feat(marketing): implement flash sale module api and app layer

src/Api/TakeoutSaaS.TenantApi/Contracts/Marketing/FlashSaleContracts.cs

@@ -0,0 +1,643 @@
+namespace TakeoutSaaS.TenantApi.Contracts.Marketing;
+
+/// <summary>
+/// 限时折扣列表查询请求。
+/// </summary>
+public sealed class FlashSaleListRequest
+{
+    /// <summary>
+    /// 门店 ID（可空，空表示全部门店）。
+    /// </summary>
+    public string? StoreId { get; set; }
+
+    /// <summary>
+    /// 活动名称关键字。
+    /// </summary>
+    public string? Keyword { get; set; }
+
+    /// <summary>
+    /// 展示状态筛选（ongoing/upcoming/ended）。
+    /// </summary>
+    public string? Status { get; set; }
+
+    /// <summary>
+    /// 页码。
+    /// </summary>
+    public int Page { get; set; } = 1;
+
+    /// <summary>
+    /// 每页条数。
+    /// </summary>
+    public int PageSize { get; set; } = 4;
+}
+
+/// <summary>
+/// 限时折扣详情请求。
+/// </summary>
+public sealed class FlashSaleDetailRequest
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public string StoreId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public string ActivityId { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// 保存限时折扣请求。
+/// </summary>
+public sealed class SaveFlashSaleRequest
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public string StoreId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动 ID（编辑时传）。
+    /// </summary>
+    public string? Id { get; set; }
+
+    /// <summary>
+    /// 活动名称。
+    /// </summary>
+    public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动周期（once/recurring）。
+    /// </summary>
+    public string CycleType { get; set; } = "once";
+
+    /// <summary>
+    /// 周期日期模式（fixed/long_term）。
+    /// </summary>
+    public string RecurringDateMode { get; set; } = "fixed";
+
+    /// <summary>
+    /// 活动开始日期（yyyy-MM-dd）。
+    /// </summary>
+    public string? StartDate { get; set; }
+
+    /// <summary>
+    /// 活动结束日期（yyyy-MM-dd）。
+    /// </summary>
+    public string? EndDate { get; set; }
+
+    /// <summary>
+    /// 每日开始时间（HH:mm）。
+    /// </summary>
+    public string? TimeStart { get; set; }
+
+    /// <summary>
+    /// 每日结束时间（HH:mm）。
+    /// </summary>
+    public string? TimeEnd { get; set; }
+
+    /// <summary>
+    /// 循环星期（1-7，周一到周日）。
+    /// </summary>
+    public List<int>? WeekDays { get; set; }
+
+    /// <summary>
+    /// 适用渠道（delivery/pickup/dine_in）。
+    /// </summary>
+    public List<string>? Channels { get; set; }
+
+    /// <summary>
+    /// 活动每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; set; }
+
+    /// <summary>
+    /// 活动门店 ID。
+    /// </summary>
+    public List<string>? StoreIds { get; set; }
+
+    /// <summary>
+    /// 折扣商品列表。
+    /// </summary>
+    public List<FlashSaleSaveProductRequest> Products { get; set; } = [];
+
+    /// <summary>
+    /// 活动指标。
+    /// </summary>
+    public FlashSaleMetricsRequest? Metrics { get; set; }
+}
+
+/// <summary>
+/// 修改限时折扣状态请求。
+/// </summary>
+public sealed class ChangeFlashSaleStatusRequest
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public string StoreId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public string ActivityId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 状态（active/completed）。
+    /// </summary>
+    public string Status { get; set; } = "completed";
+}
+
+/// <summary>
+/// 删除限时折扣请求。
+/// </summary>
+public sealed class DeleteFlashSaleRequest
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public string StoreId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public string ActivityId { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// 限时折扣列表响应。
+/// </summary>
+public sealed class FlashSaleListResultResponse
+{
+    /// <summary>
+    /// 列表项。
+    /// </summary>
+    public List<FlashSaleListItemResponse> Items { get; set; } = [];
+
+    /// <summary>
+    /// 总条数。
+    /// </summary>
+    public int Total { get; set; }
+
+    /// <summary>
+    /// 页码。
+    /// </summary>
+    public int Page { get; set; }
+
+    /// <summary>
+    /// 每页条数。
+    /// </summary>
+    public int PageSize { get; set; }
+
+    /// <summary>
+    /// 统计数据。
+    /// </summary>
+    public FlashSaleStatsResponse Stats { get; set; } = new();
+}
+
+/// <summary>
+/// 限时折扣列表项响应。
+/// </summary>
+public sealed class FlashSaleListItemResponse
+{
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public string Id { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动名称。
+    /// </summary>
+    public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动周期（once/recurring）。
+    /// </summary>
+    public string CycleType { get; set; } = "once";
+
+    /// <summary>
+    /// 周期日期模式（fixed/long_term）。
+    /// </summary>
+    public string RecurringDateMode { get; set; } = "fixed";
+
+    /// <summary>
+    /// 活动开始日期（yyyy-MM-dd）。
+    /// </summary>
+    public string? StartDate { get; set; }
+
+    /// <summary>
+    /// 活动结束日期（yyyy-MM-dd）。
+    /// </summary>
+    public string? EndDate { get; set; }
+
+    /// <summary>
+    /// 每日开始时间（HH:mm）。
+    /// </summary>
+    public string? TimeStart { get; set; }
+
+    /// <summary>
+    /// 每日结束时间（HH:mm）。
+    /// </summary>
+    public string? TimeEnd { get; set; }
+
+    /// <summary>
+    /// 循环星期（1-7）。
+    /// </summary>
+    public List<int> WeekDays { get; set; } = [];
+
+    /// <summary>
+    /// 编辑状态（active/completed）。
+    /// </summary>
+    public string Status { get; set; } = "active";
+
+    /// <summary>
+    /// 展示状态（ongoing/upcoming/ended）。
+    /// </summary>
+    public string DisplayStatus { get; set; } = "ongoing";
+
+    /// <summary>
+    /// 是否弱化展示。
+    /// </summary>
+    public bool IsDimmed { get; set; }
+
+    /// <summary>
+    /// 适用渠道。
+    /// </summary>
+    public List<string> Channels { get; set; } = [];
+
+    /// <summary>
+    /// 活动每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; set; }
+
+    /// <summary>
+    /// 活动门店。
+    /// </summary>
+    public List<string> StoreIds { get; set; } = [];
+
+    /// <summary>
+    /// 折扣商品。
+    /// </summary>
+    public List<FlashSaleProductResponse> Products { get; set; } = [];
+
+    /// <summary>
+    /// 活动指标。
+    /// </summary>
+    public FlashSaleMetricsResponse Metrics { get; set; } = new();
+
+    /// <summary>
+    /// 更新时间（yyyy-MM-dd HH:mm:ss）。
+    /// </summary>
+    public string UpdatedAt { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// 限时折扣详情响应。
+/// </summary>
+public sealed class FlashSaleDetailResponse
+{
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public string Id { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动名称。
+    /// </summary>
+    public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 活动周期（once/recurring）。
+    /// </summary>
+    public string CycleType { get; set; } = "once";
+
+    /// <summary>
+    /// 周期日期模式（fixed/long_term）。
+    /// </summary>
+    public string RecurringDateMode { get; set; } = "fixed";
+
+    /// <summary>
+    /// 活动开始日期（yyyy-MM-dd）。
+    /// </summary>
+    public string? StartDate { get; set; }
+
+    /// <summary>
+    /// 活动结束日期（yyyy-MM-dd）。
+    /// </summary>
+    public string? EndDate { get; set; }
+
+    /// <summary>
+    /// 每日开始时间（HH:mm）。
+    /// </summary>
+    public string? TimeStart { get; set; }
+
+    /// <summary>
+    /// 每日结束时间（HH:mm）。
+    /// </summary>
+    public string? TimeEnd { get; set; }
+
+    /// <summary>
+    /// 循环星期（1-7）。
+    /// </summary>
+    public List<int> WeekDays { get; set; } = [];
+
+    /// <summary>
+    /// 编辑状态（active/completed）。
+    /// </summary>
+    public string Status { get; set; } = "active";
+
+    /// <summary>
+    /// 展示状态（ongoing/upcoming/ended）。
+    /// </summary>
+    public string DisplayStatus { get; set; } = "ongoing";
+
+    /// <summary>
+    /// 适用渠道。
+    /// </summary>
+    public List<string> Channels { get; set; } = [];
+
+    /// <summary>
+    /// 活动每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; set; }
+
+    /// <summary>
+    /// 活动门店。
+    /// </summary>
+    public List<string> StoreIds { get; set; } = [];
+
+    /// <summary>
+    /// 折扣商品。
+    /// </summary>
+    public List<FlashSaleProductResponse> Products { get; set; } = [];
+
+    /// <summary>
+    /// 活动指标。
+    /// </summary>
+    public FlashSaleMetricsResponse Metrics { get; set; } = new();
+
+    /// <summary>
+    /// 更新时间（yyyy-MM-dd HH:mm:ss）。
+    /// </summary>
+    public string UpdatedAt { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// 限时折扣统计响应。
+/// </summary>
+public sealed class FlashSaleStatsResponse
+{
+    /// <summary>
+    /// 活动总数。
+    /// </summary>
+    public int TotalCount { get; set; }
+
+    /// <summary>
+    /// 进行中数量。
+    /// </summary>
+    public int OngoingCount { get; set; }
+
+    /// <summary>
+    /// 参与商品数。
+    /// </summary>
+    public int ParticipatingProductCount { get; set; }
+
+    /// <summary>
+    /// 本月折扣销量。
+    /// </summary>
+    public int MonthlyDiscountSalesCount { get; set; }
+}
+
+/// <summary>
+/// 限时折扣商品请求。
+/// </summary>
+public sealed class FlashSaleSaveProductRequest
+{
+    /// <summary>
+    /// 商品 ID。
+    /// </summary>
+    public string ProductId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 折扣价。
+    /// </summary>
+    public decimal DiscountPrice { get; set; }
+
+    /// <summary>
+    /// 商品每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; set; }
+}
+
+/// <summary>
+/// 限时折扣商品响应。
+/// </summary>
+public sealed class FlashSaleProductResponse
+{
+    /// <summary>
+    /// 商品 ID。
+    /// </summary>
+    public string ProductId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 分类 ID。
+    /// </summary>
+    public string CategoryId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 分类名称。
+    /// </summary>
+    public string CategoryName { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 商品名称。
+    /// </summary>
+    public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// SPU 编码。
+    /// </summary>
+    public string SpuCode { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 商品状态（on_sale/off_shelf/sold_out）。
+    /// </summary>
+    public string Status { get; set; } = "off_shelf";
+
+    /// <summary>
+    /// 原价。
+    /// </summary>
+    public decimal OriginalPrice { get; set; }
+
+    /// <summary>
+    /// 折扣价。
+    /// </summary>
+    public decimal DiscountPrice { get; set; }
+
+    /// <summary>
+    /// 商品每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; set; }
+
+    /// <summary>
+    /// 已售数量。
+    /// </summary>
+    public int SoldCount { get; set; }
+}
+
+/// <summary>
+/// 限时折扣指标请求。
+/// </summary>
+public sealed class FlashSaleMetricsRequest
+{
+    /// <summary>
+    /// 活动销量（单）。
+    /// </summary>
+    public int ActivitySalesCount { get; set; }
+
+    /// <summary>
+    /// 折扣总额。
+    /// </summary>
+    public decimal DiscountTotalAmount { get; set; }
+
+    /// <summary>
+    /// 已循环周数。
+    /// </summary>
+    public int LoopedWeeks { get; set; }
+
+    /// <summary>
+    /// 本月折扣销量（单）。
+    /// </summary>
+    public int MonthlyDiscountSalesCount { get; set; }
+}
+
+/// <summary>
+/// 限时折扣指标响应。
+/// </summary>
+public sealed class FlashSaleMetricsResponse
+{
+    /// <summary>
+    /// 活动销量（单）。
+    /// </summary>
+    public int ActivitySalesCount { get; set; }
+
+    /// <summary>
+    /// 折扣总额。
+    /// </summary>
+    public decimal DiscountTotalAmount { get; set; }
+
+    /// <summary>
+    /// 已循环周数。
+    /// </summary>
+    public int LoopedWeeks { get; set; }
+
+    /// <summary>
+    /// 本月折扣销量（单）。
+    /// </summary>
+    public int MonthlyDiscountSalesCount { get; set; }
+}
+
+/// <summary>
+/// 限时折扣商品分类选择器请求。
+/// </summary>
+public sealed class FlashSalePickerCategoriesRequest
+{
+    /// <summary>
+    /// 门店 ID。
+    /// </summary>
+    public string StoreId { get; set; } = string.Empty;
+}
+
+/// <summary>
+/// 限时折扣商品分类选择器响应项。
+/// </summary>
+public sealed class FlashSalePickerCategoryItemResponse
+{
+    /// <summary>
+    /// 分类 ID。
+    /// </summary>
+    public string Id { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 分类名称。
+    /// </summary>
+    public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 商品数量。
+    /// </summary>
+    public int ProductCount { get; set; }
+}
+
+/// <summary>
+/// 限时折扣商品选择器请求。
+/// </summary>
+public sealed class FlashSalePickerProductsRequest
+{
+    /// <summary>
+    /// 门店 ID。
+    /// </summary>
+    public string StoreId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 分类 ID（可空）。
+    /// </summary>
+    public string? CategoryId { get; set; }
+
+    /// <summary>
+    /// 关键字。
+    /// </summary>
+    public string? Keyword { get; set; }
+
+    /// <summary>
+    /// 数量上限。
+    /// </summary>
+    public int? Limit { get; set; }
+}
+
+/// <summary>
+/// 限时折扣商品选择器响应项。
+/// </summary>
+public sealed class FlashSalePickerProductItemResponse
+{
+    /// <summary>
+    /// 商品 ID。
+    /// </summary>
+    public string Id { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 分类 ID。
+    /// </summary>
+    public string CategoryId { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 分类名称。
+    /// </summary>
+    public string CategoryName { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 商品名称。
+    /// </summary>
+    public string Name { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 售价。
+    /// </summary>
+    public decimal Price { get; set; }
+
+    /// <summary>
+    /// 库存。
+    /// </summary>
+    public int Stock { get; set; }
+
+    /// <summary>
+    /// SPU 编码。
+    /// </summary>
+    public string SpuCode { get; set; } = string.Empty;
+
+    /// <summary>
+    /// 状态（on_sale/off_shelf/sold_out）。
+    /// </summary>
+    public string Status { get; set; } = "off_shelf";
+}

