#!/usr/bin/env python

###
# Copyright (c) 2002, Jeremiah Fincher
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###

"""
Provides a great number of useful utility functions IRC.  Things to muck around
with hostmasks, set bold or color on strings, IRC-case-insensitive dicts, a
nick class to handle nicks (so comparisons and hashing and whatnot work in an
IRC-case-insensitive fashion), and numerous other things.
"""

import fix

import re
import sets
import string
import fnmatch
import operator

def isUserHostmask(s):
    """Returns whether or not the string s is a valid User hostmask."""
    p1 = s.find('!')
    p2 = s.find('@')
    if p1 < p2-1 and p1 >= 1 and p2 >= 3 and len(s) > p2+1:
        return True
    else:
        return False

def isServerHostmask(s):
    """Returns True if s is a valid server hostmask."""
    return not isUserHostmask(s)

def nickFromHostmask(hostmask):
    """Returns the nick from a user hostmask."""
    assert isUserHostmask(hostmask)
    return hostmask.split('!', 1)[0]

def userFromHostmask(hostmask):
    """Returns the user from a user hostmask."""
    assert isUserHostmask(hostmask)
    return hostmask.split('!', 1)[1].split('@', 1)[0]

def hostFromHostmask(hostmask):
    """Returns the host from a user hostmask."""
    assert isUserHostmask(hostmask)
    return hostmask.split('@', 1)[1]

def splitHostmask(hostmask):
    """Returns the nick, user, host of a user hostmask."""
    assert isUserHostmask(hostmask)
    nick, rest = hostmask.split('!', 1)
    user, host = rest.split('@', 1)
    return (nick, user, host)

def joinHostmask(nick, ident, host):
    """Joins the nick, ident, host into a user hostmask."""
    assert nick and ident and host
    return '%s!%s@%s' % (nick, ident, host)

_lowertrans = string.maketrans(string.ascii_uppercase + r'\[]~',
                               string.ascii_lowercase + r'|{}^')
def toLower(s):
    """Returns the string s lowered according to IRC case rules."""
    return s.translate(_lowertrans)

def nickEqual(nick1, nick2):
    """Returns True if nick1 == nick2 according to IRC case rules."""
    return toLower(nick1) == toLower(nick2)

_nickchars = r'_[]\`^{}|-'
_nickre = re.compile(r'^[A-Za-z%s][0-9A-Za-z%s]+$' % (re.escape(_nickchars),
                                                      re.escape(_nickchars)))
def isNick(s):
    """Returns True if s is a valid IRC nick."""
    if re.match(_nickre, s):
        return True
    else:
        return False

def isChannel(s):
    """Returns True if s is a valid IRC channel name."""
    return (s and s[0] in '#&+!' and len(s) <= 50 and \
            '\x07' not in s and ',' not in s and ' ' not in s)

def hostmaskPatternEqual(pattern, hostmask):
    """Returns True if hostmask matches the hostmask pattern pattern."""
    return fnmatch.fnmatch(toLower(hostmask), toLower(pattern))

_ipchars = string.digits + '.'
def isIP(s):
    """Not quite perfect, but close enough until I can find the regexp I want.

    >>> isIP('255.255.255.255')
    1

    >>> isIP('abc.abc.abc.abc')
    0
    """
    if s.translate(string.ascii, _ipchars) == '':
        quads = s.split('.')
        if len(quads) <= 4:
            for quad in quads:
                if int(quad) >= 256:
                    return False
            return True
        else:
            return False
    else:
        return False

def banmask(hostmask):
    """Returns a properly generic banning hostmask for a hostmask.

    >>> banmask('nick!user@host.domain.tld')
    '*!*@*.domain.tld'

    >>> banmask('nick!user@10.0.0.1')
    '*!*@10.0.0.*'
    """
    assert isUserHostmask(hostmask)
    host = hostFromHostmask(hostmask)
    if isIP(host):
        return ('*!*@%s.*' % host[:host.rfind('.')])
    else:
        return ('*!*@*%s' % host[host.find('.'):])

_argModes = 'ovhblkqe'
def separateModes(args):
    """Separates modelines into single mode change tuples.  Basically, you
    should give it the .args of a MODE IrcMsg.

    Examples:

    >>> separateModes(['+ooo', 'jemfinch', 'StoneTable', 'philmes'])
    [('+o', 'jemfinch'), ('+o', 'StoneTable'), ('+o', 'philmes')]

    >>> separateModes(['+o-o', 'jemfinch', 'PeterB'])
    [('+o', 'jemfinch'), ('-o', 'PeterB')]

    >>> separateModes(['+s-o', 'test'])
    [('+s', None), ('-o', 'test')]

    >>> separateModes(['+sntl', '100'])
    [('+s', None), ('+n', None), ('+t', None), ('+l', '100')]
    """
    modes = args[0]
    assert modes[0] in '+-', 'Invalid args: %r' % args
    args = list(args[1:])
    ret = []
    index = 0
    length = len(modes)
    while index < length:
        if modes[index] in '+-':
            last = modes[index]
            index += 1
        else:
            if modes[index] in _argModes:
                ret.append((last + modes[index], args.pop(0)))
            else:
                ret.append((last + modes[index], None))
            index += 1
    return ret

def joinModes(modes):
    """Joins modes of the same form as returned by separateModes."""
    args = []
    modeChars = []
    currentMode = '\x00'
    for (mode, arg) in modes:
        if arg is not None:
            args.append(arg)
        if not mode.startswith(currentMode):
            currentMode = mode[0]
            modeChars.append(mode[0])
        modeChars.append(mode[1])
    args.insert(0, ''.join(modeChars))
    return args

