"""Utilities for writing code that runs on Python 2 and 3"""

# Copyright (c) 2010-2014 Benjamin Peterson
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

import operator
import sys
import types

__author__ = "Benjamin Peterson <benjamin@python.org>"
__version__ = "1.6.1"

# Useful for very coarse version differentiation.
PY2 = sys.version_info[0] == 2
PY3 = sys.version_info[0] == 3

if PY3:
  string_types = str,
  integer_types = int,
  class_types = type,
  text_type = str
  binary_type = bytes

  MAXSIZE = sys.maxsize
else:
  string_types = basestring,
  integer_types = (int, long)
  class_types = (type, types.ClassType)
  text_type = unicode
  binary_type = str

  if sys.platform.startswith("java"):
    # Jython always uses 32 bits.
    MAXSIZE = int((1 << 31) - 1)
  else:
    # It's possible to have sizeof(long) != sizeof(Py_ssize_t).
    class X(object):

      def __len__(self):
        return 1 << 31

    try:
      len(X())
    except OverflowError:
      # 32-bit
      MAXSIZE = int((1 << 31) - 1)
    else:
      # 64-bit
      MAXSIZE = int((1 << 63) - 1)
    del X


def _add_doc(func, doc):
  """Add documentation to a function."""
  func.__doc__ = doc


def _import_module(name):
  """Import module, returning the module after the last dot."""
  __import__(name)
  return sys.modules[name]


class _LazyDescr(object):

  def __init__(self, name):
    self.name = name

  def __get__(self, obj, tp):
    try:
      result = self._resolve()
    except ImportError:
      # See the nice big comment in MovedModule.__getattr__.
      raise AttributeError("%s could not be imported " % self.name)
    setattr(obj, self.name, result)  # Invokes __set__.
    # This is a bit ugly, but it avoids running this again.
    delattr(obj.__class__, self.name)
    return result


class MovedModule(_LazyDescr):

  def __init__(self, name, old, new=None):
    super(MovedModule, self).__init__(name)
    if PY3:
      if new is None:
        new = name
      self.mod = new
    else:
      self.mod = old

  def _resolve(self):
    return _import_module(self.mod)

  def __getattr__(self, attr):
    # It turns out many Python frameworks like to traverse sys.modules and
    # try to load various attributes. This causes problems if this is a
    # platform-specific module on the wrong platform, like _winreg on
    # Unixes. Therefore, we silently pretend unimportable modules do not
    # have any attributes. See issues #51, #53, #56, and #63 for the full
    # tales of woe.
    #
    # First, if possible, avoid loading the module just to look at __file__,
    # __name__, or __path__.
    if (attr in ("__file__", "__name__", "__path__") and self.mod not in sys.modules):
      raise AttributeError(attr)
    try:
      _module = self._resolve()
    except ImportError:
      raise AttributeError(attr)
    value = getattr(_module, attr)
    setattr(self, attr, value)
    return value


class _LazyModule(types.ModuleType):

  def __init__(self, name):
    super(_LazyModule, self).__init__(name)
    self.__doc__ = self.__class__.__doc__

  def __dir__(self):
    attrs = ["__doc__", "__name__"]
    attrs += [attr.name for attr in self._moved_attributes]
    return attrs

  # Subclasses should override this
  _moved_attributes = []


class MovedAttribute(_LazyDescr):

  def __init__(self, name, old_mod, new_mod, old_attr=None, new_attr=None):
    super(MovedAttribute, self).__init__(name)
    if PY3:
      if new_mod is None:
        new_mod = name
      self.mod = new_mod
      if new_attr is None:
        if old_attr is None:
          new_attr = name
        else:
          new_attr = old_attr
      self.attr = new_attr
    else:
      self.mod = old_mod
      if old_attr is None:
        old_attr = name
      self.attr = old_attr

  def _resolve(self):
    module = _import_module(self.mod)
    return getattr(module, self.attr)


class _MovedItems(_LazyModule):
  """Lazy loading of moved objects"""


