# Copyright (C) 2001-2006 Python Software Foundation

# Author: Barry Warsaw

# Contact: email-sig@python.org

"""Miscellaneous utilities."""

__all__ = [

    'collapse_rfc2231_value',

    'decode_params',

    'decode_rfc2231',

    'encode_rfc2231',

    'formataddr',

    'formatdate',

    'getaddresses',

    'make_msgid',

    'parseaddr',

    'parsedate',

    'parsedate_tz',

    'unquote',

    ]

import os

import re

import time

import base64

import random

import socket

import urllib

import warnings

from cStringIO import StringIO

from email._parseaddr import quote

from email._parseaddr import AddressList as _AddressList

from email._parseaddr import mktime_tz

# We need wormarounds for bugs in these methods in older Pythons (see below)

from email._parseaddr import parsedate as _parsedate

from email._parseaddr import parsedate_tz as _parsedate_tz

from quopri import decodestring as _qdecode

# Intrapackage imports

from email.encoders import _bencode, _qencode

COMMASPACE = ', '

EMPTYSTRING = ''

UEMPTYSTRING = u''

CRLF = '\r\n'

TICK = "'"

specialsre = re.compile(r'[][\\()<>@,:;".]')

escapesre = re.compile(r'[][\\()"]')

# Helpers

def _identity(s):

    return s

def _bdecode(s):

    # We can't quite use base64.encodestring() since it tacks on a "courtesy

    # newline".  Blech!

    if not s:

        return s

    value = base64.decodestring(s)

    if not s.endswith('\n') and value.endswith('\n'):

        return value[:-1]

    return value

def fix_eols(s):

    """Replace all line-ending characters with \r\n."""

    # Fix newlines with no preceding carriage return

    s = re.sub(r'(?<!\r)\n', CRLF, s)

    # Fix carriage returns with no following newline

    s = re.sub(r'\r(?!\n)', CRLF, s)

    return s

def formataddr(pair):

    """The inverse of parseaddr(), this takes a 2-tuple of the form

    (realname, email_address) and returns the string value suitable

    for an RFC 2822 From, To or Cc header.

    If the first element of pair is false, then the second element is

    returned unmodified.

    """

    name, address = pair

    if name:

        quotes = ''

        if specialsre.search(name):

            quotes = '"'

        name = escapesre.sub(r'\\\g<0>', name)

        return '%s%s%s <%s>' % (quotes, name, quotes, address)

    return address

def getaddresses(fieldvalues):

    """Return a list of (REALNAME, EMAIL) for each fieldvalue."""

    all = COMMASPACE.join(fieldvalues)

    a = _AddressList(all)

    return a.addresslist

ecre = re.compile(r'''

  =\?                   # literal =?

  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset

  \?                    # literal ?

  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive

  \?                    # literal ?

  (?P<atom>.*?)         # non-greedy up to the next ?= is the atom

  \?=                   # literal ?=

  ''', re.VERBOSE | re.IGNORECASE)

def formatdate(timeval=None, localtime=False, usegmt=False):

    """Returns a date string as specified by RFC 2822, e.g.:

    Fri, 09 Nov 2001 01:08:47 -0000

    Optional timeval if given is a floating point time value as accepted by

    gmtime() and localtime(), otherwise the current time is used.

    Optional localtime is a flag that when True, interprets timeval, and

    returns a date relative to the local timezone instead of UTC, properly

    taking daylight savings time into account.

    Optional argument usegmt means that the timezone is written out as

    an ascii string, not numeric one (so "GMT" instead of "+0000"). This

    is needed for HTTP, and is only used when localtime==False.

    """

    # Note: we cannot use strftime() because that honors the locale and RFC

    # 2822 requires that day and month names be the English abbreviations.

    if timeval is None:

        timeval = time.time()

    if localtime:

        now = time.localtime(timeval)

        # Calculate timezone offset, based on whether the local zone has

        # daylight savings time, and whether DST is in effect.

        if time.daylight and now[-1]:

            offset = time.altzone

        else:

            offset = time.timezone

        hours, minutes = divmod(abs(offset), 3600)

        # Remember offset is in seconds west of UTC, but the timezone is in

        # minutes east of UTC, so the signs differ.

        if offset > 0:

            sign = '-'

        else:

            sign = '+'

        zone = '%s%02d%02d' % (sign, hours, minutes // 60)

    else:

        now = time.gmtime(timeval)

        # Timezone offset is always -0000

        if usegmt:

            zone = 'GMT'

        else:

            zone = '-0000'

    return '%s, %02d %s %04d %02d:%02d:%02d %s' % (

        ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][now[6]],

        now[2],

        ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',

         'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][now[1] - 1],

        now[0], now[3], now[4], now[5],

        zone)

def make_msgid(idstring=None):

    """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:

    <20020201195627.33539.96671@nightshade.la.mastaler.com>

    Optional idstring if given is a string used to strengthen the

    uniqueness of the message id.

