Add google-endpoints to third_party/.

third_party/google-endpoints/future/backports/email/headerregistry.py

Index: third_party/google-endpoints/future/backports/email/headerregistry.py
diff --git a/third_party/google-endpoints/future/backports/email/headerregistry.py b/third_party/google-endpoints/future/backports/email/headerregistry.py
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index 0000000000000000000000000000000000000000..9aaad65a149fcf7c1824561be665fe3d3a467a4a
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+++ b/third_party/google-endpoints/future/backports/email/headerregistry.py
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+"""Representing and manipulating email headers via custom objects.
+
+This module provides an implementation of the HeaderRegistry API.
+The implementation is designed to flexibly follow RFC5322 rules.
+
+Eventually HeaderRegistry will be a public API, but it isn't yet,
+and will probably change some before that happens.
+
+"""
+from __future__ import unicode_literals
+from __future__ import division
+from __future__ import absolute_import
+
+from future.builtins import super
+from future.builtins import str
+from future.utils import text_to_native_str
+from future.backports.email import utils
+from future.backports.email import errors
+from future.backports.email import _header_value_parser as parser
+
+class Address(object):
+
+    def __init__(self, display_name='', username='', domain='', addr_spec=None):
+        """Create an object represeting a full email address.
+
+        An address can have a 'display_name', a 'username', and a 'domain'.  In
+        addition to specifying the username and domain separately, they may be
+        specified together by using the addr_spec keyword *instead of* the
+        username and domain keywords.  If an addr_spec string is specified it
+        must be properly quoted according to RFC 5322 rules; an error will be
+        raised if it is not.
+
+        An Address object has display_name, username, domain, and addr_spec
+        attributes, all of which are read-only.  The addr_spec and the string
+        value of the object are both quoted according to RFC5322 rules, but
+        without any Content Transfer Encoding.
+
+        """
+        # This clause with its potential 'raise' may only happen when an
+        # application program creates an Address object using an addr_spec
+        # keyword.  The email library code itself must always supply username
+        # and domain.
+        if addr_spec is not None:
+            if username or domain:
+                raise TypeError("addrspec specified when username and/or "
+                                "domain also specified")
+            a_s, rest = parser.get_addr_spec(addr_spec)
+            if rest:
+                raise ValueError("Invalid addr_spec; only '{}' "
+                                 "could be parsed from '{}'".format(
+                                    a_s, addr_spec))
+            if a_s.all_defects:
+                raise a_s.all_defects[0]
+            username = a_s.local_part
+            domain = a_s.domain
+        self._display_name = display_name
+        self._username = username
+        self._domain = domain
+
+    @property
+    def display_name(self):
+        return self._display_name
+
+    @property
+    def username(self):
+        return self._username
+
+    @property
+    def domain(self):
+        return self._domain
+
+    @property
+    def addr_spec(self):
+        """The addr_spec (username@domain) portion of the address, quoted
+        according to RFC 5322 rules, but with no Content Transfer Encoding.
+        """
+        nameset = set(self.username)
+        if len(nameset) > len(nameset-parser.DOT_ATOM_ENDS):
+            lp = parser.quote_string(self.username)
+        else:
+            lp = self.username
+        if self.domain:
+            return lp + '@' + self.domain
+        if not lp:
+            return '<>'
+        return lp
+
+    def __repr__(self):
+        return "Address(display_name={!r}, username={!r}, domain={!r})".format(
+                        self.display_name, self.username, self.domain)
+
+    def __str__(self):
+        nameset = set(self.display_name)
+        if len(nameset) > len(nameset-parser.SPECIALS):
+            disp = parser.quote_string(self.display_name)
+        else:
+            disp = self.display_name
+        if disp:
+            addr_spec = '' if self.addr_spec=='<>' else self.addr_spec
+            return "{} <{}>".format(disp, addr_spec)
+        return self.addr_spec
+
+    def __eq__(self, other):
+        if type(other) != type(self):
+            return False
+        return (self.display_name == other.display_name and
+                self.username == other.username and
+                self.domain == other.domain)
+
+
+class Group(object):
+
+    def __init__(self, display_name=None, addresses=None):
+        """Create an object representing an address group.
