"""IMAP4 client.

Based on RFC 2060.

Public class:           IMAP4

Public variable:        Debug

Public functions:       Internaldate2tuple

                        Int2AP

                        ParseFlags

                        Time2Internaldate

"""

# Author: Piers Lauder <piers@cs.su.oz.au> December 1997.

#

# Authentication code contributed by Donn Cave <donn@u.washington.edu> June 1998.

# String method conversion by ESR, February 2001.

# GET/SETACL contributed by Anthony Baxter <anthony@interlink.com.au> April 2001.

# IMAP4_SSL contributed by Tino Lange <Tino.Lange@isg.de> March 2002.

# GET/SETQUOTA contributed by Andreas Zeidler <az@kreativkombinat.de> June 2002.

# PROXYAUTH contributed by Rick Holbert <holbert.13@osu.edu> November 2002.

# GET/SETANNOTATION contributed by Tomas Lindroos <skitta@abo.fi> June 2005.

__version__ = "2.58"

import binascii, os, random, re, socket, sys, time

__all__ = ["IMAP4", "IMAP4_stream", "Internaldate2tuple",

           "Int2AP", "ParseFlags", "Time2Internaldate"]

#       Globals

CRLF = '\r\n'

Debug = 0

IMAP4_PORT = 143

IMAP4_SSL_PORT = 993

AllowedVersions = ('IMAP4REV1', 'IMAP4')        # Most recent first

#       Commands

Commands = {

        # name            valid states

        'APPEND':       ('AUTH', 'SELECTED'),

        'AUTHENTICATE': ('NONAUTH',),

        'CAPABILITY':   ('NONAUTH', 'AUTH', 'SELECTED', 'LOGOUT'),

        'CHECK':        ('SELECTED',),

        'CLOSE':        ('SELECTED',),

        'COPY':         ('SELECTED',),

        'CREATE':       ('AUTH', 'SELECTED'),

        'DELETE':       ('AUTH', 'SELECTED'),

        'DELETEACL':    ('AUTH', 'SELECTED'),

        'EXAMINE':      ('AUTH', 'SELECTED'),

        'EXPUNGE':      ('SELECTED',),

        'FETCH':        ('SELECTED',),

        'GETACL':       ('AUTH', 'SELECTED'),

        'GETANNOTATION':('AUTH', 'SELECTED'),

        'GETQUOTA':     ('AUTH', 'SELECTED'),

        'GETQUOTAROOT': ('AUTH', 'SELECTED'),

        'MYRIGHTS':     ('AUTH', 'SELECTED'),

        'LIST':         ('AUTH', 'SELECTED'),

        'LOGIN':        ('NONAUTH',),

        'LOGOUT':       ('NONAUTH', 'AUTH', 'SELECTED', 'LOGOUT'),

        'LSUB':         ('AUTH', 'SELECTED'),

        'NAMESPACE':    ('AUTH', 'SELECTED'),

        'NOOP':         ('NONAUTH', 'AUTH', 'SELECTED', 'LOGOUT'),

        'PARTIAL':      ('SELECTED',),                                  # NB: obsolete

        'PROXYAUTH':    ('AUTH',),

        'RENAME':       ('AUTH', 'SELECTED'),

        'SEARCH':       ('SELECTED',),

        'SELECT':       ('AUTH', 'SELECTED'),

        'SETACL':       ('AUTH', 'SELECTED'),

        'SETANNOTATION':('AUTH', 'SELECTED'),

        'SETQUOTA':     ('AUTH', 'SELECTED'),

        'SORT':         ('SELECTED',),

        'STATUS':       ('AUTH', 'SELECTED'),

        'STORE':        ('SELECTED',),

        'SUBSCRIBE':    ('AUTH', 'SELECTED'),

        'THREAD':       ('SELECTED',),

        'UID':          ('SELECTED',),

        'UNSUBSCRIBE':  ('AUTH', 'SELECTED'),

        }

#       Patterns to match server responses

Continuation = re.compile(r'\+( (?P<data>.*))?')

