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    # Copyright (C) 2002-2007 Python Software Foundation
# Contact: email-sig@python.org

"""Email address parsing code.

Lifted directly from rfc822.py.  This should eventually be rewritten.
"""

__all__ = [
    'mktime_tz',
    'parsedate',
    'parsedate_tz',
    'quote',
    ]

import time, calendar

SPACE = ' '
EMPTYSTRING = ''
COMMASPACE = ', '

# Parse a date field
_monthnames = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul',
               'aug', 'sep', 'oct', 'nov', 'dec',
               'january', 'february', 'march', 'april', 'may', 'june', 'july',
               'august', 'september', 'october', 'november', 'december']

_daynames = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']

# The timezone table does not include the military time zones defined
# in RFC822, other than Z.  According to RFC1123, the description in
# RFC822 gets the signs wrong, so we can't rely on any such time
# zones.  RFC1123 recommends that numeric timezone indicators be used
# instead of timezone names.

_timezones = {'UT':0, 'UTC':0, 'GMT':0, 'Z':0,
              'AST': -400, 'ADT': -300,  # Atlantic (used in Canada)
              'EST': -500, 'EDT': -400,  # Eastern
              'CST': -600, 'CDT': -500,  # Central
              'MST': -700, 'MDT': -600,  # Mountain
              'PST': -800, 'PDT': -700   # Pacific
              }


def parsedate_tz(data):
    """Convert a date string to a time tuple.

    Accounts for military timezones.
    """
    data = data.split()
    # The FWS after the comma after the day-of-week is optional, so search and
    # adjust for this.
    if data[0].endswith(',') or data[0].lower() in _daynames:
        # There's a dayname here. Skip it
        del data[0]
    else:
        i = data[0].rfind(',')
        if i >= 0:
            data[0] = data[0][i+1:]
    if len(data) == 3: # RFC 850 date, deprecated
        stuff = data[0].split('-')
        if len(stuff) == 3:
            data = stuff + data[1:]
    if len(data) == 4:
        s = data[3]
        i = s.find('+')
        if i > 0:
            data[3:] = [s[:i], s[i+1:]]
        else:
            data.append('') # Dummy tz
    if len(data) < 5:
        return None
    data = data[:5]
    [dd, mm, yy, tm, tz] = data
    mm = mm.lower()
    if mm not in _monthnames:
        dd, mm = mm, dd.lower()
        if mm not in _monthnames:
            return None
    mm = _monthnames.index(mm) + 1
    if mm > 12:
        mm -= 12
    if dd[-1] == ',':
        dd = dd[:-1]
    i = yy.find(':')
    if i > 0:
        yy, tm = tm, yy
    if yy[-1] == ',':
        yy = yy[:-1]
    if not yy[0].isdigit():
        yy, tz = tz, yy
    if tm[-1] == ',':
        tm = tm[:-1]
    tm = tm.split(':')
    if len(tm) == 2:
        [thh, tmm] = tm
        tss = '0'
    elif len(tm) == 3:
        [thh, tmm, tss] = tm
    else:
        return None
    try:
        yy = int(yy)
        dd = int(dd)
        thh = int(thh)
        tmm = int(tmm)
        tss = int(tss)
    except ValueError:
        return None
    # Check for a yy specified in two-digit format, then convert it to the
    # appropriate four-digit format, according to the POSIX standard. RFC 822
    # calls for a two-digit yy, but RFC 2822 (which obsoletes RFC 822)
    # mandates a 4-digit yy. For more information, see the documentation for
    # the time module.
    if yy < 100:
        # The year is between 1969 and 1999 (inclusive).
        if yy > 68:
            yy += 1900
        # The year is between 2000 and 2068 (inclusive).
        else:
            yy += 2000
    tzoffset = None
    tz = tz.upper()
    if tz in _timezones:
        tzoffset = _timezones[tz]
    else:
        try:
            tzoffset = int(tz)
        except ValueError:
            pass
    # Convert a timezone offset into seconds ; -0500 -> -18000
    if tzoffset:
        if tzoffset < 0:
            tzsign = -1
            tzoffset = -tzoffset
        else:
            tzsign = 1
        tzoffset = tzsign * ( (tzoffset//100)*3600 + (tzoffset % 100)*60)
    # Daylight Saving Tim