_moved_attributes = [
  MovedAttribute("cStringIO", "cStringIO", "io", "StringIO"),
  MovedAttribute("filter", "itertools", "builtins", "ifilter", "filter"),
  MovedAttribute("filterfalse", "itertools", "itertools", "ifilterfalse", "filterfalse"),
  MovedAttribute("input", "__builtin__", "builtins", "raw_input", "input"),
  MovedAttribute("map", "itertools", "builtins", "imap", "map"),
  MovedAttribute("range", "__builtin__", "builtins", "xrange", "range"),
  MovedAttribute("reload_module", "__builtin__", "imp", "reload"),
  MovedAttribute("reduce", "__builtin__", "functools"),
  MovedAttribute("StringIO", "StringIO", "io"),
  MovedAttribute("UserDict", "UserDict", "collections"),
  MovedAttribute("UserList", "UserList", "collections"),
  MovedAttribute("UserString", "UserString", "collections"),
  MovedAttribute("xrange", "__builtin__", "builtins", "xrange", "range"),
  MovedAttribute("zip", "itertools", "builtins", "izip", "zip"),
  MovedAttribute("zip_longest", "itertools", "itertools", "izip_longest", "zip_longest"),
  MovedModule("builtins", "__builtin__"),
  MovedModule("configparser", "ConfigParser"),
  MovedModule("copyreg", "copy_reg"),
  MovedModule("dbm_gnu", "gdbm", "dbm.gnu"),
  MovedModule("http_cookiejar", "cookielib", "http.cookiejar"),
  MovedModule("http_cookies", "Cookie", "http.cookies"),
  MovedModule("html_entities", "htmlentitydefs", "html.entities"),
  MovedModule("html_parser", "HTMLParser", "html.parser"),
  MovedModule("http_client", "httplib", "http.client"),
  MovedModule("email_mime_multipart", "email.MIMEMultipart", "email.mime.multipart"),
  MovedModule("email_mime_text", "email.MIMEText", "email.mime.text"),
  MovedModule("email_mime_base", "email.MIMEBase", "email.mime.base"),
  MovedModule("BaseHTTPServer", "BaseHTTPServer", "http.server"),
  MovedModule("CGIHTTPServer", "CGIHTTPServer", "http.server"),
  MovedModule("SimpleHTTPServer", "SimpleHTTPServer", "http.server"),
  MovedModule("cPickle", "cPickle", "pickle"),
  MovedModule("queue", "Queue"),
  MovedModule("reprlib", "repr"),
  MovedModule("socketserver", "SocketServer"),
  MovedModule("_thread", "thread", "_thread"),
  MovedModule("tkinter", "Tkinter"),
  MovedModule("tkinter_dialog", "Dialog", "tkinter.dialog"),
  MovedModule("tkinter_filedialog", "FileDialog", "tkinter.filedialog"),
  MovedModule("tkinter_scrolledtext", "ScrolledText", "tkinter.scrolledtext"),
  MovedModule("tkinter_simpledialog", "SimpleDialog", "tkinter.simpledialog"),
  MovedModule("tkinter_tix", "Tix", "tkinter.tix"),
  MovedModule("tkinter_ttk", "ttk", "tkinter.ttk"),
  MovedModule("tkinter_constants", "Tkconstants", "tkinter.constants"),
  MovedModule("tkinter_dnd", "Tkdnd", "tkinter.dnd"),
  MovedModule("tkinter_colorchooser", "tkColorChooser", "tkinter.colorchooser"),
  MovedModule("tkinter_commondialog", "tkCommonDialog", "tkinter.commondialog"),
  MovedModule("tkinter_tkfiledialog", "tkFileDialog", "tkinter.filedialog"),
  MovedModule("tkinter_font", "tkFont", "tkinter.font"),
  MovedModule("tkinter_messagebox", "tkMessageBox", "tkinter.messagebox"),
  MovedModule("tkinter_tksimpledialog", "tkSimpleDialog", "tkinter.simpledialog"),
  MovedModule("urllib_parse", __name__ + ".moves.urllib_parse", "urllib.parse"),
  MovedModule("urllib_error", __name__ + ".moves.urllib_error", "urllib.error"),
  MovedModule("urllib", __name__ + ".moves.urllib", __name__ + ".moves.urllib"),
  MovedModule("urllib_robotparser", "robotparser", "urllib.robotparser"),
  MovedModule("xmlrpc_client", "xmlrpclib", "xmlrpc.client"),
  MovedModule("xmlrpc_server", "xmlrpclib", "xmlrpc.server"),
  MovedModule("winreg", "_winreg"),
]
for attr in _moved_attributes:
  setattr(_MovedItems, attr.name, attr)
  if isinstance(attr, MovedModule):
    sys.modules[__name__ + ".moves." + attr.name] = attr
del attr

