text: """Internationalization and localization support.
  
  This module provides internationalization (I18N) and localization (L10N)
  support for your Python programs by providing an interface to the GNU gettext
  message catalog library.
  
  I18N refers to the operation by which a program is made aware of multiple
  languages.  L10N refers to the adaptation of your program, once
  internationalized, to the local language and cultural habits.
  
  """
  
  # This module represents the integration of work, contributions, feedback, and
  # suggestions from the following people:
  #
  # Martin von Loewis, who wrote the initial implementation of the underlying
  # C-based libintlmodule (later renamed _gettext), along with a skeletal
  # gettext.py implementation.
  #
  # Peter Funk, who wrote fintl.py, a fairly complete wrapper around intlmodule,
  # which also included a pure-Python implementation to read .mo files if
  # intlmodule wasn't available.
  #
  # James Henstridge, who also wrote a gettext.py module, which has some
  # interesting, but currently unsupported experimental features: the notion of
  # a Catalog class and instances, and the ability to add to a catalog file via
  # a Python API.
  #
  # Barry Warsaw integrated these modules, wrote the .install() API and code,
  # and conformed all C and Python code to Python's coding standards.
  #
  # Francois Pinard and Marc-Andre Lemburg also contributed valuably to this
  # module.
  #
  # J. David Ibanez implemented plural forms. Bruno Haible fixed some bugs.
  #
  # TODO:
  # - Lazy loading of .mo files.  Currently the entire catalog is loaded into
  #   memory, but that's probably bad for large translated programs.  Instead,
  #   the lexical sort of original strings in GNU .mo files should be exploited
  #   to do binary searches and lazy initializations.  Or you might want to use
  #   the undocumented double-hash algorithm for .mo files with hash tables, but
  #   you'll need to study the GNU gettext code to do this.
  #
  # - Support Solaris .mo file formats.  Unfortunately, we've been unable to
  #   find this format documented anywhere.
  
  
  import locale, copy, io, os, re, struct, sys
  from errno import ENOENT
  
  
  __all__ = ['NullTranslations', 'GNUTranslations', 'Catalog',
             'find', 'translation', 'install', 'textdomain', 'bindtextdomain',
             'bind_textdomain_codeset',
             'dgettext', 'dngettext', 'gettext', 'lgettext', 'ldgettext',
             'ldngettext', 'lngettext', 'ngettext',
             ]
  
  _default_localedir = os.path.join(sys.base_prefix, 'share', 'locale')
  
  # Expression parsing for plural form selection.
  #
  # The gettext library supports a small subset of C syntax.  The only
  # incompatible difference is that integer literals starting with zero are
  # decimal.
  #
  # https://www.gnu.org/software/gettext/manual/gettext.html#Plural-forms
  # http://git.savannah.gnu.org/cgit/gettext.git/tree/gettext-runtime/intl/plural.y
  
  _token_pattern = re.compile(r"""
          (?P<WHITESPACES>[ \t]+)                    | # spaces and horizontal tabs
          (?P<NUMBER>[0-9]+\b)                       | # decimal integer
          (?P<NAME>n\b)                              | # only n is allowed
          (?P<PARENTHESIS>[()])                      |
          (?P<OPERATOR>[-*/%+?:]|[><!]=?|==|&&|\|\|) | # !, *, /, %, +, -, <, >,
                                                       # <=, >=, ==, !=, &&, ||,
                                                       # ? :
                                                       # unary and bitwise ops
                                                       # not allowed
          (?P<INVALID>\w+|.)                           # invalid token
      """, re.VERBOSE|re.DOTALL)
  
  def _tokenize(plural):
      for mo in re.finditer(_token_pattern, plural):
          kind = mo.lastgroup
          if kind == 'WHITESPACES':
              continue
          value = mo.group(kind)
          if kind == 'INVALID':
              raise ValueError('invalid token in plural form: %s' % value)
          yield value
      yield ''
  
  def _error(value):
      if value:
          return ValueError('unexpected token in plural form: %s' % value)
      else:
          return ValueError('unexpected end of plural form')
  
