feat: 增加分页排序与FluentValidation

src/Application/TakeoutSaaS.Application/App/Merchants/Dto/MerchantDto.cs

@@ -60,4 +60,9 @@ public sealed class MerchantDto
     /// 入驻时间。
     /// </summary>
     public DateTime? JoinedAt { get; init; }
+
+    /// <summary>
+    /// 创建时间。
+    /// </summary>
+    public DateTime CreatedAt { get; init; }
 }

src/Application/TakeoutSaaS.Application/App/Merchants/Handlers/CreateMerchantCommandHandler.cs

@@ -49,6 +49,7 @@ public sealed class CreateMerchantCommandHandler(IMerchantRepository merchantRep
         ContactPhone = merchant.ContactPhone,
         ContactEmail = merchant.ContactEmail,
         Status = merchant.Status,
-        JoinedAt = merchant.JoinedAt
+        JoinedAt = merchant.JoinedAt,
+        CreatedAt = merchant.CreatedAt
     };
 }

src/Application/TakeoutSaaS.Application/App/Merchants/Handlers/GetMerchantByIdQueryHandler.cs

@@ -36,7 +36,8 @@ public sealed class GetMerchantByIdQueryHandler(IMerchantRepository merchantRepo
             ContactPhone = merchant.ContactPhone,
             ContactEmail = merchant.ContactEmail,
             Status = merchant.Status,
-            JoinedAt = merchant.JoinedAt
+            JoinedAt = merchant.JoinedAt,
+            CreatedAt = merchant.CreatedAt
         };
     }
 }

src/Application/TakeoutSaaS.Application/App/Merchants/Handlers/SearchMerchantsQueryHandler.cs

@@ -23,20 +23,44 @@ public sealed class SearchMerchantsQueryHandler(
         var tenantId = _tenantProvider.GetCurrentTenantId();
         var merchants = await _merchantRepository.SearchAsync(tenantId, request.Status, cancellationToken);
 
-        return merchants
-            .Select(merchant => new MerchantDto
-            {
-                Id = merchant.Id,
-                TenantId = merchant.TenantId,
-                BrandName = merchant.BrandName,
-                BrandAlias = merchant.BrandAlias,
-                LogoUrl = merchant.LogoUrl,
-                Category = merchant.Category,
-                ContactPhone = merchant.ContactPhone,
-                ContactEmail = merchant.ContactEmail,
-                Status = merchant.Status,
-                JoinedAt = merchant.JoinedAt
-            })
+        var sorted = ApplySorting(merchants, request.SortBy, request.SortDescending);
+        var paged = sorted
+            .Skip((request.Page - 1) * request.PageSize)
+            .Take(request.PageSize)
             .ToList();
+
+        return paged.Select(merchant => new MerchantDto
+        {
+            Id = merchant.Id,
+            TenantId = merchant.TenantId,
+            BrandName = merchant.BrandName,
+            BrandAlias = merchant.BrandAlias,
+            LogoUrl = merchant.LogoUrl,
+            Category = merchant.Category,
+            ContactPhone = merchant.ContactPhone,
+            ContactEmail = merchant.ContactEmail,
+            Status = merchant.Status,
+            JoinedAt = merchant.JoinedAt,
+            CreatedAt = merchant.CreatedAt
+        }).ToList();
+    }
+
+    private static IOrderedEnumerable<Domain.Merchants.Entities.Merchant> ApplySorting(
+        IReadOnlyCollection<Domain.Merchants.Entities.Merchant> merchants,
+        string? sortBy,
+        bool sortDescending)
+    {
+        return sortBy?.ToLowerInvariant() switch
+        {
+            "brandname" => sortDescending
+                ? merchants.OrderByDescending(x => x.BrandName)
+                : merchants.OrderBy(x => x.BrandName),
+            "status" => sortDescending
+                ? merchants.OrderByDescending(x => x.Status)
+                : merchants.OrderBy(x => x.Status),
+            _ => sortDescending
+                ? merchants.OrderByDescending(x => x.CreatedAt)
+                : merchants.OrderBy(x => x.CreatedAt)
+        };
     }
 }

src/Application/TakeoutSaaS.Application/App/Merchants/Handlers/UpdateMerchantCommandHandler.cs