_MovedItems._moved_attributes = _moved_attributes

moves = sys.modules[__name__ + ".moves"] = _MovedItems(__name__ + ".moves")


class Module_six_moves_urllib_parse(_LazyModule):
  """Lazy loading of moved objects in six.moves.urllib_parse"""


_urllib_parse_moved_attributes = [
  MovedAttribute("ParseResult", "urlparse", "urllib.parse"),
  MovedAttribute("SplitResult", "urlparse", "urllib.parse"),
  MovedAttribute("parse_qs", "urlparse", "urllib.parse"),
  MovedAttribute("parse_qsl", "urlparse", "urllib.parse"),
  MovedAttribute("urldefrag", "urlparse", "urllib.parse"),
  MovedAttribute("urljoin", "urlparse", "urllib.parse"),
  MovedAttribute("urlparse", "urlparse", "urllib.parse"),
  MovedAttribute("urlsplit", "urlparse", "urllib.parse"),
  MovedAttribute("urlunparse", "urlparse", "urllib.parse"),
  MovedAttribute("urlunsplit", "urlparse", "urllib.parse"),
  MovedAttribute("quote", "urllib", "urllib.parse"),
  MovedAttribute("quote_plus", "urllib", "urllib.parse"),
  MovedAttribute("unquote", "urllib", "urllib.parse"),
  MovedAttribute("unquote_plus", "urllib", "urllib.parse"),
  MovedAttribute("urlencode", "urllib", "urllib.parse"),
  MovedAttribute("splitquery", "urllib", "urllib.parse"),
]
for attr in _urllib_parse_moved_attributes:
  setattr(Module_six_moves_urllib_parse, attr.name, attr)
del attr

Module_six_moves_urllib_parse._moved_attributes = _urllib_parse_moved_attributes

sys.modules[__name__ + ".moves.urllib_parse"] = sys.modules[
  __name__ + ".moves.urllib.parse"] = Module_six_moves_urllib_parse(__name__ +
                                                                    ".moves.urllib_parse")


class Module_six_moves_urllib_error(_LazyModule):
  """Lazy loading of moved objects in six.moves.urllib_error"""


_urllib_error_moved_attributes = [
  MovedAttribute("URLError", "urllib2", "urllib.error"),
  MovedAttribute("HTTPError", "urllib2", "urllib.error"),
  MovedAttribute("ContentTooShortError", "urllib", "urllib.error"),
]
for attr in _urllib_error_moved_attributes:
  setattr(Module_six_moves_urllib_error, attr.name, attr)
del attr

Module_six_moves_urllib_error._moved_attributes = _urllib_error_moved_attributes

sys.modules[__name__ + ".moves.urllib_error"] = sys.modules[
  __name__ + ".moves.urllib.error"] = Module_six_moves_urllib_error(__name__ +
                                                                    ".moves.urllib.error")


class Module_six_moves_urllib_request(_LazyModule):
  """Lazy loading of moved objects in six.moves.urllib_request"""