src/Api/TakeoutSaaS.TenantApi/Controllers/MarketingFlashSaleController.cs

@@ -0,0 +1,427 @@
+using System.Globalization;
+using MediatR;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+using TakeoutSaaS.Application.App.Stores.Services;
+using TakeoutSaaS.Infrastructure.App.Persistence;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Results;
+using TakeoutSaaS.Shared.Web.Api;
+using TakeoutSaaS.TenantApi.Contracts.Marketing;
+
+namespace TakeoutSaaS.TenantApi.Controllers;
+
+/// <summary>
+/// 营销中心限时折扣活动管理。
+/// </summary>
+[ApiVersion("1.0")]
+[Authorize]
+[Route("api/tenant/v{version:apiVersion}/marketing/flash-sale")]
+public sealed class MarketingFlashSaleController(
+    IMediator mediator,
+    TakeoutAppDbContext dbContext,
+    StoreContextService storeContextService) : BaseApiController
+{
+    /// <summary>
+    /// 获取限时折扣活动列表。
+    /// </summary>
+    [HttpGet("list")]
+    [ProducesResponseType(typeof(ApiResponse<FlashSaleListResultResponse>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<FlashSaleListResultResponse>> List(
+        [FromQuery] FlashSaleListRequest request,
+        CancellationToken cancellationToken)
+    {
+        var visibleStoreIds = await ResolveVisibleStoreIdsAsync(request.StoreId, cancellationToken);
+
+        var result = await mediator.Send(new GetFlashSaleCampaignListQuery
+        {
+            VisibleStoreIds = visibleStoreIds,
+            Keyword = request.Keyword,
+            Status = request.Status,
+            Page = request.Page,
+            PageSize = request.PageSize
+        }, cancellationToken);
+
+        return ApiResponse<FlashSaleListResultResponse>.Ok(new FlashSaleListResultResponse
+        {
+            Items = result.Items.Select(MapListItem).ToList(),
+            Total = result.TotalCount,
+            Page = result.Page,
+            PageSize = result.PageSize,
+            Stats = new FlashSaleStatsResponse
+            {
+                TotalCount = result.Stats.TotalCount,
+                OngoingCount = result.Stats.OngoingCount,
+                ParticipatingProductCount = result.Stats.ParticipatingProductCount,
+                MonthlyDiscountSalesCount = result.Stats.MonthlyDiscountSalesCount
+            }
+        });
+    }
+
+    /// <summary>
+    /// 获取限时折扣活动详情。
+    /// </summary>
+    [HttpGet("detail")]
+    [ProducesResponseType(typeof(ApiResponse<FlashSaleDetailResponse>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<FlashSaleDetailResponse>> Detail(
+        [FromQuery] FlashSaleDetailRequest request,
+        CancellationToken cancellationToken)
+    {
+        var operationStoreId = StoreApiHelpers.ParseRequiredSnowflake(request.StoreId, nameof(request.StoreId));
+        await EnsureStoreAccessibleAsync(operationStoreId, cancellationToken);
+
+        var result = await mediator.Send(new GetFlashSaleCampaignDetailQuery
+        {
+            OperationStoreId = operationStoreId,
+            CampaignId = StoreApiHelpers.ParseRequiredSnowflake(request.ActivityId, nameof(request.ActivityId))
+        }, cancellationToken);
+
+        if (result is null)
+        {
+            return ApiResponse<FlashSaleDetailResponse>.Error(ErrorCodes.NotFound, "活动不存在");
+        }
+
+        return ApiResponse<FlashSaleDetailResponse>.Ok(MapDetail(result));
+    }
+
+    /// <summary>
+    /// 保存限时折扣活动（新增/编辑）。
+    /// </summary>
+    [HttpPost("save")]
+    [ProducesResponseType(typeof(ApiResponse<FlashSaleDetailResponse>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<FlashSaleDetailResponse>> Save(
+        [FromBody] SaveFlashSaleRequest request,
+        CancellationToken cancellationToken)
+    {
+        var operationStoreId = StoreApiHelpers.ParseRequiredSnowflake(request.StoreId, nameof(request.StoreId));
+        await EnsureStoreAccessibleAsync(operationStoreId, cancellationToken);
+
+        var resolvedStoreIds = await ResolveStoreIdsForSaveAsync(
+            request.StoreIds,
+            operationStoreId,
+            cancellationToken);
+
+        var result = await mediator.Send(new SaveFlashSaleCampaignCommand
+        {
+            OperationStoreId = operationStoreId,
+            CampaignId = StoreApiHelpers.ParseSnowflakeOrNull(request.Id),
+            Name = request.Name,
+            CycleType = request.CycleType,
+            RecurringDateMode = request.RecurringDateMode,
+            StartDate = ParseDateOnlyOrNull(request.StartDate, nameof(request.StartDate)),
+            EndDate = ParseDateOnlyOrNull(request.EndDate, nameof(request.EndDate)),
+            TimeStart = ParseTimeOrNull(request.TimeStart, nameof(request.TimeStart)),
+            TimeEnd = ParseTimeOrNull(request.TimeEnd, nameof(request.TimeEnd)),
+            WeekDays = request.WeekDays ?? [],
+            Channels = request.Channels ?? [],
+            PerUserLimit = request.PerUserLimit,
+            StoreIds = resolvedStoreIds,
+            Products = request.Products.Select(item => new FlashSaleSaveProductInputDto
+            {
+                ProductId = StoreApiHelpers.ParseRequiredSnowflake(item.ProductId, nameof(item.ProductId)),
+                DiscountPrice = item.DiscountPrice,
+                PerUserLimit = item.PerUserLimit
+            }).ToList(),
+            Metrics = request.Metrics is null
+                ? null
+                : new FlashSaleMetricsDto
+                {
+                    ActivitySalesCount = request.Metrics.ActivitySalesCount,
+                    DiscountTotalAmount = request.Metrics.DiscountTotalAmount,
+                    LoopedWeeks = request.Metrics.LoopedWeeks,
+                    MonthlyDiscountSalesCount = request.Metrics.MonthlyDiscountSalesCount
+                }
+        }, cancellationToken);
+
+        return ApiResponse<FlashSaleDetailResponse>.Ok(MapDetail(result));
+    }
+
+    /// <summary>
+    /// 修改限时折扣活动状态。
+    /// </summary>
+    [HttpPost("status")]
+    [ProducesResponseType(typeof(ApiResponse<FlashSaleDetailResponse>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<FlashSaleDetailResponse>> ChangeStatus(
+        [FromBody] ChangeFlashSaleStatusRequest request,
+        CancellationToken cancellationToken)
+    {
+        var operationStoreId = StoreApiHelpers.ParseRequiredSnowflake(request.StoreId, nameof(request.StoreId));
+        await EnsureStoreAccessibleAsync(operationStoreId, cancellationToken);
+
+        var result = await mediator.Send(new ChangeFlashSaleCampaignStatusCommand
+        {
+            OperationStoreId = operationStoreId,
+            CampaignId = StoreApiHelpers.ParseRequiredSnowflake(request.ActivityId, nameof(request.ActivityId)),
+            Status = request.Status
+        }, cancellationToken);
+
+        return ApiResponse<FlashSaleDetailResponse>.Ok(MapDetail(result));
+    }
+
+    /// <summary>
+    /// 删除限时折扣活动。
+    /// </summary>
+    [HttpPost("delete")]
+    [ProducesResponseType(typeof(ApiResponse<object>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<object>> Delete(
+        [FromBody] DeleteFlashSaleRequest request,
+        CancellationToken cancellationToken)
+    {
+        var operationStoreId = StoreApiHelpers.ParseRequiredSnowflake(request.StoreId, nameof(request.StoreId));
+        await EnsureStoreAccessibleAsync(operationStoreId, cancellationToken);
+
+        await mediator.Send(new DeleteFlashSaleCampaignCommand
+        {
+            OperationStoreId = operationStoreId,
+            CampaignId = StoreApiHelpers.ParseRequiredSnowflake(request.ActivityId, nameof(request.ActivityId))
+        }, cancellationToken);
+
+        return ApiResponse<object>.Ok(null);
+    }
+
+    /// <summary>
+    /// 获取限时折扣选品分类。
+    /// </summary>
+    [HttpGet("picker/categories")]
+    [ProducesResponseType(typeof(ApiResponse<List<FlashSalePickerCategoryItemResponse>>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<List<FlashSalePickerCategoryItemResponse>>> PickerCategories(
+        [FromQuery] FlashSalePickerCategoriesRequest request,
+        CancellationToken cancellationToken)
+    {
+        var operationStoreId = StoreApiHelpers.ParseRequiredSnowflake(request.StoreId, nameof(request.StoreId));
+        await EnsureStoreAccessibleAsync(operationStoreId, cancellationToken);
+
+        var result = await mediator.Send(new GetFlashSalePickerCategoriesQuery
+        {
+            OperationStoreId = operationStoreId
+        }, cancellationToken);
+
+        return ApiResponse<List<FlashSalePickerCategoryItemResponse>>.Ok(result
+            .Select(item => new FlashSalePickerCategoryItemResponse
+            {
+                Id = item.Id.ToString(),
+                Name = item.Name,
+                ProductCount = item.ProductCount
+            })
+            .ToList());
+    }
+
+    /// <summary>
+    /// 获取限时折扣选品商品。
+    /// </summary>
+    [HttpGet("picker/products")]
+    [ProducesResponseType(typeof(ApiResponse<List<FlashSalePickerProductItemResponse>>), StatusCodes.Status200OK)]
+    public async Task<ApiResponse<List<FlashSalePickerProductItemResponse>>> PickerProducts(
+        [FromQuery] FlashSalePickerProductsRequest request,
+        CancellationToken cancellationToken)
+    {
+        var operationStoreId = StoreApiHelpers.ParseRequiredSnowflake(request.StoreId, nameof(request.StoreId));
+        await EnsureStoreAccessibleAsync(operationStoreId, cancellationToken);
+
+        var result = await mediator.Send(new GetFlashSalePickerProductsQuery
+        {
+            OperationStoreId = operationStoreId,
+            CategoryId = StoreApiHelpers.ParseSnowflakeOrNull(request.CategoryId),
+            Keyword = request.Keyword,
+            Limit = request.Limit
+        }, cancellationToken);
+
+        return ApiResponse<List<FlashSalePickerProductItemResponse>>.Ok(result
+            .Select(item => new FlashSalePickerProductItemResponse
+            {
+                Id = item.Id.ToString(),
+                CategoryId = item.CategoryId.ToString(),
+                CategoryName = item.CategoryName,
+                Name = item.Name,
+                Price = item.Price,
+                Stock = item.Stock,
+                SpuCode = item.SpuCode,
+                Status = item.Status
+            })
+            .ToList());
+    }
+
+    private async Task<IReadOnlyCollection<long>> ResolveVisibleStoreIdsAsync(
+        string? storeId,
+        CancellationToken cancellationToken)
+    {
+        var (tenantId, merchantId) = StoreApiHelpers.GetTenantMerchantContext(storeContextService);
+
+        if (!string.IsNullOrWhiteSpace(storeId))
+        {
+            var parsedStoreId = StoreApiHelpers.ParseRequiredSnowflake(storeId, nameof(storeId));
+            await StoreApiHelpers.EnsureStoreAccessibleAsync(dbContext, tenantId, merchantId, parsedStoreId, cancellationToken);
+            return [parsedStoreId];
+        }
+
+        var allStoreIds = await dbContext.Stores
+            .AsNoTracking()
+            .Where(item => item.TenantId == tenantId && item.MerchantId == merchantId)
+            .Select(item => item.Id)
+            .OrderBy(item => item)
+            .ToListAsync(cancellationToken);
+
+        if (allStoreIds.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "当前商户下不存在可用门店");
+        }
+
+        return allStoreIds;
+    }
+
+    private async Task<IReadOnlyCollection<long>> ResolveStoreIdsForSaveAsync(
+        IEnumerable<string>? storeIds,
+        long operationStoreId,
+        CancellationToken cancellationToken)
+    {
+        var parsedStoreIds = StoreApiHelpers.ParseSnowflakeList(storeIds);
+        if (parsedStoreIds.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "storeIds 不能为空");
+        }
+
+        var (tenantId, merchantId) = StoreApiHelpers.GetTenantMerchantContext(storeContextService);
+        var accessibleStoreIds = await StoreApiHelpers.FilterAccessibleStoreIdsAsync(
+            dbContext,
+            tenantId,
+            merchantId,
+            parsedStoreIds,
+            cancellationToken);
+
+        if (accessibleStoreIds.Count != parsedStoreIds.Count)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "storeIds 存在无权限门店");
+        }
+
+        if (!accessibleStoreIds.Contains(operationStoreId))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "storeIds 必须包含当前操作门店");
+        }
+
+        return accessibleStoreIds.OrderBy(item => item).ToList();
+    }
+
+    private async Task EnsureStoreAccessibleAsync(long storeId, CancellationToken cancellationToken)
+    {
+        var (tenantId, merchantId) = StoreApiHelpers.GetTenantMerchantContext(storeContextService);
+        await StoreApiHelpers.EnsureStoreAccessibleAsync(dbContext, tenantId, merchantId, storeId, cancellationToken);
+    }
+
+    private static DateTime? ParseDateOnlyOrNull(string? value, string fieldName)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return null;
+        }
+
+        if (!DateTime.TryParseExact(value, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out var parsed))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, $"{fieldName} 日期格式必须为 yyyy-MM-dd");
+        }
+
+        return DateTime.SpecifyKind(parsed.Date, DateTimeKind.Utc);
+    }
+
+    private static TimeSpan? ParseTimeOrNull(string? value, string fieldName)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            return null;
+        }
+
+        return StoreApiHelpers.ParseRequiredTime(value, fieldName);
+    }
+
+    private static FlashSaleListItemResponse MapListItem(FlashSaleListItemDto source)
+    {
+        return new FlashSaleListItemResponse
+        {
+            Id = source.Id.ToString(),
+            Name = source.Name,
+            CycleType = source.Rules.CycleType,
+            RecurringDateMode = source.Rules.RecurringDateMode,
+            StartDate = ToDateOnly(source.Rules.StartDate),
+            EndDate = ToDateOnly(source.Rules.EndDate),
+            TimeStart = StoreApiHelpers.ToHHmm(source.Rules.TimeStart),
+            TimeEnd = StoreApiHelpers.ToHHmm(source.Rules.TimeEnd),
+            WeekDays = source.Rules.WeekDays.ToList(),
+            Status = source.Status,
+            DisplayStatus = source.DisplayStatus,
+            IsDimmed = source.IsDimmed,
+            Channels = source.Rules.Channels.ToList(),
+            PerUserLimit = source.Rules.PerUserLimit,
+            StoreIds = source.Rules.StoreIds.Select(item => item.ToString()).ToList(),
+            Products = source.Rules.Products.Select(MapProduct).ToList(),
+            Metrics = MapMetrics(source.Rules.Metrics),
+            UpdatedAt = ToDateTime(source.UpdatedAt)
+        };
+    }
+
+    private static FlashSaleDetailResponse MapDetail(FlashSaleDetailDto source)
+    {
+        return new FlashSaleDetailResponse
+        {
+            Id = source.Id.ToString(),
+            Name = source.Name,
+            CycleType = source.Rules.CycleType,
+            RecurringDateMode = source.Rules.RecurringDateMode,
+            StartDate = ToDateOnly(source.Rules.StartDate),
+            EndDate = ToDateOnly(source.Rules.EndDate),
+            TimeStart = StoreApiHelpers.ToHHmm(source.Rules.TimeStart),
+            TimeEnd = StoreApiHelpers.ToHHmm(source.Rules.TimeEnd),
+            WeekDays = source.Rules.WeekDays.ToList(),
+            Status = source.Status,
+            DisplayStatus = source.DisplayStatus,
+            Channels = source.Rules.Channels.ToList(),
+            PerUserLimit = source.Rules.PerUserLimit,
+            StoreIds = source.Rules.StoreIds.Select(item => item.ToString()).ToList(),
+            Products = source.Rules.Products.Select(MapProduct).ToList(),
+            Metrics = MapMetrics(source.Rules.Metrics),
+            UpdatedAt = ToDateTime(source.UpdatedAt)
+        };
+    }
+
+    private static FlashSaleProductResponse MapProduct(FlashSaleProductRuleDto source)
+    {
+        return new FlashSaleProductResponse
+        {
+            ProductId = source.ProductId.ToString(),
+            CategoryId = source.CategoryId.ToString(),
+            CategoryName = source.CategoryName,
+            Name = source.Name,
+            SpuCode = source.SpuCode,
+            Status = source.Status,
+            OriginalPrice = source.OriginalPrice,
+            DiscountPrice = source.DiscountPrice,
+            PerUserLimit = source.PerUserLimit,
+            SoldCount = source.SoldCount
+        };
+    }
+
+    private static FlashSaleMetricsResponse MapMetrics(FlashSaleMetricsDto source)
+    {
+        return new FlashSaleMetricsResponse
+        {
+            ActivitySalesCount = source.ActivitySalesCount,
+            DiscountTotalAmount = source.DiscountTotalAmount,
+            LoopedWeeks = source.LoopedWeeks,
+            MonthlyDiscountSalesCount = source.MonthlyDiscountSalesCount
+        };
+    }
+
+    private static string? ToDateOnly(DateTime? value)
+    {
+        return value?.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture);
+    }
+
+    private static string ToDateTime(DateTime value)
+    {
+        return value.ToString("yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture);
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Commands/ChangeFlashSaleCampaignStatusCommand.cs

@@ -0,0 +1,26 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+
+/// <summary>
+/// 修改限时折扣活动状态命令。
+/// </summary>
+public sealed class ChangeFlashSaleCampaignStatusCommand : IRequest<FlashSaleDetailDto>
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public long OperationStoreId { get; init; }
+
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public long CampaignId { get; init; }
+
+    /// <summary>
+    /// 状态（active/completed）。
+    /// </summary>
+    public string Status { get; init; } = "completed";
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Commands/DeleteFlashSaleCampaignCommand.cs

@@ -0,0 +1,20 @@
+using MediatR;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+
+/// <summary>
+/// 删除限时折扣活动命令。
+/// </summary>
+public sealed class DeleteFlashSaleCampaignCommand : IRequest<Unit>
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public long OperationStoreId { get; init; }
+
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public long CampaignId { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Commands/SaveFlashSaleCampaignCommand.cs

