新增消息已读状态

复用 chat_participants.last_read_at 推导已读，无需新表/迁移。

- 后端：MessageDTO 增加 is_read，toMessageDTOs 按「全部已读」语义计算
  （所有其他参与者均已读才算已读，1对1 即对方已读）；MarkRead 成功后
  推送 conversation_read 事件（含 reader 与 read_at），NotifyConversation
  与 NotifyAllAdmins 双通道通知，使发送方/客服实时刷新已读
- 前端：ChatMessage 增加 is_read，ChatView/AdminChatsView/MobileChatView
  在自己的消息下渲染「已读/未读」；收到 conversation_read 且本端仍有
  未获回执的自己消息时才重载，避免无谓请求

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/internal/modules/chat/dto.go

@@ -45,6 +45,7 @@ type MessageDTO struct {
 	SenderName     string    `json:"sender_name"`
 	SenderAvatar   string    `json:"sender_avatar"`
 	IsSelf         bool      `json:"is_self"`
+	IsRead         bool      `json:"is_read"`
 	ContentType    string    `json:"content_type"`
 	Content        string    `json:"content"`
 	AttachmentURLS []string  `json:"attachment_urls"`

backend/internal/modules/chat/message.go

@@ -160,7 +160,9 @@ func (r *Repository) SendMessage(ctx context.Context, principal Principal, conve
 	return &items[0], nil
 }
 func (r *Repository) MarkRead(ctx context.Context, principal Principal, conversationID uint64) error {
-	return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
+	now := time.Now()
+	updated := false
+	err := r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
 		// 管理员可以不是 participant，直接返回成功
 		if principal.Type == "admin" {
 			// 尝试查找 participant 记录，如果有就更新
@@ -169,7 +171,7 @@ func (r *Repository) MarkRead(ctx context.Context, principal Principal, conversa
 				conversationID, principal.Type, principal.ID).First(&participant).Error
 			if err == nil {
 				// 有 participant 记录，更新已读时间
-				now := time.Now()
+				updated = true
 				return tx.Model(&participant).Update("last_read_at", now).Error
 			} else if errors.Is(err, gorm.ErrRecordNotFound) {
 				// 没有 participant 记录，直接返回成功（管理员无需记录已读）
@@ -183,7 +185,24 @@ func (r *Repository) MarkRead(ctx context.Context, principal Principal, conversa
 		if err != nil {
 			return err
 		}
-		now := time.Now()
+		updated = true
 		return tx.Model(participant).Update("last_read_at", now).Error
 	})
+	if err != nil {
+		return err
+	}
+	// 已读时间发生变化时，通知会话内其他参与者刷新「已读」状态。
+	if updated && r.hub != nil {
+		event := &chathub.ChatEvent{
+			Type:           "conversation_read",
+			ConversationID: conversationID,
+			ReaderType:     principal.Type,
+			ReaderID:       principal.ID,
+			ReadAt:         now.Format(time.RFC3339),
+		}
+		r.hub.NotifyConversation(conversationID, event)
+		// 同时广播给所有在线客服，覆盖未分配会话中非参与者客服的「已读」刷新。
+		r.hub.NotifyAllAdmins(event)
+	}
+	return nil
 }

