"""Windows."""

from __future__ import annotations

import os
import sys
from functools import lru_cache
from typing import TYPE_CHECKING

from .api import PlatformDirsABC

if TYPE_CHECKING:
    from collections.abc import Callable


class Windows(PlatformDirsABC):
    """
    `MSDN on where to store app data files <https://learn.microsoft.com/en-us/windows/win32/shell/knownfolderid>`_.

    Makes use of the `appname <platformdirs.api.PlatformDirsABC.appname>`, `appauthor
    <platformdirs.api.PlatformDirsABC.appauthor>`, `version <platformdirs.api.PlatformDirsABC.version>`, `roaming
    <platformdirs.api.PlatformDirsABC.roaming>`, `opinion <platformdirs.api.PlatformDirsABC.opinion>`, `ensure_exists
    <platformdirs.api.PlatformDirsABC.ensure_exists>`.

    """

    @property
    def user_data_dir(self) -> str:
        """
        :return: data directory tied to the user, e.g.
         ``%USERPROFILE%\\AppData\\Local\\$appauthor\\$appname`` (not roaming) or
         ``%USERPROFILE%\\AppData\\Roaming\\$appauthor\\$appname`` (roaming)
        """
        const = "CSIDL_APPDATA" if self.roaming else "CSIDL_LOCAL_APPDATA"
        path = os.path.normpath(get_win_folder(const))
        return self._append_parts(path)

    def _append_parts(self, path: str, *, opinion_value: str | None = None) -> str:
        params = []
        if self.appname:
            if self.appauthor is not False:
                author = self.appauthor or self.appname
                params.append(author)
            params.append(self.appname)
            if opinion_value is not None and self.opinion:
                params.append(opinion_value)
            if self.version:
                params.append(self.version)
        path = os.path.join(path, *params)  # noqa: PTH118
        self._optionally_create_directory(path)
        return path

    @property
    def site_data_dir(self) -> str:
        """:return: data directory shared by users, e.g. ``C:\\ProgramData\\$appauthor\\$appname``"""
        path = os.path.normpath(get_win_folder("CSIDL_COMMON_APPDATA"))
        return self._append_parts(path)

    @property
    def user_config_dir(self) -> str:
        """:return: config directory tied to the user, same as `user_data_dir`"""
        return self.user_data_dir

    @property
    def site_config_dir(self) -> str:
        """:return: config directory shared by the users, same as `site_data_dir`"""
        return self.site_data_dir

    @property
    def user_cache_dir(self) -> str:
        """
        :return: cache directory tied to the user (if opinionated with ``Cache`` folder within ``$appname``) e.g.
         ``%USERPROFILE%\\AppData\\Local\\$appauthor\\$appname\\Cache\\$version``
        """
        path = os.path.normpath(get_win_folder("CSIDL_LOCAL_APPDATA"))
        return self._append_parts(path, opinion_value="Cache")

    @property
    def site_cache_dir(self) -> str:
        """:return: cache directory shared by users, e.g. ``C:\\ProgramData\\$appauthor\\$appname\\Cache\\$version``"""
        path = os.path.normpath(get_win_folder("CSIDL_COMMON_APPDATA"))
        return self._append_parts(path, opinion_value="Cache")

    @property
    def user_state_dir(self) -> str:
        """:return: state directory tied to the user, same as `user_data_dir`"""
        return self.user_data_dir

    @property
    def user_log_dir(self) -> str:
        """:return: log directory tied to the user, same as `user_data_dir` if not opinionated else ``Logs`` in it"""
        path = self.user_data_dir
        if self.opinion:
            path = os.path.join(path, "Logs")  # noqa: PTH118
            self._optionally_create_directory(path)
        return path

    @property
    def user_documents_dir(self) -> str:
        """:return: documents directory tied to the user e.g. ``%USERPROFILE%\\Documents``"""
        return os.path.normpath(get_win_folder("CSIDL_PERSONAL"))

    @property
    def user_downloads_dir(self) -> str:
        """:return: downloads directory tied to the user e.g. ``%USERPROFILE%\\Downloads``"""
        return os.path.normpath(get_win_folder("CSIDL_DOWNLOADS"))

    @property
    def user_pictures_dir(self) -> str:
        """:return: pictures directory tied to the user e.g. ``%USERPROFILE%\\Pictures``"""
        return os.path.normpath(get_win_folder("CSIDL_MYPICTURES"))

    @property
    def user_videos_dir(self) -> str:
        """:return: videos directory tied to the user e.g. ``%USERPROFILE%\\Videos``"""
        return os.path.normpath(get_win_folder("CSIDL_MYVIDEO"))

    @property
    def user_music_dir(self) -> str:
        """:return: music directory tied to the user e.g. ``%USERPROFILE%\\Music``"""
        return os.path.normpath(get_win_folder("CSIDL_MYMUSIC"))

    @property
    def user_desktop_dir(self) -> str:
        """:return: desktop directory tied to the user, e.g. ``%USERPROFILE%\\Desktop``"""
        return os.path.normpath(get_win_folder("CSIDL_DESKTOPDIRECTORY"))

    @property
    def user_runtime_dir(self) -> str:
        """
        :return: runtime directory tied to the user, e.g.
         ``%USERPROFILE%\\AppData\\Local\\Temp\\$appauthor\\$appname``
        """
        path = os.path.normpath(os.path.join(get_win_folder("CSIDL_LOCAL_APPDATA"), "Temp"))  # noqa: PTH118
        return self._append_parts(path)