@@ -0,0 +1,86 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+
+/// <summary>
+/// 保存限时折扣活动命令。
+/// </summary>
+public sealed class SaveFlashSaleCampaignCommand : IRequest<FlashSaleDetailDto>
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public long OperationStoreId { get; init; }
+
+    /// <summary>
+    /// 活动 ID（编辑时传）。
+    /// </summary>
+    public long? CampaignId { get; init; }
+
+    /// <summary>
+    /// 活动名称。
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 活动周期（once/recurring）。
+    /// </summary>
+    public string CycleType { get; init; } = "once";
+
+    /// <summary>
+    /// 周期日期模式（fixed/long_term）。
+    /// </summary>
+    public string RecurringDateMode { get; init; } = "fixed";
+
+    /// <summary>
+    /// 活动开始日期（UTC 日期）。
+    /// </summary>
+    public DateTime? StartDate { get; init; }
+
+    /// <summary>
+    /// 活动结束日期（UTC 日期）。
+    /// </summary>
+    public DateTime? EndDate { get; init; }
+
+    /// <summary>
+    /// 每日开始时间。
+    /// </summary>
+    public TimeSpan? TimeStart { get; init; }
+
+    /// <summary>
+    /// 每日结束时间。
+    /// </summary>
+    public TimeSpan? TimeEnd { get; init; }
+
+    /// <summary>
+    /// 循环星期（1-7）。
+    /// </summary>
+    public IReadOnlyCollection<int> WeekDays { get; init; } = [];
+
+    /// <summary>
+    /// 适用渠道。
+    /// </summary>
+    public IReadOnlyCollection<string> Channels { get; init; } = [];
+
+    /// <summary>
+    /// 活动每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; init; }
+
+    /// <summary>
+    /// 活动门店。
+    /// </summary>
+    public IReadOnlyCollection<long> StoreIds { get; init; } = [];
+
+    /// <summary>
+    /// 商品配置输入。
+    /// </summary>
+    public IReadOnlyCollection<FlashSaleSaveProductInputDto> Products { get; init; } = [];
+
+    /// <summary>
+    /// 活动指标。
+    /// </summary>
+    public FlashSaleMetricsDto? Metrics { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleDetailDto.cs

@@ -0,0 +1,38 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣活动详情 DTO。
+/// </summary>
+public sealed class FlashSaleDetailDto
+{
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public long Id { get; init; }
+
+    /// <summary>
+    /// 活动名称。
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 编辑状态（active/completed）。
+    /// </summary>
+    public string Status { get; init; } = "active";
+
+    /// <summary>
+    /// 展示状态（ongoing/upcoming/ended）。
+    /// </summary>
+    public string DisplayStatus { get; init; } = "ongoing";
+
+    /// <summary>
+    /// 更新时间。
+    /// </summary>
+    public DateTime UpdatedAt { get; init; }
+
+    /// <summary>
+    /// 活动规则。
+    /// </summary>
+    public FlashSaleRulesDto Rules { get; init; } = new();
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleListItemDto.cs

@@ -0,0 +1,43 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣活动列表项 DTO。
+/// </summary>
+public sealed class FlashSaleListItemDto
+{
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public long Id { get; init; }
+
+    /// <summary>
+    /// 活动名称。
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 编辑状态（active/completed）。
+    /// </summary>
+    public string Status { get; init; } = "active";
+
+    /// <summary>
+    /// 展示状态（ongoing/upcoming/ended）。
+    /// </summary>
+    public string DisplayStatus { get; init; } = "ongoing";
+
+    /// <summary>
+    /// 是否弱化展示。
+    /// </summary>
+    public bool IsDimmed { get; init; }
+
+    /// <summary>
+    /// 更新时间。
+    /// </summary>
+    public DateTime UpdatedAt { get; init; }
+
+    /// <summary>
+    /// 活动规则。
+    /// </summary>
+    public FlashSaleRulesDto Rules { get; init; } = new();
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleListResultDto.cs

@@ -0,0 +1,33 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣活动列表结果 DTO。
+/// </summary>
+public sealed class FlashSaleListResultDto
+{
+    /// <summary>
+    /// 列表数据。
+    /// </summary>
+    public IReadOnlyList<FlashSaleListItemDto> Items { get; init; } = [];
+
+    /// <summary>
+    /// 总条数。
+    /// </summary>
+    public int TotalCount { get; init; }
+
+    /// <summary>
+    /// 页码。
+    /// </summary>
+    public int Page { get; init; }
+
+    /// <summary>
+    /// 每页条数。
+    /// </summary>
+    public int PageSize { get; init; }
+
+    /// <summary>
+    /// 统计信息。
+    /// </summary>
+    public FlashSaleStatsDto Stats { get; init; } = new();
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleMetricsDto.cs

@@ -0,0 +1,28 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣活动指标 DTO。
+/// </summary>
+public sealed class FlashSaleMetricsDto
+{
+    /// <summary>
+    /// 活动销量（单）。
+    /// </summary>
+    public int ActivitySalesCount { get; init; }
+
+    /// <summary>
+    /// 折扣总额。
+    /// </summary>
+    public decimal DiscountTotalAmount { get; init; }
+
+    /// <summary>
+    /// 已循环周数。
+    /// </summary>
+    public int LoopedWeeks { get; init; }
+
+    /// <summary>
+    /// 本月折扣销量（单）。
+    /// </summary>
+    public int MonthlyDiscountSalesCount { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSalePickerCategoryItemDto.cs

@@ -0,0 +1,23 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣选品分类项 DTO。
+/// </summary>
+public sealed class FlashSalePickerCategoryItemDto
+{
+    /// <summary>
+    /// 分类 ID。
+    /// </summary>
+    public long Id { get; init; }
+
+    /// <summary>
+    /// 分类名称。
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 商品数量。
+    /// </summary>
+    public int ProductCount { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSalePickerProductItemDto.cs

@@ -0,0 +1,48 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣选品商品项 DTO。
+/// </summary>
+public sealed class FlashSalePickerProductItemDto
+{
+    /// <summary>
+    /// 商品 ID。
+    /// </summary>
+    public long Id { get; init; }
+
+    /// <summary>
+    /// 分类 ID。
+    /// </summary>
+    public long CategoryId { get; init; }
+
+    /// <summary>
+    /// 分类名称。
+    /// </summary>
+    public string CategoryName { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 商品名称。
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 售价。
+    /// </summary>
+    public decimal Price { get; init; }
+
+    /// <summary>
+    /// 库存。
+    /// </summary>
+    public int Stock { get; init; }
+
+    /// <summary>
+    /// SPU 编码。
+    /// </summary>
+    public string SpuCode { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 状态（on_sale/off_shelf/sold_out）。
+    /// </summary>
+    public string Status { get; init; } = "off_shelf";
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleProductRuleDto.cs

@@ -0,0 +1,58 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣商品规则 DTO。
+/// </summary>
+public sealed class FlashSaleProductRuleDto
+{
+    /// <summary>
+    /// 商品 ID。
+    /// </summary>
+    public long ProductId { get; init; }
+
+    /// <summary>
+    /// 分类 ID。
+    /// </summary>
+    public long CategoryId { get; init; }
+
+    /// <summary>
+    /// 分类名称。
+    /// </summary>
+    public string CategoryName { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 商品名称。
+    /// </summary>
+    public string Name { get; init; } = string.Empty;
+
+    /// <summary>
+    /// SPU 编码。
+    /// </summary>
+    public string SpuCode { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 商品状态（on_sale/off_shelf/sold_out）。
+    /// </summary>
+    public string Status { get; init; } = "off_shelf";
+
+    /// <summary>
+    /// 原价。
+    /// </summary>
+    public decimal OriginalPrice { get; init; }
+
+    /// <summary>
+    /// 折扣价。
+    /// </summary>
+    public decimal DiscountPrice { get; init; }
+
+    /// <summary>
+    /// 商品每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; init; }
+
+    /// <summary>
+    /// 已售数量。
+    /// </summary>
+    public int SoldCount { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleRulesDto.cs

@@ -0,0 +1,68 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣活动规则 DTO。
+/// </summary>
+public sealed class FlashSaleRulesDto
+{
+    /// <summary>
+    /// 活动周期（once/recurring）。
+    /// </summary>
+    public string CycleType { get; init; } = "once";
+
+    /// <summary>
+    /// 周期日期模式（fixed/long_term）。
+    /// </summary>
+    public string RecurringDateMode { get; init; } = "fixed";
+
+    /// <summary>
+    /// 活动开始日期（UTC 日期）。
+    /// </summary>
+    public DateTime? StartDate { get; init; }
+
+    /// <summary>
+    /// 活动结束日期（UTC 日期）。
+    /// </summary>
+    public DateTime? EndDate { get; init; }
+
+    /// <summary>
+    /// 每日开始时间。
+    /// </summary>
+    public TimeSpan? TimeStart { get; init; }
+
+    /// <summary>
+    /// 每日结束时间。
+    /// </summary>
+    public TimeSpan? TimeEnd { get; init; }
+
+    /// <summary>
+    /// 循环星期（1-7，周一到周日）。
+    /// </summary>
+    public IReadOnlyList<int> WeekDays { get; init; } = [];
+
+    /// <summary>
+    /// 适用渠道（delivery/pickup/dine_in）。
+    /// </summary>
+    public IReadOnlyList<string> Channels { get; init; } = [];
+
+    /// <summary>
+    /// 活动每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; init; }
+
+    /// <summary>
+    /// 活动门店 ID。
+    /// </summary>
+    public IReadOnlyList<long> StoreIds { get; init; } = [];
+
+    /// <summary>
+    /// 折扣商品。
+    /// </summary>
+    public IReadOnlyList<FlashSaleProductRuleDto> Products { get; init; } = [];
+
+    /// <summary>
+    /// 活动指标。
+    /// </summary>
+    public FlashSaleMetricsDto Metrics { get; init; } = new();
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleSaveProductInputDto.cs

@@ -0,0 +1,23 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣保存商品输入 DTO。
+/// </summary>
+public sealed class FlashSaleSaveProductInputDto
+{
+    /// <summary>
+    /// 商品 ID。
+    /// </summary>
+    public long ProductId { get; init; }
+
+    /// <summary>
+    /// 折扣价。
+    /// </summary>
+    public decimal DiscountPrice { get; init; }
+
+    /// <summary>
+    /// 商品每人限购（空表示不限）。
+    /// </summary>
+    public int? PerUserLimit { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Dto/FlashSaleStatsDto.cs

@@ -0,0 +1,28 @@
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+/// <summary>
+/// 限时折扣活动统计 DTO。
+/// </summary>
+public sealed class FlashSaleStatsDto
+{
+    /// <summary>
+    /// 活动总数。
+    /// </summary>
+    public int TotalCount { get; init; }
+
+    /// <summary>
+    /// 进行中数量。
+    /// </summary>
+    public int OngoingCount { get; init; }
+
+    /// <summary>
+    /// 参与商品数。
+    /// </summary>
+    public int ParticipatingProductCount { get; init; }
+
+    /// <summary>
+    /// 本月折扣销量（单）。
+    /// </summary>
+    public int MonthlyDiscountSalesCount { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/FlashSaleDtoFactory.cs

