In fact, it is a very lucky thing to be friends with a foreigner. They will teach us a lot of things. Christmas is a big festival for them, just like the Spring Festival is for us. However, they work or study in China and have no chance to go back to meet their families. As his good friend, you should accompany him well.
As for what gift to give, you can ask him what he likes and then give him something he likes. Or if you are embarrassed to ask him, you can secretly observe his hobbies and then decide what gift to give him.
In addition, give him the general idea of gifts from foreigners. Because they are foreigners, they will definitely like things with Chinese style. You can give him a tag or something like that, and write down your Christmas wishes for him. Or you can give him an agate bracelet, which is also good. In short, no matter what gift you give him, you must spend Christmas with him and have a happy time.