"""
Improved support for Microsoft Visual C++ compilers.

Known supported compilers:
--------------------------
Microsoft Visual C++ 9.0:
    Microsoft Visual C++ Compiler for Python 2.7 (x86, amd64)
    Microsoft Windows SDK 6.1 (x86, x64, ia64)
    Microsoft Windows SDK 7.0 (x86, x64, ia64)

Microsoft Visual C++ 10.0:
    Microsoft Windows SDK 7.1 (x86, x64, ia64)

Microsoft Visual C++ 14.0:
    Microsoft Visual C++ Build Tools 2015 (x86, x64, arm)
    Microsoft Visual Studio 2017 (x86, x64, arm, arm64)
    Microsoft Visual Studio Build Tools 2017 (x86, x64, arm, arm64)
"""

import os
import sys
import platform
import itertools
import distutils.errors
from setuptools.extern.packaging.version import LegacyVersion

from setuptools.extern.six.moves import filterfalse

from .monkey import get_unpatched

if platform.system() == 'Windows':
    from setuptools.extern.six.moves import winreg
    safe_env = os.environ
else:
    """
    Mock winreg and environ so the module can be imported
    on this platform.
    """

    class winreg:
        HKEY_USERS = None
        HKEY_CURRENT_USER = None
        HKEY_LOCAL_MACHINE = None
        HKEY_CLASSES_ROOT = None

    safe_env = dict()

_msvc9_suppress_errors = (
    # msvc9compiler isn't available on some platforms
    ImportError,

    # msvc9compiler raises DistutilsPlatformError in some
    # environments. See #1118.
    distutils.errors.DistutilsPlatformError,
)

try:
    from distutils.msvc9compiler import Reg
except _msvc9_suppress_errors:
    pass


def msvc9_find_vcvarsall(version):
    """
    Patched "distutils.msvc9compiler.find_vcvarsall" to use the standalone
    compiler build for Python (VCForPython). Fall back to original behavior
    when the standalone compiler is not available.

    Redirect the path of "vcvarsall.bat".

    Known supported compilers
    -------------------------
    Microsoft Visual C++ 9.0:
        Microsoft Visual C++ Compiler for Python 2.7 (x86, amd64)

    Parameters
    ----------
    version: float
        Required Microsoft Visual C++ version.

    Return
    ------
    vcvarsall.bat path: str
    """
    VC_BASE = r'Software\%sMicrosoft\DevDiv\VCForPython\%0.1f'
    key = VC_BASE % ('', version)
    try:
        # Per-user installs register the compiler path here
        productdir = Reg.get_value(key, "installdir")
    except KeyError:
        try:
            # All-user installs on a 64-bit system register here
            key = VC_BASE % ('Wow6432Node\\', version)
            productdir = Reg.get_value(key, "installdir")
        except KeyError:
            productdir = None

    if productdir:
        vcvarsall = os.path.os.path.join(productdir, "vcvarsall.bat")
        if os.path.isfile(vcvarsall):
            return vcvarsall

    return get_unpatched(msvc9_find_vcvarsall)(version)


def msvc9_query_vcvarsall(ver, arch='x86', *args, **kwargs):
    """
    Patched "distutils.msvc9compiler.query_vcvarsall" for support extra
    compilers.

    Set environment without use of "vcvarsall.bat".

    Known supported compilers
    -------------------------
    Microsoft Visual C++ 9.0:
        Microsoft Visual C++ Compiler for Python 2.7 (x86, amd64)
        Microsoft Windows SDK 6.1 (x86, x64, ia64)
        Microsoft Windows SDK 7.0 (x86, x64, ia64)

    Microsoft Visual C++ 10.0:
        Microsoft Windows SDK 7.1 (x86, x64, ia64)

    Parameters
    ----------
    ver: float
        Required Microsoft Visual C++ version.
    arch: str
        Target architecture.

    Return
    ------
    environment: dict
    """
    # Try to get environement from vcvarsall.bat (Classical way)
    try:
        orig = get_unpatched(msvc9_query_vcvarsall)
        return orig(ver, arch, *args, **kwargs)
    except distutils.errors.DistutilsPlatformError:
        # Pass error if Vcvarsall.bat is missing
        pass
    except ValueError:
        # Pass error if environment not set after executing vcvarsall.bat
        pass

    # If error, try to set environment directly
    try:
        return EnvironmentInfo(arch, ver).return_env()
    except distutils.errors.DistutilsPlatformError as exc:
        _augment_exception(exc, ver, arch)
        raise


def msvc14_get_vc_env(plat_spec):
    """
    Patched "distutils._msvccompiler._get_vc_env" for support extra
    compilers.

    Set environment without use of "vcvarsall.bat".

    Known supported compilers
    -------------------------
    Microsoft Visual C++ 14.0:
        Microsoft Visual C++ Build Tools 2015 (x86, x64, arm)
        Microsoft Visual Studio 2017 (x86, x64, arm, arm64)
        Microsoft Visual Studio Build Tools 2017 (x86, x64, arm, arm64)

    Parameters
    ----------
    plat_spec: str
        Target architecture.