@@ -0,0 +1,102 @@
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Domain.Coupons.Entities;
+using TakeoutSaaS.Domain.Coupons.Enums;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale;
+
+/// <summary>
+/// 限时折扣 DTO 映射工厂。
+/// </summary>
+internal static class FlashSaleDtoFactory
+{
+    /// <summary>
+    /// 构建列表项 DTO。
+    /// </summary>
+    public static FlashSaleListItemDto ToListItemDto(
+        PromotionCampaign campaign,
+        FlashSaleRulesDto rules,
+        DateTime nowUtc)
+    {
+        var displayStatus = FlashSaleMapping.ResolveDisplayStatus(campaign, rules, nowUtc);
+        return new FlashSaleListItemDto
+        {
+            Id = campaign.Id,
+            Name = campaign.Name,
+            Status = FlashSaleMapping.ToStatusText(campaign.Status),
+            DisplayStatus = displayStatus,
+            IsDimmed = FlashSaleMapping.IsDimmed(displayStatus),
+            UpdatedAt = campaign.UpdatedAt ?? campaign.CreatedAt,
+            Rules = rules
+        };
+    }
+
+    /// <summary>
+    /// 构建详情 DTO。
+    /// </summary>
+    public static FlashSaleDetailDto ToDetailDto(
+        PromotionCampaign campaign,
+        FlashSaleRulesDto rules,
+        DateTime nowUtc)
+    {
+        return new FlashSaleDetailDto
+        {
+            Id = campaign.Id,
+            Name = campaign.Name,
+            Status = FlashSaleMapping.ToStatusText(campaign.Status),
+            DisplayStatus = FlashSaleMapping.ResolveDisplayStatus(campaign, rules, nowUtc),
+            UpdatedAt = campaign.UpdatedAt ?? campaign.CreatedAt,
+            Rules = rules
+        };
+    }
+
+    /// <summary>
+    /// 构建统计 DTO。
+    /// </summary>
+    public static FlashSaleStatsDto ToStatsDto(IReadOnlyCollection<FlashSaleListItemDto> items)
+    {
+        if (items.Count == 0)
+        {
+            return new FlashSaleStatsDto();
+        }
+
+        var participatingProductCount = items
+            .SelectMany(item => item.Rules.Products)
+            .Select(item => item.ProductId)
+            .Distinct()
+            .Count();
+
+        var monthlyDiscountSalesCount = items.Sum(item => item.Rules.Metrics.MonthlyDiscountSalesCount);
+
+        return new FlashSaleStatsDto
+        {
+            TotalCount = items.Count,
+            OngoingCount = items.Count(item => string.Equals(item.DisplayStatus, "ongoing", StringComparison.Ordinal)),
+            ParticipatingProductCount = participatingProductCount,
+            MonthlyDiscountSalesCount = monthlyDiscountSalesCount
+        };
+    }
+
+    /// <summary>
+    /// 构建默认新增活动实体。
+    /// </summary>
+    public static PromotionCampaign CreateNewCampaign(
+        string name,
+        DateTime startAt,
+        DateTime endAt,
+        string rulesJson)
+    {
+        return new PromotionCampaign
+        {
+            Name = name,
+            PromotionType = PromotionType.FlashSale,
+            Status = PromotionStatus.Active,
+            StartAt = startAt,
+            EndAt = endAt,
+            RulesJson = rulesJson,
+            AudienceDescription = null,
+            Budget = null,
+            BannerUrl = null
+        };
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/FlashSaleMapping.cs