Flags = re.compile(r'.*FLAGS \((?P<flags>[^\)]*)\)')

InternalDate = re.compile(r'.*INTERNALDATE "'

        r'(?P<day>[ 0123][0-9])-(?P<mon>[A-Z][a-z][a-z])-(?P<year>[0-9][0-9][0-9][0-9])'

        r' (?P<hour>[0-9][0-9]):(?P<min>[0-9][0-9]):(?P<sec>[0-9][0-9])'

        r' (?P<zonen>[-+])(?P<zoneh>[0-9][0-9])(?P<zonem>[0-9][0-9])'

        r'"')

Literal = re.compile(r'.*{(?P<size>\d+)}$')

MapCRLF = re.compile(r'\r\n|\r|\n')

Response_code = re.compile(r'\[(?P<type>[A-Z-]+)( (?P<data>[^\]]*))?\]')

Untagged_response = re.compile(r'\* (?P<type>[A-Z-]+)( (?P<data>.*))?')

Untagged_status = re.compile(r'\* (?P<data>\d+) (?P<type>[A-Z-]+)( (?P<data2>.*))?')

class IMAP4:

    """IMAP4 client class.

    Instantiate with: IMAP4([host[, port]])

            host - host's name (default: localhost);

            port - port number (default: standard IMAP4 port).

    All IMAP4rev1 commands are supported by methods of the same

    name (in lower-case).

    All arguments to commands are converted to strings, except for

    AUTHENTICATE, and the last argument to APPEND which is passed as

    an IMAP4 literal.  If necessary (the string contains any

    non-printing characters or white-space and isn't enclosed with

    either parentheses or double quotes) each string is quoted.

    However, the 'password' argument to the LOGIN command is always

    quoted.  If you want to avoid having an argument string quoted

    (eg: the 'flags' argument to STORE) then enclose the string in

    parentheses (eg: "(\Deleted)").

    Each command returns a tuple: (type, [data, ...]) where 'type'

    is usually 'OK' or 'NO', and 'data' is either the text from the

    tagged response, or untagged results from command. Each 'data'

    is either a string, or a tuple. If a tuple, then the first part

    is the header of the response, and the second part contains

    the data (ie: 'literal' value).

    Errors raise the exception class <instance>.error("<reason>").

    IMAP4 server errors raise <instance>.abort("<reason>"),

    which is a sub-class of 'error'. Mailbox status changes

    from READ-WRITE to READ-ONLY raise the exception class

    <instance>.readonly("<reason>"), which is a sub-class of 'abort'.

    "error" exceptions imply a program error.

    "abort" exceptions imply the connection should be reset, and

            the command re-tried.

    "readonly" exceptions imply the command should be re-tried.

    Note: to use this module, you must read the RFCs pertaining to the

    IMAP4 protocol, as the semantics of the arguments to each IMAP4

    command are left to the invoker, not to mention the results. Also,

    most IMAP servers implement a sub-set of the commands available here.

    """

    class error(Exception): pass    # Logical errors - debug required

    class abort(error): pass        # Service errors - close and retry

    class readonly(abort): pass     # Mailbox status changed to READ-ONLY

    mustquote = re.compile(r"[^\w!#$%&'*+,.:;<=>?^`|~-]")

    def __init__(self, host = '', port = IMAP4_PORT):

        self.debug = Debug

        self.state = 'LOGOUT'

        self.literal = None             # A literal argument to a command

        self.tagged_commands = {}       # Tagged commands awaiting response

        self.untagged_responses = {}    # {typ: [data, ...], ...}

        self.continuation_response = '' # Last continuation response

        self.is_readonly = False        # READ-ONLY desired state

        self.tagnum = 0

        # Open socket to server.

        self.open(host, port)

        # Create unique tag for this session,

        # and compile tagged response matcher.

        self.tagpre = Int2AP(random.randint(4096, 65535))

        self.tagre = re.compile(r'(?P<tag>'

                        + self.tagpre

                        + r'\d+) (?P<type>[A-Z]+) (?P<data>.*)')

        # Get server welcome message,

        # request and store CAPABILITY response.

        if __debug__:

            self._cmd_log_len = 10

            self._cmd_log_idx = 0

            self._cmd_log = {}           # Last `_cmd_log_len' interactions

            if self.debug >= 1:

                self._mesg('imaplib version %s' % __version__)

                self._mesg('new IMAP4 connection, tag=%s' % self.tagpre)

        self.welcome = self._get_response()

        if 'PREAUTH' in self.untagged_responses:

            self.state = 'AUTH'

        elif 'OK' in self.untagged_responses:

            self.state = 'NONAUTH'

        else:

            raise self.error(self.welcome)

        typ, dat = self.capability()

        if dat == [None]:

            raise self.error('no CAPABILITY response from server')

        self.capabilities = tuple(dat[-1].upper().split())

        if __debug__:

            if self.debug >= 3:

                self._mesg('CAPABILITIES: %r' % (self.capabilities,))

        for version in AllowedVersions:

            if not version in self.capabilities:

                continue

            self.PROTOCOL_VERSION = version

            return

        raise self.error('server not IMAP4 compliant')

    def __getattr__(self, attr):

        #       Allow UPPERCASE variants of IMAP4 command methods.

        if attr in Commands:

            return getattr(self, attr.lower())

        raise AttributeError("Unknown IMAP4 command: '%s'" % attr)

    #       Overridable methods

    def open(self, host = '', port = IMAP4_PORT):

        """Setup connection to remote server on "host:port"

            (default: localhost:standard IMAP4 port).

