#[ODM\Document]
class TestDocument
{
    #[ODM\Id]
    public ?string $id = null;

    #[ODM\Field(type: 'int')]
    public int $removedCount = 0;

    #[ODM\EmbedMany(targetDocument: TestEmbeddedDocument::class)]
    public $embeddedDocuments;

    public function __construct(array $embeddedDocuments)
    {
        $this->embeddedDocuments = new ArrayCollection($embeddedDocuments);
    }

    public function incrementRemovedCount(): void
    {
        $this->removedCount++;
        foreach ($this->embeddedDocuments as $embeddedDocument) {
            $embeddedDocument->removedCount++;
        }
    }
}

#[ODM\EmbeddedDocument]
class TestEmbeddedDocument
{
    #[ODM\Field(type: 'int')]
    public int $removedCount = 0;
}

// Save the parent document with 1 embedded document, both initialized
// with a `removedCount` of 0.
$document = new TestDocument([new TestEmbeddedDocument()]);
$dm->persist($document);
$dm->flush();

// Sometime later, not necessarily in the same script that initially saves
// the document, remove the document and trigger the event listener.
$dm->remove($document);
$dm->flush();

class MyEventListener
{
    public function onFlush(OnFlushEventArgs $eventArgs): void
    {
        $dm = $eventArgs->getDocumentManager();
        $uow = $dm->getUnitOfWork();

        foreach ($uow->getScheduledDocumentDeletions() as $document) {
            if ($document instanceof TestDocument) {
                // Increment the `removedCount` on both the parent document and
                // the embedded document
                $document->incrementRemovedCount();
                // Re-persist the same document & recompute changeset to change the operation from a
                // removal to an update.
                $dm->persist($document);
                $uow->recomputeSingleDocumentChangeSet($dm->getClassMetadata(TestDocument::class), $document);
            }
        }
    }
}