"""
Support code for building Python extensions on Windows.

    # NT stuff
    # 1. Make sure libpython<version>.a exists for gcc.  If not, build it.
    # 2. Force windows to use gcc (we're struggling with MSVC and g77 support)
    # 3. Force windows to use g77

"""
import os
import sys
import subprocess
import re
import textwrap

# Overwrite certain distutils.ccompiler functions:
import numpy.distutils.ccompiler  # noqa: F401
from numpy.distutils import log
# NT stuff
# 1. Make sure libpython<version>.a exists for gcc.  If not, build it.
# 2. Force windows to use gcc (we're struggling with MSVC and g77 support)
#    --> this is done in numpy/distutils/ccompiler.py
# 3. Force windows to use g77

import distutils.cygwinccompiler
from distutils.version import StrictVersion
from distutils.unixccompiler import UnixCCompiler
from distutils.msvccompiler import get_build_version as get_build_msvc_version
from distutils.errors import UnknownFileError
from numpy.distutils.misc_util import (msvc_runtime_library,
                                       msvc_runtime_version,
                                       msvc_runtime_major,
                                       get_build_architecture)

def get_msvcr_replacement():
    """Replacement for outdated version of get_msvcr from cygwinccompiler"""
    msvcr = msvc_runtime_library()
    return [] if msvcr is None else [msvcr]

# monkey-patch cygwinccompiler with our updated version from misc_util
# to avoid getting an exception raised on Python 3.5
distutils.cygwinccompiler.get_msvcr = get_msvcr_replacement

# Useful to generate table of symbols from a dll
_START = re.compile(r'\[Ordinal/Name Pointer\] Table')
_TABLE = re.compile(r'^\s+\[([\s*[0-9]*)\] ([a-zA-Z0-9_]*)')

# the same as cygwin plus some additional parameters
class Mingw32CCompiler(distutils.cygwinccompiler.CygwinCCompiler):
    """ A modified MingW32 compiler compatible with an MSVC built Python.

    """

    compiler_type = 'mingw32'

    def __init__ (self,
                  verbose=0,
                  dry_run=0,
                  force=0):

        distutils.cygwinccompiler.CygwinCCompiler.__init__ (self, verbose,
                                                            dry_run, force)

        # we need to support 3.2 which doesn't match the standard
        # get_versions methods regex
        if self.gcc_version is None:
            try:
                out_string  = subprocess.check_output(['gcc', '-dumpversion'])
            except (OSError, CalledProcessError):
                out_string = ""  # ignore failures to match old behavior
            result = re.search(r'(\d+\.\d+)', out_string)
            if result:
                self.gcc_version = StrictVersion(result.group(1))

        # A real mingw32 doesn't need to specify a different entry point,
        # but cygwin 2.91.57 in no-cygwin-mode needs it.
        if self.gcc_version <= "2.91.57":
            entry_point = '--entry _DllMain@12'
        else:
            entry_point = ''

        if self.linker_dll == 'dllwrap':
            # Commented out '--driver-name g++' part that fixes weird
            #   g++.exe: g++: No such file or directory
            # error (mingw 1.0 in Enthon24 tree, gcc-3.4.5).
            # If the --driver-name part is required for some environment
            # then make the inclusion of this part specific to that
            # environment.
            self.linker = 'dllwrap' #  --driver-name g++'
        elif self.linker_dll == 'gcc':
            self.linker = 'g++'

        # **changes: eric jones 4/11/01
        # 1. Check for import library on Windows.  Build if it doesn't exist.

        build_import_library()

        # Check for custom msvc runtime library on Windows. Build if it doesn't exist.
        msvcr_success = build_msvcr_library()
        msvcr_dbg_success = build_msvcr_library(debug=True)
        if msvcr_success or msvcr_dbg_success:
            # add preprocessor statement for using customized msvcr lib
            self.define_macro('NPY_MINGW_USE_CUSTOM_MSVCR')

        # Define the MSVC version as hint for MinGW
        msvcr_version = msvc_runtime_version()
        if msvcr_version:
            self.define_macro('__MSVCRT_VERSION__', '0x%04i' % msvcr_version)

