mws.backend.dotnet/mws.application/Roles/Commands/DeleteRole.cs

using MediatR;
using Mws.Application.Common;

namespace Mws.Application.Roles;

public record DeleteRoleCommand(Guid Id) : IRequest;

public class DeleteRoleHandler(IUnitOfWork uow) : IRequestHandler<DeleteRoleCommand>
{
    public async Task Handle(DeleteRoleCommand command, CancellationToken ct)
    {
        var role = await uow.Roles.GetByIdAsync(command.Id, ct)
            ?? throw new NotFoundException("Role not found");

        if (role.IsSystem)
        {
            throw new BadRequestException("Cannot delete a system role");
        }

        if (await uow.Users.ExistsByRoleIdAsync(command.Id, ct))
        {
            throw new BadRequestException("Cannot delete a role that is assigned to accounts");
        }

        uow.Roles.Remove(role);
        await uow.SaveChangesAsync(ct);
    }
}