# 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.
    """
    res = _parsedate_tz(data)
    if not res:
        return
    if res[9] is None:
        res[9] = 0
    return tuple(res)


def _parsedate_tz(data):
    """Convert date to extended time tuple.

    The last (additional) element is the time zone offset in seconds, except if
    the timezone was specified as -0000.  In that case the last element is
    None.  This indicates a UTC timestamp that explicitly declaims knowledge of
    the source timezone, as opposed to a +0000 timestamp that indicates the
    source timezone really was UTC.

    """
    if not data:
        return
    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 == -1:
            i = s.find("-")
        if i > 0:
            data[3:] = [s[:i], s[i:]]
        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
    elif len(tm) == 1 and "." in tm[0]:
        # Some non-compliant MUAs use '.' to separate time elements.
        tm = tm[0].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
        if tzoffset == 0 and tz.startswith("-"):
            tzoffset = None
    # 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 Time flag is set to -1, since DST is unknown.
    return [yy, mm, dd, thh, tmm, tss, 0, 1, -1, tzoffset]


def parsedate(data):
    """Convert a time string to a time tuple."""
    t = parsedate_tz(data)
    if isinstance(t, tuple):
        return t[:9]
    else:
        return t


def mktime_tz(data):
    """Turn a 10-tuple as returned by parsedate_tz() into a POSIX timestamp."""
    if data[9] is None:
        # No zone info, so localtime is better assumption than GMT
        return time.mktime(data[:8] + (-1,))
    else:
        t = calendar.timegm(data)
        return t - data[9]


def quote(str):
    """Prepare string to be used in a quoted string.

    Turns backslash and double quote characters into quoted pairs.  These
    are the only characters that need to be quoted inside a quoted string.
    Does not add the surrounding double quotes.
    """
    return str.replace("\\", "\\\\").replace('"', '\\"')


class AddrlistClass:
    """Address parser class by Ben Escoto.

    To understand what this class does, it helps to have a copy of RFC 2822 in
    front of you.

    Note: this class interface is deprecated and may be removed in the future.
    Use email.utils.AddressList instead.
    """

    def __init__(self, field):
        """Initialize a new instance.

        `field' is an unparsed address header field, containing
        one or more addresses.
        """
        self.specials = '()<>@,:;."[]'
        self.pos = 0
        self.LWS = " \t"
        self.CR = "\r\n"
        self.FWS = self.LWS + self.CR
        self.atomends = self.specials + self.LWS + self.CR
        # Note that RFC 2822 now specifies `.' as obs-phrase, meaning that it
        # is obsolete syntax.  RFC 2822 requires that we recognize obsolete
        # syntax, so allow dots in phrases.
        self.phraseends = self.atomends.replace(".", "")
        self.field = field
        self.commentlist = []

    def gotonext(self):
        """Skip white space and extract comments."""
        wslist = []
        while self.pos < len(self.field):
            if self.field[self.pos] in self.LWS + "\n\r":
                if self.field[self.pos] not in "\n\r":
                    wslist.append(self.field[self.pos])
                self.pos += 1
            elif self.field[self.pos] == "(":
                self.commentlist.append(self.getcomment())
            else:
                break
        return EMPTYSTRING.join(wslist)

    def getaddrlist(self):
        """Parse all addresses.

        Returns a list containing all of the addresses.
        """
        result = []
        while self.pos < len(self.field):
            ad = self.getaddress()
            if ad:
                result += ad
            else:
                result.append(("", ""))
        return result

    def getaddress(self):
        """Parse the next address."""
        self.commentlist = []
        self.gotonext()

        oldpos = self.pos
        oldcl = self.commentlist
        plist = self.getphraselist()

        self.gotonext()
        returnlist = []

        if self.pos >= len(self.field):
            # Bad email address technically, no domain.
            if plist:
                returnlist = [(SPACE.join(self.commentlist), plist[0])]

        elif self.field[self.pos] in ".@":
            # email address is just an addrspec
            # this isn't very efficient since we start over
            self.pos = oldpos
            self.commentlist = oldcl
            addrspec = self.getaddrspec()
            returnlist = [(SPACE.join(self.commentlist), addrspec)]

        elif self.field[self.pos] == ":":
            # address is a group
            returnlist = []

            fieldlen = len(self.field)
            self.pos += 1
            while self.pos < len(self.field):
                self.gotonext()
                if self.pos < fieldlen and self.field[self.pos] == ";":
                    self.pos += 1
                    break
                returnlist = returnlist + self.getaddress()

        elif self.field[self.pos] == "<":
            # Address is a phrase then a route addr
            routeaddr = self.getrouteaddr()

            if self.commentlist:
                returnlist = [
                    (SPACE.join(plist) + " (" + " ".join(self.commentlist) + ")", routeaddr)
                ]
            else:
                returnlist = [(SPACE.join(plist), routeaddr)]

        else:
            if plist:
                returnlist = [(SPACE.join(self.commentlist), plist[0])]
            elif self.field[self.pos] in self.specials:
                self.pos += 1

        self.gotonext()
        if self.pos < len(self.field) and self.field[self.pos] == ",":
            self.pos += 1
        return returnlist

    def getrouteaddr(self):
        """Parse a route address (Return-path value).

