feat: 增加分页排序与FluentValidation

src/Application/TakeoutSaaS.Application/App/Orders/Handlers/SearchOrdersQueryHandler.cs

@@ -36,7 +36,13 @@ public sealed class SearchOrdersQueryHandler(
                 .ToList();
         }
 
-        return orders.Select(order => new OrderDto
+        var sorted = ApplySorting(orders, request.SortBy, request.SortDescending);
+        var paged = sorted
+            .Skip((request.Page - 1) * request.PageSize)
+            .Take(request.PageSize)
+            .ToList();
+
+        return paged.Select(order => new OrderDto
         {
             Id = order.Id,
             TenantId = order.TenantId,
@@ -59,7 +65,22 @@ public sealed class SearchOrdersQueryHandler(
             FinishedAt = order.FinishedAt,
             CancelledAt = order.CancelledAt,
             CancelReason = order.CancelReason,
-            Remark = order.Remark
+            Remark = order.Remark,
+            CreatedAt = order.CreatedAt
         }).ToList();
     }
+
+    private static IOrderedEnumerable<Domain.Orders.Entities.Order> ApplySorting(
+        IReadOnlyCollection<Domain.Orders.Entities.Order> orders,
+        string? sortBy,
+        bool sortDescending)
+    {
+        return sortBy?.ToLowerInvariant() switch
+        {
+            "paidat" => sortDescending ? orders.OrderByDescending(x => x.PaidAt) : orders.OrderBy(x => x.PaidAt),
+            "status" => sortDescending ? orders.OrderByDescending(x => x.Status) : orders.OrderBy(x => x.Status),
+            "payableamount" => sortDescending ? orders.OrderByDescending(x => x.PayableAmount) : orders.OrderBy(x => x.PayableAmount),
+            _ => sortDescending ? orders.OrderByDescending(x => x.CreatedAt) : orders.OrderBy(x => x.CreatedAt)
+        };
+    }
 }