    Return
    ------
    environment: dict
    """
    # Try to get environment from vcvarsall.bat (Classical way)
    try:
        return get_unpatched(msvc14_get_vc_env)(plat_spec)
    except distutils.errors.DistutilsPlatformError:
        # Pass error Vcvarsall.bat is missing
        pass

    # If error, try to set environment directly
    try:
        return EnvironmentInfo(plat_spec, vc_min_ver=14.0).return_env()
    except distutils.errors.DistutilsPlatformError as exc:
        _augment_exception(exc, 14.0)
        raise


def msvc14_gen_lib_options(*args, **kwargs):
    """
    Patched "distutils._msvccompiler.gen_lib_options" for fix
    compatibility between "numpy.distutils" and "distutils._msvccompiler"
    (for Numpy < 1.11.2)
    """
    if "numpy.distutils" in sys.modules:
        import numpy as np
        if LegacyVersion(np.__version__) < LegacyVersion('1.11.2'):
            return np.distutils.ccompiler.gen_lib_options(*args, **kwargs)
    return get_unpatched(msvc14_gen_lib_options)(*args, **kwargs)


def _augment_exception(exc, version, arch=''):
    """
    Add details to the exception message to help guide the user
    as to what action will resolve it.
    """
    # Error if MSVC++ directory not found or environment not set
    message = exc.args[0]

    if "vcvarsall" in message.lower() or "visual c" in message.lower():
        # Special error message if MSVC++ not installed
        tmpl = 'Microsoft Visual C++ {version:0.1f} is required.'
        message = tmpl.format(**locals())
        msdownload = 'www.microsoft.com/download/details.aspx?id=%d'
        if version == 9.0:
            if arch.lower().find('ia64') > -1:
                # For VC++ 9.0, if IA64 support is needed, redirect user
                # to Windows SDK 7.0
                message += ' Get it with "Microsoft Windows SDK 7.0": '
                message += msdownload % 3138
            else:
                # For VC++ 9.0 redirect user to Vc++ for Python 2.7 :
                # This redirection link is maintained by Microsoft.
                # Contact vspython@microsoft.com if it needs updating.
                message += ' Get it from http://aka.ms/vcpython27'
        elif version == 10.0:
            # For VC++ 10.0 Redirect user to Windows SDK 7.1
            message += ' Get it with "Microsoft Windows SDK 7.1": '
            message += msdownload % 8279
        elif version >= 14.0:
            # For VC++ 14.0 Redirect user to Visual C++ Build Tools
            message += (' Get it with "Microsoft Visual C++ Build Tools": '
                        r'https://visualstudio.microsoft.com/downloads/')

    exc.args = (message, )


class PlatformInfo:
    """
    Current and Target Architectures informations.

    Parameters
    ----------
    arch: str
        Target architecture.
    """
    current_cpu = safe_env.get('processor_architecture', '').lower()

    def __init__(self, arch):
        self.arch = arch.lower().replace('x64', 'amd64')

    @property
    def target_cpu(self):
        return self.arch[self.arch.find('_') + 1:]

    def target_is_x86(self):
        return self.target_cpu == 'x86'

    def current_is_x86(self):
        return self.current_cpu == 'x86'

    def current_dir(self, hidex86=False, x64=False):
        """
        Current platform specific subfolder.

        Parameters
        ----------
        hidex86: bool
            return '' and not '\x86' if architecture is x86.
        x64: bool
            return '\x64' and not '\amd64' if architecture is amd64.

        Return
        ------
        subfolder: str
            '\target', or '' (see hidex86 parameter)
        """
        return (
            '' if (self.current_cpu == 'x86' and hidex86) else
            r'\x64' if (self.current_cpu == 'amd64' and x64) else
            r'\%s' % self.current_cpu
        )

    def target_dir(self, hidex86=False, x64=False):
        r"""
        Target platform specific subfolder.

        Parameters
        ----------
        hidex86: bool
            return '' and not '\x86' if architecture is x86.
        x64: bool
            return '\x64' and not '\amd64' if architecture is amd64.

        Return
        ------
        subfolder: str
            '\current', or '' (see hidex86 parameter)
        """
        return (
            '' if (self.target_cpu == 'x86' and hidex86) else
            r'\x64' if (self.target_cpu == 'amd64' and x64) else
            r'\%s' % self.target_cpu
        )

    def cross_dir(self, forcex86=False):
        r"""
        Cross platform specific subfolder.

        Parameters
        ----------
        forcex86: bool
            Use 'x86' as current architecture even if current acritecture is
            not x86.

        Return
        ------
        subfolder: str
            '' if target architecture is current architecture,
            '\current_target' if not.
        """
        current = 'x86' if forcex86 else self.current_cpu
        return (
            '' if self.target_cpu == current else
            self.target_dir().replace('\\', '\\%s_' % current)
        )


class RegistryInfo:
    """
    Microsoft Visual Studio related registry informations.

    Parameters
    ----------
    platform_info: PlatformInfo
        "PlatformInfo" instance.
    """
    HKEYS = (winreg.HKEY_USERS,
             winreg.HKEY_CURRENT_USER,
             winreg.HKEY_LOCAL_MACHINE,
             winreg.HKEY_CLASSES_ROOT)

    def __init__(self, platform_info):