@@ -0,0 +1,581 @@
+using System.Text.Json;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Domain.Coupons.Entities;
+using TakeoutSaaS.Domain.Coupons.Enums;
+using TakeoutSaaS.Domain.Products.Enums;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale;
+
+/// <summary>
+/// 限时折扣映射与规则校验辅助。
+/// </summary>
+internal static class FlashSaleMapping
+{
+    private const string CycleTypeOnce = "once";
+    private const string CycleTypeRecurring = "recurring";
+
+    private const string RecurringDateModeFixed = "fixed";
+    private const string RecurringDateModeLongTerm = "long_term";
+
+    private const string DisplayStatusEnded = "ended";
+    private const string DisplayStatusOngoing = "ongoing";
+    private const string DisplayStatusUpcoming = "upcoming";
+
+    private static readonly HashSet<string> AllowedChannels =
+    [
+        "delivery",
+        "pickup",
+        "dine_in"
+    ];
+
+    private static readonly HashSet<string> AllowedDisplayStatuses =
+    [
+        DisplayStatusOngoing,
+        DisplayStatusUpcoming,
+        DisplayStatusEnded
+    ];
+
+    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web)
+    {
+        PropertyNameCaseInsensitive = true
+    };
+
+    /// <summary>
+    /// 校验并标准化展示状态筛选。
+    /// </summary>
+    public static bool TryNormalizeDisplayStatusFilter(string? value, out string? normalized)
+    {
+        var candidate = (value ?? string.Empty).Trim().ToLowerInvariant();
+        if (string.IsNullOrWhiteSpace(candidate))
+        {
+            normalized = null;
+            return true;
+        }
+
+        if (AllowedDisplayStatuses.Contains(candidate))
+        {
+            normalized = candidate;
+            return true;
+        }
+
+        normalized = null;
+        return false;
+    }
+
+    /// <summary>
+    /// 解析状态文本为领域状态。
+    /// </summary>
+    public static PromotionStatus ParseStatus(string? value)
+    {
+        var candidate = (value ?? string.Empty).Trim().ToLowerInvariant();
+        return candidate switch
+        {
+            "active" => PromotionStatus.Active,
+            "completed" => PromotionStatus.Completed,
+            _ => throw new BusinessException(ErrorCodes.BadRequest, "status 参数不合法")
+        };
+    }
+
+    /// <summary>
+    /// 输出状态文本。
+    /// </summary>
+    public static string ToStatusText(PromotionStatus status)
+    {
+        return status switch
+        {
+            PromotionStatus.Active => "active",
+            PromotionStatus.Completed => "completed",
+            _ => "completed"
+        };
+    }
+
+    /// <summary>
+    /// 商品状态输出文本。
+    /// </summary>
+    public static string ToProductStatusText(ProductStatus status, ProductSoldoutMode? soldoutMode)
+    {
+        if (soldoutMode.HasValue)
+        {
+            return "sold_out";
+        }
+
+        return status switch
+        {
+            ProductStatus.OnSale => "on_sale",
+            _ => "off_shelf"
+        };
+    }
+
+    /// <summary>
+    /// 将开始时间规范为当天 00:00:00（UTC）。
+    /// </summary>
+    public static DateTime NormalizeStartOfDay(DateTime dateTime)
+    {
+        var utc = dateTime.Kind == DateTimeKind.Utc
+            ? dateTime
+            : DateTime.SpecifyKind(dateTime, DateTimeKind.Utc);
+        return utc.Date;
+    }
+
+    /// <summary>
+    /// 将结束时间规范为当天 23:59:59.9999999（UTC）。
+    /// </summary>
+    public static DateTime NormalizeEndOfDay(DateTime dateTime)
+    {
+        var utc = dateTime.Kind == DateTimeKind.Utc
+            ? dateTime
+            : DateTime.SpecifyKind(dateTime, DateTimeKind.Utc);
+        return utc.Date.AddDays(1).AddTicks(-1);
+    }
+
+    /// <summary>
+    /// 解析活动规则。
+    /// </summary>
+    public static FlashSaleRulesDto DeserializeRules(string? rulesJson, long campaignId)
+    {
+        if (string.IsNullOrWhiteSpace(rulesJson))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, $"活动[{campaignId}]规则缺失");
+        }
+
+        var payload = JsonSerializer.Deserialize<FlashSaleRulesDto>(rulesJson, JsonOptions)
+            ?? throw new BusinessException(ErrorCodes.BadRequest, $"活动[{campaignId}]规则格式错误");
+
+        return NormalizeRulesForSave(
+            payload.CycleType,
+            payload.RecurringDateMode,
+            payload.StartDate,
+            payload.EndDate,
+            payload.TimeStart,
+            payload.TimeEnd,
+            payload.WeekDays,
+            payload.Channels,
+            payload.PerUserLimit,
+            payload.StoreIds,
+            payload.Products,
+            payload.Metrics,
+            null);
+    }
+
+    /// <summary>
+    /// 序列化活动规则。
+    /// </summary>
+    public static string SerializeRules(FlashSaleRulesDto rules)
+    {
+        return JsonSerializer.Serialize(rules, JsonOptions);
+    }
+
+    /// <summary>
+    /// 标准化并校验保存规则。
+    /// </summary>
+    public static FlashSaleRulesDto NormalizeRulesForSave(
+        string? cycleType,
+        string? recurringDateMode,
+        DateTime? startDate,
+        DateTime? endDate,
+        TimeSpan? timeStart,
+        TimeSpan? timeEnd,
+        IReadOnlyCollection<int>? weekDays,
+        IReadOnlyCollection<string>? channels,
+        int? perUserLimit,
+        IReadOnlyCollection<long>? storeIds,
+        IReadOnlyCollection<FlashSaleProductRuleDto>? products,
+        FlashSaleMetricsDto? metrics,
+        FlashSaleMetricsDto? fallbackMetrics)
+    {
+        var normalizedCycleType = NormalizeCycleType(cycleType);
+        var normalizedRecurringDateMode = NormalizeRecurringDateMode(recurringDateMode, normalizedCycleType);
+        var (normalizedStartDate, normalizedEndDate) = NormalizeDateRange(
+            normalizedCycleType,
+            normalizedRecurringDateMode,
+            startDate,
+            endDate);
+        var (normalizedTimeStart, normalizedTimeEnd) = NormalizeTimeRange(timeStart, timeEnd);
+
+        var normalizedWeekDays = NormalizeWeekDays(normalizedCycleType, weekDays);
+        var normalizedChannels = NormalizeChannels(channels);
+        var normalizedPerUserLimit = NormalizeOptionalLimit(perUserLimit, "perUserLimit 参数不合法");
+        var normalizedStoreIds = NormalizeStoreIds(storeIds);
+        var normalizedProducts = NormalizeProducts(products, normalizedPerUserLimit);
+        var normalizedMetrics = NormalizeMetrics(metrics ?? fallbackMetrics);
+
+        return new FlashSaleRulesDto
+        {
+            CycleType = normalizedCycleType,
+            RecurringDateMode = normalizedRecurringDateMode,
+            StartDate = normalizedStartDate,
+            EndDate = normalizedEndDate,
+            TimeStart = normalizedTimeStart,
+            TimeEnd = normalizedTimeEnd,
+            WeekDays = normalizedWeekDays,
+            Channels = normalizedChannels,
+            PerUserLimit = normalizedPerUserLimit,
+            StoreIds = normalizedStoreIds,
+            Products = normalizedProducts,
+            Metrics = normalizedMetrics
+        };
+    }
+
+    /// <summary>
+    /// 判断活动是否对可见门店可见。
+    /// </summary>
+    public static bool HasVisibleStore(FlashSaleRulesDto rules, IReadOnlyCollection<long> visibleStoreIds)
+    {
+        if (visibleStoreIds.Count == 0)
+        {
+            return false;
+        }
+
+        return rules.StoreIds.Any(visibleStoreIds.Contains);
+    }
+
+    /// <summary>
+    /// 解析活动展示状态。
+    /// </summary>
+    public static string ResolveDisplayStatus(
+        PromotionCampaign campaign,
+        FlashSaleRulesDto rules,
+        DateTime nowUtc)
+    {
+        if (campaign.Status is PromotionStatus.Completed or PromotionStatus.Paused)
+        {
+            return DisplayStatusEnded;
+        }
+
+        if (string.Equals(rules.CycleType, CycleTypeRecurring, StringComparison.Ordinal) &&
+            string.Equals(rules.RecurringDateMode, RecurringDateModeLongTerm, StringComparison.Ordinal))
+        {
+            return DisplayStatusOngoing;
+        }
+
+        if (nowUtc < campaign.StartAt)
+        {
+            return DisplayStatusUpcoming;
+        }
+
+        if (nowUtc > campaign.EndAt)
+        {
+            return DisplayStatusEnded;
+        }
+
+        return DisplayStatusOngoing;
+    }
+
+    /// <summary>
+    /// 判断是否弱化展示。
+    /// </summary>
+    public static bool IsDimmed(string displayStatus)
+    {
+        return string.Equals(displayStatus, DisplayStatusEnded, StringComparison.Ordinal);
+    }
+
+    /// <summary>
+    /// 计算活动实体起止时间窗口。
+    /// </summary>
+    public static (DateTime StartAt, DateTime EndAt) ResolveCampaignWindow(FlashSaleRulesDto rules, DateTime nowUtc)
+    {
+        if (string.Equals(rules.CycleType, CycleTypeRecurring, StringComparison.Ordinal) &&
+            string.Equals(rules.RecurringDateMode, RecurringDateModeLongTerm, StringComparison.Ordinal) &&
+            (!rules.StartDate.HasValue || !rules.EndDate.HasValue))
+        {
+            var defaultStart = NormalizeStartOfDay(nowUtc);
+            var defaultEnd = NormalizeEndOfDay(defaultStart.AddYears(20));
+            return (defaultStart, defaultEnd);
+        }
+
+        if (!rules.StartDate.HasValue || !rules.EndDate.HasValue)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "活动日期范围缺失");
+        }
+
+        return (NormalizeStartOfDay(rules.StartDate.Value), NormalizeEndOfDay(rules.EndDate.Value));
+    }
+
+    private static string NormalizeCycleType(string? value)
+    {