backend/internal/modules/chat/participant.go

@@ -105,6 +105,7 @@ func (r *Repository) participants(ctx context.Context, conversationID uint64) ([
 func (r *Repository) toMessageDTOs(ctx context.Context, principal Principal, rows []model.ChatMessage) ([]MessageDTO, error) {
 	userIDs := make([]uint64, 0)
 	adminIDs := make([]uint64, 0)
+	conversationIDSet := make(map[uint64]struct{})
 	for _, row := range rows {
 		if row.SenderType == "user" && row.SenderID > 0 {
 			userIDs = append(userIDs, row.SenderID)
@@ -112,6 +113,7 @@ func (r *Repository) toMessageDTOs(ctx context.Context, principal Principal, row
 		if row.SenderType == "admin" && row.SenderID > 0 {
 			adminIDs = append(adminIDs, row.SenderID)
 		}
+		conversationIDSet[row.ConversationID] = struct{}{}
 	}
 	userNames, userAvatars, err := r.userNames(ctx, userIDs)
 	if err != nil {
@@ -121,6 +123,11 @@ func (r *Repository) toMessageDTOs(ctx context.Context, principal Principal, row
 	if err != nil {
 		return nil, err
 	}
+	// 加载相关会话的参与者已读时间，用于推导「自己发出的消息」是否已被对方读取。
+	readParticipants, err := r.conversationReadParticipants(ctx, conversationIDSet)
+	if err != nil {
+		return nil, err
+	}
 	items := make([]MessageDTO, 0, len(rows))
 	for _, row := range rows {
 		name := "系统"
@@ -136,6 +143,7 @@ func (r *Repository) toMessageDTOs(ctx context.Context, principal Principal, row
 				name = name + " (管理员)"
 			}
 		}
+		isSelf := row.SenderType == principal.Type && row.SenderID == principal.ID
 		items = append(items, MessageDTO{
 			ID:             row.ID,
 			ConversationID: row.ConversationID,
@@ -144,7 +152,9 @@ func (r *Repository) toMessageDTOs(ctx context.Context, principal Principal, row
 			SenderRole:     row.SenderRole,
 			SenderName:     fallbackName(row.SenderType, row.SenderID, name),
 			SenderAvatar:   avatar,
-			IsSelf:         row.SenderType == principal.Type && row.SenderID == principal.ID,
+			IsSelf:         isSelf,
+			// 仅对自己发出的消息计算已读：是否已被所有其他参与者读取。
+			IsRead:         isSelf && messageReadByOthers(readParticipants[row.ConversationID], row),
 			ContentType:    row.ContentType,
 			Content:        row.Content,
 			AttachmentURLS: decodeStringList(row.AttachmentURLS),
@@ -153,6 +163,62 @@ func (r *Repository) toMessageDTOs(ctx context.Context, principal Principal, row
 	}
 	return items, nil
 }
+
+type readParticipant struct {
+	ParticipantType string
+	ParticipantID   uint64
+	LastReadAt      *time.Time
+}
+
+// conversationReadParticipants 批量加载若干会话的参与者已读时间。
+func (r *Repository) conversationReadParticipants(ctx context.Context, ids map[uint64]struct{}) (map[uint64][]readParticipant, error) {
+	result := make(map[uint64][]readParticipant)
+	if len(ids) == 0 {
+		return result, nil
+	}
+	idList := make([]uint64, 0, len(ids))
+	for id := range ids {
+		idList = append(idList, id)
+	}
+	type row struct {
+		ConversationID  uint64
+		ParticipantType string
+		ParticipantID   uint64
+		LastReadAt      *time.Time
+	}
+	var rows []row
+	if err := r.db.WithContext(ctx).Table("chat_participants").
+		Select("conversation_id, participant_type, participant_id, last_read_at").
+		Where("conversation_id IN ?", idList).
+		Find(&rows).Error; err != nil {
+		return nil, err
+	}
+	for _, rw := range rows {
+		result[rw.ConversationID] = append(result[rw.ConversationID], readParticipant{
+			ParticipantType: rw.ParticipantType,
+			ParticipantID:   rw.ParticipantID,
+			LastReadAt:      rw.LastReadAt,
+		})
+	}
+	return result, nil
+}
+
+// messageReadByOthers 采用「全部已读」语义：所有其他参与者的 last_read_at 均不早于该消息时间。
+// 1对1 即对方已读；群聊需所有其他成员都已读。无其他参与者时返回 false。
+func messageReadByOthers(participants []readParticipant, msg model.ChatMessage) bool {
+	others := 0
+	for _, p := range participants {
+		// 排除发送者本人
+		if p.ParticipantType == msg.SenderType && p.ParticipantID == msg.SenderID {
+			continue
+		}
+		others++
+		if p.LastReadAt == nil || p.LastReadAt.Before(msg.CreatedAt) {
+			return false
+		}
+	}
+	return others > 0
+}
 func (r *Repository) participantNames(ctx context.Context, rows []model.ChatParticipant) (map[uint64]string, map[uint64]string, map[uint64]string, error) {
 	userIDs := make([]uint64, 0)
 	adminIDs := make([]uint64, 0)

