"""Base API."""

from __future__ import annotations

import os
from abc import ABC, abstractmethod
from contextlib import suppress
from pathlib import Path
from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from collections.abc import Iterable, Iterator
    from typing import Literal


class PlatformDirsABC(ABC):  # ruff:ignore[too-many-public-methods]
    """Abstract base class defining all platform directory properties, their :class:`~pathlib.Path` variants, and iterators.

    Platform-specific subclasses (e.g. :class:`~platformdirs.windows.Windows`, :class:`~platformdirs.macos.MacOS`,
    :class:`~platformdirs.unix.Unix`) implement the abstract properties to return the appropriate paths for each
    operating system.

    """

    def __init__(  # ruff:ignore[too-many-arguments, too-many-positional-arguments]
        self,
        appname: str | None = None,
        appauthor: str | Literal[False] | None = None,
        version: str | None = None,
        roaming: bool = False,  # ruff:ignore[boolean-type-hint-positional-argument, boolean-default-value-positional-argument]
        multipath: bool = False,  # ruff:ignore[boolean-type-hint-positional-argument, boolean-default-value-positional-argument]
        opinion: bool = True,  # ruff:ignore[boolean-type-hint-positional-argument, boolean-default-value-positional-argument]
        ensure_exists: bool = False,  # ruff:ignore[boolean-type-hint-positional-argument, boolean-default-value-positional-argument]
        use_site_for_root: bool = False,  # ruff:ignore[boolean-type-hint-positional-argument, boolean-default-value-positional-argument]
    ) -> None:
        """Create a new platform directory.

        :param appname: See `appname`.
        :param appauthor: See `appauthor`.
        :param version: See `version`.
        :param roaming: See `roaming`.
        :param multipath: See `multipath`.
        :param opinion: See `opinion`.
        :param ensure_exists: See `ensure_exists`.
        :param use_site_for_root: See `use_site_for_root`.

        """
        self.appname = appname
        self.appauthor = appauthor
        self.version = version
        self.roaming = roaming
        """Whether to use the roaming appdata directory on Windows.

        That means that for users on a Windows network setup for roaming profiles, this user data will be synced on
        login (see `here <https://technet.microsoft.com/en-us/library/cc766489(WS.10).aspx>`_).

        """
        self.multipath = multipath
        """An optional parameter which indicates that the entire list of data dirs should be returned.

        When ``False``, only the first item is returned. Affects ``site_data_dir``, ``site_config_dir`` and
        ``site_applications_dir`` on Unix and macOS, and ``site_cache_dir`` on macOS under Homebrew.

        """
        self.opinion = opinion
        """Whether to use opinionated values.

        When enabled, appends an additional subdirectory for certain directories: e.g. ``Cache`` for cache and ``Logs``
        for logs on Windows, ``log`` for logs on Unix.

        """
        self.ensure_exists = ensure_exists
        """Create the directory a property returns, with missing parents, each time the property is read.

        Media directories qualify only when the user set them through XDG. platformdirs never creates fonts, bin,
        applications or default media directories. Off by default.

        """
        self.use_site_for_root = use_site_for_root
        """Whether to redirect ``user_*_dir`` calls to their ``site_*_dir`` equivalents when running as root (uid 0).

        Only has an effect on Unix. Disabled by default for backwards compatibility. When enabled, XDG user environment
        variables (e.g. ``XDG_DATA_HOME``) are bypassed for the redirected directories.

        """

    @property
    def appname(self) -> str | None:
        """The name of the application."""
        return self._appname

    @appname.setter
    def appname(self, value: str | None) -> None:
        _ensure_inside_base("appname", value)
        self._appname = value

    @property
    def appauthor(self) -> str | Literal[False] | None:
        """The name of the app author or distributing body for this application.

        Typically, it is the owning company name. Defaults to `appname`. You may pass ``False`` to disable it.

        .. note::

            On Windows, the directory structure is ``<base>/<appauthor>/<appname>``. When ``appauthor`` is ``None`` (the
            default), it falls back to ``appname``, resulting in ``<base>/<appname>/<appname>`` (e.g.
            ``AppData/Local/myapp/myapp``). Pass ``appauthor=False`` to omit the author directory entirely and get
            ``<base>/<appname>``.

