import os
import sys
from os.path import pardir, realpath
__all__ = ['get_config_h_filename', 'get_config_var', 'get_config_vars', 'get_makefile_filename', 'get_path', 'get_path_names', 'get_paths', 'get_platform', 'get_python_version', 'get_scheme_names', 'parse_config_h']
_INSTALL_SCHEMES = {'posix_prefix': {'stdlib': '{installed_base}/lib/python{py_version_short}', 'platstdlib': '{platbase}/lib/python{py_version_short}', 'purelib': '{base}/lib/python{py_version_short}/site-packages', 'platlib': '{platbase}/lib/python{py_version_short}/site-packages', 'include': '{installed_base}/include/python{py_version_short}{abiflags}', 'platinclude': '{installed_platbase}/include/python{py_version_short}{abiflags}', 'scripts': '{base}/bin', 'data': '{base}'}, 'posix_home': {'stdlib': '{installed_base}/lib/python', 'platstdlib': '{base}/lib/python', 'purelib': '{base}/lib/python', 'platlib': '{base}/lib/python', 'include': '{installed_base}/include/python', 'platinclude': '{installed_base}/include/python', 'scripts': '{base}/bin', 'data': '{base}'}, 'nt': {'stdlib': '{installed_base}/Lib', 'platstdlib': '{base}/Lib', 'purelib': '{base}/Lib/site-packages', 'platlib': '{base}/Lib/site-packages', 'include': '{installed_base}/Include', 'platinclude': '{installed_base}/Include', 'scripts': '{base}/Scripts', 'data': '{base}'}, 'nt_user': {'stdlib': '{userbase}/Python{py_version_nodot}', 'platstdlib': '{userbase}/Python{py_version_nodot}', 'purelib': '{userbase}/Python{py_version_nodot}/site-packages', 'platlib': '{userbase}/Python{py_version_nodot}/site-packages', 'include': '{userbase}/Python{py_version_nodot}/Include', 'scripts': '{userbase}/Python{py_version_nodot}/Scripts', 'data': '{userbase}'}, 'posix_user': {'stdlib': '{userbase}/lib/python{py_version_short}', 'platstdlib': '{userbase}/lib/python{py_version_short}', 'purelib': '{userbase}/lib/python{py_version_short}/site-packages', 'platlib': '{userbase}/lib/python{py_version_short}/site-packages', 'include': '{userbase}/include/python{py_version_short}', 'scripts': '{userbase}/bin', 'data': '{userbase}'}, 'osx_framework_user': {'stdlib': '{userbase}/lib/python', 'platstdlib': '{userbase}/lib/python', 'purelib': '{userbase}/lib/python/site-packages', 'platlib': '{userbase}/lib/python/site-packages', 'include': '{userbase}/include', 'scripts': '{userbase}/bin', 'data': '{userbase}'}}
_SCHEME_KEYS = ('stdlib', 'platstdlib', 'purelib', 'platlib', 'include', 'scripts', 'data')
_PY_VERSION = sys.version.split()[0]
_PY_VERSION_SHORT = '%d.%d' % sys.version_info[:2]
_PY_VERSION_SHORT_NO_DOT = '%d%d' % sys.version_info[:2]
_PREFIX = os.path.normpath(sys.prefix)
_BASE_PREFIX = os.path.normpath(sys.base_prefix)
_EXEC_PREFIX = os.path.normpath(sys.exec_prefix)
_BASE_EXEC_PREFIX = os.path.normpath(sys.base_exec_prefix)
_CONFIG_VARS = None
_USER_BASE = None

def _safe_realpath(path):
    try:
        return realpath(path)
    except OSError:
        return path

if sys.executable:
    _PROJECT_BASE = os.path.dirname(_safe_realpath(sys.executable))
else:
    _PROJECT_BASE = _safe_realpath(os.getcwd())
if _PROJECT_BASE.lower().endswith(('\\pcbuild\\win32', '\\pcbuild\\amd64')):
    _PROJECT_BASE = _safe_realpath(os.path.join(_PROJECT_BASE, pardir, pardir))
if os.name == 'nt' and '_PYTHON_PROJECT_BASE' in os.environ:
    _PROJECT_BASE = _safe_realpath(os.environ['_PYTHON_PROJECT_BASE'])

def _is_python_source_dir(d):
    for fn in ('Setup.dist', 'Setup.local'):
        if os.path.isfile(os.path.join(d, 'Modules', fn)):
            return True
    return False