        # MS_WIN64 should be defined when building for amd64 on windows,
        # but python headers define it only for MS compilers, which has all
        # kind of bad consequences, like using Py_ModuleInit4 instead of
        # Py_ModuleInit4_64, etc... So we add it here
        if get_build_architecture() == 'AMD64':
            if self.gcc_version < "4.0":
                self.set_executables(
                    compiler='gcc -g -DDEBUG -DMS_WIN64 -mno-cygwin -O0 -Wall',
                    compiler_so='gcc -g -DDEBUG -DMS_WIN64 -mno-cygwin -O0'
                                ' -Wall -Wstrict-prototypes',
                    linker_exe='gcc -g -mno-cygwin',
                    linker_so='gcc -g -mno-cygwin -shared')
            else:
                # gcc-4 series releases do not support -mno-cygwin option
                self.set_executables(
                    compiler='gcc -g -DDEBUG -DMS_WIN64 -O0 -Wall',
                    compiler_so='gcc -g -DDEBUG -DMS_WIN64 -O0 -Wall -Wstrict-prototypes',
                    linker_exe='gcc -g',
                    linker_so='gcc -g -shared')
        else:
            if self.gcc_version <= "3.0.0":
                self.set_executables(
                    compiler='gcc -mno-cygwin -O2 -w',
                    compiler_so='gcc -mno-cygwin -mdll -O2 -w'
                                ' -Wstrict-prototypes',
                    linker_exe='g++ -mno-cygwin',
                    linker_so='%s -mno-cygwin -mdll -static %s' %
                              (self.linker, entry_point))
            elif self.gcc_version < "4.0":
                self.set_executables(
                    compiler='gcc -mno-cygwin -O2 -Wall',
                    compiler_so='gcc -mno-cygwin -O2 -Wall'
                                ' -Wstrict-prototypes',
                    linker_exe='g++ -mno-cygwin',
                    linker_so='g++ -mno-cygwin -shared')
            else:
                # gcc-4 series releases do not support -mno-cygwin option
                self.set_executables(compiler='gcc -O2 -Wall',
                                     compiler_so='gcc -O2 -Wall -Wstrict-prototypes',
                                     linker_exe='g++ ',
                                     linker_so='g++ -shared')
        # added for python2.3 support
        # we can't pass it through set_executables because pre 2.2 would fail
        self.compiler_cxx = ['g++']

        # Maybe we should also append -mthreads, but then the finished dlls
        # need another dll (mingwm10.dll see Mingw32 docs) (-mthreads: Support
        # thread-safe exception handling on `Mingw32')

        # no additional libraries needed
        #self.dll_libraries=[]
        return

    # __init__ ()

    def link(self,
             target_desc,
             objects,
             output_filename,
             output_dir,
             libraries,
             library_dirs,
             runtime_library_dirs,
             export_symbols = None,
             debug=0,
             extra_preargs=None,
             extra_postargs=None,
             build_temp=None,
             target_lang=None):
        # Include the appropriate MSVC runtime library if Python was built
        # with MSVC >= 7.0 (MinGW standard is msvcrt)
        runtime_library = msvc_runtime_library()
        if runtime_library:
            if not libraries:
                libraries = []
            libraries.append(runtime_library)
        args = (self,
                target_desc,
                objects,
                output_filename,
                output_dir,
                libraries,
                library_dirs,
                runtime_library_dirs,
                None, #export_symbols, we do this in our def-file
                debug,
                extra_preargs,
                extra_postargs,
                build_temp,
                target_lang)
        if self.gcc_version < "3.0.0":
            func = distutils.cygwinccompiler.CygwinCCompiler.link
        else:
            func = UnixCCompiler.link
        func(*args[:func.__code__.co_argcount])
        return

    def object_filenames (self,
                          source_filenames,
                          strip_dir=0,
                          output_dir=''):
        if output_dir is None: output_dir = ''
        obj_names = []
        for src_name in source_filenames:
            # use normcase to make sure '.rc' is really '.rc' and not '.RC'
            (base, ext) = os.path.splitext (os.path.normcase(src_name))