  _binary_ops = (
      ('||',),
      ('&&',),
      ('==', '!='),
      ('<', '>', '<=', '>='),
      ('+', '-'),
      ('*', '/', '%'),
  )
  _binary_ops = {op: i for i, ops in enumerate(_binary_ops, 1) for op in ops}
  _c2py_ops = {'||': 'or', '&&': 'and', '/': '//'}
  
  def _parse(tokens, priority=-1):
      result = ''
      nexttok = next(tokens)
      while nexttok == '!':
          result += 'not '
          nexttok = next(tokens)
  
      if nexttok == '(':
          sub, nexttok = _parse(tokens)
          result = '%s(%s)' % (result, sub)
          if nexttok != ')':
              raise ValueError('unbalanced parenthesis in plural form')
      elif nexttok == 'n':
          result = '%s%s' % (result, nexttok)
      else:
          try:
              value = int(nexttok, 10)
          except ValueError:
              raise _error(nexttok) from None
          result = '%s%d' % (result, value)
      nexttok = next(tokens)
  
      j = 100
      while nexttok in _binary_ops:
          i = _binary_ops[nexttok]
          if i < priority:
              break
          # Break chained comparisons
          if i in (3, 4) and j in (3, 4):  # '==', '!=', '<', '>', '<=', '>='
              result = '(%s)' % result
          # Replace some C operators by their Python equivalents
          op = _c2py_ops.get(nexttok, nexttok)
          right, nexttok = _parse(tokens, i + 1)
          result = '%s %s %s' % (result, op, right)
          j = i
      if j == priority == 4:  # '<', '>', '<=', '>='
          result = '(%s)' % result
  
      if nexttok == '?' and priority <= 0:
          if_true, nexttok = _parse(tokens, 0)
          if nexttok != ':':
              raise _error(nexttok)
          if_false, nexttok = _parse(tokens)
          result = '%s if %s else %s' % (if_true, result, if_false)
          if priority == 0:
              result = '(%s)' % result
  
      return result, nexttok
  
  def _as_int(n):
      try:
          i = round(n)
      except TypeError:
          raise TypeError('Plural value must be an integer, got %s' %
                          (n.__class__.__name__,)) from None
      return n
  
  def c2py(plural):
      """Gets a C expression as used in PO files for plural forms and returns a
      Python function that implements an equivalent expression.
      """
  
      if len(plural) > 1000:
          raise ValueError('plural form expression is too long')
      try:
          result, nexttok = _parse(_tokenize(plural))
          if nexttok:
              raise _error(nexttok)
  
          depth = 0
          for c in result:
              if c == '(':
                  depth += 1
                  if depth > 20:
                      # Python compiler limit is about 90.
                      # The most complex example has 2.
                      raise ValueError('plural form expression is too complex')
              elif c == ')':
                  depth -= 1
  
          ns = {'_as_int': _as_int}
          exec('''if True:
              def func(n):
                  if not isinstance(n, int):
                      n = _as_int(n)
                  return int(%s)
              ''' % result, ns)
          return ns['func']
      except RecursionError:
          # Recursion error can be raised in _parse() or exec().
          raise ValueError('plural form expression is too complex')
  
  
  def _expand_lang(loc):
      loc = locale.normalize(loc)
      COMPONENT_CODESET   = 1 << 0
      COMPONENT_TERRITORY = 1 << 1
      COMPONENT_MODIFIER  = 1 << 2
      # split up the locale into its base components
      mask = 0
      pos = loc.find('@')
      if pos >= 0:
          modifier = loc[pos:]
          loc = loc[:pos]
          mask |= COMPONENT_MODIFIER
      else:
          modifier = ''
      pos = loc.find('.')
      if pos >= 0:
          codeset = loc[pos:]
          loc = loc[:pos]
          mask |= COMPONENT_CODESET
      else:
          codeset = ''
      pos = loc.find('_')
      if pos >= 0:
          territory = loc[pos:]
          loc = loc[:pos]
          mask |= COMPONENT_TERRITORY
      else:
          territory = ''
      language = loc
      ret = []
      for i in range(mask+1):
          if not (i & ~mask):  # if all components for this combo exist ...
              val = language
              if i & COMPONENT_TERRITORY: val += territory
              if i & COMPONENT_CODESET:   val += codeset
              if i & COMPONENT_MODIFIER:  val += modifier
              ret.append(val)
      ret.reverse()
      return ret
  