+        var candidate = (value ?? string.Empty).Trim().ToLowerInvariant();
+        if (candidate is not (CycleTypeOnce or CycleTypeRecurring))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "cycleType 参数不合法");
+        }
+
+        return candidate;
+    }
+
+    private static string NormalizeRecurringDateMode(string? value, string cycleType)
+    {
+        if (string.Equals(cycleType, CycleTypeOnce, StringComparison.Ordinal))
+        {
+            return RecurringDateModeFixed;
+        }
+
+        var candidate = (value ?? string.Empty).Trim().ToLowerInvariant();
+        if (candidate is not (RecurringDateModeFixed or RecurringDateModeLongTerm))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "recurringDateMode 参数不合法");
+        }
+
+        return candidate;
+    }
+
+    private static (DateTime? StartDate, DateTime? EndDate) NormalizeDateRange(
+        string cycleType,
+        string recurringDateMode,
+        DateTime? startDate,
+        DateTime? endDate)
+    {
+        var normalizedStart = startDate.HasValue ? NormalizeStartOfDay(startDate.Value) : (DateTime?)null;
+        var normalizedEnd = endDate.HasValue ? NormalizeStartOfDay(endDate.Value) : (DateTime?)null;
+
+        if (string.Equals(cycleType, CycleTypeOnce, StringComparison.Ordinal) ||
+            string.Equals(recurringDateMode, RecurringDateModeFixed, StringComparison.Ordinal))
+        {
+            if (!normalizedStart.HasValue || !normalizedEnd.HasValue)
+            {
+                throw new BusinessException(ErrorCodes.BadRequest, "startDate 与 endDate 不能为空");
+            }
+
+            if (normalizedStart.Value > normalizedEnd.Value)
+            {
+                throw new BusinessException(ErrorCodes.BadRequest, "活动开始日期不能晚于结束日期");
+            }
+
+            return (normalizedStart, normalizedEnd);
+        }
+
+        if (normalizedStart.HasValue != normalizedEnd.HasValue)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "startDate 与 endDate 必须同时传入");
+        }
+
+        if (normalizedStart.HasValue && normalizedEnd.HasValue && normalizedStart.Value > normalizedEnd.Value)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "活动开始日期不能晚于结束日期");
+        }
+
+        return (normalizedStart, normalizedEnd);
+    }
+
+    private static (TimeSpan? TimeStart, TimeSpan? TimeEnd) NormalizeTimeRange(TimeSpan? timeStart, TimeSpan? timeEnd)
+    {
+        if (!timeStart.HasValue && !timeEnd.HasValue)
+        {
+            return (null, null);
+        }
+
+        if (!timeStart.HasValue || !timeEnd.HasValue)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "timeStart 与 timeEnd 必须同时传入");
+        }
+
+        if (timeStart.Value >= timeEnd.Value)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "每日开始时间必须早于结束时间");
+        }
+
+        return (timeStart.Value, timeEnd.Value);
+    }
+
+    private static IReadOnlyList<int> NormalizeWeekDays(string cycleType, IReadOnlyCollection<int>? weekDays)
+    {
+        if (string.Equals(cycleType, CycleTypeOnce, StringComparison.Ordinal))
+        {
+            return [];
+        }
+
+        var normalized = (weekDays ?? Array.Empty<int>())
+            .Where(day => day is >= 1 and <= 7)
+            .Distinct()
+            .OrderBy(day => day)
+            .ToList();
+
+        if (normalized.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "weekDays 不能为空");
+        }
+
+        return normalized;
+    }
+
+    private static IReadOnlyList<string> NormalizeChannels(IReadOnlyCollection<string>? channels)
+    {
+        var normalized = (channels ?? Array.Empty<string>())
+            .Select(item => (item ?? string.Empty).Trim().ToLowerInvariant())
+            .Where(item => !string.IsNullOrWhiteSpace(item))
+            .Distinct()
+            .ToList();
+
+        if (normalized.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "channels 不能为空");
+        }
+
+        if (normalized.Any(item => !AllowedChannels.Contains(item)))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "channels 存在非法值");
+        }
+
+        return normalized;
+    }
+
+    private static IReadOnlyList<long> NormalizeStoreIds(IReadOnlyCollection<long>? storeIds)
+    {
+        var normalized = (storeIds ?? Array.Empty<long>())
+            .Where(id => id > 0)
+            .Distinct()
+            .OrderBy(id => id)
+            .ToList();
+
+        if (normalized.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "storeIds 不能为空");
+        }
+
+        return normalized;
+    }
+
+    private static IReadOnlyList<FlashSaleProductRuleDto> NormalizeProducts(
+        IReadOnlyCollection<FlashSaleProductRuleDto>? products,
+        int? campaignPerUserLimit)
+    {
+        var normalized = (products ?? Array.Empty<FlashSaleProductRuleDto>())
+            .Select(item =>
+            {
+                if (item.ProductId <= 0)
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, "productId 参数不合法");
+                }
+
+                if (item.CategoryId <= 0)
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, "categoryId 参数不合法");
+                }
+
+                var normalizedName = (item.Name ?? string.Empty).Trim();
+                if (string.IsNullOrWhiteSpace(normalizedName))
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, "商品名称不能为空");
+                }
+
+                var normalizedSpuCode = (item.SpuCode ?? string.Empty).Trim();
+                if (string.IsNullOrWhiteSpace(normalizedSpuCode))
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, "商品 SPU 编码不能为空");
+                }
+
+                var normalizedStatus = NormalizeProductStatus(item.Status);
+                var normalizedOriginalPrice = NormalizeMoney(item.OriginalPrice, "商品原价必须大于 0");
+                var normalizedDiscountPrice = NormalizeMoney(item.DiscountPrice, "折扣价必须大于 0");
+                if (normalizedDiscountPrice > normalizedOriginalPrice)
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, "折扣价不能高于原价");
+                }
+
+                var normalizedPerUserLimit = NormalizeOptionalLimit(item.PerUserLimit, "商品每人限购必须大于 0");
+                if (campaignPerUserLimit.HasValue &&
+                    normalizedPerUserLimit.HasValue &&
+                    normalizedPerUserLimit.Value > campaignPerUserLimit.Value)
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, "商品每人限购不能大于活动每人限购");
+                }
+
+                return new FlashSaleProductRuleDto
+                {
+                    ProductId = item.ProductId,
+                    CategoryId = item.CategoryId,
+                    CategoryName = (item.CategoryName ?? string.Empty).Trim(),
+                    Name = normalizedName,
+                    SpuCode = normalizedSpuCode,
+                    Status = normalizedStatus,
+                    OriginalPrice = normalizedOriginalPrice,
+                    DiscountPrice = normalizedDiscountPrice,
+                    PerUserLimit = normalizedPerUserLimit,
+                    SoldCount = Math.Max(0, item.SoldCount)
+                };
+            })
+            .OrderBy(item => item.Name)
+            .ThenBy(item => item.ProductId)
+            .ToList();
+
+        if (normalized.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "products 不能为空");
+        }
+
+        var duplicateProductId = normalized
+            .GroupBy(item => item.ProductId)
+            .FirstOrDefault(group => group.Count() > 1)?
+            .Key;
+        if (duplicateProductId.HasValue)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, $"商品重复: {duplicateProductId.Value}");
+        }
+
+        return normalized;
+    }
+
+    private static string NormalizeProductStatus(string? value)
+    {
+        var candidate = (value ?? string.Empty).Trim().ToLowerInvariant();
+        return candidate switch
+        {
+            "on_sale" => "on_sale",
+            "off_shelf" => "off_shelf",
+            "sold_out" => "sold_out",
+            _ => throw new BusinessException(ErrorCodes.BadRequest, "商品状态不合法")
+        };
+    }
+
+    private static int? NormalizeOptionalLimit(int? value, string errorMessage)
+    {
+        if (!value.HasValue)
+        {
+            return null;
+        }
+
+        if (value.Value <= 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, errorMessage);
+        }
+
+        return value.Value;
+    }
+
+    private static FlashSaleMetricsDto NormalizeMetrics(FlashSaleMetricsDto? metrics)
+    {
+        if (metrics is null)
+        {
+            return new FlashSaleMetricsDto();
+        }
+
+        return new FlashSaleMetricsDto
+        {
+            ActivitySalesCount = Math.Max(0, metrics.ActivitySalesCount),
+            DiscountTotalAmount = NormalizeNonNegativeMoney(metrics.DiscountTotalAmount),
+            LoopedWeeks = Math.Max(0, metrics.LoopedWeeks),
+            MonthlyDiscountSalesCount = Math.Max(0, metrics.MonthlyDiscountSalesCount)
+        };
+    }
+
+    private static decimal NormalizeMoney(decimal value, string errorMessage)
+    {
+        if (value <= 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, errorMessage);
+        }
+
+        return decimal.Round(value, 2, MidpointRounding.AwayFromZero);
+    }
+
+    private static decimal NormalizeNonNegativeMoney(decimal value)
+    {
+        if (value <= 0)
+        {
+            return 0m;
+        }
+
+        return decimal.Round(value, 2, MidpointRounding.AwayFromZero);
+    }
+}