_urllib_request_moved_attributes = [
  MovedAttribute("urlopen", "urllib2", "urllib.request"),
  MovedAttribute("install_opener", "urllib2", "urllib.request"),
  MovedAttribute("build_opener", "urllib2", "urllib.request"),
  MovedAttribute("pathname2url", "urllib", "urllib.request"),
  MovedAttribute("url2pathname", "urllib", "urllib.request"),
  MovedAttribute("getproxies", "urllib", "urllib.request"),
  MovedAttribute("Request", "urllib2", "urllib.request"),
  MovedAttribute("OpenerDirector", "urllib2", "urllib.request"),
  MovedAttribute("HTTPDefaultErrorHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPRedirectHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPCookieProcessor", "urllib2", "urllib.request"),
  MovedAttribute("ProxyHandler", "urllib2", "urllib.request"),
  MovedAttribute("BaseHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPPasswordMgr", "urllib2", "urllib.request"),
  MovedAttribute("HTTPPasswordMgrWithDefaultRealm", "urllib2", "urllib.request"),
  MovedAttribute("AbstractBasicAuthHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPBasicAuthHandler", "urllib2", "urllib.request"),
  MovedAttribute("ProxyBasicAuthHandler", "urllib2", "urllib.request"),
  MovedAttribute("AbstractDigestAuthHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPDigestAuthHandler", "urllib2", "urllib.request"),
  MovedAttribute("ProxyDigestAuthHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPSHandler", "urllib2", "urllib.request"),
  MovedAttribute("FileHandler", "urllib2", "urllib.request"),
  MovedAttribute("FTPHandler", "urllib2", "urllib.request"),
  MovedAttribute("CacheFTPHandler", "urllib2", "urllib.request"),
  MovedAttribute("UnknownHandler", "urllib2", "urllib.request"),
  MovedAttribute("HTTPErrorProcessor", "urllib2", "urllib.request"),
  MovedAttribute("urlretrieve", "urllib", "urllib.request"),
  MovedAttribute("urlcleanup", "urllib", "urllib.request"),
  MovedAttribute("URLopener", "urllib", "urllib.request"),
  MovedAttribute("FancyURLopener", "urllib", "urllib.request"),
  MovedAttribute("proxy_bypass", "urllib", "urllib.request"),
]
for attr in _urllib_request_moved_attributes:
  setattr(Module_six_moves_urllib_request, attr.name, attr)
del attr

Module_six_moves_urllib_request._moved_attributes = _urllib_request_moved_attributes

sys.modules[__name__ + ".moves.urllib_request"] = sys.modules[
  __name__ + ".moves.urllib.request"] = Module_six_moves_urllib_request(__name__ +
                                                                        ".moves.urllib.request")


class Module_six_moves_urllib_response(_LazyModule):
  """Lazy loading of moved objects in six.moves.urllib_response"""


_urllib_response_moved_attributes = [
  MovedAttribute("addbase", "urllib", "urllib.response"),
  MovedAttribute("addclosehook", "urllib", "urllib.response"),
  MovedAttribute("addinfo", "urllib", "urllib.response"),
  MovedAttribute("addinfourl", "urllib", "urllib.response"),
]
for attr in _urllib_response_moved_attributes:
  setattr(Module_six_moves_urllib_response, attr.name, attr)
del attr

Module_six_moves_urllib_response._moved_attributes = _urllib_response_moved_attributes

sys.modules[__name__ + ".moves.urllib_response"] = sys.modules[
  __name__ + ".moves.urllib.response"] = Module_six_moves_urllib_response(__name__ +
                                                                          ".moves.urllib.response")


class Module_six_moves_urllib_robotparser(_LazyModule):
  """Lazy loading of moved objects in six.moves.urllib_robotparser"""


_urllib_robotparser_moved_attributes = [
  MovedAttribute("RobotFileParser", "robotparser", "urllib.robotparser"),
]
for attr in _urllib_robotparser_moved_attributes:
  setattr(Module_six_moves_urllib_robotparser, attr.name, attr)
del attr