    @property
    def site_runtime_dir(self) -> str:
        """:return: runtime directory shared by users, same as `user_runtime_dir`"""
        return self.user_runtime_dir


def get_win_folder_from_env_vars(csidl_name: str) -> str:
    """Get folder from environment variables."""
    result = get_win_folder_if_csidl_name_not_env_var(csidl_name)
    if result is not None:
        return result

    env_var_name = {
        "CSIDL_APPDATA": "APPDATA",
        "CSIDL_COMMON_APPDATA": "ALLUSERSPROFILE",
        "CSIDL_LOCAL_APPDATA": "LOCALAPPDATA",
    }.get(csidl_name)
    if env_var_name is None:
        msg = f"Unknown CSIDL name: {csidl_name}"
        raise ValueError(msg)
    result = os.environ.get(env_var_name)
    if result is None:
        msg = f"Unset environment variable: {env_var_name}"
        raise ValueError(msg)
    return result


def get_win_folder_if_csidl_name_not_env_var(csidl_name: str) -> str | None:
    """Get a folder for a CSIDL name that does not exist as an environment variable."""
    if csidl_name == "CSIDL_PERSONAL":
        return os.path.join(os.path.normpath(os.environ["USERPROFILE"]), "Documents")  # noqa: PTH118

    if csidl_name == "CSIDL_DOWNLOADS":
        return os.path.join(os.path.normpath(os.environ["USERPROFILE"]), "Downloads")  # noqa: PTH118

    if csidl_name == "CSIDL_MYPICTURES":
        return os.path.join(os.path.normpath(os.environ["USERPROFILE"]), "Pictures")  # noqa: PTH118

    if csidl_name == "CSIDL_MYVIDEO":
        return os.path.join(os.path.normpath(os.environ["USERPROFILE"]), "Videos")  # noqa: PTH118

    if csidl_name == "CSIDL_MYMUSIC":
        return os.path.join(os.path.normpath(os.environ["USERPROFILE"]), "Music")  # noqa: PTH118
    return None


def get_win_folder_from_registry(csidl_name: str) -> str:
    """
    Get folder from the registry.

    This is a fallback technique at best. I'm not sure if using the registry for these guarantees us the correct answer
    for all CSIDL_* names.

    """
    machine_names = {
        "CSIDL_COMMON_APPDATA",
    }
    shell_folder_name = {
        "CSIDL_APPDATA": "AppData",
        "CSIDL_COMMON_APPDATA": "Common AppData",
        "CSIDL_LOCAL_APPDATA": "Local AppData",
        "CSIDL_PERSONAL": "Personal",
        "CSIDL_DOWNLOADS": "{374DE290-123F-4565-9164-39C4925E467B}",
        "CSIDL_MYPICTURES": "My Pictures",
        "CSIDL_MYVIDEO": "My Video",
        "CSIDL_MYMUSIC": "My Music",
    }.get(csidl_name)
    if shell_folder_name is None:
        msg = f"Unknown CSIDL name: {csidl_name}"
        raise ValueError(msg)
    if sys.platform != "win32":  # only needed for mypy type checker to know that this code runs only on Windows
        raise NotImplementedError
    import winreg  # noqa: PLC0415

    # Use HKEY_LOCAL_MACHINE for system-wide folders, HKEY_CURRENT_USER for user-specific folders
    hkey = winreg.HKEY_LOCAL_MACHINE if csidl_name in machine_names else winreg.HKEY_CURRENT_USER

    key = winreg.OpenKey(hkey, r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders")
    directory, _ = winreg.QueryValueEx(key, shell_folder_name)
    return str(directory)


def get_win_folder_via_ctypes(csidl_name: str) -> str:
    """Get folder with ctypes."""
    # There is no 'CSIDL_DOWNLOADS'.
    # Use 'CSIDL_PROFILE' (40) and append the default folder 'Downloads' instead.
    # https://learn.microsoft.com/en-us/windows/win32/shell/knownfolderid

    import ctypes  # noqa: PLC0415

    csidl_const = {
        "CSIDL_APPDATA": 26,
        "CSIDL_COMMON_APPDATA": 35,
        "CSIDL_LOCAL_APPDATA": 28,
        "CSIDL_PERSONAL": 5,
        "CSIDL_MYPICTURES": 39,
        "CSIDL_MYVIDEO": 14,
        "CSIDL_MYMUSIC": 13,
        "CSIDL_DOWNLOADS": 40,
        "CSIDL_DESKTOPDIRECTORY": 16,
    }.get(csidl_name)
    if csidl_const is None:
        msg = f"Unknown CSIDL name: {csidl_name}"
        raise ValueError(msg)

    buf = ctypes.create_unicode_buffer(1024)
    windll = getattr(ctypes, "windll")  # noqa: B009 # using getattr to avoid false positive with mypy type checker
    windll.shell32.SHGetFolderPathW(None, csidl_const, None, 0, buf)

    # Downgrade to short path name if it has high-bit chars.
    if any(ord(c) > 255 for c in buf):  # noqa: PLR2004
        buf2 = ctypes.create_unicode_buffer(1024)
        if windll.kernel32.GetShortPathNameW(buf.value, buf2, 1024):
            buf = buf2

    if csidl_name == "CSIDL_DOWNLOADS":
        return os.path.join(buf.value, "Downloads")  # noqa: PTH118

    return buf.value


def _pick_get_win_folder() -> Callable[[str], str]:
    try:
        import ctypes  # noqa: PLC0415
    except ImportError:
        pass
    else:
        if hasattr(ctypes, "windll"):
            return get_win_folder_via_ctypes
    try:
        import winreg  # noqa: PLC0415, F401
    except ImportError:
        return get_win_folder_from_env_vars
    else:
        return get_win_folder_from_registry


get_win_folder = lru_cache(maxsize=None)(_pick_get_win_folder())

__all__ = [
    "Windows",
]