+
+        An address group consists of a display_name followed by colon and an
+        list of addresses (see Address) terminated by a semi-colon.  The Group
+        is created by specifying a display_name and a possibly empty list of
+        Address objects.  A Group can also be used to represent a single
+        address that is not in a group, which is convenient when manipulating
+        lists that are a combination of Groups and individual Addresses.  In
+        this case the display_name should be set to None.  In particular, the
+        string representation of a Group whose display_name is None is the same
+        as the Address object, if there is one and only one Address object in
+        the addresses list.
+
+        """
+        self._display_name = display_name
+        self._addresses = tuple(addresses) if addresses else tuple()
+
+    @property
+    def display_name(self):
+        return self._display_name
+
+    @property
+    def addresses(self):
+        return self._addresses
+
+    def __repr__(self):
+        return "Group(display_name={!r}, addresses={!r}".format(
+                 self.display_name, self.addresses)
+
+    def __str__(self):
+        if self.display_name is None and len(self.addresses)==1:
+            return str(self.addresses[0])
+        disp = self.display_name
+        if disp is not None:
+            nameset = set(disp)
+            if len(nameset) > len(nameset-parser.SPECIALS):
+                disp = parser.quote_string(disp)
+        adrstr = ", ".join(str(x) for x in self.addresses)
+        adrstr = ' ' + adrstr if adrstr else adrstr
+        return "{}:{};".format(disp, adrstr)
+
+    def __eq__(self, other):
+        if type(other) != type(self):
+            return False
+        return (self.display_name == other.display_name and
+                self.addresses == other.addresses)
+
+
+# Header Classes #
+
+class BaseHeader(str):
+
+    """Base class for message headers.
+
+    Implements generic behavior and provides tools for subclasses.
+
+    A subclass must define a classmethod named 'parse' that takes an unfolded
+    value string and a dictionary as its arguments.  The dictionary will
+    contain one key, 'defects', initialized to an empty list.  After the call
+    the dictionary must contain two additional keys: parse_tree, set to the
+    parse tree obtained from parsing the header, and 'decoded', set to the
+    string value of the idealized representation of the data from the value.
+    (That is, encoded words are decoded, and values that have canonical
+    representations are so represented.)
+
+    The defects key is intended to collect parsing defects, which the message
+    parser will subsequently dispose of as appropriate.  The parser should not,
+    insofar as practical, raise any errors.  Defects should be added to the
+    list instead.  The standard header parsers register defects for RFC
+    compliance issues, for obsolete RFC syntax, and for unrecoverable parsing
+    errors.
+
+    The parse method may add additional keys to the dictionary.  In this case
+    the subclass must define an 'init' method, which will be passed the
+    dictionary as its keyword arguments.  The method should use (usually by
+    setting them as the value of similarly named attributes) and remove all the
+    extra keys added by its parse method, and then use super to call its parent
+    class with the remaining arguments and keywords.
+
+    The subclass should also make sure that a 'max_count' attribute is defined
+    that is either None or 1. XXX: need to better define this API.
+
+    """
+
+    def __new__(cls, name, value):
+        kwds = {'defects': []}
+        cls.parse(value, kwds)
+        if utils._has_surrogates(kwds['decoded']):
+            kwds['decoded'] = utils._sanitize(kwds['decoded'])
+        self = str.__new__(cls, kwds['decoded'])
+        # del kwds['decoded']
+        self.init(name, **kwds)
+        return self
+
+    def init(self, name, **_3to2kwargs):
+        defects = _3to2kwargs['defects']; del _3to2kwargs['defects']
+        parse_tree = _3to2kwargs['parse_tree']; del _3to2kwargs['parse_tree']
+        self._name = name
+        self._parse_tree = parse_tree
+        self._defects = defects
+
+    @property
+    def name(self):
+        return self._name
+
+    @property
+    def defects(self):
+        return tuple(self._defects)
+
+    def __reduce__(self):
+        return (
+            _reconstruct_header,
+            (
+                self.__class__.__name__,
+                self.__class__.__bases__,
+                str(self),
+            ),
+            self.__dict__)
+
+    @classmethod
+    def _reconstruct(cls, value):
+        return str.__new__(cls, value)
+
+    def fold(self, **_3to2kwargs):
+        policy = _3to2kwargs['policy']; del _3to2kwargs['policy']
+        """Fold header according to policy.
