"""
Helpers for Python and platform compatibility. To distinguish them from
the builtin functions, replacement functions are suffixed with an underscore,
e.g. `unicode_`.

DOCS: https://spacy.io/api/top-level#compat
"""
import os
import sys

from thinc.neural.util import copy_array

try:
    import cPickle as pickle
except ImportError:
    import pickle

try:
    import copy_reg
except ImportError:
    import copyreg as copy_reg

try:
    from cupy.cuda.stream import Stream as CudaStream
except ImportError:
    CudaStream = None

try:
    import cupy
except ImportError:
    cupy = None

try:
    from thinc.neural.optimizers import Optimizer  # noqa: F401
except ImportError:
    from thinc.neural.optimizers import Adam as Optimizer  # noqa: F401

pickle = pickle
copy_reg = copy_reg
CudaStream = CudaStream
cupy = cupy
copy_array = copy_array

is_windows = sys.platform.startswith("win")
is_linux = sys.platform.startswith("linux")
is_osx = sys.platform == "darwin"


def symlink_to(orig, dest):
    """Create a symlink. Used for model shortcut links.

    orig (unicode / Path): The origin path.
    dest (unicode / Path): The destination path of the symlink.
    """
    if is_windows:
        import subprocess

        subprocess.check_call(["mklink", "/d", str(orig), str(dest)], shell=True)
    else:
        orig.symlink_to(dest)


def symlink_remove(link):
    """Remove a symlink. Used for model shortcut links.

    link (unicode / Path): The path to the symlink.
    """
    # https://stackoverflow.com/q/26554135/6400719
    if os.path.isdir(str(link)) and is_windows:
        # this should only be on Py2.7 and windows
        os.rmdir(str(link))
    else:
        os.unlink(str(link))


def is_config(windows=None, linux=None, osx=None, **kwargs):
    """Check if a specific configuration of Python version and operating system
    matches the user's setup. Mostly used to display targeted error messages.

    windows (bool): spaCy is executed on Windows.
    linux (bool): spaCy is executed on Linux.
    osx (bool): spaCy is executed on OS X or macOS.
    RETURNS (bool): Whether the configuration matches the user's platform.

    DOCS: https://spacy.io/api/top-level#compat.is_config
    """
    return (
        windows in (None, is_windows)
        and linux in (None, is_linux)
        and osx in (None, is_osx)
    )