优化咨询客服

backend/internal/model/chat.go

@@ -8,7 +8,7 @@ import (
 
 type ChatConversation struct {
 	ID                 uint64     `gorm:"primaryKey" json:"id"`
-	OrderID            uint64     `gorm:"not null;uniqueIndex" json:"order_id"`
+	OrderID            *uint64    `gorm:"uniqueIndex" json:"order_id"`
 	Type               string     `gorm:"size:32;not null;default:'order_group'" json:"type"`
 	Title              string     `gorm:"size:128;not null" json:"title"`
 	Status             string     `gorm:"size:32;not null;default:'active'" json:"status"`

backend/internal/modules/chat/dto.go

@@ -9,7 +9,7 @@ type Principal struct {
 
 type ConversationDTO struct {
 	ID                 uint64           `json:"id"`
-	OrderID            uint64           `json:"order_id"`
+	OrderID            *uint64          `json:"order_id"`
 	Type               string           `json:"type"`
 	Title              string           `json:"title"`
 	Status             string           `json:"status"`

backend/internal/modules/chat/handler.go

@@ -81,6 +81,20 @@ func (h *Handler) OrderConversation(c *gin.Context) {
 	response.OK(c, item)
 }
 
+func (h *Handler) EnsureSupportConversation(c *gin.Context) {
+	userID, ok := currentUserID(c)
+	if !ok {
+		response.Unauthorized(c, "缺少用户上下文")
+		return
+	}
+	item, err := h.service.EnsureSupportConversation(userID)
+	if err != nil {
+		writeChatError(c, err)
+		return
+	}
+	response.OK(c, item)
+}
+
 func (h *Handler) Messages(c *gin.Context) {
 	userID, ok := currentUserID(c)
 	if !ok {

backend/internal/modules/chat/repository.go

@@ -43,7 +43,7 @@ func EnsureOrderConversation(tx *gorm.DB, order model.RentalOrder) (*model.ChatC
 
 	now := time.Now()
 	conversation := model.ChatConversation{
-		OrderID: order.ID,
+		OrderID: &order.ID,
 		Type:    "order_group",
 		Title:   orderConversationTitle(order),
 		Status:  "active",
@@ -182,6 +182,89 @@ func (r *Repository) FindOrderConversation(userID uint64, orderID uint64) (*Conv
 	return &dto, nil
 }
 
+func (r *Repository) EnsureSupportConversation(userID uint64) (*ConversationDTO, error) {
+	var conversationID uint64
+	err := r.db.Transaction(func(tx *gorm.DB) error {
+		var existing model.ChatConversation
+		err := tx.Table("chat_conversations AS c").
+			Select("c.*").
+			Joins("JOIN chat_participants AS cp ON cp.conversation_id = c.id").
+			Where("c.type = ? AND cp.participant_type = ? AND cp.participant_id = ?", "general_support", "user", userID).
+			Order("c.id ASC").
+			First(&existing).Error
+		if err == nil {
+			conversationID = existing.ID
+			return nil
+		}
+		if !errors.Is(err, gorm.ErrRecordNotFound) {
+			return err
+		}
+
+		now := time.Now()
+		conversation := model.ChatConversation{
+			Type:   "general_support",
+			Title:  "平台客服",
+			Status: "active",
+		}
+		if err := tx.Create(&conversation).Error; err != nil {
+			return err
+		}
+
+		participants := []model.ChatParticipant{
+			{
+				ConversationID:  conversation.ID,
+				ParticipantType: "user",
+				ParticipantID:   userID,
+				Role:            "customer",
+				JoinedAt:        now,
+			},
+		}
+		if supportID := defaultSupportAdminID(tx); supportID > 0 {
+			participants = append(participants, model.ChatParticipant{
+				ConversationID:  conversation.ID,
+				ParticipantType: "admin",
+				ParticipantID:   supportID,
+				Role:            "support",
+				JoinedAt:        now,
+			})
+		}
+		for _, participant := range participants {
+			if err := tx.Clauses(clause.OnConflict{DoNothing: true}).Create(&participant).Error; err != nil {
+				return err
+			}
+		}
+
+		message := model.ChatMessage{
+			ConversationID: conversation.ID,
+			SenderType:     "system",
+			SenderRole:     "system",
+			ContentType:    "system",
+			Content:        "您好，客服会尽快回复，请直接描述您遇到的问题。",
+			AttachmentURLS: emptyJSONList(),
+		}
+		if err := tx.Create(&message).Error; err != nil {
+			return err
+		}
+		conversation.LastMessageID = &message.ID
+		conversation.LastMessagePreview = truncatePreview(message.Content)
+		conversation.LastMessageAt = &message.CreatedAt
+		if err := tx.Save(&conversation).Error; err != nil {
+			return err
+		}
+		conversationID = conversation.ID
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	item, err := r.FindConversation(Principal{Type: "user", ID: userID}, conversationID)
+	if err != nil {
+		return nil, err
+	}
+	r.NotifyNewConversation(conversationID)
+	return item, nil
+}
+
 func (r *Repository) Messages(principal Principal, conversationID uint64, page, pageSize int) (*PaginatedResult, error) {
 	page, pageSize = normalizePagination(page, pageSize)
 	if _, err := r.findParticipant(r.db, principal, conversationID, false); err != nil {
@@ -473,7 +556,7 @@ func (r *Repository) adminNames(ids []uint64) (map[uint64]string, error) {
 
 type conversationRow struct {
 	ID                 uint64
-	OrderID            uint64
+	OrderID            *uint64
 	Type               string
 	Title              string
 	Status             string

backend/internal/modules/chat/service.go

@@ -41,6 +41,16 @@ func (s *Service) FindOrderConversation(userID uint64, orderID uint64) (*Convers
 	return s.repo.FindOrderConversation(userID, orderID)
 }
 
+func (s *Service) EnsureSupportConversation(userID uint64) (*ConversationDTO, error) {
+	if s.repo == nil {
+		return nil, ErrDependencyUnavailable
+	}
+	if userID == 0 {
+		return nil, ErrPermissionDenied
+	}
+	return s.repo.EnsureSupportConversation(userID)
+}
+
 func (s *Service) Messages(principal Principal, conversationID uint64, page, pageSize int) (*PaginatedResult, error) {
 	if s.repo == nil {
 		return nil, ErrDependencyUnavailable

backend/internal/router/router.go

@@ -247,6 +247,7 @@ func New(cfg config.Config, deps Dependencies, logger *zap.Logger) *gin.Engine {
 			if chatHubHandler != nil {
 				chatRoutes.GET("/events", chatHubHandler.UserEvents)
 			}
+			chatRoutes.POST("/support", chatHandler.EnsureSupportConversation)
 			chatRoutes.GET("", chatHandler.List)
 			chatRoutes.GET("/:id", chatHandler.Detail)
 			chatRoutes.GET("/:id/messages", chatHandler.Messages)

backend/migrations/000001_init.sql

@@ -315,7 +315,7 @@ CREATE TABLE system_configs (
 
 CREATE TABLE chat_conversations (
   id BIGINT UNSIGNED PRIMARY KEY AUTO_INCREMENT,
-  order_id BIGINT UNSIGNED NOT NULL,
+  order_id BIGINT UNSIGNED NULL,
   type VARCHAR(32) NOT NULL DEFAULT 'order_group',
   title VARCHAR(128) NOT NULL,
   status VARCHAR(32) NOT NULL DEFAULT 'active',

backend/migrations/000004_support_chat.sql

@@ -0,0 +1,2 @@
+ALTER TABLE chat_conversations
+  MODIFY order_id BIGINT UNSIGNED NULL;