        """
        return self._appauthor

    @appauthor.setter
    def appauthor(self, value: str | Literal[False] | None) -> None:
        _ensure_inside_base("appauthor", value)
        self._appauthor = value

    @property
    def version(self) -> str | None:
        """An optional version path element to append to the path.

        You might want to use this if you want multiple versions of your app to be able to run independently. If used,
        this would typically be ``<major>.<minor>``.

        """
        return self._version

    @version.setter
    def version(self, value: str | None) -> None:
        _ensure_inside_base("version", value)
        self._version = value

    def _append_app_name_and_version(self, *base: str) -> str:
        path = self._join_app_name_and_version(*base)
        self._optionally_create_directory(path)
        return path

    def _join_app_name_and_version(self, *base: str) -> str:
        params = list(base[1:])
        if self.appname:
            params.append(self.appname)
            if self.version:
                params.append(self.version)
        return os.path.join(base[0], *params)  # ruff:ignore[os-path-join]

    def _optionally_create_directory(self, path: str) -> None:
        if not self.ensure_exists:
            return
        # expanduser leaves "~" when the home is unknown, and creating it would make a "~" directory in the cwd.
        if path.startswith("~"):
            msg = f"could not determine the home directory, refusing to create {path!r}"
            raise RuntimeError(msg)
        Path(path).mkdir(parents=True, exist_ok=True)

    def _optionally_create_media_directory(self, path: str) -> None:
        # Only called for a media directory the user configured. Media directories are often symlinks to removable or
        # network storage, so a dangling link is returned as-is, like before ensure_exists covered them.
        with suppress(FileExistsError):
            self._optionally_create_directory(path)

    def _select_site_dirs(self, dirs: list[str]) -> str:
        # Site lists are built without touching the disk, so ensure_exists only creates what the caller gets back.
        selected = dirs if self.multipath else dirs[:1]
        for path in selected:
            self._optionally_create_directory(path)
        return os.pathsep.join(selected)

    def _create_as_yielded(self, dirs: Iterable[str]) -> Iterator[str]:
        for path in dirs:
            self._optionally_create_directory(path)
            yield path

    def _first_site_dir_as_path(self, dirs: list[str]) -> Path:
        # A *_path property always returns the first entry, regardless of multipath, so only that entry is created.
        path = dirs[0]
        self._optionally_create_directory(path)
        return Path(path)

    def _first_item_as_path_if_multipath(self, directory: str) -> Path:
        if self.multipath:
            # If multipath is True, the first path is returned.
            directory = directory.partition(os.pathsep)[0]
        return Path(directory)

    @property
    @abstractmethod
    def user_data_dir(self) -> str:
        """Data directory tied to the user."""

    @property
    @abstractmethod
    def site_data_dir(self) -> str:
        """Data directory shared by users."""

    @property
    def _site_data_dirs(self) -> list[str]:
        raise NotImplementedError

    @property
    @abstractmethod
    def user_config_dir(self) -> str:
        """Config directory tied to the user."""

    @property
    @abstractmethod
    def site_config_dir(self) -> str:
        """Config directory shared by users."""

    @property
    def _site_config_dirs(self) -> list[str]:
        raise NotImplementedError

    @property
    @abstractmethod
    def user_cache_dir(self) -> str:
        """Cache directory tied to the user."""

    @property
    @abstractmethod
    def site_cache_dir(self) -> str:
        """Cache directory shared by users."""

    @property
    @abstractmethod
    def user_state_dir(self) -> str:
        """State directory tied to the user."""

    @property
    @abstractmethod
    def site_state_dir(self) -> str:
        """State directory shared by users."""

    @property
    @abstractmethod
    def user_log_dir(self) -> str:
        """Log directory tied to the user."""

    @property
    @abstractmethod
    def site_log_dir(self) -> str:
        """Log directory shared by users."""

    @property
    @abstractmethod
    def user_documents_dir(self) -> str:
        """Documents directory tied to the user."""

    @property
    @abstractmethod
    def user_downloads_dir(self) -> str:
        """Downloads directory tied to the user."""

    @property
    @abstractmethod
    def user_pictures_dir(self) -> str:
        """Pictures directory tied to the user."""

    @property
    @abstractmethod
    def user_videos_dir(self) -> str:
        """Videos directory tied to the user."""

    @property
    @abstractmethod
    def user_music_dir(self) -> str:
        """Music directory tied to the user."""