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/ChangeFlashSaleCampaignStatusCommandHandler.cs

@@ -0,0 +1,44 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Domain.Coupons.Enums;
+using TakeoutSaaS.Domain.Coupons.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 修改限时折扣活动状态命令处理器。
+/// </summary>
+public sealed class ChangeFlashSaleCampaignStatusCommandHandler(
+    IPromotionCampaignRepository promotionCampaignRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<ChangeFlashSaleCampaignStatusCommand, FlashSaleDetailDto>
+{
+    /// <inheritdoc />
+    public async Task<FlashSaleDetailDto> Handle(ChangeFlashSaleCampaignStatusCommand request, CancellationToken cancellationToken)
+    {
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var campaign = await promotionCampaignRepository.FindByIdAsync(
+            request.CampaignId,
+            tenantId,
+            PromotionType.FlashSale,
+            cancellationToken)
+            ?? throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+
+        var rules = FlashSaleMapping.DeserializeRules(campaign.RulesJson, campaign.Id);
+        if (!rules.StoreIds.Contains(request.OperationStoreId))
+        {
+            throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+        }
+
+        campaign.Status = FlashSaleMapping.ParseStatus(request.Status);
+
+        await promotionCampaignRepository.UpdateAsync(campaign, cancellationToken);
+        await promotionCampaignRepository.SaveChangesAsync(cancellationToken);
+        return FlashSaleDtoFactory.ToDetailDto(campaign, rules, DateTime.UtcNow);
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/DeleteFlashSaleCampaignCommandHandler.cs

@@ -0,0 +1,41 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+using TakeoutSaaS.Domain.Coupons.Enums;
+using TakeoutSaaS.Domain.Coupons.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 删除限时折扣活动命令处理器。
+/// </summary>
+public sealed class DeleteFlashSaleCampaignCommandHandler(
+    IPromotionCampaignRepository promotionCampaignRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<DeleteFlashSaleCampaignCommand, Unit>
+{
+    /// <inheritdoc />
+    public async Task<Unit> Handle(DeleteFlashSaleCampaignCommand request, CancellationToken cancellationToken)
+    {
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var campaign = await promotionCampaignRepository.FindByIdAsync(
+            request.CampaignId,
+            tenantId,
+            PromotionType.FlashSale,
+            cancellationToken)
+            ?? throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+
+        var rules = FlashSaleMapping.DeserializeRules(campaign.RulesJson, campaign.Id);
+        if (!rules.StoreIds.Contains(request.OperationStoreId))
+        {
+            throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+        }
+
+        await promotionCampaignRepository.DeleteAsync(campaign, cancellationToken);
+        await promotionCampaignRepository.SaveChangesAsync(cancellationToken);
+        return Unit.Value;
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/GetFlashSaleCampaignDetailQueryHandler.cs

@@ -0,0 +1,44 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+using TakeoutSaaS.Domain.Coupons.Enums;
+using TakeoutSaaS.Domain.Coupons.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 限时折扣活动详情查询处理器。
+/// </summary>
+public sealed class GetFlashSaleCampaignDetailQueryHandler(
+    IPromotionCampaignRepository promotionCampaignRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<GetFlashSaleCampaignDetailQuery, FlashSaleDetailDto?>
+{
+    /// <inheritdoc />
+    public async Task<FlashSaleDetailDto?> Handle(GetFlashSaleCampaignDetailQuery request, CancellationToken cancellationToken)
+    {
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var campaign = await promotionCampaignRepository.FindByIdAsync(
+            request.CampaignId,
+            tenantId,
+            PromotionType.FlashSale,
+            cancellationToken);
+
+        if (campaign is null)
+        {
+            return null;
+        }
+
+        var rules = FlashSaleMapping.DeserializeRules(campaign.RulesJson, campaign.Id);
+        if (!rules.StoreIds.Contains(request.OperationStoreId))
+        {
+            throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+        }
+
+        return FlashSaleDtoFactory.ToDetailDto(campaign, rules, DateTime.UtcNow);
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/GetFlashSaleCampaignListQueryHandler.cs

@@ -0,0 +1,112 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+using TakeoutSaaS.Domain.Coupons.Enums;
+using TakeoutSaaS.Domain.Coupons.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 限时折扣活动列表查询处理器。
+/// </summary>
+public sealed class GetFlashSaleCampaignListQueryHandler(
+    IPromotionCampaignRepository promotionCampaignRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<GetFlashSaleCampaignListQuery, FlashSaleListResultDto>
+{
+    /// <inheritdoc />
+    public async Task<FlashSaleListResultDto> Handle(GetFlashSaleCampaignListQuery request, CancellationToken cancellationToken)
+    {
+        var page = Math.Max(1, request.Page);
+        var pageSize = Math.Clamp(request.PageSize, 1, 200);
+
+        if (!FlashSaleMapping.TryNormalizeDisplayStatusFilter(request.Status, out var normalizedStatus))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "status 参数不合法");
+        }
+
+        if (request.VisibleStoreIds.Count == 0)
+        {
+            return new FlashSaleListResultDto
+            {
+                Items = [],
+                TotalCount = 0,
+                Page = page,
+                PageSize = pageSize,
+                Stats = new FlashSaleStatsDto()
+            };
+        }
+
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var campaigns = await promotionCampaignRepository.GetByPromotionTypeAsync(
+            tenantId,
+            PromotionType.FlashSale,
+            cancellationToken);
+
+        if (campaigns.Count == 0)
+        {
+            return new FlashSaleListResultDto
+            {
+                Items = [],
+                TotalCount = 0,
+                Page = page,
+                PageSize = pageSize,
+                Stats = new FlashSaleStatsDto()
+            };
+        }
+
+        var nowUtc = DateTime.UtcNow;
+
+        var visibleItems = new List<FlashSaleListItemDto>(campaigns.Count);
+        foreach (var campaign in campaigns)
+        {
+            var rules = FlashSaleMapping.DeserializeRules(campaign.RulesJson, campaign.Id);
+            if (!FlashSaleMapping.HasVisibleStore(rules, request.VisibleStoreIds))
+            {
+                continue;
+            }
+
+            visibleItems.Add(FlashSaleDtoFactory.ToListItemDto(campaign, rules, nowUtc));
+        }
+
+        var stats = FlashSaleDtoFactory.ToStatsDto(visibleItems);
+
+        IEnumerable<FlashSaleListItemDto> filtered = visibleItems;
+        if (!string.IsNullOrWhiteSpace(normalizedStatus))
+        {
+            filtered = filtered.Where(item =>
+                string.Equals(item.DisplayStatus, normalizedStatus, StringComparison.Ordinal));
+        }
+
+        var keyword = request.Keyword?.Trim();
+        if (!string.IsNullOrWhiteSpace(keyword))
+        {
+            filtered = filtered.Where(item =>
+                item.Name.Contains(keyword, StringComparison.OrdinalIgnoreCase));
+        }
+
+        var ordered = filtered
+            .OrderByDescending(item => item.UpdatedAt)
+            .ThenByDescending(item => item.Id)
+            .ToList();
+
+        var total = ordered.Count;
+        var paged = ordered
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .ToList();
+
+        return new FlashSaleListResultDto
+        {
+            Items = paged,
+            TotalCount = total,
+            Page = page,
+            PageSize = pageSize,
+            Stats = stats
+        };
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/GetFlashSalePickerCategoriesQueryHandler.cs

@@ -0,0 +1,50 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+using TakeoutSaaS.Domain.Products.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 限时折扣选品分类查询处理器。
+/// </summary>
+public sealed class GetFlashSalePickerCategoriesQueryHandler(
+    IProductRepository productRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<GetFlashSalePickerCategoriesQuery, IReadOnlyList<FlashSalePickerCategoryItemDto>>
+{
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<FlashSalePickerCategoryItemDto>> Handle(
+        GetFlashSalePickerCategoriesQuery request,
+        CancellationToken cancellationToken)
+    {
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var categories = await productRepository.GetCategoriesByStoreAsync(
+            tenantId,
+            request.OperationStoreId,
+            true,
+            cancellationToken);
+        if (categories.Count == 0)
+        {
+            return [];
+        }
+
+        var categoryIds = categories.Select(item => item.Id).ToList();
+        var productCountLookup = await productRepository.CountProductsByCategoryIdsAsync(
+            tenantId,
+            request.OperationStoreId,
+            categoryIds,
+            cancellationToken);
+
+        return categories
+            .Select(item => new FlashSalePickerCategoryItemDto
+            {
+                Id = item.Id,
+                Name = item.Name,
+                ProductCount = productCountLookup.GetValueOrDefault(item.Id, 0)
+            })
+            .ToList();
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/GetFlashSalePickerProductsQueryHandler.cs

@@ -0,0 +1,60 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+using TakeoutSaaS.Domain.Products.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 限时折扣选品商品查询处理器。
+/// </summary>
+public sealed class GetFlashSalePickerProductsQueryHandler(
+    IProductRepository productRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<GetFlashSalePickerProductsQuery, IReadOnlyList<FlashSalePickerProductItemDto>>
+{
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<FlashSalePickerProductItemDto>> Handle(
+        GetFlashSalePickerProductsQuery request,
+        CancellationToken cancellationToken)
+    {
+        var tenantId = tenantProvider.GetCurrentTenantId();
+
+        var limit = Math.Clamp(request.Limit ?? 200, 1, 500);
+        var products = await productRepository.SearchPickerAsync(
+            tenantId,
+            request.OperationStoreId,
+            request.CategoryId,
+            request.Keyword,
+            limit,
+            cancellationToken);
+
+        if (products.Count == 0)
+        {
+            return [];
+        }
+
+        var categoryLookup = (await productRepository.GetCategoriesByStoreAsync(
+                tenantId,
+                request.OperationStoreId,
+                false,
+                cancellationToken))
+            .ToDictionary(item => item.Id, item => item.Name);
+
+        return products
+            .Select(item => new FlashSalePickerProductItemDto
+            {
+                Id = item.Id,
+                CategoryId = item.CategoryId,
+                CategoryName = categoryLookup.GetValueOrDefault(item.CategoryId, string.Empty),
+                Name = item.Name,
+                Price = decimal.Round(item.Price, 2, MidpointRounding.AwayFromZero),
+                Stock = Math.Max(0, item.StockQuantity ?? 0),
+                SpuCode = item.SpuCode,
+                Status = FlashSaleMapping.ToProductStatusText(item.Status, item.SoldoutMode)
+            })
+            .ToList();
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Handlers/SaveFlashSaleCampaignCommandHandler.cs

