"""
Utility methods to print system info for debugging

adapted from :func:`pandas.show_versions`
"""
# License: BSD 3 clause

import platform
import sys
import importlib

from ._openmp_helpers import _openmp_parallelism_enabled


def _get_sys_info():
    """System information

    Return
    ------
    sys_info : dict
        system and Python version information

    """
    python = sys.version.replace('\n', ' ')

    blob = [
        ("python", python),
        ('executable', sys.executable),
        ("machine", platform.platform()),
    ]

    return dict(blob)


def _get_deps_info():
    """Overview of the installed version of main dependencies

    Returns
    -------
    deps_info: dict
        version information on relevant Python libraries

    """
    deps = [
        "pip",
        "setuptools",
        "sklearn",
        "numpy",
        "scipy",
        "Cython",
        "pandas",
        "matplotlib",
        "joblib",
        "threadpoolctl"
    ]

    def get_version(module):
        return module.__version__

    deps_info = {}

    for modname in deps:
        try:
            if modname in sys.modules:
                mod = sys.modules[modname]
            else:
                mod = importlib.import_module(modname)
            ver = get_version(mod)
            deps_info[modname] = ver
        except ImportError:
            deps_info[modname] = None

    return deps_info


def show_versions():
    """Print useful debugging information"

    .. versionadded:: 0.20
    """

    sys_info = _get_sys_info()
    deps_info = _get_deps_info()

    print('\nSystem:')
    for k, stat in sys_info.items():
        print("{k:>10}: {stat}".format(k=k, stat=stat))

    print('\nPython dependencies:')
    for k, stat in deps_info.items():
        print("{k:>13}: {stat}".format(k=k, stat=stat))

    print("\n{k}: {stat}".format(k="Built with OpenMP",
                                 stat=_openmp_parallelism_enabled()))