from __future__ import annotations

import hashlib
import io
import os
import shutil
import stat
import sys
import tempfile

from contextlib import contextmanager
from pathlib import Path
from typing import TYPE_CHECKING
from typing import Any
from typing import Iterator
from typing import Mapping

from poetry.utils.constants import REQUESTS_TIMEOUT


if TYPE_CHECKING:
    from collections.abc import Callable
    from io import BufferedWriter

    from poetry.core.packages.package import Package
    from requests import Session

    from poetry.utils.authenticator import Authenticator


@contextmanager
def directory(path: Path) -> Iterator[Path]:
    cwd = Path.cwd()
    try:
        os.chdir(path)
        yield path
    finally:
        os.chdir(cwd)


@contextmanager
def atomic_open(filename: str | os.PathLike[str]) -> Iterator[BufferedWriter]:
    """
    write a file to the disk in an atomic fashion

    Taken from requests.utils
    (https://github.com/psf/requests/blob/7104ad4b135daab0ed19d8e41bd469874702342b/requests/utils.py#L296)
    """
    tmp_descriptor, tmp_name = tempfile.mkstemp(dir=os.path.dirname(filename))
    try:
        with os.fdopen(tmp_descriptor, "wb") as tmp_handler:
            yield tmp_handler
        os.replace(tmp_name, filename)
    except BaseException:
        os.remove(tmp_name)
        raise


def _on_rm_error(func: Callable[[str], None], path: str, exc_info: Exception) -> None:
    if not os.path.exists(path):
        return

    os.chmod(path, stat.S_IWRITE)
    func(path)


def remove_directory(
    path: Path, *args: Any, force: bool = False, **kwargs: Any
) -> None:
    """
    Helper function handle safe removal, and optionally forces stubborn file removal.
    This is particularly useful when dist files are read-only or git writes read-only
    files on Windows.

    Internally, all arguments are passed to `shutil.rmtree`.
    """
    if path.is_symlink():
        return os.unlink(path)

    kwargs["onerror"] = kwargs.pop("onerror", _on_rm_error if force else None)
    shutil.rmtree(path, *args, **kwargs)


def merge_dicts(d1: dict[str, Any], d2: dict[str, Any]) -> None:
    for k in d2.keys():
        if k in d1 and isinstance(d1[k], dict) and isinstance(d2[k], Mapping):
            merge_dicts(d1[k], d2[k])
        else:
            d1[k] = d2[k]


def download_file(
    url: str,
    dest: Path,
    session: Authenticator | Session | None = None,
    chunk_size: int = 1024,
) -> None:
    import requests

    from poetry.puzzle.provider import Indicator

    get = requests.get if not session else session.get

    response = get(url, stream=True, timeout=REQUESTS_TIMEOUT)
    response.raise_for_status()

    set_indicator = False
    with Indicator.context() as update_context:
        update_context(f"Downloading {url}")

        if "Content-Length" in response.headers:
            try:
                total_size = int(response.headers["Content-Length"])
            except ValueError:
                total_size = 0

            fetched_size = 0
            last_percent = 0

            # if less than 1MB, we simply show that we're downloading
            # but skip the updating
            set_indicator = total_size > 1024 * 1024

        with open(dest, "wb") as f:
            for chunk in response.iter_content(chunk_size=chunk_size):
                if chunk:
                    f.write(chunk)

                    if set_indicator:
                        fetched_size += len(chunk)
                        percent = (fetched_size * 100) // total_size
                        if percent > last_percent:
                            last_percent = percent
                            update_context(f"Downloading {url} {percent:3}%")


def get_package_version_display_string(
    package: Package, root: Path | None = None
) -> str:
    if package.source_type in ["file", "directory"] and root:
        assert package.source_url is not None
        path = Path(os.path.relpath(package.source_url, root)).as_posix()
        return f"{package.version} {path}"

    pretty_version: str = package.full_pretty_version
    return pretty_version


def paths_csv(paths: list[Path]) -> str:
    return ", ".join(f'"{c!s}"' for c in paths)


def is_dir_writable(path: Path, create: bool = False) -> bool:
    try:
        if not path.exists():
            if not create:
                return False
            path.mkdir(parents=True, exist_ok=True)

        with tempfile.TemporaryFile(dir=str(path)):
            pass
    except OSError:
        return False
    else:
        return True


def pluralize(count: int, word: str = "") -> str:
    if count == 1:
        return word
    return word + "s"


def _get_win_folder_from_registry(csidl_name: str) -> str:
    if sys.platform != "win32":
        raise RuntimeError("Method can only be called on Windows.")

    import winreg as _winreg

    shell_folder_name = {
        "CSIDL_APPDATA": "AppData",
        "CSIDL_COMMON_APPDATA": "Common AppData",
        "CSIDL_LOCAL_APPDATA": "Local AppData",
        "CSIDL_PROGRAM_FILES": "Program Files",
    }[csidl_name]

    key = _winreg.OpenKey(
        _winreg.HKEY_CURRENT_USER,
        r"Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders",
    )
    dir, type = _winreg.QueryValueEx(key, shell_folder_name)

    assert isinstance(dir, str)
    return dir


def _get_win_folder_with_ctypes(csidl_name: str) -> str:
    if sys.platform != "win32":
        raise RuntimeError("Method can only be called on Windows.")

    import ctypes

    csidl_const = {
        "CSIDL_APPDATA": 26,
        "CSIDL_COMMON_APPDATA": 35,
        "CSIDL_LOCAL_APPDATA": 28,
        "CSIDL_PROGRAM_FILES": 38,
    }[csidl_name]

    buf = ctypes.create_unicode_buffer(1024)
    ctypes.windll.shell32.SHGetFolderPathW(None, csidl_const, None, 0, buf)

    # Downgrade to short path name if have highbit chars. See
    # <http://bugs.activestate.com/show_bug.cgi?id=85099>.
    has_high_char = False
    for c in buf:
        if ord(c) > 255:
            has_high_char = True
            break
    if has_high_char:
        buf2 = ctypes.create_unicode_buffer(1024)
        if ctypes.windll.kernel32.GetShortPathNameW(buf.value, buf2, 1024):
            buf = buf2

    return buf.value


def get_win_folder(csidl_name: str) -> Path:
    if sys.platform == "win32":
        try:
            from ctypes import windll  # noqa: F401

            _get_win_folder = _get_win_folder_with_ctypes
        except ImportError:
            _get_win_folder = _get_win_folder_from_registry

        return Path(_get_win_folder(csidl_name))

    raise RuntimeError("Method can only be called on Windows.")


def get_real_windows_path(path: Path) -> Path:
    program_files = get_win_folder("CSIDL_PROGRAM_FILES")
    local_appdata = get_win_folder("CSIDL_LOCAL_APPDATA")

    path = Path(
        str(path).replace(
            str(program_files / "WindowsApps"),
            str(local_appdata / "Microsoft/WindowsApps"),
        )
    )

    if path.as_posix().startswith(local_appdata.as_posix()):
        path = path.resolve()

    return path


def get_file_hash(path: Path, hash_name: str = "sha256") -> str:
    h = hashlib.new(hash_name)
    with path.open("rb") as fp:
        for content in iter(lambda: fp.read(io.DEFAULT_BUFFER_SIZE), b""):
            h.update(content)

    return h.hexdigest()
