feat: 添加用户购买作品数量统计功能

backend_v1/app/http/admin/users.go

@@ -7,22 +7,53 @@ import (
 	"quyun/v2/database/models"
 
 	"github.com/gofiber/fiber/v3"
+	"github.com/samber/lo"
 )
 
 // @provider
 type users struct{}
 
+type UserItem struct {
+	*models.User
+	BoughtCount int64 `json:"bought_count"` // 用户已购作品数量（统计 user_posts 记录数，含赠送/免费购买）
+}
+
 // List users
 //
 //	@Summary	用户列表
 //	@Tags		Admin Users
 //	@Produce	json
 //	@Param		query		query		UserListQuery						false	"筛选条件"
-//	@Success	200			{object}	requests.Pager{items=models.User}	"成功"
+//	@Success	200			{object}	requests.Pager{items=UserItem}	"成功"
 //	@Router		/admin/v1/users [get]
 //	@Bind		query query
 func (ctl *users) List(ctx fiber.Ctx, query *dto.UserListQuery) (*requests.Pager, error) {
-	return services.Users.List(ctx, query)
+	pager, err := services.Users.List(ctx, query)
+	if err != nil {
+		return nil, err
+	}
+
+	userIDs := lo.Map(pager.Items.([]*models.User), func(item *models.User, _ int) int64 {
+		return item.ID
+	})
+	if len(userIDs) == 0 {
+		return pager, nil
+	}
+
+	cntMap, err := services.Users.BoughtStatistics(ctx, userIDs)
+	if err != nil {
+		return pager, err
+	}
+
+	items := lo.Map(pager.Items.([]*models.User), func(item *models.User, _ int) UserItem {
+		cnt := int64(0)
+		if v, ok := cntMap[item.ID]; ok {
+			cnt = v
+		}
+		return UserItem{User: item, BoughtCount: cnt}
+	})
+	pager.Items = items
+	return pager, nil
 }
 
 // Show user