  
  
  class NullTranslations:
      def __init__(self, fp=None):
          self._info = {}
          self._charset = None
          self._output_charset = None
          self._fallback = None
          if fp is not None:
              self._parse(fp)
  
      def _parse(self, fp):
          pass
  
      def add_fallback(self, fallback):
          if self._fallback:
              self._fallback.add_fallback(fallback)
          else:
              self._fallback = fallback
  
      def gettext(self, message):
          if self._fallback:
              return self._fallback.gettext(message)
          return message
  
      def lgettext(self, message):
          if self._fallback:
              return self._fallback.lgettext(message)
          return message
  
      def ngettext(self, msgid1, msgid2, n):
          if self._fallback:
              return self._fallback.ngettext(msgid1, msgid2, n)
          if n == 1:
              return msgid1
          else:
              return msgid2
  
      def lngettext(self, msgid1, msgid2, n):
          if self._fallback:
              return self._fallback.lngettext(msgid1, msgid2, n)
          if n == 1:
              return msgid1
          else:
              return msgid2
  
      def info(self):
          return self._info
  
      def charset(self):
          return self._charset
  
      def output_charset(self):
          return self._output_charset
  
      def set_output_charset(self, charset):
          self._output_charset = charset
  
      def install(self, names=None):
          import builtins
          builtins.__dict__['_'] = self.gettext
          if hasattr(names, "__contains__"):
              if "gettext" in names:
                  builtins.__dict__['gettext'] = builtins.__dict__['_']
              if "ngettext" in names:
                  builtins.__dict__['ngettext'] = self.ngettext
              if "lgettext" in names:
                  builtins.__dict__['lgettext'] = self.lgettext
              if "lngettext" in names:
                  builtins.__dict__['lngettext'] = self.lngettext
  
  
  class GNUTranslations(NullTranslations):
      # Magic number of .mo files
      LE_MAGIC = 0x950412de
      BE_MAGIC = 0xde120495
  
      # Acceptable .mo versions
      VERSIONS = (0, 1)
  
      def _get_versions(self, version):
          """Returns a tuple of major version, minor version"""
          return (version >> 16, version & 0xffff)
  
      def _parse(self, fp):
          """Override this method to support alternative .mo formats."""
          unpack = struct.unpack
          filename = getattr(fp, 'name', '')
          # Parse the .mo file header, which consists of 5 little endian 32
          # bit words.
          self._catalog = catalog = {}
          self.plural = lambda n: int(n != 1) # germanic plural by default
          buf = fp.read()
          buflen = len(buf)
          # Are we big endian or little endian?
          magic = unpack('<I', buf[:4])[0]
          if magic == self.LE_MAGIC:
              version, msgcount, masteridx, transidx = unpack('<4I', buf[4:20])
              ii = '<II'
          elif magic == self.BE_MAGIC:
              version, msgcount, masteridx, transidx = unpack('>4I', buf[4:20])
              ii = '>II'
          else:
              raise OSError(0, 'Bad magic number', filename)
  
          major_version, minor_version = self._get_versions(version)
  
          if major_version not in self.VERSIONS:
              raise OSError(0, 'Bad version number ' + str(major_version), filename)
  
