from typing import Any

from pydantic import GetCoreSchemaHandler
from pydantic_core import CoreSchema, core_schema


class CountryCode(str):
    """An ISO-3166 alpha-2 country code. Always uppercase."""

    def __str__(self) -> str:
        return self

    @classmethod
    def __get_pydantic_core_schema__(
        cls, source_type: Any, handler: GetCoreSchemaHandler
    ) -> CoreSchema:
        return core_schema.no_info_after_validator_function(cls, handler(str))