Iterate through any Property, nested objects and Lists C#

Question

I get 2 objects of Type "Shipment" ("Shipment1" and "Shipment2") and must read each value of them. If the value of Shipment1 is NULL/empty I want to look into the same Value of Shipment2 and if the Value is not NULL/empty I have to copy it to Shipment1. I tried to iterate through my objects with Reflection but the nested Objects "Consignor", "Consignee", "Invoices" let me fail. I hope you can help me. I have the following simplified class structure:

public class Shipment
{
    public int Id { get; set; }
    public Address Consignor { get; set; }
    public Address Consignee { get; set; }
    public IEnumerable<Invoice> Invoices{ get; set; }
} 
public class Address
{
    public string Name { get; set; }
    public string Street{ get; set; }
    public string Zip { get; set; }
    public string City{ get; set; }
    public string Country{ get; set; }
}
public class Invoice
{
    public IEnumerable<Item> Items{ get; set; }
}
public class Item
{
    public string Description{ get; set; }
    public int Amount { get; set; }
}

I tried it this way. It worked for the top level properties of shipment, but not for Consignor, Consignee, Invoices etc.

            foreach (PropertyInfo info1 in shipment1.GetType().GetProperties())
        {
            var datatype = info1.PropertyType;
            switch (datatype.Name.ToLower())
            {
                case "string":

                    if (!string.IsNullOrEmpty((string)info1.GetValue(shipment1)))
                    {
                        string value= (string)info1.GetValue(shipment1);
                        string name = info1.Name;
                        Type type = input.GetType();
                        PropertyInfo info2 = shipment2.GetType().GetProperty(name);


                        if (string.IsNullOrEmpty((string)info2.GetValue(shipment2)))
                        {
                            info2.SetValue(shipment2, value, null);
                        }
                    }
                    break;

                case "integer":
                    // and so on
             }       
       }

Answer 1

I ended up with this, having shipment1 with the same values that shipment2 , even if shipment1 was null at the beginning.

Please note that it copies IEnumerable like pointers. After the copy, editing copy.Invoices will also edit source.Invoices, and vice versa.

// used for my test:
Shipment shipment1 = null;
Shipment shipment2 = new Shipment { Id = 42, Consignor = new Address { Name = "Foo1", Street = "Bar1", Zip = "Baz1", City = "Qux1", Country = "Quux1" }, Consignee = new Address { Name = "Foo2", Street = "Bar2", Zip = "Baz2", City = "Qux2", Country = "Quux2" }, Invoices = new Invoice[] { new Invoice { Items = new Item[] { new Item { Description = "FooBar1", Amount = 1 }, new Item { Description = "BazQux1", Amount = 1 } } }, new Invoice { Items = new Item[] { new Item { Description = "FooBar2", Amount = 2 }, new Item { Description = "BazQux2", Amount = 2 } } } } };
// kind of ugly but I didn't manage to do it prettier:
shipment1 = Work(shipment2, shipment1);

private T Work<T>(T source, T copy)
{
    if (source == null)
        return copy;
    if (copy == null)
        copy = Activator.CreateInstance<T>();

    foreach (PropertyInfo prop in typeof(T).GetProperties())
    {
        switch (prop.PropertyType.Name.ToLower())
        {
            case "string":
                string str = (string)prop.GetValue(source);
                if (!string.IsNullOrEmpty(str))
                    if (string.IsNullOrEmpty((string)prop.GetValue(copy)))
                        prop.SetValue(copy, str);
                break;
            case "int32":
                int i = (int)prop.GetValue(source);
                if (i != 0)
                    if ((int)prop.GetValue(copy) == 0)
                        prop.SetValue(copy, i);
                break;
            case "address":
                prop.SetValue(copy, Work(prop.GetValue(source) as Address, prop.GetValue(copy) as Address));
                break;
            case "ienumerable`1":
                switch (prop.PropertyType.GetGenericArguments()[0].Name.ToLower())
                {
                    case "invoice":
                        IEnumerable<Invoice> invoices = (IEnumerable<Invoice>)prop.GetValue(source);
                        if (invoices != null && invoices.Count() > 0)
                            if ((IEnumerable<Invoice>)prop.GetValue(copy) == null)
                                prop.SetValue(copy, invoices);
                        break;
                    // edit: this is actually useless
                    /*
                    case "item":
                        IEnumerable<Item> items = (IEnumerable<Item>)prop.GetValue(source);
                        if (items != null && items.Count() > 0)
                            if ((IEnumerable<Item>)prop.GetValue(copy) == null)
                                prop.SetValue(copy, items);
                        break;
                    */
                }
                break;
        }
    }

    return copy;
}