_sys_home = getattr(sys, '_home', None)
if _sys_home.lower().endswith(('\\pcbuild\\win32', '\\pcbuild\\amd64')):
    _sys_home = os.path.dirname(os.path.dirname(_sys_home))

def is_python_build(check_home=False):
    if check_home and _sys_home:
        return _is_python_source_dir(_sys_home)
    return _is_python_source_dir(_PROJECT_BASE)

_PYTHON_BUILD = is_python_build(True)
if _sys_home and os.name == 'nt' and _PYTHON_BUILD:
    for scheme in ('posix_prefix', 'posix_home'):
        _INSTALL_SCHEMES[scheme]['include'] = '{srcdir}/Include'
        _INSTALL_SCHEMES[scheme]['platinclude'] = '{projectbase}/.'

def _subst_vars(s, local_vars):
    try:
        return s.format(**local_vars)
    except KeyError:
        try:
            return s.format(**os.environ)
        except KeyError as var:
            raise AttributeError('{%s}' % var) from None


def _extend_dict(target_dict, other_dict):
    target_keys = target_dict.keys()
    for (key, value) in other_dict.items():
        if key in target_keys:
            pass
        else:
            target_dict[key] = value


def _expand_vars(scheme, vars):
    res = {}
    if vars is None:
        vars = {}
    _extend_dict(vars, get_config_vars())
    for (key, value) in _INSTALL_SCHEMES[scheme].items():
        if os.name in ('posix', 'nt'):
            value = os.path.expanduser(value)
        res[key] = os.path.normpath(_subst_vars(value, vars))
    return res


def _get_default_scheme():
    if os.name == 'posix':
        return 'posix_prefix'
    return os.name


def _getuserbase():
    env_base = os.environ.get('PYTHONUSERBASE', None)
    if env_base:
        return env_base

    def joinuser(*args):
        return os.path.expanduser(os.path.join(*args))

    if os.name == 'nt':
        base = os.environ.get('APPDATA') or '~'
        return joinuser(base, 'Python')
    if sys.platform == 'darwin' and sys._framework:
        return joinuser('~', 'Library', sys._framework, '%d.%d' % sys.version_info[:2])
    return joinuser('~', '.local')


def _parse_makefile(filename, vars=None):
    import re
    _variable_rx = re.compile('([a-zA-Z][a-zA-Z0-9_]+)\\s*=\\s*(.*)')
    _findvar1_rx = re.compile('\\$\\(([A-Za-z][A-Za-z0-9_]*)\\)')
    _findvar2_rx = re.compile('\\${([A-Za-z][A-Za-z0-9_]*)}')
    if vars is None:
        vars = {}
    done = {}
    notdone = {}
    with open(filename, errors='surrogateescape') as f:
        lines = f.readlines()
    for line in lines:
        if not line.startswith('#'):
            if line.strip() == '':
                pass
            else:
                m = _variable_rx.match(line)
                if m:
                    (n, v) = m.group(1, 2)
                    v = v.strip()
                    tmpv = v.replace('$$', '')
                    if '$' in tmpv:
                        notdone[n] = v
                    else:
                        try:
                            v = int(v)
                        except ValueError:
                            done[n] = v.replace('$$', '$')
                        done[n] = v
    variables = list(notdone.keys())
    renamed_variables = ('CFLAGS', 'LDFLAGS', 'CPPFLAGS')
    while len(variables) > 0:
        for name in tuple(variables):
            value = notdone[name]
            m1 = _findvar1_rx.search(value)
            m2 = _findvar2_rx.search(value)
            if m1 and m2:
                m = m1 if m1.start() < m2.start() else m2
            else:
                m = m1 if m1 else m2
            if m is not None:
                n = m.group(1)
                found = True
                if n in done:
                    item = str(done[n])
                elif n in notdone:
                    found = False
                elif n in os.environ:
                    item = os.environ[n]
                elif n in renamed_variables:
                    if name.startswith('PY_') and name[3:] in renamed_variables:
                        item = ''
                    elif 'PY_' + n in notdone:
                        found = False
                    else:
                        item = str(done['PY_' + n])
                else:
                    done[n] = item = ''
                if found:
                    after = value[m.end():]
                    value = value[:m.start()] + item + after
                    if '$' in after:
                        notdone[name] = value
                    else:
                        try:
                            value = int(value)
                        except ValueError:
                            done[name] = value.strip()
                        done[name] = value
                        variables.remove(name)
                        if name.startswith('PY_') and name[3:] in renamed_variables:
                            name = name[3:]
                            if name not in done:
                                done[name] = value
            else:
                done[name] = value
                variables.remove(name)
    for (k, v) in done.items():
        if isinstance(v, str):
            done[k] = v.strip()
    vars.update(done)
    return vars


