feat: long task summary

backend/biz/task/service/tasksummary.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"log/slog"
+	"slices"
 	"strings"
 	"sync"
 	"time"
@@ -261,9 +262,14 @@ func (s *TaskSummaryService) handleJob(ctx context.Context, job *delayqueue.Job[
 	return nil
 }
 
-// fetchConversation 从 Loki 获取历史对话，返回消息数组
+// fetchConversation 从 Loki 获取历史对话，只保留最近 N 轮对话（user-input / reply-question 及其对应的 agent 回复）。
+// 使用倒序查询，从最新的日志往前查，收集到足够轮用户消息后立即停止，避免遍历全部历史。
 func (s *TaskSummaryService) fetchConversation(ctx context.Context, taskID string, createdAt time.Time) ([]llm.Message, error) {
-	var messages []llm.Message
+	maxRounds := s.cfg.TaskSummary.MaxRounds
+	if maxRounds <= 0 {
+		maxRounds = 3
+	}
+	const pageSize = 200
 
 	taskUUID, err := uuid.Parse(taskID)
 	if err != nil {
@@ -274,64 +280,107 @@ func (s *TaskSummaryService) fetchConversation(ctx context.Context, taskID strin
 	if err != nil {
 		return nil, fmt.Errorf("failed to get task: %w", err)
 	}
-	messages = append(messages, llm.Message{Role: "user", Content: t.Content})
 
-	agentMsg := []string{}
-	_, err = s.loki.History(ctx, taskID, createdAt, func(entries []loki.LogEntry) {
+	// 从后往前分页查 Loki，收集到足够的用户轮次后停止
+	start := createdAt
+	end := time.Now()
+	var tailEntries []loki.LogEntry
+	userRoundCount := 0
+
+	for {
+		entries, err := s.loki.QueryByTaskID(ctx, taskID, start, end, pageSize, "backward")
+		if err != nil {
+			return nil, fmt.Errorf("failed to fetch loki history: %w", err)
+		}
+
+		done := false
 		for _, entry := range entries {
+			tailEntries = append(tailEntries, entry)
+
 			if entry.Line == "" {
 				continue
 			}
-
-			s.logger.DebugContext(ctx, "loki entry", "entry", entry.Line)
-
 			var lokiEnt lokiEntry
 			if err := json.Unmarshal([]byte(entry.Line), &lokiEnt); err != nil {
-				s.logger.ErrorContext(ctx, "failed to unmarshal loki entry", "task_id", taskID, "error", err)
 				continue
 			}
-
-			if lokiEnt.Data == "" {
-				continue
+			if lokiEnt.Event == "user-input" || lokiEnt.Event == "reply-question" {
+				userRoundCount++
+				if userRoundCount >= maxRounds {
+					done = true
+					break
+				}
 			}
+		}
 
-			decoded, err := base64.StdEncoding.DecodeString(lokiEnt.Data)
-			if err != nil {
-				s.logger.ErrorContext(ctx, "failed to decode base64 data", "task_id", taskID, "error", err)
-				continue
-			}
+		if done || len(entries) < pageSize {
+			break
+		}
+		// 向更早的时间翻页
+		end = entries[len(entries)-1].Timestamp.Add(-time.Nanosecond)
+	}
 
-			switch lokiEnt.Event {
-			case "user-input", "reply-question":
-				var userInputText string
-				var ur userReply
-				if err := json.Unmarshal(decoded, &ur); err != nil {
-					userInputText = string(decoded)
-				} else {
-					userInputText = ur.AnswersJSON
-				}
+	// 反转为时间正序
+	slices.Reverse(tailEntries)
 
-				if len(agentMsg) > 0 {
-					agentContent := strings.Join(agentMsg, "")
-					messages = append(messages, llm.Message{Role: "assistant", Content: agentContent})
-					agentMsg = []string{}
-				}
+	// 按正序解析为 messages
+	var messages []llm.Message
+	// 如果 Loki 中用户轮次不足 3 轮，补上初始任务内容
+	if userRoundCount < maxRounds {
+		messages = append(messages, llm.Message{Role: "user", Content: t.Content})
+	}
+
+	agentMsg := []string{}
+	for _, entry := range tailEntries {
+		if entry.Line == "" {
+			continue
+		}
 