def bold(s):
    """Returns the string s, bolded."""
    return '\x02%s\x0F' % s

def reverse(s):
    """Returns the string s, reverse-videoed."""
    return '\x16%s\x0F' % s

def underline(s):
    """Returns the string s, underlined."""
    return '\x1F%s\x0F' % s

mircColors = {
    None: '',
    'white': 0,
    'black': 1,
    'blue': 2,
    'green': 3,
    'red': 4,
    'brown': 5,
    'purple': 6,
    'orange': 7,
    'yellow': 8,
    'light green': 9,
    'teal': 10,
    'light blue': 11,
    'dark blue': 12,
    'pink': 13,
    'dark grey': 14,
    'light grey': 15,
}

# Offer a reverse mapping from integers to their associated colors.
for (k, v) in mircColors.items():
    if k is not None: # Ignore empty string for None.
        mircColors[v] = k

def mircColor(s, fg=None, bg=None):
    """Returns s with the appropriate mIRC color codes applied."""
    if fg is None and bg is None:
        return s
    if fg is None or isinstance(fg, str):
        fg = mircColors[fg]
    if bg is None:
        return '\x03%s%s\x0F' % (fg, s)
    else:
        if isinstance(bg, str):
            bg = mircColors[bg]
        return '\x03%s,%s%s\x0F' % (fg, bg, s)

def canonicalColor(s, bg=False, shift=0):
    """Assigns an (fg, bg) canonical color pair to a string based on its hash
    value.  This means it might change between Python versions.  This pair can
    be used as a *parameter to mircColor.  The shift parameter is how much to
    right-shift the hash value initially.
    """
    h = hash(s) >> shift
    fg = h % 14 + 2 # The + 2 is to rule out black and white.
    if bg:
        bg = (h >> 4) & 3 # The 5th, 6th, and 7th least significant bits.
        if fg < 8:
            bg += 8
        else:
            bg += 2
        return (fg, bg)
    else:
        return (fg, None)

_unColorRe = re.compile('(?:\x03\\d{1,2},\\d{1,2})|\x03\\d{1,2}|\x03|\x0F')
def unColor(s):
    """Removes the color from a string."""
    return _unColorRe.sub('', s)

def isValidArgument(s):
    """Returns if s is strictly a valid argument for an IRC message."""
    return '\r' not in s and '\n' not in s and '\x00' not in s

notFunky = string.ascii[32:]+'\x02\x03\x0F\x16\x1F'
def safeArgument(s):
    """If s is unsafe for IRC, returns a safe version."""
    if isValidArgument(s) and s.translate(string.ascii, notFunky) == '':
        return s
    else:
        return repr(s)

def replyTo(msg):
    """Returns the appropriate target to send responses to msg."""
    if isChannel(msg.args[0]):
        return msg.args[0]
    else:
        return msg.nick

def privmsgPayload(L, sep, limit=425):
    """Returns a valid privmsg payload given a list of strings and a separator.

    Items are popped from the back of the list until the payload is small
    enough to fit into a single PRIVMSG payload.
    """
    shrinkList(L, sep, limit)
    return sep.join(L)

def shrinkList(L, sep='', limit=425):
    """Shrinks a list of strings to a given combined length of limit."""
    length = len(sep)
    count = 0
    while reduce(operator.add, map(length.__add__, map(len, L)), 0) > limit:
        L.pop()
        count += 1
    return count

def dccIP(ip):
    """Returns in IP in the proper for DCC."""
    assert isIP(ip), 'argument must be a string ip in xxx.yyy.zzz.www format.'
    i = 0
    x = 256**3
    for quad in ip.split('.'):
        i += int(quad)*x
        x /= 256
    return i

def unDccIP(i):
    """Takes an integer DCC IP and return a normal string IP."""
    assert isinstance(i, (int, long)), '%r is not an number.' % i
    L = []
    while len(L) < 4:
        L.insert(0, i % 256)
        i /= 256
    return '.'.join(map(str, L))
        

class IrcString(str):
    """This class does case-insensitive comparison and hashing of nicks."""
    def __init__(self, s):
        str.__init__(self, s)
        self.lowered = toLower(s)

    def __eq__(self, s):
        try:
            return toLower(s) == self.lowered
        except:
            return False

    def __ne__(self, s):
        return not self == s

    def __hash__(self):
        return hash(self.lowered)


class IrcDict(dict):
    """Subclass of dict to make key comparison IRC-case insensitive."""
    __slots__ = ()
    def __contains__(self, s):
        return dict.__contains__(self, IrcString(s))
    has_key = __contains__

    def __setitem__(self, s, v):
        dict.__setitem__(self, IrcString(s), v)

    def __getitem__(self, s):
        return dict.__getitem__(self, IrcString(s))

    def __delitem__(self, s):
        dict.__delitem__(self, IrcString(s))

class IrcSet(sets.Set):
    """A sets.Set using IrcStrings instead of regular strings."""
    __slots__ = ()
    def add(self, s):
        return sets.Set.add(self, IrcString(s))

    def remove(self, s):
        return sets.Set.remove(self, IrcString(s))

    def discard(self, s):
        return sets.Set.discard(self, IrcString(s))

    def __contains__(self, s):
        return sets.Set.__contains__(self, IrcString(s))

    has_key = __contains__


if __name__ == '__main__':
    import sys, doctest
    doctest.testmod(sys.modules['__main__'])
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