feat: initialize mini api skeleton

src/Application/TakeoutSaaS.Application/App/Common/Behaviors/ValidationBehavior.cs

@@ -0,0 +1,44 @@
+using FluentValidation;
+using MediatR;
+using SharedValidationException = TakeoutSaaS.Shared.Abstractions.Exceptions.ValidationException;
+
+namespace TakeoutSaaS.Application.App.Common.Behaviors;
+
+/// <summary>
+/// MediatR 校验行为。
+/// </summary>
+/// <typeparam name="TRequest">请求类型。</typeparam>
+/// <typeparam name="TResponse">响应类型。</typeparam>
+public sealed class ValidationBehavior<TRequest, TResponse>(IEnumerable<IValidator<TRequest>> validators)
+    : IPipelineBehavior<TRequest, TResponse>
+    where TRequest : notnull
+{
+    /// <inheritdoc />
+    public async Task<TResponse> Handle(
+        TRequest request,
+        RequestHandlerDelegate<TResponse> next,
+        CancellationToken cancellationToken)
+    {
+        if (!validators.Any())
+        {
+            return await next();
+        }
+
+        var context = new ValidationContext<TRequest>(request);
+        var validationResults = await Task.WhenAll(validators.Select(validator => validator.ValidateAsync(context, cancellationToken)));
+        var failures = validationResults
+            .SelectMany(result => result.Errors)
+            .Where(error => error is not null)
+            .GroupBy(error => error.PropertyName)
+            .ToDictionary(
+                group => group.Key,
+                group => group.Select(error => error.ErrorMessage).Distinct().ToArray());
+
+        if (failures.Count > 0)
+        {
+            throw new SharedValidationException(failures);
+        }
+
+        return await next();
+    }
+}

src/Application/TakeoutSaaS.Application/App/Extensions/AppApplicationServiceCollectionExtensions.cs

@@ -0,0 +1,26 @@
+using FluentValidation;
+using MediatR;
+using Microsoft.Extensions.DependencyInjection;
+using System.Reflection;
+using TakeoutSaaS.Application.App.Common.Behaviors;
+
+namespace TakeoutSaaS.Application.App.Extensions;
+
+/// <summary>
+/// 业务应用层服务注册。
+/// </summary>
+public static class AppApplicationServiceCollectionExtensions
+{
+    /// <summary>
+    /// 注册应用层处理器与验证管道。
+    /// </summary>
+    /// <param name="services">服务集合。</param>
+    /// <returns>服务集合。</returns>
+    public static IServiceCollection AddAppApplication(this IServiceCollection services)
+    {
+        services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(Assembly.GetExecutingAssembly()));
+        services.AddValidatorsFromAssembly(Assembly.GetExecutingAssembly());
+        services.AddTransient(typeof(IPipelineBehavior<,>), typeof(ValidationBehavior<,>));
+        return services;
+    }
+}

src/Application/TakeoutSaaS.Application/App/Mini/Bootstrap/GetMiniBootstrapQuery.cs

@@ -0,0 +1,8 @@
+using MediatR;
+
+namespace TakeoutSaaS.Application.App.Mini.Bootstrap;
+
+/// <summary>
+/// 获取小程序端启动引导信息。
+/// </summary>
+public sealed record GetMiniBootstrapQuery : IRequest<MiniBootstrapResponse>;

src/Application/TakeoutSaaS.Application/App/Mini/Bootstrap/GetMiniBootstrapQueryHandler.cs

@@ -0,0 +1,33 @@
+using MediatR;
+using Microsoft.Extensions.Hosting;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.App.Mini.Bootstrap;
+
+/// <summary>
+/// 小程序端启动引导查询处理器。
+/// </summary>
+public sealed class GetMiniBootstrapQueryHandler(
+    IHostEnvironment environment,
+    ITenantContextAccessor tenantContextAccessor)
+    : IRequestHandler<GetMiniBootstrapQuery, MiniBootstrapResponse>
+{
+    private static readonly string[] Scenes = ["Delivery", "Pickup", "DineIn"];
+    private static readonly string[] Channels = ["WeChatMiniProgram"];
+
+    /// <inheritdoc />
+    public Task<MiniBootstrapResponse> Handle(GetMiniBootstrapQuery request, CancellationToken cancellationToken)
+    {
+        var response = new MiniBootstrapResponse
+        {
+            Service = "TakeoutSaaS.MiniApi",
+            Environment = environment.EnvironmentName,
+            ServerTime = DateTime.UtcNow,
+            SupportedScenes = Scenes,
+            SupportedChannels = Channels,
+            TenantCode = tenantContextAccessor.Current?.TenantCode
+        };
+
+        return Task.FromResult(response);
+    }
+}

src/Application/TakeoutSaaS.Application/App/Mini/Bootstrap/MiniBootstrapResponse.cs

@@ -0,0 +1,37 @@
+namespace TakeoutSaaS.Application.App.Mini.Bootstrap;
+
+/// <summary>
+/// 小程序端启动引导响应。
+/// </summary>
+public sealed record MiniBootstrapResponse
+{
+    /// <summary>
+    /// 服务标识。
+    /// </summary>
+    public string Service { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 当前环境名称。
+    /// </summary>
+    public string Environment { get; init; } = string.Empty;
+
+    /// <summary>
+    /// 服务端时间。
+    /// </summary>
+    public DateTime ServerTime { get; init; }
+
+    /// <summary>
+    /// 支持的履约场景。
+    /// </summary>
+    public IReadOnlyList<string> SupportedScenes { get; init; } = [];
+
+    /// <summary>
+    /// 支持的渠道。
+    /// </summary>
+    public IReadOnlyList<string> SupportedChannels { get; init; } = [];
+
+    /// <summary>
+    /// 当前请求解析到的租户编码。
+    /// </summary>
+    public string? TenantCode { get; init; }
+}

src/Application/TakeoutSaaS.Application/TakeoutSaaS.Application.csproj

@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="MediatR" Version="14.0.0" />
+    <PackageReference Include="FluentValidation.DependencyInjectionExtensions" Version="12.1.1" />
+    <PackageReference Include="Microsoft.Extensions.Hosting.Abstractions" Version="10.0.1" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\TakeoutSaaS.BuildingBlocks\src\Core\TakeoutSaaS.Shared.Abstractions\TakeoutSaaS.Shared.Abstractions.csproj" />
+    <ProjectReference Include="..\..\Domain\TakeoutSaaS.Domain\TakeoutSaaS.Domain.csproj" />
+  </ItemGroup>
+</Project>