ref: project structure

application/Users/Commands/DeleteUser.cs

@@ -0,0 +1,34 @@
+using MediatR;
+using mws.backend.dotnet.application.Common;
+using mws.backend.dotnet.application.Permissions;
+
+namespace mws.backend.dotnet.application.Users;
+
+public record DeleteUserCommand(Guid ActorUserId, Guid Id) : IRequest;
+
+public class DeleteUserHandler(IUnitOfWork uow, IPermissionService permissions) : IRequestHandler<DeleteUserCommand>
+{
+    private const string Screen = "users";
+
+    public async Task Handle(DeleteUserCommand command, CancellationToken ct)
+    {
+        await permissions.EnsureAsync(command.ActorUserId, Screen, PermissionAction.Delete, ct);
+
+        var user = await uow.Users.GetByIdAsync(command.Id, ct)
+            ?? throw new NotFoundException("User not found");
+
+        var soleOwnerProjectIds = await uow.Projects.GetOwnedProjectIdsAsync(command.Id, ct);
+
+        foreach (var projectId in soleOwnerProjectIds)
+        {
+            var ownerCount = await uow.Projects.CountOwnersAsync(projectId, ct);
+            if (ownerCount <= 1)
+            {
+                throw new BadRequestException("Cannot delete a user that is the sole owner of a project");
+            }
+        }
+
+        uow.Users.Remove(user);
+        await uow.SaveChangesAsync(ct);
+    }
+}