Module_six_moves_urllib_robotparser._moved_attributes = _urllib_robotparser_moved_attributes

sys.modules[__name__ + ".moves.urllib_robotparser"] = sys.modules[
  __name__ +
  ".moves.urllib.robotparser"] = Module_six_moves_urllib_robotparser(__name__ +
                                                                     ".moves.urllib.robotparser")


class Module_six_moves_urllib(types.ModuleType):
  """Create a six.moves.urllib namespace that resembles the Python 3 namespace"""
  parse = sys.modules[__name__ + ".moves.urllib_parse"]
  error = sys.modules[__name__ + ".moves.urllib_error"]
  request = sys.modules[__name__ + ".moves.urllib_request"]
  response = sys.modules[__name__ + ".moves.urllib_response"]
  robotparser = sys.modules[__name__ + ".moves.urllib_robotparser"]

  def __dir__(self):
    return ['parse', 'error', 'request', 'response', 'robotparser']


sys.modules[__name__ + ".moves.urllib"] = Module_six_moves_urllib(__name__ + ".moves.urllib")


def add_move(move):
  """Add an item to six.moves."""
  setattr(_MovedItems, move.name, move)


def remove_move(name):
  """Remove item from six.moves."""
  try:
    delattr(_MovedItems, name)
  except AttributeError:
    try:
      del moves.__dict__[name]
    except KeyError:
      raise AttributeError("no such move, %r" % (name, ))


if PY3:
  _meth_func = "__func__"
  _meth_self = "__self__"

  _func_closure = "__closure__"
  _func_code = "__code__"
  _func_defaults = "__defaults__"
  _func_globals = "__globals__"
else:
  _meth_func = "im_func"
  _meth_self = "im_self"

  _func_closure = "func_closure"
  _func_code = "func_code"
  _func_defaults = "func_defaults"
  _func_globals = "func_globals"

try:
  advance_iterator = next
except NameError:

  def advance_iterator(it):
    return it.next()


next = advance_iterator

try:
  callable = callable
except NameError:

  def callable(obj):
    return any("__call__" in klass.__dict__ for klass in type(obj).__mro__)


if PY3:

  def get_unbound_function(unbound):
    return unbound

  create_bound_method = types.MethodType

  Iterator = object
else:

  def get_unbound_function(unbound):
    return unbound.im_func

  def create_bound_method(func, obj):
    return types.MethodType(func, obj, obj.__class__)

  class Iterator(object):

    def next(self):
      return type(self).__next__(self)

  callable = callable
_add_doc(get_unbound_function, """Get the function out of a possibly unbound function""")

get_method_function = operator.attrgetter(_meth_func)
get_method_self = operator.attrgetter(_meth_self)
get_function_closure = operator.attrgetter(_func_closure)
get_function_code = operator.attrgetter(_func_code)
get_function_defaults = operator.attrgetter(_func_defaults)
get_function_globals = operator.attrgetter(_func_globals)

if PY3:

  def iterkeys(d, **kw):
    return iter(d.keys(**kw))

  def itervalues(d, **kw):
    return iter(d.values(**kw))

  def iteritems(d, **kw):
    return iter(d.items(**kw))

  def iterlists(d, **kw):
    return iter(d.lists(**kw))
else:

  def iterkeys(d, **kw):
    return iter(d.iterkeys(**kw))

  def itervalues(d, **kw):
    return iter(d.itervalues(**kw))

  def iteritems(d, **kw):
    return iter(d.iteritems(**kw))

  def iterlists(d, **kw):
    return iter(d.iterlists(**kw))


_add_doc(iterkeys, "Return an iterator over the keys of a dictionary.")
_add_doc(itervalues, "Return an iterator over the values of a dictionary.")
_add_doc(iteritems, "Return an iterator over the (key, value) pairs of a dictionary.")
_add_doc(iterlists, "Return an iterator over the (key, [values]) pairs of a dictionary.")