          # Now put all messages from the .mo file buffer into the catalog
          # dictionary.
          for i in range(0, msgcount):
              mlen, moff = unpack(ii, buf[masteridx:masteridx+8])
              mend = moff + mlen
              tlen, toff = unpack(ii, buf[transidx:transidx+8])
              tend = toff + tlen
              if mend < buflen and tend < buflen:
                  msg = buf[moff:mend]
                  tmsg = buf[toff:tend]
              else:
                  raise OSError(0, 'File is corrupt', filename)
              # See if we're looking at GNU .mo conventions for metadata
              if mlen == 0:
                  # Catalog description
                  lastk = None
                  for b_item in tmsg.split('\n'.encode("ascii")):
                      item = b_item.decode().strip()
                      if not item:
                          continue
                      k = v = None
                      if ':' in item:
                          k, v = item.split(':', 1)
                          k = k.strip().lower()
                          v = v.strip()
                          self._info[k] = v
                          lastk = k
                      elif lastk:
                          self._info[lastk] += '\n' + item
                      if k == 'content-type':
                          self._charset = v.split('charset=')[1]
                      elif k == 'plural-forms':
                          v = v.split(';')
                          plural = v[1].split('plural=')[1]
                          self.plural = c2py(plural)
              # Note: we unconditionally convert both msgids and msgstrs to
              # Unicode using the character encoding specified in the charset
              # parameter of the Content-Type header.  The gettext documentation
              # strongly encourages msgids to be us-ascii, but some applications
              # require alternative encodings (e.g. Zope's ZCML and ZPT).  For
              # traditional gettext applications, the msgid conversion will
              # cause no problems since us-ascii should always be a subset of
              # the charset encoding.  We may want to fall back to 8-bit msgids
              # if the Unicode conversion fails.
              charset = self._charset or 'ascii'
              if b'\x00' in msg:
                  # Plural forms
                  msgid1, msgid2 = msg.split(b'\x00')
                  tmsg = tmsg.split(b'\x00')
                  msgid1 = str(msgid1, charset)
                  for i, x in enumerate(tmsg):
                      catalog[(msgid1, i)] = str(x, charset)
              else:
                  catalog[str(msg, charset)] = str(tmsg, charset)
              # advance to next entry in the seek tables
              masteridx += 8
              transidx += 8
  
      def lgettext(self, message):
          missing = object()
          tmsg = self._catalog.get(message, missing)
          if tmsg is missing:
              if self._fallback:
                  return self._fallback.lgettext(message)
              return message
          if self._output_charset:
              return tmsg.encode(self._output_charset)
          return tmsg.encode(locale.getpreferredencoding())
  
      def lngettext(self, msgid1, msgid2, n):
          try:
              tmsg = self._catalog[(msgid1, self.plural(n))]
              if self._output_charset:
                  return tmsg.encode(self._output_charset)
              return tmsg.encode(locale.getpreferredencoding())
          except KeyError:
              if self._fallback:
                  return self._fallback.lngettext(msgid1, msgid2, n)
              if n == 1:
                  return msgid1
              else:
                  return msgid2
  
      def gettext(self, message):
          missing = object()
          tmsg = self._catalog.get(message, missing)
          if tmsg is missing:
              if self._fallback:
                  return self._fallback.gettext(message)
              return message
          return tmsg
  
      def ngettext(self, msgid1, msgid2, n):
          try:
              tmsg = self._catalog[(msgid1, self.plural(n))]
          except KeyError:
              if self._fallback:
                  return self._fallback.ngettext(msgid1, msgid2, n)
              if n == 1:
                  tmsg = msgid1
              else:
                  tmsg = msgid2
          return tmsg
  
  
  # Locate a .mo file using the gettext strategy
  def find(domain, localedir=None, languages=None, all=False):
      # Get some reasonable defaults for arguments that were not supplied
      if localedir is None:
          localedir = _default_localedir
      if languages is None:
          languages = []
          for envar in ('LANGUAGE', 'LC_ALL', 'LC_MESSAGES', 'LANG'):
              val = os.environ.get(envar)
              if val:
                  languages = val.split(':')
                  break
          if 'C' not in languages:
              languages.append('C')
      # now normalize and expand the languages
      nelangs = []
      for lang in languages:
          for nelang in _expand_lang(lang):
              if nelang not in nelangs:
                  nelangs.append(nelang)
      # select a language
      if all:
          result = []
      else:
          result = None
      for lang in nelangs:
          if lang == 'C':
              break
          mofile = os.path.join(localedir, lang, 'LC_MESSAGES', '%s.mo' % domain)
          if os.path.exists(mofile):
              if all:
                  result.append(mofile)
              else:
                  return mofile
      return result
  