        This method just skips all the route stuff and returns the addrspec.
        """
        if self.field[self.pos] != "<":
            return

        expectroute = False
        self.pos += 1
        self.gotonext()
        adlist = ""
        while self.pos < len(self.field):
            if expectroute:
                self.getdomain()
                expectroute = False
            elif self.field[self.pos] == ">":
                self.pos += 1
                break
            elif self.field[self.pos] == "@":
                self.pos += 1
                expectroute = True
            elif self.field[self.pos] == ":":
                self.pos += 1
            else:
                adlist = self.getaddrspec()
                self.pos += 1
                break
            self.gotonext()

        return adlist

    def getaddrspec(self):
        """Parse an RFC 2822 addr-spec."""
        aslist = []

        self.gotonext()
        while self.pos < len(self.field):
            preserve_ws = True
            if self.field[self.pos] == ".":
                if aslist and not aslist[-1].strip():
                    aslist.pop()
                aslist.append(".")
                self.pos += 1
                preserve_ws = False
            elif self.field[self.pos] == '"':
                aslist.append('"%s"' % quote(self.getquote()))
            elif self.field[self.pos] in self.atomends:
                if aslist and not aslist[-1].strip():
                    aslist.pop()
                break
            else:
                aslist.append(self.getatom())
            ws = self.gotonext()
            if preserve_ws and ws:
                aslist.append(ws)

        if self.pos >= len(self.field) or self.field[self.pos] != "@":
            return EMPTYSTRING.join(aslist)

        aslist.append("@")
        self.pos += 1
        self.gotonext()
        return EMPTYSTRING.join(aslist) + self.getdomain()

    def getdomain(self):
        """Get the complete domain name from an address."""
        sdlist = []
        while self.pos < len(self.field):
            if self.field[self.pos] in self.LWS:
                self.pos += 1
            elif self.field[self.pos] == "(":
                self.commentlist.append(self.getcomment())
            elif self.field[self.pos] == "[":
                sdlist.append(self.getdomainliteral())
            elif self.field[self.pos] == ".":
                self.pos += 1
                sdlist.append(".")
            elif self.field[self.pos] in self.atomends:
                break
            else:
                sdlist.append(self.getatom())
        return EMPTYSTRING.join(sdlist)

    def getdelimited(self, beginchar, endchars, allowcomments=True):
        """Parse a header fragment delimited by special characters.

        `beginchar' is the start character for the fragment.
        If self is not looking at an instance of `beginchar' then
        getdelimited returns the empty string.

        `endchars' is a sequence of allowable end-delimiting characters.
        Parsing stops when one of these is encountered.

        If `allowcomments' is non-zero, embedded RFC 2822 comments are allowed
        within the parsed fragment.
        """
        if self.field[self.pos] != beginchar:
            return ""

        slist = [""]
        quote = False
        self.pos += 1
        while self.pos < len(self.field):
            if quote:
                slist.append(self.field[self.pos])
                quote = False
            elif self.field[self.pos] in endchars:
                self.pos += 1
                break
            elif allowcomments and self.field[self.pos] == "(":
                slist.append(self.getcomment())
                continue  # have already advanced pos from getcomment
            elif self.field[self.pos] == "\\":
                quote = True
            else:
                slist.append(self.field[self.pos])
            self.pos += 1

        return EMPTYSTRING.join(slist)

    def getquote(self):
        """Get a quote-delimited fragment from self's field."""
        return self.getdelimited('"', '"\r', False)

    def getcomment(self):
        """Get a parenthesis-delimited fragment from self's field."""
        return self.getdelimited("(", ")\r", True)

    def getdomainliteral(self):
        """Parse an RFC 2822 domain-literal."""
        return "[%s]" % self.getdelimited("[", "]\r", False)

    def getatom(self, atomends=None):
        """Parse an RFC 2822 atom.

        Optional atomends specifies a different set of end token delimiters
        (the default is to use self.atomends).  This is used e.g. in
        getphraselist() since phrase endings must not include the `.' (which
        is legal in phrases)."""
        atomlist = [""]
        if atomends is None:
            atomends = self.atomends

        while self.pos < len(self.field):
            if self.field[self.pos] in atomends:
                break
            else:
                atomlist.append(self.field[self.pos])
            self.pos += 1

        return EMPTYSTRING.join(atomlist)

    def getphraselist(self):
        """Parse a sequence of RFC 2822 phrases.

        A phrase is a sequence of words, which are in turn either RFC 2822
        atoms or quoted-strings.  Phrases are canonicalized by squeezing all
        runs of continuous whitespace into one space.
        """
        plist = []

        while self.pos < len(self.field):
            if self.field[self.pos] in self.FWS:
                self.pos += 1
            elif self.field[self.pos] == '"':
                plist.append(self.getquote())
            elif self.field[self.pos] == "(":
                self.commentlist.append(self.getcomment())
            elif self.field[self.pos] in self.phraseends:
                break
            else:
                plist.append(self.getatom(self.phraseends))

        return plist


class AddressList(AddrlistClass):
    """An AddressList encapsulates a list of parsed RFC 2822 addresses."""

    def __init__(self, field):
        AddrlistClass.__init__(self, field)
        if field:
            self.addresslist = self.getaddrlist()
        else:
            self.addresslist = []

    def __len__(self):
        return len(self.addresslist)

    def __add__(self, other):
        # Set union
        newaddr = AddressList(None)
        newaddr.addresslist = self.addresslist[:]
        for x in other.addresslist:
            if not x in self.addresslist:
                newaddr.addresslist.append(x)
        return newaddr

    def __iadd__(self, other):
        # Set union, in-place
        for x in other.addresslist:
            if not x in self.addresslist:
                self.addresslist.append(x)
        return self

    def __sub__(self, other):
        # Set difference
        newaddr = AddressList(None)
        for x in self.addresslist:
            if not x in other.addresslist:
                newaddr.addresslist.append(x)
        return newaddr

    def __isub__(self, other):
        # Set difference, in-place
        for x in other.addresslist:
            if x in self.addresslist:
                self.addresslist.remove(x)
        return self

    def __getitem__(self, index):
        # Make indexing, slices, and 'in' work
        return self.addresslist[index]