from collections.abc import Generator, Iterator, Sequence
from email import _ParamsType, _ParamType
from email.charset import Charset
from email.contentmanager import ContentManager
from email.errors import MessageDefect
from email.policy import Policy
from typing import Any, Generic, Literal, Protocol, TypeVar, overload
from typing_extensions import Self, TypeAlias

__all__ = ["Message", "EmailMessage"]

_T = TypeVar("_T")
# Type returned by Policy.header_fetch_parse, often str or Header.
_HeaderT = TypeVar("_HeaderT", default=str)
_HeaderParamT = TypeVar("_HeaderParamT", default=str)
# Represents headers constructed by HeaderRegistry. Those are sub-classes
# of BaseHeader and another header type.
_HeaderRegistryT = TypeVar("_HeaderRegistryT", default=Any)
_HeaderRegistryParamT = TypeVar("_HeaderRegistryParamT", default=Any)

_PayloadType: TypeAlias = Message | str
_EncodedPayloadType: TypeAlias = Message | bytes
_MultipartPayloadType: TypeAlias = list[_PayloadType]
_CharsetType: TypeAlias = Charset | str | None

class _SupportsEncodeToPayload(Protocol):
    def encode(self, encoding: str, /) -> _PayloadType | _MultipartPayloadType | _SupportsDecodeToPayload: ...

class _SupportsDecodeToPayload(Protocol):
    def decode(self, encoding: str, errors: str, /) -> _PayloadType | _MultipartPayloadType: ...

class Message(Generic[_HeaderT, _HeaderParamT]):
    policy: Policy  # undocumented
    preamble: str | None
    epilogue: str | None
    defects: list[MessageDefect]
    def is_multipart(self) -> bool: ...
    def set_unixfrom(self, unixfrom: str) -> None: ...
    def get_unixfrom(self) -> str | None: ...
    def attach(self, payload: _PayloadType) -> None: ...
    # `i: int` without a multipart payload results in an error
    # `| Any`: can be None for cleared or unset payload, but annoying to check
    @overload  # multipart
    def get_payload(self, i: int, decode: Literal[True]) -> None: ...
    @overload  # multipart
    def get_payload(self, i: int, decode: Literal[False] = False) -> _PayloadType | Any: ...
    @overload  # either
    def get_payload(self, i: None = None, decode: Literal[False] = False) -> _PayloadType | _MultipartPayloadType | Any: ...
    @overload  # not multipart
    def get_payload(self, i: None = None, *, decode: Literal[True]) -> _EncodedPayloadType | Any: ...
    @overload  # not multipart, IDEM but w/o kwarg
    def get_payload(self, i: None, decode: Literal[True]) -> _EncodedPayloadType | Any: ...
    # If `charset=None` and payload supports both `encode` AND `decode`,
    # then an invalid payload could be passed, but this is unlikely
    # Not[_SupportsEncodeToPayload]
    @overload
    def set_payload(
        self, payload: _SupportsDecodeToPayload | _PayloadType | _MultipartPayloadType, charset: None = None
    ) -> None: ...
    @overload
    def set_payload(
        self,
        payload: _SupportsEncodeToPayload | _SupportsDecodeToPayload | _PayloadType | _MultipartPayloadType,
        charset: Charset | str,
    ) -> None: ...
    def set_charset(self, charset: _CharsetType) -> None: ...
    def get_charset(self) -> _CharsetType: ...
    def __len__(self) -> int: ...
    def __contains__(self, name: str) -> bool: ...
    def __iter__(self) -> Iterator[str]: ...
    # Same as `get` with `failobj=None`, but with the expectation that it won't return None in most scenarios
    # This is important for protocols using __getitem__, like SupportsKeysAndGetItem
    # Morally, the return type should be `AnyOf[_HeaderType, None]`,
    # so using "the Any trick" instead.
    def __getitem__(self, name: str) -> _HeaderT | Any: ...
    def __setitem__(self, name: str, val: _HeaderParamT) -> None: ...
    def __delitem__(self, name: str) -> None: ...
    def keys(self) -> list[str]: ...
    def values(self) -> list[_HeaderT]: ...
    def items(self) -> list[tuple[str, _HeaderT]]: ...
    @overload
    def get(self, name: str, failobj: None = None) -> _HeaderT | None: ...
    @overload
    def get(self, name: str, failobj: _T) -> _HeaderT | _T: ...
    @overload
    def get_all(self, name: str, failobj: None = None) -> list[_HeaderT] | None: ...
    @overload
    def get_all(self, name: str, failobj: _T) -> list[_HeaderT] | _T: ...
    def add_header(self, _name: str, _value: str, **_params: _ParamsType) -> None: ...
    def replace_header(self, _name: str, _value: _HeaderParamT) -> None: ...
    def get_content_type(self) -> str: ...
    def get_content_maintype(self) -> str: ...
    def get_content_subtype(self) -> str: ...
    def get_default_type(self) -> str: ...
    def set_default_type(self, ctype: str) -> None: ...
    @overload
    def get_params(
        self, failobj: None = None, header: str = "content-type", unquote: bool = True
    ) -> list[tuple[str, str]] | None: ...
    @overload
    def get_params(self, failobj: _T, header: str = "content-type", unquote: bool = True) -> list[tuple[str, str]] | _T: ...
    @overload
    def get_param(
        self, param: str, failobj: None = None, header: str = "content-type", unquote: bool = True
    ) -> _ParamType | None: ...
    @overload
    def get_param(self, param: str, failobj: _T, header: str = "content-type", unquote: bool = True) -> _ParamType | _T: ...
    def del_param(self, param: str, header: str = "content-type", requote: bool = True) -> None: ...
    def set_type(self, type: str, header: str = "Content-Type", requote: bool = True) -> None: ...
    @overload
    def get_filename(self, failobj: None = None) -> str | None: ...
    @overload
    def get_filename(self, failobj: _T) -> str | _T: ...
    @overload
    def get_boundary(self, failobj: None = None) -> str | None: ...
    @overload
    def get_boundary(self, failobj: _T) -> str | _T: ...
    def set_boundary(self, boundary: str) -> None: ...
    @overload
    def get_content_charset(self) -> str | None: ...
    @overload
    def get_content_charset(self, failobj: _T) -> str | _T: ...
    @overload
    def get_charsets(self, failobj: None = None) -> list[str | None]: ...
    @overload
    def get_charsets(self, failobj: _T) -> list[str | _T]: ...
    def walk(self) -> Generator[Self, None, None]: ...
    def get_content_disposition(self) -> str | None: ...
    def as_string(self, unixfrom: bool = False, maxheaderlen: int = 0, policy: Policy | None = None) -> str: ...
    def as_bytes(self, unixfrom: bool = False, policy: Policy | None = None) -> bytes: ...
    def __bytes__(self) -> bytes: ...
    def set_param(
        self,
        param: str,
        value: str,
        header: str = "Content-Type",
        requote: bool = True,
        charset: str | None = None,
        language: str = "",
        replace: bool = False,
    ) -> None: ...
    def __init__(self, policy: Policy = ...) -> None: ...
    # The following two methods are undocumented, but a source code comment states that they are public API
    def set_raw(self, name: str, value: _HeaderParamT) -> None: ...
    def raw_items(self) -> Iterator[tuple[str, _HeaderT]]: ...

