feat(session): 优化工作台会话分页与筛选

server/internal/service/session.go

@@ -41,15 +41,17 @@ type AgentItem struct {
 
 // SessionFilter 会话列表筛选。
 type SessionFilter struct {
-	Status    string
-	Priority  string
-	AgentID   string
-	ChannelID string
-	Search    string
-	From      string
-	To        string
-	Page      int
-	PageSize  int
+	Scope      string
+	Status     string
+	Priority   string
+	AgentID    string
+	ChannelID  string
+	CustomerID string
+	Search     string
+	From       string
+	To         string
+	Page       int
+	PageSize   int
 }
 
 // LoadTenantSession 加载本租户会话；跨租户访问返回 403。
@@ -120,21 +122,30 @@ func assignableRoleCodes(tenantID uint) []string {
 	return append(codes, customCodes...)
 }
 
-func unreadCount(session model.Session) int {
-	var count int64
-	model.DB.Model(&model.Message{}).
-		Where("session_id = ? AND sender_type = ? AND seq > ?", session.ID, "visitor", session.LastReadSeq).
-		Count(&count)
-	return int(count)
-}
-
-// ListSessions 会话列表：筛选、分页并批量补全客户/坐席/渠道/消息数。
+// ListSessions 会话列表：筛选、分页并批量补全客户/坐席/渠道/消息摘要。
 func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListItem, int64, error) {
 	var sessions []model.Session
 	var total int64
 
+	page := f.Page
+	pageSize := f.PageSize
+	if page < 1 {
+		page = 1
+	}
+	if pageSize < 1 {
+		pageSize = 20
+	}
+	if pageSize > 100 {
+		pageSize = 100
+	}
+
 	query := model.DB.Model(&model.Session{}).Where("sessions.tenant_id = ?", tenantID)
-	if !actor.SessionAll || !actor.HistoryAll {
+	if f.Scope == "workbench" {
+		query = query.Where("sessions.status IN ?", []string{"waiting", "active"})
+		if !actor.SessionAll {
+			query = query.Where("sessions.agent_id = ? OR sessions.status = ?", actor.UserID, "waiting")
+		}
+	} else if !actor.SessionAll || !actor.HistoryAll {
 		query = query.Where("sessions.agent_id = ? OR sessions.status = ?", actor.UserID, "waiting")
 	}
 	if f.Status != "" {
@@ -149,6 +160,9 @@ func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListIte
 	if f.ChannelID != "" {
 		query = query.Where("sessions.channel_id = ?", f.ChannelID)
 	}
+	if f.CustomerID != "" {
+		query = query.Where("sessions.customer_id = ?", f.CustomerID)
+	}
 	if f.From != "" {
 		if t, err := time.ParseInLocation("2006-01-02", f.From, time.Local); err == nil {
 			query = query.Where("sessions.created_at >= ?", t)
@@ -161,16 +175,52 @@ func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListIte
 	}
 	if f.Search != "" {
 		like := "%" + f.Search + "%"
-		query = query.Joins("LEFT JOIN customers ON customers.id = sessions.customer_id").
-			Where("customers.name LIKE ? OR CAST(sessions.id AS TEXT) LIKE ? OR COALESCE(sessions.end_reason, '') LIKE ?", like, like, like)
+		query = query.Where(
+			`EXISTS (
+				SELECT 1 FROM customers AS search_customers
+				WHERE search_customers.id = sessions.customer_id
+					AND search_customers.name LIKE ?
+			) OR CAST(sessions.id AS TEXT) LIKE ? OR EXISTS (
+				SELECT 1 FROM messages AS search_messages
+				WHERE search_messages.session_id = sessions.id
+					AND search_messages.seq = (
+						SELECT MAX(latest_message.seq)
+						FROM messages AS latest_message
+						WHERE latest_message.session_id = sessions.id
+					)
+					AND search_messages.content LIKE ?
+			)`,
+			like, like, like,
+		)
 	}
 
-	query.Count(&total)
-	if err := query.Order("sessions.created_at desc").Offset((f.Page - 1) * f.PageSize).Limit(f.PageSize).Find(&sessions).Error; err != nil {
+	if err := query.Count(&total).Error; err != nil {
+		return nil, 0, Internal("统计会话失败")
+	}
+	if f.Scope == "workbench" {
+		query = query.
+			Order(`CASE
+				WHEN sessions.priority = 'urgent' THEN 0
+				WHEN sessions.status = 'waiting' THEN 1
+				ELSE 2
+			END ASC`).
+			Order(`COALESCE(
+				(SELECT order_messages.sent_at
+				 FROM messages AS order_messages
+				 WHERE order_messages.session_id = sessions.id
+				 ORDER BY order_messages.seq DESC
+				 LIMIT 1),
+				sessions.created_at
+			) DESC`).
+			Order("sessions.id DESC")
+	} else {
+		query = query.Order("sessions.created_at DESC").Order("sessions.id DESC")
+	}
+	if err := query.Offset((page - 1) * pageSize).Limit(pageSize).Find(&sessions).Error; err != nil {
 		return nil, 0, Internal("查询会话失败")
 	}
 