backend/internal/modules/chathub/hub.go

@@ -9,9 +9,13 @@ import (
 
 // ChatEvent 是通过 SSE 推送给客户端的事件。
 type ChatEvent struct {
-	Type           string       `json:"type"` // "new_message" | "conversation_updated"
+	Type           string       `json:"type"` // "new_message" | "conversation_updated" | "conversation_read"
 	ConversationID uint64       `json:"conversation_id"`
 	Message        *MessageData `json:"message,omitempty"`
+	// 以下字段仅在 conversation_read 事件中使用，标识谁在何时读取了会话。
+	ReaderType string `json:"reader_type,omitempty"`
+	ReaderID   uint64 `json:"reader_id,omitempty"`
+	ReadAt     string `json:"read_at,omitempty"`
 }
 
 // MessageData 是事件中携带的消息数据，与 chat.MessageDTO 对齐。

frontend/src/features/admin/views/AdminChatsView.vue

@@ -71,6 +71,15 @@ function handleSSEEvent(event: ChatEvent) {
   if (event.type === 'conversation_updated') {
     loadConversations(false)
   }
+  if (event.type === 'conversation_read') {
+    // 对方已读：仅当本端仍有未获回执的自己消息时重载，刷新「已读」状态
+    if (active.value && event.conversation_id === active.value.id) {
+      const isSelfReader = event.reader_type === 'admin' && event.reader_id === currentAdminId
+      if (!isSelfReader && messages.value.some(m => m.is_self && !m.is_read)) {
+        loadMessages(active.value.id, false)
+      }
+    }
+  }
   if (event.type === 'new_message') {
     const msg = event.message
     if (!msg) return
@@ -91,6 +100,7 @@ function handleSSEEvent(event: ChatEvent) {
           sender_name: msg.sender_name,
           sender_avatar: '',
           is_self: isSelf,
+          is_read: false,
           content_type: msg.content_type as ChatMessage['content_type'],
           content: msg.content,
           attachment_urls: msg.attachment_urls || [],
@@ -441,6 +451,9 @@ function getSupportName(item: ChatConversation) {
                     admin
                   />
                 </div>
+                <small v-if="item.is_self" class="read-status" :class="{ read: item.is_read }">
+                  {{ item.is_read ? '已读' : '未读' }}
+                </small>
               </template>
             </div>
           </div>
@@ -729,6 +742,16 @@ function getSupportName(item: ChatConversation) {
   color: #8a94a6;
 }
 
+.read-status {
+  margin-top: 4px;
+  margin-bottom: 0;
+  font-size: 11px;
+}
+
+.read-status.read {
+  color: #67c23a;
+}
+
 .message-row p {
   display: inline-block;
   margin: 0;

frontend/src/features/chats/api/chats.ts

@@ -39,6 +39,7 @@ export interface ChatMessage {
   sender_name: string
   sender_avatar: string
   is_self: boolean
+  is_read: boolean
   content_type: 'text' | 'system'
   content: string
   attachment_urls: string[]

frontend/src/features/chats/composables/useChatSSE.ts

@@ -16,9 +16,12 @@ export interface SSEMessage {
 }
 
 export interface ChatEvent {
-  type: 'new_message' | 'conversation_updated'
+  type: 'new_message' | 'conversation_updated' | 'conversation_read'
   conversation_id: number
   message?: SSEMessage
+  reader_type?: string
+  reader_id?: number
+  read_at?: string
 }
 
 type EventHandler = (event: ChatEvent) => void
@@ -69,6 +72,15 @@ export function useChatSSE(scope: AuthScope, endpoint: string) {
       }
     })
 