@@ -60,6 +60,7 @@ public sealed class UpdateMerchantCommandHandler(
         ContactPhone = merchant.ContactPhone,
         ContactEmail = merchant.ContactEmail,
         Status = merchant.Status,
-        JoinedAt = merchant.JoinedAt
+        JoinedAt = merchant.JoinedAt,
+        CreatedAt = merchant.CreatedAt
     };
 }

src/Application/TakeoutSaaS.Application/App/Merchants/Queries/SearchMerchantsQuery.cs

@@ -13,4 +13,24 @@ public sealed class SearchMerchantsQuery : IRequest<IReadOnlyList<MerchantDto>>
     /// 按状态过滤。
     /// </summary>
     public MerchantStatus? Status { get; init; }
+
+    /// <summary>
+    /// 页码（从 1 开始）。
+    /// </summary>
+    public int Page { get; init; } = 1;
+
+    /// <summary>
+    /// 每页条数。
+    /// </summary>
+    public int PageSize { get; init; } = 20;
+
+    /// <summary>
+    /// 排序字段（brandName/status/createdAt）。
+    /// </summary>
+    public string? SortBy { get; init; }
+
+    /// <summary>
+    /// 是否倒序。
+    /// </summary>
+    public bool SortDescending { get; init; } = true;
 }

src/Application/TakeoutSaaS.Application/App/Merchants/Validators/CreateMerchantCommandValidator.cs

@@ -0,0 +1,23 @@
+using FluentValidation;
+using TakeoutSaaS.Application.App.Merchants.Commands;
+
+namespace TakeoutSaaS.Application.App.Merchants.Validators;
+
+/// <summary>
+/// 创建商户命令验证器。
+/// </summary>
+public sealed class CreateMerchantCommandValidator : AbstractValidator<CreateMerchantCommand>
+{
+    /// <summary>
+    /// 初始化验证规则。
+    /// </summary>
+    public CreateMerchantCommandValidator()
+    {
+        RuleFor(x => x.BrandName).NotEmpty().MaximumLength(128);
+        RuleFor(x => x.BrandAlias).MaximumLength(64);
+        RuleFor(x => x.LogoUrl).MaximumLength(256);
+        RuleFor(x => x.Category).MaximumLength(64);
+        RuleFor(x => x.ContactPhone).NotEmpty().MaximumLength(32);
+        RuleFor(x => x.ContactEmail).EmailAddress().When(x => !string.IsNullOrWhiteSpace(x.ContactEmail));
+    }
+}

src/Application/TakeoutSaaS.Application/App/Merchants/Validators/SearchMerchantsQueryValidator.cs

@@ -0,0 +1,20 @@
+using FluentValidation;
+using TakeoutSaaS.Application.App.Merchants.Queries;
+
+namespace TakeoutSaaS.Application.App.Merchants.Validators;
+
+/// <summary>
+/// 商户列表查询验证器。
+/// </summary>
+public sealed class SearchMerchantsQueryValidator : AbstractValidator<SearchMerchantsQuery>
+{
+    /// <summary>
+    /// 初始化验证规则。
+    /// </summary>
+    public SearchMerchantsQueryValidator()
+    {
+        RuleFor(x => x.Page).GreaterThan(0);
+        RuleFor(x => x.PageSize).InclusiveBetween(1, 200);
+        RuleFor(x => x.SortBy).MaximumLength(64);
+    }
+}

src/Application/TakeoutSaaS.Application/App/Merchants/Validators/UpdateMerchantCommandValidator.cs

@@ -0,0 +1,24 @@
+using FluentValidation;
+using TakeoutSaaS.Application.App.Merchants.Commands;
+
+namespace TakeoutSaaS.Application.App.Merchants.Validators;
+
+/// <summary>
+/// 更新商户命令验证器。
+/// </summary>
+public sealed class UpdateMerchantCommandValidator : AbstractValidator<UpdateMerchantCommand>
+{
+    /// <summary>
+    /// 初始化验证规则。
+    /// </summary>
+    public UpdateMerchantCommandValidator()
+    {
+        RuleFor(x => x.MerchantId).GreaterThan(0);
+        RuleFor(x => x.BrandName).NotEmpty().MaximumLength(128);
+        RuleFor(x => x.BrandAlias).MaximumLength(64);
+        RuleFor(x => x.LogoUrl).MaximumLength(256);
+        RuleFor(x => x.Category).MaximumLength(64);
+        RuleFor(x => x.ContactPhone).NotEmpty().MaximumLength(32);
+        RuleFor(x => x.ContactEmail).EmailAddress().When(x => !string.IsNullOrWhiteSpace(x.ContactEmail));
+    }
+}