encoders.py

# copied from fastapi.encoders
import dataclasses
import datetime
from collections import defaultdict, deque
from decimal import Decimal
from enum import Enum
from ipaddress import (
    IPv4Address,
    IPv4Interface,
    IPv4Network,
    IPv6Address,
    IPv6Interface,
    IPv6Network,
)
from pathlib import Path, PurePath
from re import Pattern
from types import GeneratorType
from typing import Any, Callable, Dict, List, Literal, Optional, Set, Tuple, Type, Union
from uuid import UUID

from permit import PYDANTIC_VERSION

if PYDANTIC_VERSION < (2, 0):
    from pydantic import BaseModel
    from pydantic.color import Color
    from pydantic.networks import AnyUrl, NameEmail
    from pydantic.types import SecretBytes, SecretStr

    def _model_dump(model: BaseModel, mode: Literal["json", "python"] = "json", **kwargs: Any) -> Any:  # noqa: ARG001
        return model.dict(**kwargs)
else:
    from pydantic.v1 import BaseModel  # type: ignore[assignment]
    from pydantic.v1.color import Color  # type: ignore[assignment]
    from pydantic.v1.networks import AnyUrl, NameEmail  # type: ignore[assignment]
    from pydantic.v1.types import SecretBytes, SecretStr  # type: ignore[assignment]

    def _model_dump(model: BaseModel, mode: Literal["json", "python"] = "json", **kwargs: Any) -> Any:  # noqa: ARG001
        return model.dict(**kwargs)


def isoformat(o: Union[datetime.date, datetime.time]) -> str:
    return o.isoformat()


def decimal_encoder(dec_value: Decimal) -> Union[int, float]:
    """
    Encodes a Decimal as int of there's no exponent, otherwise float

    This is useful when we use ConstrainedDecimal to represent Numeric(x,0)
    where a integer (but not int typed) is used. Encoding this as a float
    results in failed round-tripping between encode and parse.
    Our Id type is a prime example of this.

    >>> decimal_encoder(Decimal("1.0"))
    1.0

    >>> decimal_encoder(Decimal("1"))
    1
    """
    if dec_value.as_tuple().exponent >= 0:  # type: ignore[operator]
        return int(dec_value)
    else:
        return float(dec_value)


IncEx = Union[Set[int], Set[str], Dict[int, Any], Dict[str, Any]]
ENCODERS_BY_TYPE: Dict[Type[Any], Callable[[Any], Any]] = {
    bytes: lambda o: o.decode(),
    Color: str,
    datetime.date: isoformat,
    datetime.datetime: isoformat,
    datetime.time: isoformat,
    datetime.timedelta: lambda td: td.total_seconds(),
    Decimal: decimal_encoder,
    Enum: lambda o: o.value,
    frozenset: list,
    deque: list,
    GeneratorType: list,
    IPv4Address: str,
    IPv4Interface: str,
    IPv4Network: str,
    IPv6Address: str,
    IPv6Interface: str,
    IPv6Network: str,
    NameEmail: str,
    Path: str,
    Pattern: lambda o: o.pattern,
    SecretBytes: str,
    SecretStr: str,
    set: list,
    UUID: str,
    AnyUrl: str,
}


def generate_encoders_by_class_tuples(
    type_encoder_map: Dict[Any, Callable[[Any], Any]],
) -> Dict[Callable[[Any], Any], Tuple[Any, ...]]:
    encoders_by_class_tuples: Dict[Callable[[Any], Any], Tuple[Any, ...]] = defaultdict(tuple)
    for type_, encoder in type_encoder_map.items():
        encoders_by_class_tuples[encoder] += (type_,)
    return encoders_by_class_tuples


encoders_by_class_tuples = generate_encoders_by_class_tuples(ENCODERS_BY_TYPE)


def jsonable_encoder(
    obj: Any,
    *,
    include: Optional[IncEx] = None,
    exclude: Optional[IncEx] = None,
    by_alias: bool = True,
    exclude_unset: bool = False,
    exclude_defaults: bool = False,
    exclude_none: bool = False,
    custom_encoder: Optional[Dict[Any, Callable[[Any], Any]]] = None,
    sqlalchemy_safe: bool = True,
) -> Any:
    """
    Convert any object to something that can be encoded in JSON.

    This is used internally by FastAPI to make sure anything you return can be
    encoded as JSON before it is sent to the client.

    You can also use it yourself, for example to convert objects before saving them
    in a database that supports only JSON.

