"""distutils._msvccompiler

Contains MSVCCompiler, an implementation of the abstract CCompiler class
for Microsoft Visual Studio 2015.

The module is compatible with VS 2015 and later. You can find legacy support
for older versions in distutils.msvc9compiler and distutils.msvccompiler.
"""

# Written by Perry Stoll
# hacked by Robin Becker and Thomas Heller to do a better job of
#   finding DevStudio (through the registry)
# ported to VS 2005 and VS 2008 by Christian Heimes
# ported to VS 2015 by Steve Dower

import os
import subprocess
import winreg

from distutils.errors import DistutilsPlatformError
from distutils.ccompiler import CCompiler
from distutils import log

from itertools import count

def _find_vc2015():
    try:
        key = winreg.OpenKeyEx(
            winreg.HKEY_LOCAL_MACHINE,
            r"Software\Microsoft\VisualStudio\SxS\VC7",
            access=winreg.KEY_READ | winreg.KEY_WOW64_32KEY
        )
    except OSError:
        log.debug("Visual C++ is not registered")
        return None, None

    best_version = 0
    best_dir = None
    with key:
        for i in count():
            try:
                v, vc_dir, vt = winreg.EnumValue(key, i)
            except OSError:
                break
            if v and vt == winreg.REG_SZ and os.path.isdir(vc_dir):
                try:
                    version = int(float(v))
                except (ValueError, TypeError):
                    continue
                if version >= 14 and version > best_version:
                    best_version, best_dir = version, vc_dir
    return best_version, best_dir

def _find_vc2017():
    """Returns "15, path" based on the result of invoking vswhere.exe
    If no install is found, returns "None, None"

    The version is returned to avoid unnecessarily changing the function
    result. It may be ignored when the path is not None.

    If vswhere.exe is not available, by definition, VS 2017 is not
    installed.
    """
    root = os.environ.get("ProgramFiles(x86)") or os.environ.get("ProgramFiles")
    if not root:
        return None, None

    try:
        path = subprocess.check_output([
            os.path.join(root, "Microsoft Visual Studio", "Installer", "vswhere.exe"),
            "-latest",
            "-prerelease",
            "-requires", "Microsoft.VisualStudio.Component.VC.Tools.x86.x64",
            "-property", "installationPath",
            "-products", "*",
        ], encoding="mbcs", errors="strict").strip()
    except (subprocess.CalledProcessError, OSError, UnicodeDecodeError):
        return None, None

    path = os.path.join(path, "VC", "Auxiliary", "Build")
    if os.path.isdir(path):
        return 15, path

    return None, None

PLAT_SPEC_TO_RUNTIME = {
    'x86' : 'x86',
    'x86_amd64' : 'x64',
    'x86_arm' : 'arm',
    'x86_arm64' : 'arm64'
}

def _find_vcvarsall(plat_spec):
    # bpo-38597: Removed vcruntime return value
    _, best_dir = _find_vc2017()

    if not best_dir:
        best_version, best_dir = _find_vc2015()

    if not best_dir:
        log.debug("No suitable Visual C++ version found")
        return None, None

    vcvarsall = os.path.join(best_dir, "vcvarsall.bat")
    if not os.path.isfile(vcvarsall):
        log.debug("%s cannot be found", vcvarsall)
        return None, None

    return vcvarsall, None

def _get_vc_env(plat_spec):
    if os.getenv("DISTUTILS_USE_SDK"):
        return {
            key.lower(): value
            for key, value in os.environ.items()
        }

    vcvarsall, _ = _find_vcvarsall(plat_spec)
    if not vcvarsall:
        raise DistutilsPlatformError("Unable to find vcvarsall.bat")

    try:
        out = subprocess.check_output(
            'cmd /u /c "{}" {} && set'.format(vcvarsall, plat_spec),
            stderr=subprocess.STDOUT,
        ).decode('utf-16le', errors='replace')
    except subprocess.CalledProcessError as exc:
        log.error(exc.output)
        raise DistutilsPlatformError("Error executing {}"
                .format(exc.cmd))

    env = {
        key.lower(): value
        for key, _, value in
        (line.partition('=') for line in out.splitlines())
        if key and value
    }

    return env

def _find_exe(exe, paths=None):
    """Return path to an MSVC executable program.

    Tries to find the program in several places: first, one of the
    MSVC program search paths from the registry; next, the directories
    in the PATH environment variable.  If any of those work, return an
    absolute path that is known to exist.  If none of them work, just
    return the original program name, 'exe'.
    """
    if not paths:
        paths = os.getenv('path').split(os.pathsep)
    for p in paths:
        fn = os.path.join(os.path.abspath(p), exe)
        if os.path.isfile(fn):
            return fn
    return exe

# A map keyed by get_platform() return values to values accepted by
# 'vcvarsall.bat'. Always cross-compile from x86 to work with the
# lighter-weight MSVC installs that do not include native 64-bit tools.
PLAT_TO_VCVARS = {
    'win32' : 'x86',
    'win-amd64' : 'x86_amd64',
    'win-arm32' : 'x86_arm',
    'win-arm64' : 'x86_arm64'
}

class MSVCCompiler(CCompiler) :
    """Concrete class that implements an interface to Microsoft Visual C++,
       as defined by the CCompiler abstract class."""

    compiler_type = 'msvc'

    # Just set this so CCompiler's constructor doesn't barf.  We currently
    # don't use the 'set_executables()' bureaucracy provided by CCompiler,
    # as it really isn't necessary for this sort of single-compiler class.
    # Would be nice to have a consistent interface with UnixCCompiler,
    # though, so it's worth thinking about.
    executables = {}

    # Private class data (need to distinguish C from C++ source for compiler)
    _c_extensions = ['.c']
    _cpp_extensions = ['.cc', '.cpp', '.cxx']
    _rc_extensions = ['.rc']
    _mc_extensions = ['.mc']

    # Needed for the filename generation methods provided by the
    # base class, CCompiler.
    src_extensions = (_c_extensions + _cpp_extensions +
                      _rc_extensions + _mc_extensions)
    res_extension = '.res'
    obj_extension = '.obj'
    static_lib_extension = '.lib'
    shared_lib_extension = '.dll'
    static_lib_format = shared_lib_format = '%s%s'
    exe_extension = '.exe'


    def __init__(self, verbose=0, dry_run=0, force=0):
        CCompiler.__init__ (self, verbose, dry_run, force)
        # target platform (.plat_name is consistent with 'bdist')
        self.plat_name = None
        self.initialized = False