def get_makefile_filename():
    if _PYTHON_BUILD:
        return os.path.join(_sys_home or _PROJECT_BASE, 'Makefile')
    if hasattr(sys, 'abiflags'):
        config_dir_name = 'config-%s%s' % (_PY_VERSION_SHORT, sys.abiflags)
    else:
        config_dir_name = 'config'
    if hasattr(sys.implementation, '_multiarch'):
        config_dir_name += '-%s' % sys.implementation._multiarch
    return os.path.join(get_path('stdlib'), config_dir_name, 'Makefile')


def _get_sysconfigdata_name():
    return os.environ.get('_PYTHON_SYSCONFIGDATA_NAME', '_sysconfigdata_{abi}_{platform}_{multiarch}'.format(abi=sys.abiflags, platform=sys.platform, multiarch=getattr(sys.implementation, '_multiarch', '')))


def _generate_posix_vars():
    import pprint
    vars = {}
    makefile = get_makefile_filename()
    try:
        _parse_makefile(makefile, vars)
    except OSError as e:
        msg = 'invalid Python installation: unable to open %s' % makefile
        if hasattr(e, 'strerror'):
            msg = msg + ' (%s)' % e.strerror
        raise OSError(msg)
    config_h = get_config_h_filename()
    try:
        with open(config_h) as f:
            parse_config_h(f, vars)
    except OSError as e:
        msg = 'invalid Python installation: unable to open %s' % config_h
        if hasattr(e, 'strerror'):
            msg = msg + ' (%s)' % e.strerror
        raise OSError(msg)
    if _PYTHON_BUILD:
        vars['BLDSHARED'] = vars['LDSHARED']
    name = _get_sysconfigdata_name()
    if 'darwin' in sys.platform:
        import types
        module = types.ModuleType(name)
        module.build_time_vars = vars
        sys.modules[name] = module
    pybuilddir = 'build/lib.%s-%s' % (get_platform(), _PY_VERSION_SHORT)
    if hasattr(sys, 'gettotalrefcount'):
        pybuilddir += '-pydebug'
    os.makedirs(pybuilddir, exist_ok=True)
    destfile = os.path.join(pybuilddir, name + '.py')
    with open(destfile, 'w', encoding='utf8') as f:
        f.write('# system configuration generated and used by the sysconfig module\n')
        f.write('build_time_vars = ')
        pprint.pprint(vars, stream=f)
    with open('pybuilddir.txt', 'w', encoding='ascii') as f:
        f.write(pybuilddir)


def _init_posix(vars):
    name = _get_sysconfigdata_name()
    _temp = __import__(name, globals(), locals(), ['build_time_vars'], 0)
    build_time_vars = _temp.build_time_vars
    vars.update(build_time_vars)


def _init_non_posix(vars):
    vars['LIBDEST'] = get_path('stdlib')
    vars['BINLIBDEST'] = get_path('platstdlib')
    vars['INCLUDEPY'] = get_path('include')
    vars['EXT_SUFFIX'] = '.pyd'
    vars['EXE'] = '.exe'
    vars['VERSION'] = _PY_VERSION_SHORT_NO_DOT
    vars['BINDIR'] = os.path.dirname(_safe_realpath(sys.executable))


def parse_config_h(fp, vars=None):
    if vars is None:
        vars = {}
    import re
    define_rx = re.compile('#define ([A-Z][A-Za-z0-9_]+) (.*)\n')
    undef_rx = re.compile('/[*] #undef ([A-Z][A-Za-z0-9_]+) [*]/\n')
    while True:
        line = fp.readline()
        if not line:
            break
        m = define_rx.match(line)
        if m:
            (n, v) = m.group(1, 2)
            try:
                v = int(v)
            except ValueError:
                pass
            vars[n] = v
        else:
            m = undef_rx.match(line)
            if m:
                vars[m.group(1)] = 0
    return vars


def get_config_h_filename():
    if _PYTHON_BUILD:
        if os.name == 'nt':
            inc_dir = os.path.join(_sys_home or _PROJECT_BASE, 'PC')
        else:
            inc_dir = _sys_home or _PROJECT_BASE
    else:
        inc_dir = get_path('platinclude')
    return os.path.join(inc_dir, 'pyconfig.h')


def get_scheme_names():
    return tuple(sorted(_INSTALL_SCHEMES))


def get_path_names():
    return _SCHEME_KEYS


def get_paths(scheme=_get_default_scheme(), vars=None, expand=True):
    if expand:
        return _expand_vars(scheme, vars)
    else:
        return _INSTALL_SCHEMES[scheme]