if PY3:

  def b(s):
    return s.encode("latin-1")

  def u(s):
    return s

  unichr = chr
  if sys.version_info[1] <= 1:

    def int2byte(i):
      return bytes((i, ))
  else:
    # This is about 2x faster than the implementation above on 3.2+
    int2byte = operator.methodcaller("to_bytes", 1, "big")
  byte2int = operator.itemgetter(0)
  indexbytes = operator.getitem
  iterbytes = iter
  import io
  StringIO = io.StringIO
  BytesIO = io.BytesIO
else:

  def b(s):
    return s

  # Workaround for standalone backslash

  def u(s):
    return unicode(s.replace(r'\\', r'\\\\'), "unicode_escape")

  unichr = unichr
  int2byte = chr

  def byte2int(bs):
    return ord(bs[0])

  def indexbytes(buf, i):
    return ord(buf[i])

  def iterbytes(buf):
    return (ord(byte) for byte in buf)

  import StringIO
  StringIO = BytesIO = StringIO.StringIO
_add_doc(b, """Byte literal""")
_add_doc(u, """Text literal""")

if PY3:
  exec_ = getattr(moves.builtins, "exec")

  def reraise(tp, value, tb=None):
    if value.__traceback__ is not tb:
      raise value.with_traceback(tb)
    raise value

else:

  def exec_(_code_, _globs_=None, _locs_=None):
    """Execute code in a namespace."""
    if _globs_ is None:
      frame = sys._getframe(1)
      _globs_ = frame.f_globals
      if _locs_ is None:
        _locs_ = frame.f_locals
      del frame
    elif _locs_ is None:
      _locs_ = _globs_
    exec("""exec _code_ in _globs_, _locs_""")

  exec_("""def reraise(tp, value, tb=None):
    raise tp, value, tb
""")

print_ = getattr(moves.builtins, "print", None)
if print_ is None:

  def print_(*args, **kwargs):
    """The new-style print function for Python 2.4 and 2.5."""
    fp = kwargs.pop("file", sys.stdout)
    if fp is None:
      return

    def write(data):
      if not isinstance(data, basestring):
        data = str(data)
      # If the file has an encoding, encode unicode with it.
      if (isinstance(fp, file) and isinstance(data, unicode) and fp.encoding is not None):
        errors = getattr(fp, "errors", None)
        if errors is None:
          errors = "strict"
        data = data.encode(fp.encoding, errors)
      fp.write(data)

    want_unicode = False
    sep = kwargs.pop("sep", None)
    if sep is not None:
      if isinstance(sep, unicode):
        want_unicode = True
      elif not isinstance(sep, str):
        raise TypeError("sep must be None or a string")
    end = kwargs.pop("end", None)
    if end is not None:
      if isinstance(end, unicode):
        want_unicode = True
      elif not isinstance(end, str):
        raise TypeError("end must be None or a string")
    if kwargs:
      raise TypeError("invalid keyword arguments to print()")
    if not want_unicode:
      for arg in args:
        if isinstance(arg, unicode):
          want_unicode = True
          break
    if want_unicode:
      newline = unicode("\n")
      space = unicode(" ")
    else:
      newline = "\n"
      space = " "
    if sep is None:
      sep = space
    if end is None:
      end = newline
    for i, arg in enumerate(args):
      if i:
        write(sep)
      write(arg)
    write(end)


_add_doc(reraise, """Reraise an exception.""")


def with_metaclass(meta, *bases):
  """Create a base class with a metaclass."""
  return meta("NewBase", bases, {})


def add_metaclass(metaclass):
  """Class decorator for creating a class with a metaclass."""

  def wrapper(cls):
    orig_vars = cls.__dict__.copy()
    orig_vars.pop('__dict__', None)
    orig_vars.pop('__weakref__', None)
    slots = orig_vars.get('__slots__')
    if slots is not None:
      if isinstance(slots, str):
        slots = [slots]
      for slots_var in slots:
        orig_vars.pop(slots_var)
    return metaclass(cls.__name__, cls.__bases__, orig_vars)

  return wrapper


# added as part of the RDKit port
if PY3:

  def cmp(t1, t2):
    return (t1 < t2) * -1 or (t1 > t2) * 1
else:
  cmp = cmp
