Source code for cattrs.preconf.ujson

"""Preconfigured converters for ujson."""

from base64 import b85decode, b85encode
from datetime import date, datetime
from typing import Any, AnyStr, Type, TypeVar, Union

from ujson import dumps, loads

from cattrs._compat import AbstractSet

from ..converters import BaseConverter, Converter
from ..strategies import configure_union_passthrough
from . import wrap

T = TypeVar("T")


class UjsonConverter(Converter):
    def dumps(self, obj: Any, unstructure_as: Any = None, **kwargs: Any) -> str:
        return dumps(self.unstructure(obj, unstructure_as=unstructure_as), **kwargs)

    def loads(self, data: AnyStr, cl: Type[T], **kwargs: Any) -> T:
        return self.structure(loads(data, **kwargs), cl)


def configure_converter(converter: BaseConverter):
    """
    Configure the converter for use with the ujson library.

    * bytes are serialized as base64 strings
    * datetimes are serialized as ISO 8601
    * sets are serialized as lists
    """
    converter.register_unstructure_hook(
        bytes, lambda v: (b85encode(v) if v else b"").decode("utf8")
    )
    converter.register_structure_hook(bytes, lambda v, _: b85decode(v))

    converter.register_unstructure_hook(datetime, lambda v: v.isoformat())
    converter.register_structure_hook(datetime, lambda v, _: datetime.fromisoformat(v))
    converter.register_unstructure_hook(date, lambda v: v.isoformat())
    converter.register_structure_hook(date, lambda v, _: date.fromisoformat(v))
    configure_union_passthrough(Union[str, bool, int, float, None], converter)


@wrap(UjsonConverter)
def make_converter(*args: Any, **kwargs: Any) -> UjsonConverter:
    kwargs["unstruct_collection_overrides"] = {
        AbstractSet: list,
        **kwargs.get("unstruct_collection_overrides", {}),
    }
    res = UjsonConverter(*args, **kwargs)
    configure_converter(res)

    return res