Hybris convert OrderModel to CartModel

I have the following requirement:

Any user should be able to restore from My Account/Order History page the entries of any order to the active cart, so I want to know if there is any OOTB mechanism or a way to convert a OrderModel to CartModel or to merge the entries from an Order to the current cart.

Yes, We can convert Order model to cart model.

There is an OOB class named DefaultCartService.java

Call the following method in a custom class or strategy

CartModel cartModel = cartService.clone(getTypeService().getComposedTypeForClass(CartModel.class),
            getTypeService().getComposedTypeForClass(CartEntryModel.class), order, keyGenerator.generate().toString());

Here is the method in Detail:

Parameters:

orderType - type of newly created cart

entryType - type of cart entry of newly created cart

original - original order

code - code of created cart

@Override
public CartModel clone(final ComposedTypeModel orderType, final ComposedTypeModel entryType,
                       final AbstractOrderModel original,
                       final String code)
{

    return (CartModel) getCloneAbstractOrderStrategy().clone(orderType, entryType, original, code, CartModel.class,
            CartEntryModel.class);
}

To get the cart entries (converted) from Order can be achieved using CloneAbstractOrderStrategy.java

List<CartEntryModel> cartEntries = cloneOrderStrategy.cloneEntries(getTypeService().getComposedTypeForClass(CartEntryModel.class), orderModel)

So, for Cloning Order to cart and its vice versa can be achieved by CloneAbstractOrderStrategy.java.

Please take a look of the class for better understanding!