+
+        The parsed representation of the header is folded according to
+        RFC5322 rules, as modified by the policy.  If the parse tree
+        contains surrogateescaped bytes, the bytes are CTE encoded using
+        the charset 'unknown-8bit".
+
+        Any non-ASCII characters in the parse tree are CTE encoded using
+        charset utf-8. XXX: make this a policy setting.
+
+        The returned value is an ASCII-only string possibly containing linesep
+        characters, and ending with a linesep character.  The string includes
+        the header name and the ': ' separator.
+
+        """
+        # At some point we need to only put fws here if it was in the source.
+        header = parser.Header([
+            parser.HeaderLabel([
+                parser.ValueTerminal(self.name, 'header-name'),
+                parser.ValueTerminal(':', 'header-sep')]),
+            parser.CFWSList([parser.WhiteSpaceTerminal(' ', 'fws')]),
+                             self._parse_tree])
+        return header.fold(policy=policy)
+
+
+def _reconstruct_header(cls_name, bases, value):
+    return type(text_to_native_str(cls_name), bases, {})._reconstruct(value)
+
+
+class UnstructuredHeader(object):
+
+    max_count = None
+    value_parser = staticmethod(parser.get_unstructured)
+
+    @classmethod
+    def parse(cls, value, kwds):
+        kwds['parse_tree'] = cls.value_parser(value)
+        kwds['decoded'] = str(kwds['parse_tree'])
+
+
+class UniqueUnstructuredHeader(UnstructuredHeader):
+
+    max_count = 1
+
+
+class DateHeader(object):
+
+    """Header whose value consists of a single timestamp.
+
+    Provides an additional attribute, datetime, which is either an aware
+    datetime using a timezone, or a naive datetime if the timezone
+    in the input string is -0000.  Also accepts a datetime as input.
+    The 'value' attribute is the normalized form of the timestamp,
+    which means it is the output of format_datetime on the datetime.
+    """
+
+    max_count = None
+
+    # This is used only for folding, not for creating 'decoded'.
+    value_parser = staticmethod(parser.get_unstructured)
+
+    @classmethod
+    def parse(cls, value, kwds):
+        if not value:
+            kwds['defects'].append(errors.HeaderMissingRequiredValue())
+            kwds['datetime'] = None
+            kwds['decoded'] = ''
+            kwds['parse_tree'] = parser.TokenList()
+            return
+        if isinstance(value, str):
+            value = utils.parsedate_to_datetime(value)
+        kwds['datetime'] = value
+        kwds['decoded'] = utils.format_datetime(kwds['datetime'])
+        kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
+
+    def init(self, *args, **kw):
+        self._datetime = kw.pop('datetime')
+        super().init(*args, **kw)
+
+    @property
+    def datetime(self):
+        return self._datetime
+
+
+class UniqueDateHeader(DateHeader):
+
+    max_count = 1
+
+
+class AddressHeader(object):
+
+    max_count = None
+
+    @staticmethod
+    def value_parser(value):
+        address_list, value = parser.get_address_list(value)
+        assert not value, 'this should not happen'
+        return address_list
+
+    @classmethod
+    def parse(cls, value, kwds):
+        if isinstance(value, str):
+            # We are translating here from the RFC language (address/mailbox)
+            # to our API language (group/address).