    """

    timeval = time.time()

    utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval))

    pid = os.getpid()

    randint = random.randrange(100000)

    if idstring is None:

        idstring = ''

    else:

        idstring = '.' + idstring

    idhost = socket.getfqdn()

    msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, idhost)

    return msgid

# These functions are in the standalone mimelib version only because they've

# subsequently been fixed in the latest Python versions.  We use this to worm

# around broken older Pythons.

def parsedate(data):

    if not data:

        return None

    return _parsedate(data)

def parsedate_tz(data):

    if not data:

        return None

    return _parsedate_tz(data)

def parseaddr(addr):

    addrs = _AddressList(addr).addresslist

    if not addrs:

        return '', ''

    return addrs[0]

# rfc822.unquote() doesn't properly de-backslash-ify in Python pre-2.3.

def unquote(str):

    """Remove quotes from a string."""

    if len(str) > 1:

        if str.startswith('"') and str.endswith('"'):

            return str[1:-1].replace('\\\\', '\\').replace('\\"', '"')

        if str.startswith('<') and str.endswith('>'):

            return str[1:-1]

    return str

# RFC2231-related functions - parameter encoding and decoding

def decode_rfc2231(s):

    """Decode string according to RFC 2231"""

    parts = s.split(TICK, 2)

    if len(parts) <= 2:

        return None, None, s

    return parts

def encode_rfc2231(s, charset=None, language=None):

    """Encode string according to RFC 2231.

    If neither charset nor language is given, then s is returned as-is.  If

    charset is given but not language, the string is encoded using the empty

    string for language.

    """

    import urllib

    s = urllib.quote(s, safe='')

    if charset is None and language is None:

        return s

    if language is None:

        language = ''

    return "%s'%s'%s" % (charset, language, s)

rfc2231_continuation = re.compile(r'^(?P<name>\w+)\*((?P<num>[0-9]+)\*?)?$')

def decode_params(params):

    """Decode parameters list according to RFC 2231.

    params is a sequence of 2-tuples containing (param name, string value).

    """

    # Copy params so we don't mess with the original

    params = params[:]

    new_params = []

    # Map parameter's name to a list of continuations.  The values are a

    # 3-tuple of the continuation number, the string value, and a flag

    # specifying whether a particular segment is %-encoded.

    rfc2231_params = {}

    name, value = params.pop(0)

    new_params.append((name, value))

    while params:

        name, value = params.pop(0)

        if name.endswith('*'):

            encoded = True

        else:

            encoded = False

        value = unquote(value)

        mo = rfc2231_continuation.match(name)

        if mo:

            name, num = mo.group('name', 'num')

            if num is not None:

                num = int(num)

            rfc2231_params.setdefault(name, []).append((num, value, encoded))

        else:

            new_params.append((name, '"%s"' % quote(value)))

    if rfc2231_params:

        for name, continuations in rfc2231_params.items():

            value = []

            extended = False

            # Sort by number

            continuations.sort()

            # And now append all values in numerical order, converting

            # %-encodings for the encoded segments.  If any of the

            # continuation names ends in a *, then the entire string, after

            # decoding segments and concatenating, must have the charset and

            # language specifiers at the beginning of the string.

            for num, s, encoded in continuations:

                if encoded:

                    s = urllib.unquote(s)

                    extended = True

                value.append(s)

            value = quote(EMPTYSTRING.join(value))

            if extended:

                charset, language, value = decode_rfc2231(value)

                new_params.append((name, (charset, language, '"%s"' % value)))

            else:

                new_params.append((name, '"%s"' % value))

    return new_params

def collapse_rfc2231_value(value, errors='replace',

                           fallback_charset='us-ascii'):

    if isinstance(value, tuple):

        rawval = unquote(value[2])

        charset = value[0] or 'us-ascii'

        try:

            return unicode(rawval, charset, errors)

        except LookupError:

            # XXX charset is unknown to Python.

            return unicode(rawval, fallback_charset, errors)

    else:

        return unquote(value)