    @property
    @abstractmethod
    def user_desktop_dir(self) -> str:
        """Desktop directory tied to the user."""

    @property
    @abstractmethod
    def user_projects_dir(self) -> str:
        """Projects directory tied to the user."""

    @property
    @abstractmethod
    def user_publicshare_dir(self) -> str:
        """Public share directory tied to the user."""

    @property
    @abstractmethod
    def user_templates_dir(self) -> str:
        """Templates directory tied to the user."""

    @property
    @abstractmethod
    def user_fonts_dir(self) -> str:
        """Fonts directory tied to the user."""

    @property
    @abstractmethod
    def user_preference_dir(self) -> str:
        """Preference directory tied to the user."""

    @property
    @abstractmethod
    def user_bin_dir(self) -> str:
        """Bin directory tied to the user."""

    @property
    @abstractmethod
    def site_bin_dir(self) -> str:
        """Bin directory shared by users."""

    @property
    @abstractmethod
    def user_applications_dir(self) -> str:
        """Applications directory tied to the user."""

    @property
    @abstractmethod
    def site_applications_dir(self) -> str:
        """Applications directory shared by users."""

    @property
    def _site_applications_dirs(self) -> list[str]:
        raise NotImplementedError

    @property
    @abstractmethod
    def user_runtime_dir(self) -> str:
        """Runtime directory tied to the user."""

    @property
    @abstractmethod
    def site_runtime_dir(self) -> str:
        """Runtime directory shared by users."""

    @property
    def user_data_path(self) -> Path:
        """Data path tied to the user."""
        return Path(self.user_data_dir)

    @property
    def site_data_path(self) -> Path:
        """Data path shared by users."""
        return Path(self.site_data_dir)

    @property
    def user_config_path(self) -> Path:
        """Config path tied to the user."""
        return Path(self.user_config_dir)

    @property
    def site_config_path(self) -> Path:
        """Config path shared by users."""
        return Path(self.site_config_dir)

    @property
    def user_cache_path(self) -> Path:
        """Cache path tied to the user."""
        return Path(self.user_cache_dir)

    @property
    def site_cache_path(self) -> Path:
        """Cache path shared by users."""
        return Path(self.site_cache_dir)

    @property
    def user_state_path(self) -> Path:
        """State path tied to the user."""
        return Path(self.user_state_dir)

    @property
    def site_state_path(self) -> Path:
        """State path shared by users."""
        return Path(self.site_state_dir)

    @property
    def user_log_path(self) -> Path:
        """Log path tied to the user."""
        return Path(self.user_log_dir)

    @property
    def site_log_path(self) -> Path:
        """Log path shared by users."""
        return Path(self.site_log_dir)

    @property
    def user_documents_path(self) -> Path:
        """Documents path tied to the user."""
        return Path(self.user_documents_dir)

    @property
    def user_downloads_path(self) -> Path:
        """Downloads path tied to the user."""
        return Path(self.user_downloads_dir)

    @property
    def user_pictures_path(self) -> Path:
        """Pictures path tied to the user."""
        return Path(self.user_pictures_dir)

    @property
    def user_videos_path(self) -> Path:
        """Videos path tied to the user."""
        return Path(self.user_videos_dir)

    @property
    def user_music_path(self) -> Path:
        """Music path tied to the user."""
        return Path(self.user_music_dir)

    @property
    def user_desktop_path(self) -> Path:
        """Desktop path tied to the user."""
        return Path(self.user_desktop_dir)

    @property
    def user_projects_path(self) -> Path:
        """Projects path tied to the user."""
        return Path(self.user_projects_dir)

    @property
    def user_publicshare_path(self) -> Path:
        """Public share path tied to the user."""
        return Path(self.user_publicshare_dir)

    @property
    def user_templates_path(self) -> Path:
        """Templates path tied to the user."""
        return Path(self.user_templates_dir)

    @property
    def user_fonts_path(self) -> Path:
        """Fonts path tied to the user."""
        return Path(self.user_fonts_dir)

    @property
    def user_preference_path(self) -> Path:
        """Preference path tied to the user."""
        return Path(self.user_preference_dir)

    @property
    def user_bin_path(self) -> Path:
        """Bin path tied to the user."""
        return Path(self.user_bin_dir)

