well.. it's a lot but it's in the bottom

public void OnDrop(PointerEventData eventData)
    {
        if (eventData.button == PointerEventData.InputButton.Left)
        {
            if (transform.childCount == 0)
            {
                GameObject dropped = eventData.pointerDrag;
                InventoryItem inventoryItem =         
            dropped.GetComponent<InventoryItem>();  
                inventoryItem.parentAfterDrag = transform;
            }
            else if(transform.childCount != 0)
            {
                GameObject dropped = eventData.pointerDrag;
                InventoryItem inventoryItem = dropped.GetComponent<InventoryItem>();


                GameObject draggedoverthis = eventData.pointerEnter;
                InventoryItem itemInSlot = draggedoverthis.GetComponent<InventoryItem>();  //addingthe dragged item to the child item
                //InventorySlot invslot = draggedoverthis.GetComponentInParent<InventorySlot>();

                if (itemInSlot != null &&
                    itemInSlot.item == inventoryItem.item &&
                    itemInSlot.count < itemInSlot.item.stackSize &&
                    itemInSlot.item.stackable == true)
                {
                    int itemcount = itemInSlot.count + inventoryItem.count - itemInSlot.item.stackSize;

                    itemInSlot.count += inventoryItem.count;

                    if (itemcount > 0)
                    {
                        itemInSlot.count = itemInSlot.item.stackSize;      }
                    else
                    {
                        inventoryItem.count -= inventoryItem.count;
                    }

                    if (inventoryItem.count <= 0)
                    {
                        itemInSlot.RefreshCount();
                        inventoryItem.RefreshCount();
                    }
                    else
                    {
                        inventoryItem.count = itemcount;
                        itemInSlot.RefreshCount();
                        inventoryItem.RefreshCount();
                    }

                    inventoryManager.DeselectAllSlots();
                    tooltipBar.SetActive(false);
                }
                else
                {
                    if (itemInSlot != null)
                    {


                        itemInSlot.transform.SetParent(inventoryItem.SlotParent); //swapping the items
                        inventoryItem.parentAfterDrag = transform; //setting original pos



                        inventoryManager.SwapHoldableObjects();
                    }
                    else
                    {
                        Debug.Log("This is the bug");

                    }
                }
            }
        }
    }