聊天增加图片功能

backend/internal/modules/chat/dto.go

@@ -52,7 +52,8 @@ type MessageDTO struct {
 }
 
 type SendMessageRequest struct {
-	Content string `json:"content" binding:"required"`
+	Content        string   `json:"content"`
+	AttachmentURLS []string `json:"attachment_urls"`
 }
 
 type TransferRequest struct {

backend/internal/modules/chat/handler.go

@@ -340,7 +340,7 @@ func (h *Handler) send(c *gin.Context, principal Principal) {
 	}
 	var req SendMessageRequest
 	if err := c.ShouldBindJSON(&req); err != nil {
-		response.BadRequest(c, "消息内容不能为空")
+		response.BadRequest(c, "消息格式不正确")
 		return
 	}
 	message, err := h.service.SendMessage(principal, id, req)

backend/internal/modules/chat/repository.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"strconv"
+	"strings"
 	"time"
 
 	"hfb_sys/backend/internal/model"
@@ -312,13 +313,13 @@ func (r *Repository) SendMessage(principal Principal, conversationID uint64, req
 			SenderRole:     participant.Role,
 			ContentType:    "text",
 			Content:        req.Content,
-			AttachmentURLS: emptyJSONList(),
+			AttachmentURLS: encodeStringList(req.AttachmentURLS),
 		}
 		if err := tx.Create(&message).Error; err != nil {
 			return err
 		}
 		conversation.LastMessageID = &message.ID
-		conversation.LastMessagePreview = truncatePreview(message.Content)
+		conversation.LastMessagePreview = messagePreview(message.Content, req.AttachmentURLS)
 		conversation.LastMessageAt = &message.CreatedAt
 		if err := tx.Save(&conversation).Error; err != nil {
 			return err
@@ -708,6 +709,17 @@ func truncatePreview(content string) string {
 	return string(runes[:80])
 }
 
+func messagePreview(content string, attachments []string) string {
+	content = strings.TrimSpace(content)
+	if content != "" {
+		return truncatePreview(content)
+	}
+	if len(attachments) > 0 {
+		return "[图片]"
+	}
+	return ""
+}
+
 // TransferConversation 转接会话给其他客服
 func (r *Repository) TransferConversation(principal Principal, conversationID uint64, toAdminID uint64) error {
 	return r.db.Transaction(func(tx *gorm.DB) error {
@@ -908,6 +920,11 @@ func emptyJSONList() datatypes.JSON {
 	return datatypes.JSON(raw)
 }
 
+func encodeStringList(items []string) datatypes.JSON {
+	raw, _ := json.Marshal(items)
+	return datatypes.JSON(raw)
+}
+
 // UpdateRemark 更新会话备注
 func (r *Repository) UpdateRemark(principal Principal, conversationID uint64, remark string) error {
 	return r.db.Model(&model.ChatParticipant{}).

backend/internal/modules/chat/service.go

@@ -2,6 +2,7 @@ package chat
 
 import (
 	"errors"
+	"net/url"
 	"strings"
 )
 
@@ -63,15 +64,54 @@ func (s *Service) SendMessage(principal Principal, conversationID uint64, req Se
 		return nil, ErrDependencyUnavailable
 	}
 	req.Content = strings.TrimSpace(req.Content)
-	if conversationID == 0 || req.Content == "" {
+	attachments, ok := normalizeAttachmentURLS(req.AttachmentURLS)
+	req.AttachmentURLS = attachments
+	if conversationID == 0 || (req.Content == "" && len(req.AttachmentURLS) == 0) {
 		return nil, ErrInvalidMessage
 	}
 	if len([]rune(req.Content)) > 1000 {
 		return nil, ErrInvalidMessage
 	}
+	if !ok {
+		return nil, ErrInvalidMessage
+	}
 	return s.repo.SendMessage(principal, conversationID, req)
 }
 
+func normalizeAttachmentURLS(items []string) ([]string, bool) {
+	if len(items) > 9 {
+		return nil, false
+	}
+	result := make([]string, 0, len(items))
+	for _, item := range items {
+		value := strings.TrimSpace(item)
+		if value == "" {
+			continue
+		}
+		if len(value) > 500 || strings.Contains(value, "..") {
+			return nil, false
+		}
+		parsed, err := url.Parse(value)
+		if err != nil {
+			return nil, false
+		}
+		if parsed.Host != "" {
+			return nil, false
+		}
+		switch parsed.Path {
+		case "/api/files/object", "/api/admin/files/object", "/api/public/files/object":
+		default:
+			return nil, false
+		}
+		key := strings.TrimSpace(parsed.Query().Get("key"))
+		if key == "" || strings.Contains(key, "..") {
+			return nil, false
+		}
+		result = append(result, value)
+	}
+	return result, true
+}
+
 func (s *Service) MarkRead(principal Principal, conversationID uint64) error {
 	if s.repo == nil {
 		return ErrDependencyUnavailable