def convert_bcp47_case(language_code):
    """
    en -> en
    fr -> fr
    fr-ca -> fr-CA
    es-mx -> es-MX
    zh-cn -> zh-CN
    zh-hant -> zh-Hant
    zh-hans -> zh-Hans
    """
    language_country = language_code.split('-')
    if len(language_country) > 1:
        if len(language_country[1]) > 2:
            language_code = language_country[0] + '-' + language_country[1].capitalize()
        else:
            language_code = language_country[0] + '-' + language_country[1].upper()
    return language_code