            # added these lines to strip off windows drive letters
            # without it, .o files are placed next to .c files
            # instead of the build directory
            drv, base = os.path.splitdrive(base)
            if drv:
                base = base[1:]

            if ext not in (self.src_extensions + ['.rc', '.res']):
                raise UnknownFileError(
                      "unknown file type '%s' (from '%s')" % \
                      (ext, src_name))
            if strip_dir:
                base = os.path.basename (base)
            if ext == '.res' or ext == '.rc':
                # these need to be compiled to object files
                obj_names.append (os.path.join (output_dir,
                                                base + ext + self.obj_extension))
            else:
                obj_names.append (os.path.join (output_dir,
                                                base + self.obj_extension))
        return obj_names

    # object_filenames ()


def find_python_dll():
    # We can't do much here:
    # - find it in the virtualenv (sys.prefix)
    # - find it in python main dir (sys.base_prefix, if in a virtualenv)
    # - sys.real_prefix is main dir for virtualenvs in Python 2.7
    # - in system32,
    # - ortherwise (Sxs), I don't know how to get it.
    stems = [sys.prefix]
    if hasattr(sys, 'base_prefix') and sys.base_prefix != sys.prefix:
        stems.append(sys.base_prefix)
    elif hasattr(sys, 'real_prefix') and sys.real_prefix != sys.prefix:
        stems.append(sys.real_prefix)

    sub_dirs = ['', 'lib', 'bin']
    # generate possible combinations of directory trees and sub-directories
    lib_dirs = []
    for stem in stems:
        for folder in sub_dirs:
            lib_dirs.append(os.path.join(stem, folder))

    # add system directory as well
    if 'SYSTEMROOT' in os.environ:
        lib_dirs.append(os.path.join(os.environ['SYSTEMROOT'], 'System32'))

    # search in the file system for possible candidates
    major_version, minor_version = tuple(sys.version_info[:2])
    patterns = ['python%d%d.dll']

    for pat in patterns:
        dllname = pat % (major_version, minor_version)
        print("Looking for %s" % dllname)
        for folder in lib_dirs:
            dll = os.path.join(folder, dllname)
            if os.path.exists(dll):
                return dll

    raise ValueError("%s not found in %s" % (dllname, lib_dirs))

def dump_table(dll):
    st = subprocess.check_output(["objdump.exe", "-p", dll])
    return st.split(b'\n')

def generate_def(dll, dfile):
    """Given a dll file location,  get all its exported symbols and dump them
    into the given def file.

    The .def file will be overwritten"""
    dump = dump_table(dll)
    for i in range(len(dump)):
        if _START.match(dump[i].decode()):
            break
    else:
        raise ValueError("Symbol table not found")

    syms = []
    for j in range(i+1, len(dump)):
        m = _TABLE.match(dump[j].decode())
        if m:
            syms.append((int(m.group(1).strip()), m.group(2)))
        else:
            break

    if len(syms) == 0:
        log.warn('No symbols found in %s' % dll)

    with open(dfile, 'w') as d:
        d.write('LIBRARY        %s\n' % os.path.basename(dll))
        d.write(';CODE          PRELOAD MOVEABLE DISCARDABLE\n')
        d.write(';DATA          PRELOAD SINGLE\n')
        d.write('\nEXPORTS\n')
        for s in syms:
            #d.write('@%d    %s\n' % (s[0], s[1]))
            d.write('%s\n' % s[1])

def find_dll(dll_name):

    arch = {'AMD64' : 'amd64',
            'Intel' : 'x86'}[get_build_architecture()]

    def _find_dll_in_winsxs(dll_name):
        # Walk through the WinSxS directory to find the dll.
        winsxs_path = os.path.join(os.environ.get('WINDIR', r'C:\WINDOWS'),
                                   'winsxs')
        if not os.path.exists(winsxs_path):
            return None
        for root, dirs, files in os.walk(winsxs_path):
            if dll_name in files and arch in root:
                return os.path.join(root, dll_name)
        return None

    def _find_dll_in_path(dll_name):
        # First, look in the Python directory, then scan PATH for
        # the given dll name.
        for path in [sys.prefix] + os.environ['PATH'].split(';'):
            filepath = os.path.join(path, dll_name)
            if os.path.exists(filepath):
                return os.path.abspath(filepath)

    return _find_dll_in_winsxs(dll_name) or _find_dll_in_path(dll_name)

def build_msvcr_library(debug=False):
    if os.name != 'nt':
        return False