class MIMEPart(Message[_HeaderRegistryT, _HeaderRegistryParamT]):
    def __init__(self, policy: Policy | None = None) -> None: ...
    def get_body(self, preferencelist: Sequence[str] = ("related", "html", "plain")) -> MIMEPart[_HeaderRegistryT] | None: ...
    def attach(self, payload: Self) -> None: ...  # type: ignore[override]
    # The attachments are created via type(self) in the attach method. It's theoretically
    # possible to sneak other attachment types into a MIMEPart instance, but could cause
    # cause unforseen consequences.
    def iter_attachments(self) -> Iterator[Self]: ...
    def iter_parts(self) -> Iterator[MIMEPart[_HeaderRegistryT]]: ...
    def get_content(self, *args: Any, content_manager: ContentManager | None = None, **kw: Any) -> Any: ...
    def set_content(self, *args: Any, content_manager: ContentManager | None = None, **kw: Any) -> None: ...
    def make_related(self, boundary: str | None = None) -> None: ...
    def make_alternative(self, boundary: str | None = None) -> None: ...
    def make_mixed(self, boundary: str | None = None) -> None: ...
    def add_related(self, *args: Any, content_manager: ContentManager | None = ..., **kw: Any) -> None: ...
    def add_alternative(self, *args: Any, content_manager: ContentManager | None = ..., **kw: Any) -> None: ...
    def add_attachment(self, *args: Any, content_manager: ContentManager | None = ..., **kw: Any) -> None: ...
    def clear(self) -> None: ...
    def clear_content(self) -> None: ...
    def as_string(self, unixfrom: bool = False, maxheaderlen: int | None = None, policy: Policy | None = None) -> str: ...
    def is_attachment(self) -> bool: ...

class EmailMessage(MIMEPart): ...