    Read more about it in the
    [FastAPI docs for JSON Compatible Encoder](https://fastapi.tiangolo.com/tutorial/encoder/).
    """
    custom_encoder = custom_encoder or {}
    if custom_encoder:
        if type(obj) in custom_encoder:
            return custom_encoder[type(obj)](obj)
        else:
            for encoder_type, encoder_instance in custom_encoder.items():
                if isinstance(obj, encoder_type):
                    return encoder_instance(obj)
    if include is not None and not isinstance(include, (set, dict)):
        include = set(include)  # type: ignore[unreachable]
    if exclude is not None and not isinstance(exclude, (set, dict)):
        exclude = set(exclude)  # type: ignore[unreachable]
    if isinstance(obj, BaseModel):
        encoders = getattr(obj.__config__, "json_encoders", {})  # type: ignore[attr-defined]
        if custom_encoder:
            encoders.update(custom_encoder)

        obj_dict = _model_dump(
            obj,
            mode="json",
            include=include,
            exclude=exclude,
            by_alias=by_alias,
            exclude_unset=exclude_unset,
            exclude_none=exclude_none,
            exclude_defaults=exclude_defaults,
        )
        if "__root__" in obj_dict:
            obj_dict = obj_dict["__root__"]
        return jsonable_encoder(
            obj_dict,
            exclude_none=exclude_none,
            exclude_defaults=exclude_defaults,
            # TODO: remove when deprecating Pydantic v1
            custom_encoder=encoders,
            sqlalchemy_safe=sqlalchemy_safe,
        )
    if dataclasses.is_dataclass(obj):
        obj_dict = dataclasses.asdict(obj)  # type: ignore[call-overload]
        return jsonable_encoder(
            obj_dict,
            include=include,
            exclude=exclude,
            by_alias=by_alias,
            exclude_unset=exclude_unset,
            exclude_defaults=exclude_defaults,
            exclude_none=exclude_none,
            custom_encoder=custom_encoder,
            sqlalchemy_safe=sqlalchemy_safe,
        )
    if isinstance(obj, Enum):
        return obj.value
    if isinstance(obj, PurePath):
        return str(obj)
    if isinstance(obj, (str, int, float, type(None))):
        return obj
    if isinstance(obj, dict):
        encoded_dict = {}
        allowed_keys = set(obj.keys())
        if include is not None:
            allowed_keys &= set(include)
        if exclude is not None:
            allowed_keys -= set(exclude)
        for key, value in obj.items():
            if (
                (not sqlalchemy_safe or (not isinstance(key, str)) or (not key.startswith("_sa")))
                and (value is not None or not exclude_none)
                and key in allowed_keys
            ):
                encoded_key = jsonable_encoder(
                    key,
                    by_alias=by_alias,
                    exclude_unset=exclude_unset,
                    exclude_none=exclude_none,
                    custom_encoder=custom_encoder,
                    sqlalchemy_safe=sqlalchemy_safe,
                )
                encoded_value = jsonable_encoder(
                    value,
                    by_alias=by_alias,
                    exclude_unset=exclude_unset,
                    exclude_none=exclude_none,
                    custom_encoder=custom_encoder,
                    sqlalchemy_safe=sqlalchemy_safe,
                )
                encoded_dict[encoded_key] = encoded_value
        return encoded_dict
    if isinstance(obj, (list, set, frozenset, GeneratorType, tuple, deque)):
        encoded_list = []
        for item in obj:
            encoded_list.append(
                jsonable_encoder(
                    item,
                    include=include,
                    exclude=exclude,
                    by_alias=by_alias,
                    exclude_unset=exclude_unset,
                    exclude_defaults=exclude_defaults,
                    exclude_none=exclude_none,
                    custom_encoder=custom_encoder,
                    sqlalchemy_safe=sqlalchemy_safe,
                )
            )
        return encoded_list

    if type(obj) in ENCODERS_BY_TYPE:
        return ENCODERS_BY_TYPE[type(obj)](obj)
    for encoder, classes_tuple in encoders_by_class_tuples.items():
        if isinstance(obj, classes_tuple):
            return encoder(obj)

    try:
        data = dict(obj)
    except Exception as e:  # noqa: BLE001
        errors: List[Exception] = []
        errors.append(e)
        try:
            data = vars(obj)
        except Exception as e:
            errors.append(e)
            raise ValueError(errors) from e
    return jsonable_encoder(
        data,
        include=include,
        exclude=exclude,
        by_alias=by_alias,
        exclude_unset=exclude_unset,
        exclude_defaults=exclude_defaults,
        exclude_none=exclude_none,
        custom_encoder=custom_encoder,
        sqlalchemy_safe=sqlalchemy_safe,
    )