    @property
    def site_bin_path(self) -> Path:
        """Bin path shared by users."""
        return Path(self.site_bin_dir)

    @property
    def user_applications_path(self) -> Path:
        """Applications path tied to the user."""
        return Path(self.user_applications_dir)

    @property
    def site_applications_path(self) -> Path:
        """Applications path shared by users. Only return the first item, even if ``multipath`` is set to ``True``."""
        return self._first_item_as_path_if_multipath(self.site_applications_dir)

    @property
    def user_runtime_path(self) -> Path:
        """Runtime path tied to the user."""
        return Path(self.user_runtime_dir)

    @property
    def site_runtime_path(self) -> Path:
        """Runtime path shared by users."""
        return Path(self.site_runtime_dir)

    def iter_config_dirs(self) -> Iterator[str]:
        """:yield: all user and site configuration directories."""
        yield from _unique(self._iter_config_dirs())

    def _iter_config_dirs(self) -> Iterator[str]:
        yield self.user_config_dir
        yield self.site_config_dir

    def iter_data_dirs(self) -> Iterator[str]:
        """:yield: all user and site data directories."""
        yield from _unique(self._iter_data_dirs())

    def _iter_data_dirs(self) -> Iterator[str]:
        yield self.user_data_dir
        yield self.site_data_dir

    def iter_cache_dirs(self) -> Iterator[str]:
        """:yield: all user and site cache directories."""
        yield from _unique(self._iter_cache_dirs())

    def _iter_cache_dirs(self) -> Iterator[str]:
        yield self.user_cache_dir
        yield self.site_cache_dir

    def iter_state_dirs(self) -> Iterator[str]:
        """:yield: all user and site state directories."""
        yield from _unique(self._iter_state_dirs())

    def _iter_state_dirs(self) -> Iterator[str]:
        yield self.user_state_dir
        yield self.site_state_dir

    def iter_log_dirs(self) -> Iterator[str]:
        """:yield: all user and site log directories."""
        yield from _unique(self._iter_log_dirs())

    def _iter_log_dirs(self) -> Iterator[str]:
        yield self.user_log_dir
        yield self.site_log_dir

    def iter_runtime_dirs(self) -> Iterator[str]:
        """:yield: all user and site runtime directories."""
        yield from _unique(self._iter_runtime_dirs())

    def _iter_runtime_dirs(self) -> Iterator[str]:
        yield self.user_runtime_dir
        yield self.site_runtime_dir

    def iter_config_paths(self) -> Iterator[Path]:
        """:yield: all user and site configuration paths."""
        for path in self.iter_config_dirs():
            yield Path(path)

    def iter_data_paths(self) -> Iterator[Path]:
        """:yield: all user and site data paths."""
        for path in self.iter_data_dirs():
            yield Path(path)

    def iter_cache_paths(self) -> Iterator[Path]:
        """:yield: all user and site cache paths."""
        for path in self.iter_cache_dirs():
            yield Path(path)

    def iter_state_paths(self) -> Iterator[Path]:
        """:yield: all user and site state paths."""
        for path in self.iter_state_dirs():
            yield Path(path)

    def iter_log_paths(self) -> Iterator[Path]:
        """:yield: all user and site log paths."""
        for path in self.iter_log_dirs():
            yield Path(path)

    def iter_runtime_paths(self) -> Iterator[Path]:
        """:yield: all user and site runtime paths."""
        for path in self.iter_runtime_dirs():
            yield Path(path)


def _ensure_inside_base(name: str, value: str | Literal[False] | None) -> None:
    if not value:
        return
    # os.path.join discards the base when a later component has a root or a drive, and ``..`` climbs out of it.
    drive, tail = os.path.splitdrive(value)
    if drive or tail.startswith(("/", "\\")) or ".." in tail.replace("\\", "/").split("/"):
        msg = f"{name} must stay inside the base directory, got {value!r}"
        raise ValueError(msg)


def _unique(dirs: Iterable[str]) -> Iterator[str]:
    """:yield: ``dirs`` in order, skipping any directory already yielded."""
    # Lazy on purpose: under ensure_exists reading a site_*_dir creates it, so draining ``dirs`` up front would
    # create directories for a caller that stops after the first entry.
    seen: set[str] = set()
    for path in dirs:
        if path not in seen:
            seen.add(path)
            yield path