mws.backend.dotnet/application/Projects/Commands/RemoveProjectMember.cs

using MediatR;
using mws.backend.dotnet.application.Audit;
using mws.backend.dotnet.application.Common;
using mws.backend.dotnet.domain.Projects;

namespace mws.backend.dotnet.application.Projects;

public record RemoveProjectMemberCommand(Guid UserId, Guid ProjectId, Guid MemberUserId) : IRequest, IAuditableRequest
{
    public string Action => "ProjectMember.Remove";
    public string EntityType => "ProjectMember";
    public Guid? EntityId => MemberUserId;
}

public class RemoveProjectMemberHandler(IUnitOfWork uow, IAuditContext auditContext) : IRequestHandler<RemoveProjectMemberCommand>
{
    public async Task Handle(RemoveProjectMemberCommand command, CancellationToken ct)
    {
        if (await uow.Projects.GetMemberRoleAsync(command.ProjectId, command.UserId, ct) != MemberRole.Owner)
        {
            throw new ForbiddenException("Only the project owner can remove members");
        }

        var member = await uow.Projects.GetMemberWithUserAsync(command.ProjectId, command.MemberUserId, ct)
            ?? throw new NotFoundException("Member not found in project");

        var owners = await uow.Projects.CountOwnersAsync(command.ProjectId, ct);

        if (member.Role == MemberRole.Owner && owners <= 1)
        {
            throw new BadRequestException("Cannot remove the last owner of the project");
        }

        uow.Projects.RemoveMember(member);
        await uow.SaveChangesAsync(ct);

        auditContext.EntityName = member.User.Username;
    }
}