feat: 增加角色/权限管理 API 与应用层命令

src/Application/TakeoutSaaS.Application/Identity/Handlers/CreateRoleCommandHandler.cs

@@ -0,0 +1,41 @@
+using MediatR;
+using TakeoutSaaS.Application.Identity.Commands;
+using TakeoutSaaS.Application.Identity.Contracts;
+using TakeoutSaaS.Domain.Identity.Entities;
+using TakeoutSaaS.Domain.Identity.Repositories;
+using TakeoutSaaS.Shared.Abstractions.Tenancy;
+
+namespace TakeoutSaaS.Application.Identity.Handlers;
+
+/// <summary>
+/// 创建角色处理器。
+/// </summary>
+public sealed class CreateRoleCommandHandler(
+    IRoleRepository roleRepository,
+    ITenantProvider tenantProvider)
+    : IRequestHandler<CreateRoleCommand, RoleDto>
+{
+    public async Task<RoleDto> Handle(CreateRoleCommand request, CancellationToken cancellationToken)
+    {
+        var tenantId = tenantProvider.GetCurrentTenantId();
+        var role = new Role
+        {
+            TenantId = tenantId,
+            Name = request.Name,
+            Code = request.Code,
+            Description = request.Description
+        };
+
+        await roleRepository.AddAsync(role, cancellationToken);
+        await roleRepository.SaveChangesAsync(cancellationToken);
+
+        return new RoleDto
+        {
+            Id = role.Id,
+            TenantId = role.TenantId,
+            Name = role.Name,
+            Code = role.Code,
+            Description = role.Description
+        };
+    }
+}