+            kwds['parse_tree'] = address_list = cls.value_parser(value)
+            groups = []
+            for addr in address_list.addresses:
+                groups.append(Group(addr.display_name,
+                                    [Address(mb.display_name or '',
+                                             mb.local_part or '',
+                                             mb.domain or '')
+                                     for mb in addr.all_mailboxes]))
+            defects = list(address_list.all_defects)
+        else:
+            # Assume it is Address/Group stuff
+            if not hasattr(value, '__iter__'):
+                value = [value]
+            groups = [Group(None, [item]) if not hasattr(item, 'addresses')
+                                          else item
+                                    for item in value]
+            defects = []
+        kwds['groups'] = groups
+        kwds['defects'] = defects
+        kwds['decoded'] = ', '.join([str(item) for item in groups])
+        if 'parse_tree' not in kwds:
+            kwds['parse_tree'] = cls.value_parser(kwds['decoded'])
+
+    def init(self, *args, **kw):
+        self._groups = tuple(kw.pop('groups'))
+        self._addresses = None
+        super().init(*args, **kw)
+
+    @property
+    def groups(self):
+        return self._groups
+
+    @property
+    def addresses(self):
+        if self._addresses is None:
+            self._addresses = tuple([address for group in self._groups
+                                             for address in group.addresses])
+        return self._addresses
+
+
+class UniqueAddressHeader(AddressHeader):
+
+    max_count = 1
+
+
+class SingleAddressHeader(AddressHeader):
+
+    @property
+    def address(self):
+        if len(self.addresses)!=1:
+            raise ValueError(("value of single address header {} is not "
+                "a single address").format(self.name))
+        return self.addresses[0]
+
+
+class UniqueSingleAddressHeader(SingleAddressHeader):
+
+    max_count = 1
+
+
+class MIMEVersionHeader(object):
+
+    max_count = 1
+
+    value_parser = staticmethod(parser.parse_mime_version)
+
+    @classmethod
+    def parse(cls, value, kwds):
+        kwds['parse_tree'] = parse_tree = cls.value_parser(value)
+        kwds['decoded'] = str(parse_tree)
+        kwds['defects'].extend(parse_tree.all_defects)
+        kwds['major'] = None if parse_tree.minor is None else parse_tree.major
+        kwds['minor'] = parse_tree.minor
+        if parse_tree.minor is not None:
+            kwds['version'] = '{}.{}'.format(kwds['major'], kwds['minor'])
+        else:
+            kwds['version'] = None
+
+    def init(self, *args, **kw):
+        self._version = kw.pop('version')
+        self._major = kw.pop('major')
+        self._minor = kw.pop('minor')
+        super().init(*args, **kw)
+
+    @property
+    def major(self):
+        return self._major
+
+    @property
+    def minor(self):
+        return self._minor
+
+    @property
+    def version(self):
+        return self._version
+
+
+class ParameterizedMIMEHeader(object):
+
+    # Mixin that handles the params dict.  Must be subclassed and
+    # a property value_parser for the specific header provided.
+
+    max_count = 1
+
+    @classmethod
+    def parse(cls, value, kwds):
+        kwds['parse_tree'] = parse_tree = cls.value_parser(value)
+        kwds['decoded'] = str(parse_tree)
+        kwds['defects'].extend(parse_tree.all_defects)
+        if parse_tree.params is None:
+            kwds['params'] = {}
+        else:
+            # The MIME RFCs specify that parameter ordering is arbitrary.