+    source.addEventListener('conversation_read', e => {
+      try {
+        const data = JSON.parse((e as MessageEvent).data) as ChatEvent
+        handlers.forEach(h => h(data))
+      } catch {
+        /* ignore */
+      }
+    })
+
     source.onerror = async () => {
       connected.value = false
       source?.close()

frontend/src/features/chats/views/ChatView.vue

@@ -58,6 +58,7 @@ function handleSSEEvent(event: ChatEvent) {
           sender_name: msg.sender_name,
           sender_avatar: '',
           is_self: isSelf,
+          is_read: false,
           content_type: msg.content_type as ChatMessage['content_type'],
           content: msg.content,
           attachment_urls: msg.attachment_urls || [],
@@ -76,6 +77,13 @@ function handleSSEEvent(event: ChatEvent) {
   if (event.type === 'conversation_updated' && event.conversation_id === conversationID.value) {
     loadConversation()
   }
+  if (event.type === 'conversation_read' && event.conversation_id === conversationID.value) {
+    // 对方已读：仅当本端仍有未获回执的自己消息时重载，刷新「已读」状态
+    const isSelfReader = event.reader_type === 'user' && event.reader_id === currentUserId
+    if (!isSelfReader && messages.value.some(m => m.is_self && !m.is_read)) {
+      loadMessages(false)
+    }
+  }
 }
 
 const { onEvent } = useChatSSE('user', '/api/chats/events')
@@ -305,6 +313,9 @@ function handleKeydown(e: KeyboardEvent) {
                 <ChatAttachmentImage v-for="url in item.attachment_urls" :key="url" :source="url" />
               </div>
               <span class="message-time">{{ formatDateMinute(item.created_at) }}</span>
+              <span v-if="item.is_self" class="read-status" :class="{ read: item.is_read }">
+                {{ item.is_read ? '已读' : '未读' }}
+              </span>
             </div>
           </template>
         </div>
@@ -538,6 +549,16 @@ function handleKeydown(e: KeyboardEvent) {
   font-size: 11px;
 }
 
+.read-status {
+  margin-top: 2px;
+  color: #a1a8b4;
+  font-size: 11px;
+}
+
+.read-status.read {
+  color: #67c23a;
+}
+
 .system-message {
   max-width: 80%;
   padding: 6px 12px;

frontend/src/features/chats/views/MobileChatView.vue

@@ -62,6 +62,7 @@ function handleSSEEvent(event: ChatEvent) {
             sender_name: msg.sender_name,
             sender_avatar: '',
             is_self: isSelf,
+            is_read: false,
             content_type: msg.content_type as ChatMessage['content_type'],
             content: msg.content,
             attachment_urls: msg.attachment_urls || [],
@@ -80,6 +81,13 @@ function handleSSEEvent(event: ChatEvent) {
   if (event.type === 'conversation_updated' && event.conversation_id === conversationID.value) {
     loadConversation()
   }
+  if (event.type === 'conversation_read' && event.conversation_id === conversationID.value) {
+    // 对方已读：仅当本端仍有未获回执的自己消息时重载，刷新「已读」状态
+    const isSelfReader = event.reader_type === 'user' && event.reader_id === currentUserId
+    if (!isSelfReader && messages.value.some(m => m.is_self && !m.is_read)) {
+      loadMessages(false)
+    }
+  }
 }
 
 const { onEvent } = useChatSSE('user', '/api/chats/events')
@@ -284,6 +292,9 @@ function senderLabel(message: ChatMessage) {
               <ChatAttachmentImage v-for="url in item.attachment_urls" :key="url" :source="url" />
             </div>
             <span class="message-time">{{ formatDateMinute(item.created_at) }}</span>
+            <span v-if="item.is_self" class="read-status" :class="{ read: item.is_read }">
+              {{ item.is_read ? '已读' : '未读' }}
+            </span>
           </div>
         </template>
       </div>
@@ -499,6 +510,16 @@ function senderLabel(message: ChatMessage) {
   font-size: 10px;
 }
 
+.read-status {
+  margin-top: 2px;
+  color: #a1a8b4;
+  font-size: 10px;
+}
+
+.read-status.read {
+  color: #67c23a;
+}
+
 .system-message {
   max-width: 82%;
   padding: 5px 9px;