# Copyright (C) 2016-present the asyncpg authors and contributors
# <see AUTHORS file>
#
# This module is part of asyncpg and is released under
# the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0

from __future__ import annotations

import enum
import pathlib
import platform
import typing
import sys

if typing.TYPE_CHECKING:
    import asyncio

SYSTEM: typing.Final = platform.uname().system


if sys.platform == 'win32':
    import ctypes.wintypes

    CSIDL_APPDATA: typing.Final = 0x001a

    def get_pg_home_directory() -> pathlib.Path | None:
        # We cannot simply use expanduser() as that returns the user's
        # home directory, whereas Postgres stores its config in
        # %AppData% on Windows.
        buf = ctypes.create_unicode_buffer(ctypes.wintypes.MAX_PATH)
        r = ctypes.windll.shell32.SHGetFolderPathW(0, CSIDL_APPDATA, 0, 0, buf)
        if r:
            return None
        else:
            return pathlib.Path(buf.value) / 'postgresql'

else:
    def get_pg_home_directory() -> pathlib.Path | None:
        try:
            return pathlib.Path.home()
        except (RuntimeError, KeyError):
            return None


async def wait_closed(stream: asyncio.StreamWriter) -> None:
    # Not all asyncio versions have StreamWriter.wait_closed().
    if hasattr(stream, 'wait_closed'):
        try:
            await stream.wait_closed()
        except ConnectionResetError:
            # On Windows wait_closed() sometimes propagates
            # ConnectionResetError which is totally unnecessary.
            pass


if sys.version_info < (3, 12):
    def markcoroutinefunction(c):  # type: ignore
        pass
else:
    from inspect import markcoroutinefunction  # noqa: F401


if sys.version_info < (3, 12):
    from ._asyncio_compat import wait_for as wait_for  # noqa: F401
else:
    from asyncio import wait_for as wait_for  # noqa: F401


if sys.version_info < (3, 11):
    from ._asyncio_compat import timeout_ctx as timeout  # noqa: F401
else:
    from asyncio import timeout as timeout  # noqa: F401

if sys.version_info < (3, 9):
    from typing import (  # noqa: F401
        Awaitable as Awaitable,
    )
else:
    from collections.abc import (  # noqa: F401
        Awaitable as Awaitable,
    )

if sys.version_info < (3, 11):
    class StrEnum(str, enum.Enum):
        __str__ = str.__str__
        __repr__ = enum.Enum.__repr__
else:
    from enum import StrEnum as StrEnum  # noqa: F401