-				messages = append(messages, llm.Message{Role: "user", Content: userInputText})
+		s.logger.DebugContext(ctx, "loki entry", "entry", entry.Line)
 
-			case "task-running":
-				var taskMsg wsData
-				if err := json.Unmarshal(decoded, &taskMsg); err != nil {
-					continue
-				}
-				if taskMsg.Update.SessionUpdate == "agent_message_chunk" {
-					agentMsg = append(agentMsg, taskMsg.Update.Content.Text)
-				}
+		var lokiEnt lokiEntry
+		if err := json.Unmarshal([]byte(entry.Line), &lokiEnt); err != nil {
+			s.logger.ErrorContext(ctx, "failed to unmarshal loki entry", "task_id", taskID, "error", err)
+			continue
+		}
+
+		if lokiEnt.Data == "" {
+			continue
+		}
+
+		decoded, err := base64.StdEncoding.DecodeString(lokiEnt.Data)
+		if err != nil {
+			s.logger.ErrorContext(ctx, "failed to decode base64 data", "task_id", taskID, "error", err)
+			continue
+		}
+
+		switch lokiEnt.Event {
+		case "user-input", "reply-question":
+			var userInputText string
+			var ur userReply
+			if err := json.Unmarshal(decoded, &ur); err != nil {
+				userInputText = string(decoded)
+			} else {
+				userInputText = ur.AnswersJSON
+			}
+
+			if len(agentMsg) > 0 {
+				agentContent := strings.Join(agentMsg, "")
+				messages = append(messages, llm.Message{Role: "assistant", Content: agentContent})
+				agentMsg = []string{}
+			}
+
+			messages = append(messages, llm.Message{Role: "user", Content: userInputText})
+
+		case "task-running":
+			var taskMsg wsData
+			if err := json.Unmarshal(decoded, &taskMsg); err != nil {
+				continue
+			}
+			if taskMsg.Update.SessionUpdate == "agent_message_chunk" {
+				agentMsg = append(agentMsg, taskMsg.Update.Content.Text)
 			}
 		}
-	})
-	if err != nil {
-		return nil, fmt.Errorf("failed to fetch loki history: %w", err)
 	}
 
 	if len(messages) == 0 {
@@ -343,7 +392,7 @@ func (s *TaskSummaryService) fetchConversation(ctx context.Context, taskID strin
 		messages = append(messages, llm.Message{Role: "assistant", Content: agentContent})
 	}
 
-	s.logger.DebugContext(ctx, "conversation", "messages_count", messages)
+	s.logger.DebugContext(ctx, "conversation", "messages_count", len(messages), "messages", messages)
 	return messages, nil
 }
 
@@ -367,6 +416,7 @@ func (s *TaskSummaryService) generateSummary(ctx context.Context, conversation [
   - 如果是开发任务：说明做的是什么应用/功能（如"开发五子棋游戏"）
   - 如果是问问题：说明问的是什么问题（如"React Hooks 如何管理状态"）
   - 如果是修 bug：说明修的是什么问题（如"修复用户登录失败问题"）
+- 中英文之间要加空格（如"修复 React 组件的 bug"而不是"修复React组件的bug"）
 - 如果对话无实质内容，就用最近一条用户输入作为标题`, maxChars)
 
 	messages := []llm.Message{

backend/biz/task/service/types.go

@@ -35,3 +35,4 @@ type wsContent struct {
 	Content string `json:"content"`
 	Message string `json:"message"`
 }
+

backend/config/config.go

@@ -110,6 +110,7 @@ type TaskSummary struct {
 	InterfaceType string `mapstructure:"interface_type"` // API 接口类型（openai_chat/openai_responses/anthropic）
 	Delay         int    `mapstructure:"delay"`          // 延迟时间（秒），默认 3600
 	MaxChars      int    `mapstructure:"max_chars"`      // 摘要最大字符数，默认 300
+	MaxRounds     int    `mapstructure:"max_rounds"`     // 最近对话轮数，默认 3
 	MaxWorkers    int    `mapstructure:"max_workers"`    // 最大消费者数量，默认 5
 }