Age
 	}
 }
 
+func normalizeConversationID(chatID string) string {
+	trimmed := strings.TrimSpace(chatID)
+	if trimmed == "" {
+		return uuid.NewString()
+	}
+	return trimmed
+}
+
 func (s *AgentService) AgentChat(ctx context.Context, userMessage string, ifThinking bool, userID int, chatID string) (<-chan string, <-chan error) {
 	//1. 创建一个输出通道
 	outChan := make(chan string, 5)
 	errChan := make(chan error, 1)
+	//补充：会话 ID 兜底，避免上层漏传
+	chatID = normalizeConversationID(chatID)
+
 	//2. 先确保这个会话存在（如果不存在就创建一个新的）
 	//先看看缓存里面有没有这个会话
 	result, err := s.agentCache.GetConversationStatus(ctx, chatID)
@@ -49,20 +62,23 @@ func (s *AgentService) AgentChat(ctx context.Context, userMessage string, ifThin
 		}
 		if !innerResult {
 			//如果会话不存在，先创建一个新的会话
-			_, err := s.repo.CreateNewChat(userID, chatID)
-			if err != nil {
+			if _, err = s.repo.CreateNewChat(userID, chatID); err != nil {
 				errChan <- err
 				close(outChan)
 				close(errChan)
 				return outChan, errChan
 			}
 		}
+		//补充：把“会话存在”状态回写缓存，后续请求可直接命中
+		if err = s.agentCache.SetConversationStatus(ctx, chatID); err != nil {
+			//缓存回写失败不影响主流程
+			log.Printf("failed to set conversation status cache for %s: %v", chatID, err)
+		}
 	}
 	//能走到这里，要么缓存里有这个会话，要么数据库里有这个会话了
 	//4. 提取出历史消息，构建上下文
 	//先尝试从缓存里拿历史消息
-	var chatHistory []*schema.Message
-	chatHistory, err = s.agentCache.GetHistory(ctx, chatID)
+	chatHistory, err := s.agentCache.GetHistory(ctx, chatID)
 	if err != nil {
 		errChan <- err
 		close(outChan)
@@ -82,8 +98,7 @@ func (s *AgentService) AgentChat(ctx context.Context, userMessage string, ifThin
 		//再转换成 Eino 的消息格式
 		chatHistory = conv.ToEinoMessages(histories)
 		//把历史消息放到缓存里，方便下次直接拿
-		err = s.agentCache.BackfillHistory(ctx, chatID, chatHistory)
-		if err != nil {
+		if err = s.agentCache.BackfillHistory(ctx, chatID, chatHistory); err != nil {
 			errChan <- err
 			close(outChan)
 			close(errChan)
@@ -93,16 +108,18 @@ func (s *AgentService) AgentChat(ctx context.Context, userMessage string, ifThin
 	//3. 将用户消息异步落缓存和库
 	go func() {
 		//这里先不管落库成功与否了，毕竟不想因为落库失败而影响用户的聊天体验
-		_ = s.agentCache.PushMessage(ctx, chatID, &schema.Message{
-			Role:    "user",
+		bg := context.Background()
+		_ = s.agentCache.PushMessage(bg, chatID, &schema.Message{
+			Role:    schema.User,
 			Content: userMessage,
 		})
-		_ = s.repo.SaveChatHistory(ctx, userID, chatID, "user", userMessage)
+		_ = s.repo.SaveChatHistory(bg, userID, chatID, "user", userMessage)
 	}()
 
 	//5. 启动一个 goroutine 来处理聊天逻辑
 	go func() {
 		defer close(outChan) // 确保在函数结束时关闭通道
+		defer close(errChan)
 		//3. 调用 StreamChat 函数进行流式聊天
 		fullText, err := agent.StreamChat(ctx, s.AIHub.Worker, userMessage, ifThinking, chatHistory, outChan)
 		if err != nil {
@@ -111,13 +128,13 @@ func (s *AgentService) AgentChat(ctx context.Context, userMessage string, ifThin
 		}
 		//4. 将 AI 的回复异步落缓存和库
 		go func() {
-			_ = s.agentCache.PushMessage(ctx, chatID, &schema.Message{
-				Role:    "assistant",
+			bg := context.Background()
+			_ = s.agentCache.PushMessage(bg, chatID, &schema.Message{
+				Role:    schema.Assistant,
 				Content: fullText,
 			})
-			err = s.repo.SaveChatHistory(context.Background(), userID, chatID, "assistant", fullText)
-			if err != nil {
-				log.Printf("Failed to save chat history to database: %v", err)
+			if saveErr := s.repo.SaveChatHistory(bg, userID, chatID, "assistant", fullText); saveErr != nil {
+				log.Printf("failed to save chat history to database: %v", saveErr)
 				return
 			}
 		}()