@@ -0,0 +1,177 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Commands;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+using TakeoutSaaS.Domain.Coupons.Entities;
+using TakeoutSaaS.Domain.Coupons.Enums;
+using TakeoutSaaS.Domain.Coupons.Repositories;
+using TakeoutSaaS.Domain.Products.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Constants;
+using TakeoutSaaS.Shared.Abstractions.Exceptions;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Handlers;
+
+/// <summary>
+/// 保存限时折扣活动命令处理器。
+/// </summary>
+public sealed class SaveFlashSaleCampaignCommandHandler(
+    IPromotionCampaignRepository promotionCampaignRepository,
+    IProductRepository productRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<SaveFlashSaleCampaignCommand, FlashSaleDetailDto>
+{
+    /// <inheritdoc />
+    public async Task<FlashSaleDetailDto> Handle(SaveFlashSaleCampaignCommand request, CancellationToken cancellationToken)
+    {
+        var normalizedName = request.Name.Trim();
+        if (string.IsNullOrWhiteSpace(normalizedName))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "活动名称不能为空");
+        }
+
+        if (normalizedName.Length > 64)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "活动名称长度不能超过 64");
+        }
+
+        if (request.StoreIds.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "storeIds 不能为空");
+        }
+
+        if (!request.StoreIds.Contains(request.OperationStoreId))
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "storeIds 必须包含当前操作门店");
+        }
+
+        var tenantId = tenantProvider.GetCurrentTenantId();
+
+        PromotionCampaign? campaign = null;
+        FlashSaleMetricsDto? fallbackMetrics = null;
+        var soldCountLookup = new Dictionary<long, int>();
+        if (request.CampaignId.HasValue)
+        {
+            campaign = await promotionCampaignRepository.FindByIdAsync(
+                request.CampaignId.Value,
+                tenantId,
+                PromotionType.FlashSale,
+                cancellationToken)
+                ?? throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+
+            var existingRules = FlashSaleMapping.DeserializeRules(campaign.RulesJson, campaign.Id);
+            if (!existingRules.StoreIds.Contains(request.OperationStoreId))
+            {
+                throw new BusinessException(ErrorCodes.NotFound, "活动不存在");
+            }
+
+            fallbackMetrics = existingRules.Metrics;
+            soldCountLookup = existingRules.Products
+                .GroupBy(item => item.ProductId)
+                .ToDictionary(group => group.Key, group => Math.Max(0, group.First().SoldCount));
+        }
+
+        var saveProductItems = request.Products
+            .Where(item => item.ProductId > 0)
+            .GroupBy(item => item.ProductId)
+            .Select(group => group.First())
+            .ToList();
+
+        if (saveProductItems.Count == 0)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "折扣商品不能为空");
+        }
+
+        var productIds = saveProductItems.Select(item => item.ProductId).ToList();
+        var products = await productRepository.GetByIdsAsync(
+            tenantId,
+            request.OperationStoreId,
+            productIds,
+            cancellationToken);
+
+        if (products.Count != saveProductItems.Count)
+        {
+            throw new BusinessException(ErrorCodes.BadRequest, "存在无效商品，请刷新后重试");
+        }
+
+        var categories = await productRepository.GetCategoriesByStoreAsync(
+            tenantId,
+            request.OperationStoreId,
+            false,
+            cancellationToken);
+        var categoryNameLookup = categories.ToDictionary(item => item.Id, item => item.Name);
+
+        var productLookup = products.ToDictionary(item => item.Id, item => item);
+        var normalizedProducts = saveProductItems
+            .Select(item =>
+            {
+                var product = productLookup[item.ProductId];
+                var normalizedOriginalPrice = decimal.Round(product.Price, 2, MidpointRounding.AwayFromZero);
+                if (item.DiscountPrice > normalizedOriginalPrice)
+                {
+                    throw new BusinessException(ErrorCodes.BadRequest, $"商品[{product.Name}]折扣价不能高于原价");
+                }
+
+                soldCountLookup.TryGetValue(item.ProductId, out var soldCount);
+
+                return new FlashSaleProductRuleDto
+                {
+                    ProductId = product.Id,
+                    CategoryId = product.CategoryId,
+                    CategoryName = categoryNameLookup.GetValueOrDefault(product.CategoryId, string.Empty),
+                    Name = product.Name,
+                    SpuCode = product.SpuCode,
+                    Status = FlashSaleMapping.ToProductStatusText(product.Status, product.SoldoutMode),
+                    OriginalPrice = normalizedOriginalPrice,
+                    DiscountPrice = item.DiscountPrice,
+                    PerUserLimit = item.PerUserLimit,
+                    SoldCount = soldCount
+                };
+            })
+            .ToList();
+
+        var normalizedRules = FlashSaleMapping.NormalizeRulesForSave(
+            request.CycleType,
+            request.RecurringDateMode,
+            request.StartDate,
+            request.EndDate,
+            request.TimeStart,
+            request.TimeEnd,
+            request.WeekDays,
+            request.Channels,
+            request.PerUserLimit,
+            request.StoreIds,
+            normalizedProducts,
+            request.Metrics,
+            fallbackMetrics);
+
+        var nowUtc = DateTime.UtcNow;
+        var campaignWindow = FlashSaleMapping.ResolveCampaignWindow(normalizedRules, nowUtc);
+        if (campaign is null)
+        {
+            campaign = FlashSaleDtoFactory.CreateNewCampaign(
+                normalizedName,
+                campaignWindow.StartAt,
+                campaignWindow.EndAt,
+                FlashSaleMapping.SerializeRules(normalizedRules));
+
+            await promotionCampaignRepository.AddAsync(campaign, cancellationToken);
+            await promotionCampaignRepository.SaveChangesAsync(cancellationToken);
+            return FlashSaleDtoFactory.ToDetailDto(campaign, normalizedRules, nowUtc);
+        }
+
+        campaign.Name = normalizedName;
+        campaign.StartAt = campaignWindow.StartAt;
+        campaign.EndAt = campaignWindow.EndAt;
+        campaign.RulesJson = FlashSaleMapping.SerializeRules(normalizedRules);
+
+        if (campaign.Status != PromotionStatus.Completed)
+        {
+            campaign.Status = PromotionStatus.Active;
+        }
+
+        await promotionCampaignRepository.UpdateAsync(campaign, cancellationToken);
+        await promotionCampaignRepository.SaveChangesAsync(cancellationToken);
+        return FlashSaleDtoFactory.ToDetailDto(campaign, normalizedRules, DateTime.UtcNow);
+    }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Queries/GetFlashSaleCampaignDetailQuery.cs

@@ -0,0 +1,21 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+
+/// <summary>
+/// 查询限时折扣活动详情。
+/// </summary>
+public sealed class GetFlashSaleCampaignDetailQuery : IRequest<FlashSaleDetailDto?>
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public long OperationStoreId { get; init; }
+
+    /// <summary>
+    /// 活动 ID。
+    /// </summary>
+    public long CampaignId { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Queries/GetFlashSaleCampaignListQuery.cs

@@ -0,0 +1,36 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+
+/// <summary>
+/// 查询限时折扣活动列表。
+/// </summary>
+public sealed class GetFlashSaleCampaignListQuery : IRequest<FlashSaleListResultDto>
+{
+    /// <summary>
+    /// 可见门店 ID 集合。
+    /// </summary>
+    public IReadOnlyCollection<long> VisibleStoreIds { get; init; } = [];
+
+    /// <summary>
+    /// 关键字。
+    /// </summary>
+    public string? Keyword { get; init; }
+
+    /// <summary>
+    /// 状态筛选（ongoing/upcoming/ended）。
+    /// </summary>
+    public string? Status { get; init; }
+
+    /// <summary>
+    /// 页码。
+    /// </summary>
+    public int Page { get; init; } = 1;
+
+    /// <summary>
+    /// 每页条数。
+    /// </summary>
+    public int PageSize { get; init; } = 4;
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Queries/GetFlashSalePickerCategoriesQuery.cs

@@ -0,0 +1,16 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+
+/// <summary>
+/// 查询限时折扣选品分类列表。
+/// </summary>
+public sealed class GetFlashSalePickerCategoriesQuery : IRequest<IReadOnlyList<FlashSalePickerCategoryItemDto>>
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public long OperationStoreId { get; init; }
+}
+

src/Application/TakeoutSaaS.Application/App/Coupons/FlashSale/Queries/GetFlashSalePickerProductsQuery.cs

@@ -0,0 +1,31 @@
+using MediatR;
+using TakeoutSaaS.Application.App.Coupons.FlashSale.Dto;
+
+namespace TakeoutSaaS.Application.App.Coupons.FlashSale.Queries;
+
+/// <summary>
+/// 查询限时折扣选品商品列表。
+/// </summary>
+public sealed class GetFlashSalePickerProductsQuery : IRequest<IReadOnlyList<FlashSalePickerProductItemDto>>
+{
+    /// <summary>
+    /// 操作门店 ID。
+    /// </summary>
+    public long OperationStoreId { get; init; }
+
+    /// <summary>
+    /// 分类 ID（可空）。
+    /// </summary>
+    public long? CategoryId { get; init; }
+
+    /// <summary>
+    /// 关键字。
+    /// </summary>
+    public string? Keyword { get; init; }
+
+    /// <summary>
+    /// 条数上限。
+    /// </summary>
+    public int? Limit { get; init; }
+}
+

src/Domain/TakeoutSaaS.Domain/Products/Repositories/IProductRepository.cs

@@ -140,6 +140,15 @@ public interface IProductRepository
     /// </summary>
     Task<IReadOnlyList<Product>> SearchPickerAsync(long tenantId, long storeId, long? categoryId, string? keyword, int limit, CancellationToken cancellationToken = default);
 
+    /// <summary>
+    /// 按标识批量读取商品。
+    /// </summary>
+    Task<IReadOnlyList<Product>> GetByIdsAsync(
+        long tenantId,
+        long storeId,
+        IReadOnlyCollection<long> productIds,
+        CancellationToken cancellationToken = default);
+
     /// <summary>
     /// 批量更新商品分类。
     /// </summary>

src/Infrastructure/TakeoutSaaS.Infrastructure/App/Repositories/EfProductRepository.cs

@@ -510,6 +510,29 @@ public sealed class EfProductRepository(TakeoutAppDbContext context) : IProductR
             .ToListAsync(cancellationToken);
     }
 
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<Product>> GetByIdsAsync(
+        long tenantId,
+        long storeId,
+        IReadOnlyCollection<long> productIds,
+        CancellationToken cancellationToken = default)
+    {
+        if (productIds.Count == 0)
+        {
+            return [];
+        }
+
+        return await context.Products
+            .AsNoTracking()
+            .Where(x =>
+                x.TenantId == tenantId &&
+                x.StoreId == storeId &&
+                productIds.Contains(x.Id))
+            .OrderBy(x => x.Name)
+            .ThenBy(x => x.Id)
+            .ToListAsync(cancellationToken);
+    }
+
     /// <inheritdoc />
     public async Task<int> BatchUpdateProductCategoryAsync(long tenantId, long storeId, long categoryId, IReadOnlyCollection<long> productIds, CancellationToken cancellationToken = default)
     {