        This connection will be used by the routines:

            read, readline, send, shutdown.

        """

        self.host = host

        self.port = port

        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

        self.sock.connect((host, port))

        self.file = self.sock.makefile('rb')

    def read(self, size):

        """Read 'size' bytes from remote."""

        return self.file.read(size)

    def readline(self):

        """Read line from remote."""

        return self.file.readline()

    def send(self, data):

        """Send data to remote."""

        self.sock.sendall(data)

    def shutdown(self):

        """Close I/O established in "open"."""

        self.file.close()

        self.sock.close()

    def socket(self):

        """Return socket instance used to connect to IMAP4 server.

        socket = <instance>.socket()

        """

        return self.sock

    #       Utility methods

    def recent(self):

        """Return most recent 'RECENT' responses if any exist,

        else prompt server for an update using the 'NOOP' command.

        (typ, [data]) = <instance>.recent()

        'data' is None if no new messages,

        else list of RECENT responses, most recent last.

        """

        name = 'RECENT'

        typ, dat = self._untagged_response('OK', [None], name)

        if dat[-1]:

            return typ, dat

        typ, dat = self.noop()  # Prod server for response

        return self._untagged_response(typ, dat, name)

    def response(self, code):

        """Return data for response 'code' if received, or None.

        Old value for response 'code' is cleared.

        (code, [data]) = <instance>.response(code)

        """

        return self._untagged_response(code, [None], code.upper())

    #       IMAP4 commands

    def append(self, mailbox, flags, date_time, message):

        """Append message to named mailbox.

        (typ, [data]) = <instance>.append(mailbox, flags, date_time, message)

                All args except `message' can be None.

        """

        name = 'APPEND'

        if not mailbox:

            mailbox = 'INBOX'

        if flags:

            if (flags[0],flags[-1]) != ('(',')'):

                flags = '(%s)' % flags

        else:

            flags = None

        if date_time:

            date_time = Time2Internaldate(date_time)

        else:

            date_time = None

        self.literal = MapCRLF.sub(CRLF, message)

        return self._simple_command(name, mailbox, flags, date_time)

    def authenticate(self, mechanism, authobject):

        """Authenticate command - requires response processing.

        'mechanism' specifies which authentication mechanism is to

        be used - it must appear in <instance>.capabilities in the

        form AUTH=<mechanism>.

        'authobject' must be a callable object:

                data = authobject(response)

        It will be called to process server continuation responses.

        It should return data that will be encoded and sent to server.

        It should return None if the client abort response '*' should

        be sent instead.

        """

        mech = mechanism.upper()

        # XXX: shouldn't this code be removed, not commented out?

        #cap = 'AUTH=%s' % mech

        #if not cap in self.capabilities:       # Let the server decide!

        #    raise self.error("Server doesn't allow %s authentication." % mech)

        self.literal = _Authenticator(authobject).process

        typ, dat = self._simple_command('AUTHENTICATE', mech)

        if typ != 'OK':

            raise self.error(dat[-1])

        self.state = 'AUTH'

        return typ, dat

    def capability(self):

        """(typ, [data]) = <instance>.capability()

        Fetch capabilities list from server."""

        name = 'CAPABILITY'

        typ, dat = self._simple_command(name)

        return self._untagged_response(typ, dat, name)

    def check(self):

        """Checkpoint mailbox on server.

        (typ, [data]) = <instance>.check()

        """

        return self._simple_command('CHECK')

    def close(self):

        """Close currently selected mailbox.

        Deleted messages are removed from writable mailbox.

        This is the recommended command before 'LOGOUT'.

        (typ, [data]) = <instance>.close()

        """

        try:

            typ, dat = self._simple_command('CLOSE')

        finally:

            self.state = 'AUTH'

        return typ, dat

    def copy(self, message_set, new_mailbox):

        """Copy 'message_set' messages onto end of 'new_mailbox'.

