"""Usage docs: https://docs.pydantic.dev/2.9/concepts/plugins#build-a-plugin

Plugin interface for Pydantic plugins, and related types.
"""

from __future__ import annotations

from typing import Any, Callable, NamedTuple

from pydantic_core import CoreConfig, CoreSchema, ValidationError
from typing_extensions import Literal, Protocol, TypeAlias

__all__ = (
    'PydanticPluginProtocol',
    'BaseValidateHandlerProtocol',
    'ValidatePythonHandlerProtocol',
    'ValidateJsonHandlerProtocol',
    'ValidateStringsHandlerProtocol',
    'NewSchemaReturns',
    'SchemaTypePath',
    'SchemaKind',
)

NewSchemaReturns: TypeAlias = 'tuple[ValidatePythonHandlerProtocol | None, ValidateJsonHandlerProtocol | None, ValidateStringsHandlerProtocol | None]'


class SchemaTypePath(NamedTuple):
    """Path defining where `schema_type` was defined, or where `TypeAdapter` was called."""

    module: str
    name: str


SchemaKind: TypeAlias = Literal['BaseModel', 'TypeAdapter', 'dataclass', 'create_model', 'validate_call']


class PydanticPluginProtocol(Protocol):
    """Protocol defining the interface for Pydantic plugins."""

    def new_schema_validator(
        self,
        schema: CoreSchema,
        schema_type: Any,
        schema_type_path: SchemaTypePath,
        schema_kind: SchemaKind,
        config: CoreConfig | None,
        plugin_settings: dict[str, object],
    ) -> tuple[
        ValidatePythonHandlerProtocol | None, ValidateJsonHandlerProtocol | None, ValidateStringsHandlerProtocol | None
    ]:
        """This method is called for each plugin every time a new [`SchemaValidator`][pydantic_core.SchemaValidator]
        is created.

        It should return an event handler for each of the three validation methods, or `None` if the plugin does not
        implement that method.

        Args:
            schema: The schema to validate against.
            schema_type: The original type which the schema was created from, e.g. the model class.
            schema_type_path: Path defining where `schema_type` was defined, or where `TypeAdapter` was called.
            schema_kind: The kind of schema to validate against.
            config: The config to use for validation.
            plugin_settings: Any plugin settings.

        Returns:
            A tuple of optional event handlers for each of the three validation methods -
                `validate_python`, `validate_json`, `validate_strings`.
        """
        raise NotImplementedError('Pydantic plugins should implement `new_schema_validator`.')


class BaseValidateHandlerProtocol(Protocol):
    """Base class for plugin callbacks protocols.

    You shouldn't implement this protocol directly, instead use one of the subclasses with adds the correctly
    typed `on_error` method.
    """

    on_enter: Callable[..., None]
    """`on_enter` is changed to be more specific on all subclasses"""

    def on_success(self, result: Any) -> None:
        """Callback to be notified of successful validation.

        Args:
            result: The result of the validation.
        """
        return

    def on_error(self, error: ValidationError) -> None:
        """Callback to be notified of validation errors.

        Args:
            error: The validation error.
        """
        return

    def on_exception(self, exception: Exception) -> None:
        """Callback to be notified of validation exceptions.

        Args:
            exception: The exception raised during validation.
        """
        return


class ValidatePythonHandlerProtocol(BaseValidateHandlerProtocol, Protocol):
    """Event handler for `SchemaValidator.validate_python`."""

    def on_enter(
        self,
        input: Any,
        *,
        strict: bool | None = None,
        from_attributes: bool | None = None,
        context: dict[str, Any] | None = None,
        self_instance: Any | None = None,
    ) -> None:
        """Callback to be notified of validation start, and create an instance of the event handler.

        Args:
            input: The input to be validated.
            strict: Whether to validate the object in strict mode.
            from_attributes: Whether to validate objects as inputs by extracting attributes.
            context: The context to use for validation, this is passed to functional validators.
            self_instance: An instance of a model to set attributes on from validation, this is used when running
                validation from the `__init__` method of a model.
        """
        pass


class ValidateJsonHandlerProtocol(BaseValidateHandlerProtocol, Protocol):
    """Event handler for `SchemaValidator.validate_json`."""

    def on_enter(
        self,
        input: str | bytes | bytearray,
        *,
        strict: bool | None = None,
        context: dict[str, Any] | None = None,
        self_instance: Any | None = None,
    ) -> None:
        """Callback to be notified of validation start, and create an instance of the event handler.

        Args:
            input: The JSON data to be validated.
            strict: Whether to validate the object in strict mode.
            context: The context to use for validation, this is passed to functional validators.
            self_instance: An instance of a model to set attributes on from validation, this is used when running
                validation from the `__init__` method of a model.
        """
        pass


StringInput: TypeAlias = 'dict[str, StringInput]'


class ValidateStringsHandlerProtocol(BaseValidateHandlerProtocol, Protocol):
    """Event handler for `SchemaValidator.validate_strings`."""

    def on_enter(
        self, input: StringInput, *, strict: bool | None = None, context: dict[str, Any] | None = None
    ) -> None:
        """Callback to be notified of validation start, and create an instance of the event handler.

        Args:
            input: The string data to be validated.
            strict: Whether to validate the object in strict mode.
            context: The context to use for validation, this is passed to functional validators.
        """
        pass
