聊天增加图片功能

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{}).