        (typ, [data]) = <instance>.copy(message_set, new_mailbox)

        """

        return self._simple_command('COPY', message_set, new_mailbox)

    def create(self, mailbox):

        """Create new mailbox.

        (typ, [data]) = <instance>.create(mailbox)

        """

        return self._simple_command('CREATE', mailbox)

    def delete(self, mailbox):

        """Delete old mailbox.

        (typ, [data]) = <instance>.delete(mailbox)

        """

        return self._simple_command('DELETE', mailbox)

    def deleteacl(self, mailbox, who):

        """Delete the ACLs (remove any rights) set for who on mailbox.

        (typ, [data]) = <instance>.deleteacl(mailbox, who)

        """

        return self._simple_command('DELETEACL', mailbox, who)

    def expunge(self):

        """Permanently remove deleted items from selected mailbox.

        Generates 'EXPUNGE' response for each deleted message.

        (typ, [data]) = <instance>.expunge()

        'data' is list of 'EXPUNGE'd message numbers in order received.

        """

        name = 'EXPUNGE'

        typ, dat = self._simple_command(name)

        return self._untagged_response(typ, dat, name)

    def fetch(self, message_set, message_parts):

        """Fetch (parts of) messages.

        (typ, [data, ...]) = <instance>.fetch(message_set, message_parts)

        'message_parts' should be a string of selected parts

        enclosed in parentheses, eg: "(UID BODY[TEXT])".

        'data' are tuples of message part envelope and data.

        """

        name = 'FETCH'

        typ, dat = self._simple_command(name, message_set, message_parts)

        return self._untagged_response(typ, dat, name)

    def getacl(self, mailbox):

        """Get the ACLs for a mailbox.

        (typ, [data]) = <instance>.getacl(mailbox)

        """

        typ, dat = self._simple_command('GETACL', mailbox)

        return self._untagged_response(typ, dat, 'ACL')

    def getannotation(self, mailbox, entry, attribute):

        """(typ, [data]) = <instance>.getannotation(mailbox, entry, attribute)

        Retrieve ANNOTATIONs."""

        typ, dat = self._simple_command('GETANNOTATION', mailbox, entry, attribute)

        return self._untagged_response(typ, dat, 'ANNOTATION')

    def getquota(self, root):

        """Get the quota root's resource usage and limits.

        Part of the IMAP4 QUOTA extension defined in rfc2087.

        (typ, [data]) = <instance>.getquota(root)

        """

        typ, dat = self._simple_command('GETQUOTA', root)

        return self._untagged_response(typ, dat, 'QUOTA')

    def getquotaroot(self, mailbox):

        """Get the list of quota roots for the named mailbox.

        (typ, [[QUOTAROOT responses...], [QUOTA responses]]) = <instance>.getquotaroot(mailbox)

        """

        typ, dat = self._simple_command('GETQUOTAROOT', mailbox)

        typ, quota = self._untagged_response(typ, dat, 'QUOTA')

        typ, quotaroot = self._untagged_response(typ, dat, 'QUOTAROOT')

        return typ, [quotaroot, quota]

    def list(self, directory='""', pattern='*'):

        """List mailbox names in directory matching pattern.

        (typ, [data]) = <instance>.list(directory='""', pattern='*')

        'data' is list of LIST responses.

        """

        name = 'LIST'

        typ, dat = self._simple_command(name, directory, pattern)

        return self._untagged_response(typ, dat, name)

    def login(self, user, password):

        """Identify client using plaintext password.

        (typ, [data]) = <instance>.login(user, password)

        NB: 'password' will be quoted.

        """

        typ, dat = self._simple_command('LOGIN', user, self._quote(password))

        if typ != 'OK':

            raise self.error(dat[-1])

        self.state = 'AUTH'

        return typ, dat

    def login_cram_md5(self, user, password):

        """ Force use of CRAM-MD5 authentication.

        (typ, [data]) = <instance>.login_cram_md5(user, password)

        """

        self.user, self.password = user, password

        return self.authenticate('CRAM-MD5', self._CRAM_MD5_AUTH)

    def _CRAM_MD5_AUTH(self, challenge):

        """ Authobject to use with CRAM-MD5 authentication. """

        import hmac

        return self.user + " " + hmac.HMAC(self.password, challenge).hexdigest()

    def logout(self):

        """Shutdown connection to server.

        (typ, [data]) = <instance>.logout()

        Returns server 'BYE' response.

        """

        self.state = 'LOGOUT'