-	// 批量补全客户 / 客服 / 渠道 / 消息数
+	// 批量补全客户 / 客服 / 渠道 / 消息摘要，避免按会话逐条查询。
 	customerIDs := make([]uint, 0)
 	agentIDs := make([]uint, 0)
 	channelIDs := make([]uint, 0)
@@ -186,7 +236,9 @@ func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListIte
 	customerMap := map[uint]model.Customer{}
 	if len(customerIDs) > 0 {
 		var customers []model.Customer
-		model.DB.Where("id IN ?", UniqueUint(customerIDs)).Find(&customers)
+		if err := model.DB.Where("id IN ?", UniqueUint(customerIDs)).Find(&customers).Error; err != nil {
+			return nil, 0, Internal("查询会话客户失败")
+		}
 		for _, cu := range customers {
 			customerMap[cu.ID] = cu
 		}
@@ -194,7 +246,9 @@ func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListIte
 	agentMap := map[uint]model.User{}
 	if len(agentIDs) > 0 {
 		var users []model.User
-		model.DB.Where("id IN ?", UniqueUint(agentIDs)).Find(&users)
+		if err := model.DB.Where("id IN ?", UniqueUint(agentIDs)).Find(&users).Error; err != nil {
+			return nil, 0, Internal("查询会话坐席失败")
+		}
 		for _, u := range users {
 			agentMap[u.ID] = u
 		}
@@ -202,35 +256,74 @@ func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListIte
 	channelMap := map[uint]model.Channel{}
 	if len(channelIDs) > 0 {
 		var channels []model.Channel
-		model.DB.Unscoped().Where("id IN ?", UniqueUint(channelIDs)).Find(&channels)
+		if err := model.DB.Unscoped().Where("id IN ?", UniqueUint(channelIDs)).Find(&channels).Error; err != nil {
+			return nil, 0, Internal("查询会话渠道失败")
+		}
 		for _, ch := range channels {
 			channelMap[ch.ID] = ch
 		}
 	}
 	msgCountMap := map[uint]int{}
+	lastMessageMap := map[uint]model.Message{}
+	unreadMap := map[uint]int{}
 	if len(sessionIDs) > 0 {
 		type row struct {
 			SessionID uint
-			Cnt       int
+			Cnt       int `gorm:"column:cnt"`
 		}
 		var rows []row
-		model.DB.Model(&model.Message{}).
+		if err := model.DB.Model(&model.Message{}).
 			Select("session_id, COUNT(*) as cnt").
 			Where("session_id IN ?", sessionIDs).
 			Group("session_id").
-			Scan(&rows)
+			Scan(&rows).Error; err != nil {
+			return nil, 0, Internal("统计会话消息失败")
+		}
 		for _, r := range rows {
 			msgCountMap[r.SessionID] = r.Cnt
 		}
+
+		var lastMessages []model.Message
+		if err := model.DB.Where(
+			`session_id IN ? AND seq = (
+				SELECT MAX(latest.seq)
+				FROM messages AS latest
+				WHERE latest.session_id = messages.session_id
+			)`,
+			sessionIDs,
+		).Find(&lastMessages).Error; err != nil {
+			return nil, 0, Internal("查询会话最后消息失败")
+		}
+		for _, msg := range lastMessages {
+			lastMessageMap[msg.SessionID] = msg
+		}
+
+		var unreadRows []row
+		if err := model.DB.Table("messages").
+			Select("messages.session_id, COUNT(*) AS cnt").
+			Joins("JOIN sessions AS unread_sessions ON unread_sessions.id = messages.session_id").
+			Where(
+				"messages.session_id IN ? AND messages.sender_type = ? AND messages.seq > unread_sessions.last_read_seq",
+				sessionIDs,
+				"visitor",
+			).
+			Group("messages.session_id").
+			Scan(&unreadRows).Error; err != nil {
+			return nil, 0, Internal("统计会话未读数失败")
+		}
+		for _, r := range unreadRows {
+			unreadMap[r.SessionID] = r.Cnt
+		}
 	}
 
 	items := make([]SessionListItem, 0, len(sessions))
 	for _, session := range sessions {
-		item := SessionListItem{Session: session, MessageCount: msgCountMap[session.ID]}
-		item.VisitorOnline = VisitorIsOnline(&session, time.Now())
-		if !actor.SessionAll && session.AgentID != nil && *session.AgentID == actor.UserID {
-			item.UnreadCount = unreadCount(session)
+		item := SessionListItem{
+			Session:      session,
+			MessageCount: msgCountMap[session.ID],
+			UnreadCount:  unreadMap[session.ID],
 		}
+		item.VisitorOnline = VisitorIsOnline(&session, time.Now())
 		if cu, ok := customerMap[session.CustomerID]; ok {
 			item.CustomerName = cu.Name
 		}
@@ -244,8 +337,7 @@ func ListSessions(actor Actor, tenantID uint, f SessionFilter) ([]SessionListIte
 			item.ChannelType = ch.Type
 			item.ChannelDomain = ch.SiteDomain
 		}
-		var lastMsg model.Message
-		if err := model.DB.Where("session_id = ?", session.ID).Order("seq desc").First(&lastMsg).Error; err == nil {
+		if lastMsg, ok := lastMessageMap[session.ID]; ok {
 			if lastMsg.Type == "image" {
 				item.LastMessage = "[图片]"
 			} else {