+            kwds['params'] = dict((utils._sanitize(name).lower(),
+                                   utils._sanitize(value))
+                                  for name, value in parse_tree.params)
+
+    def init(self, *args, **kw):
+        self._params = kw.pop('params')
+        super().init(*args, **kw)
+
+    @property
+    def params(self):
+        return self._params.copy()
+
+
+class ContentTypeHeader(ParameterizedMIMEHeader):
+
+    value_parser = staticmethod(parser.parse_content_type_header)
+
+    def init(self, *args, **kw):
+        super().init(*args, **kw)
+        self._maintype = utils._sanitize(self._parse_tree.maintype)
+        self._subtype = utils._sanitize(self._parse_tree.subtype)
+
+    @property
+    def maintype(self):
+        return self._maintype
+
+    @property
+    def subtype(self):
+        return self._subtype
+
+    @property
+    def content_type(self):
+        return self.maintype + '/' + self.subtype
+
+
+class ContentDispositionHeader(ParameterizedMIMEHeader):
+
+    value_parser = staticmethod(parser.parse_content_disposition_header)
+
+    def init(self, *args, **kw):
+        super().init(*args, **kw)
+        cd = self._parse_tree.content_disposition
+        self._content_disposition = cd if cd is None else utils._sanitize(cd)
+
+    @property
+    def content_disposition(self):
+        return self._content_disposition
+
+
+class ContentTransferEncodingHeader(object):
+
+    max_count = 1
+
+    value_parser = staticmethod(parser.parse_content_transfer_encoding_header)
+
+    @classmethod
+    def parse(cls, value, kwds):
+        kwds['parse_tree'] = parse_tree = cls.value_parser(value)
+        kwds['decoded'] = str(parse_tree)
+        kwds['defects'].extend(parse_tree.all_defects)
+
+    def init(self, *args, **kw):
+        super().init(*args, **kw)
+        self._cte = utils._sanitize(self._parse_tree.cte)
+
+    @property
+    def cte(self):
+        return self._cte
+
+
+# The header factory #
+
+_default_header_map = {
+    'subject':                      UniqueUnstructuredHeader,
+    'date':                         UniqueDateHeader,
+    'resent-date':                  DateHeader,
+    'orig-date':                    UniqueDateHeader,
+    'sender':                       UniqueSingleAddressHeader,
+    'resent-sender':                SingleAddressHeader,
+    'to':                           UniqueAddressHeader,
+    'resent-to':                    AddressHeader,
+    'cc':                           UniqueAddressHeader,
+    'resent-cc':                    AddressHeader,
+    'bcc':                          UniqueAddressHeader,
+    'resent-bcc':                   AddressHeader,
+    'from':                         UniqueAddressHeader,
+    'resent-from':                  AddressHeader,
+    'reply-to':                     UniqueAddressHeader,
+    'mime-version':                 MIMEVersionHeader,
+    'content-type':                 ContentTypeHeader,
+    'content-disposition':          ContentDispositionHeader,
+    'content-transfer-encoding':    ContentTransferEncodingHeader,
+    }
+
+class HeaderRegistry(object):
+
+    """A header_factory and header registry."""
+
+    def __init__(self, base_class=BaseHeader, default_class=UnstructuredHeader,
+                       use_default_map=True):
+        """Create a header_factory that works with the Policy API.
+
+        base_class is the class that will be the last class in the created
+        header class's __bases__ list.  default_class is the class that will be
+        used if "name" (see __call__) does not appear in the registry.
+        use_default_map controls whether or not the default mapping of names to
+        specialized classes is copied in to the registry when the factory is
+        created.  The default is True.
+
+        """
+        self.registry = {}
+        self.base_class = base_class
+        self.default_class = default_class
+        if use_default_map:
+            self.registry.update(_default_header_map)
+
+    def map_to_type(self, name, cls):
+        """Register cls as the specialized class for handling "name" headers.
+
+        """
+        self.registry[name.lower()] = cls
+
+    def __getitem__(self, name):
+        cls = self.registry.get(name.lower(), self.default_class)
+        return type(text_to_native_str('_'+cls.__name__), (cls, self.base_class), {})
+
+    def __call__(self, name, value):
+        """Create a header instance for header 'name' from 'value'.
+
+        Creates a header instance by creating a specialized class for parsing
+        and representing the specified header by combining the factory
+        base_class with a specialized class from the registry or the
+        default_class, and passing the name and value to the constructed
+        class's constructor.
+
+        """
+        return self[name](name, value)