def get_path(name, scheme=_get_default_scheme(), vars=None, expand=True):
    return get_paths(scheme, vars, expand)[name]


def get_config_vars(*args):
    global _CONFIG_VARS
    if _CONFIG_VARS is None:
        _CONFIG_VARS = {}
        _CONFIG_VARS['prefix'] = _PREFIX
        _CONFIG_VARS['exec_prefix'] = _EXEC_PREFIX
        _CONFIG_VARS['py_version'] = _PY_VERSION
        _CONFIG_VARS['py_version_short'] = _PY_VERSION_SHORT
        _CONFIG_VARS['py_version_nodot'] = _PY_VERSION_SHORT_NO_DOT
        _CONFIG_VARS['installed_base'] = _BASE_PREFIX
        _CONFIG_VARS['base'] = _PREFIX
        _CONFIG_VARS['installed_platbase'] = _BASE_EXEC_PREFIX
        _CONFIG_VARS['platbase'] = _EXEC_PREFIX
        _CONFIG_VARS['projectbase'] = _PROJECT_BASE
        try:
            _CONFIG_VARS['abiflags'] = sys.abiflags
        except AttributeError:
            _CONFIG_VARS['abiflags'] = ''
        if os.name == 'nt':
            _init_non_posix(_CONFIG_VARS)
        if os.name == 'posix':
            _init_posix(_CONFIG_VARS)
        SO = _CONFIG_VARS.get('EXT_SUFFIX')
        if SO is not None:
            _CONFIG_VARS['SO'] = SO
        _CONFIG_VARS['userbase'] = _getuserbase()
        srcdir = _CONFIG_VARS.get('srcdir', _PROJECT_BASE)
        if os.name == 'posix':
            if _PYTHON_BUILD:
                base = os.path.dirname(get_makefile_filename())
                srcdir = os.path.join(base, srcdir)
            else:
                srcdir = os.path.dirname(get_makefile_filename())
        _CONFIG_VARS['srcdir'] = _safe_realpath(srcdir)
        if sys.platform == 'darwin':
            import _osx_support
            _osx_support.customize_config_vars(_CONFIG_VARS)
    if args:
        vals = []
        for name in args:
            vals.append(_CONFIG_VARS.get(name))
        return vals
    else:
        return _CONFIG_VARS


def get_config_var(name):
    if name == 'SO':
        import warnings
        warnings.warn('SO is deprecated, use EXT_SUFFIX', DeprecationWarning, 2)
    return get_config_vars().get(name)


def get_platform():
    if os.name == 'nt':
        if 'amd64' in sys.version.lower():
            return 'win-amd64'
        return sys.platform
    if os.name != 'posix' or not hasattr(os, 'uname'):
        return sys.platform
    if '_PYTHON_HOST_PLATFORM' in os.environ:
        return os.environ['_PYTHON_HOST_PLATFORM']
    (osname, host, release, version, machine) = os.uname()
    osname = osname.lower().replace('/', '')
    machine = machine.replace(' ', '_')
    machine = machine.replace('/', '-')
    if osname[:5] == 'linux':
        return '%s-%s' % (osname, machine)
    if osname[:5] == 'sunos':
        if release[0] >= '5':
            osname = 'solaris'
            release = '%d.%s' % (int(release[0]) - 3, release[2:])
            bitness = {2147483647: '32bit', 9223372036854775807: '64bit'}
            machine += '.%s' % bitness[sys.maxsize]
    else:
        if osname[:3] == 'aix':
            return '%s-%s.%s' % (osname, version, release)
        if osname[:6] == 'cygwin':
            osname = 'cygwin'
            import re
            rel_re = re.compile('[\\d.]+')
            m = rel_re.match(release)
            if m:
                release = m.group()
        elif osname[:6] == 'darwin':
            import _osx_support
            (osname, release, machine) = _osx_support.get_platform_osx(get_config_vars(), osname, release, machine)
    return '%s-%s-%s' % (osname, release, machine)


def get_python_version():
    return _PY_VERSION_SHORT


def _print_dict(title, data):
    for (index, (key, value)) in enumerate(sorted(data.items())):
        if index == 0:
            print('%s: ' % title)
        print('\t%s = "%s"' % (key, value))


def _main():
    if '--generate-posix-vars' in sys.argv:
        _generate_posix_vars()
        return
    print('Platform: "%s"' % get_platform())
    print('Python version: "%s"' % get_python_version())
    print('Current installation scheme: "%s"' % _get_default_scheme())
    print()
    _print_dict('Paths', get_paths())
    print()
    _print_dict('Variables', get_config_vars())

if __name__ == '__main__':
    _main()