  
  
  # a mapping between absolute .mo file path and Translation object
  _translations = {}
  
  def translation(domain, localedir=None, languages=None,
                  class_=None, fallback=False, codeset=None):
      if class_ is None:
          class_ = GNUTranslations
      mofiles = find(domain, localedir, languages, all=True)
      if not mofiles:
          if fallback:
              return NullTranslations()
          raise OSError(ENOENT, 'No translation file found for domain', domain)
      # Avoid opening, reading, and parsing the .mo file after it's been done
      # once.
      result = None
      for mofile in mofiles:
          key = (class_, os.path.abspath(mofile))
          t = _translations.get(key)
          if t is None:
              with open(mofile, 'rb') as fp:
                  t = _translations.setdefault(key, class_(fp))
          # Copy the translation object to allow setting fallbacks and
          # output charset. All other instance data is shared with the
          # cached object.
          t = copy.copy(t)
          if codeset:
              t.set_output_charset(codeset)
          if result is None:
              result = t
          else:
              result.add_fallback(t)
      return result
  
  
  def install(domain, localedir=None, codeset=None, names=None):
      t = translation(domain, localedir, fallback=True, codeset=codeset)
      t.install(names)
  
  
  
  # a mapping b/w domains and locale directories
  _localedirs = {}
  # a mapping b/w domains and codesets
  _localecodesets = {}
  # current global domain, `messages' used for compatibility w/ GNU gettext
  _current_domain = 'messages'
  
  
  def textdomain(domain=None):
      global _current_domain
      if domain is not None:
          _current_domain = domain
      return _current_domain
  
  
  def bindtextdomain(domain, localedir=None):
      global _localedirs
      if localedir is not None:
          _localedirs[domain] = localedir
      return _localedirs.get(domain, _default_localedir)
  
  
  def bind_textdomain_codeset(domain, codeset=None):
      global _localecodesets
      if codeset is not None:
          _localecodesets[domain] = codeset
      return _localecodesets.get(domain)
  
  
  def dgettext(domain, message):
      try:
          t = translation(domain, _localedirs.get(domain, None),
                          codeset=_localecodesets.get(domain))
      except OSError:
          return message
      return t.gettext(message)
  
  def ldgettext(domain, message):
      try:
          t = translation(domain, _localedirs.get(domain, None),
                          codeset=_localecodesets.get(domain))
      except OSError:
          return message
      return t.lgettext(message)
  
  def dngettext(domain, msgid1, msgid2, n):
      try:
          t = translation(domain, _localedirs.get(domain, None),
                          codeset=_localecodesets.get(domain))
      except OSError:
          if n == 1:
              return msgid1
          else:
              return msgid2
      return t.ngettext(msgid1, msgid2, n)
  
  def ldngettext(domain, msgid1, msgid2, n):
      try:
          t = translation(domain, _localedirs.get(domain, None),
                          codeset=_localecodesets.get(domain))
      except OSError:
          if n == 1:
              return msgid1
          else:
              return msgid2
      return t.lngettext(msgid1, msgid2, n)
  
  def gettext(message):
      return dgettext(_current_domain, message)
  
  def lgettext(message):
      return ldgettext(_current_domain, message)
  
  def ngettext(msgid1, msgid2, n):
      return dngettext(_current_domain, msgid1, msgid2, n)
  
  def lngettext(msgid1, msgid2, n):
      return ldngettext(_current_domain, msgid1, msgid2, n)
  
  # dcgettext() has been deemed unnecessary and is not implemented.
  
  # James Henstridge's Catalog constructor from GNOME gettext.  Documented usage
  # was:
  #
  #    import gettext
  #    cat = gettext.Catalog(PACKAGE, localedir=LOCALEDIR)
  #    _ = cat.gettext
  #    print _('Hello World')
  
  # The resulting catalog object currently don't support access through a
  # dictionary API, which was supported (but apparently unused) in GNOME
  # gettext.
  
  Catalog = translation
  