#!/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.
"""

__revision__ = "$Id$"

import fix

import re
import copy
import sets
import time
import random
import socket
import string
import fnmatch
import operator
from itertools import imap
from cStringIO import StringIO as sio

import utils

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 intern(s.translate(_lowertrans))

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

nickEqual = strEqual

_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."""
    return bool(nickRe.match(s))

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 isCtcp(msg):
    """Returns whether or not msg is a CTCP message."""
    return msg.command == 'PRIVMSG' and \
           msg.args[1].startswith('\x01') and \
           msg.args[1].endswith('\x01')

_patternCache = {}
def _hostmaskPatternEqual(pattern, hostmask):
    """Returns True if hostmask matches the hostmask pattern pattern."""
    try:
        return _patternCache[pattern](hostmask) is not None
    except KeyError:
        # We make our own regexps, rather than use fnmatch, because fnmatch's
        # case-insensitivity is not IRC's case-insensitity.
        fd = sio()
        for c in pattern:
            if c == '*':
                fd.write('.*')
            elif c == '?':
                fd.write('.')
            elif c in '[{':
                fd.write('[[{]')
            elif c in '}]':
                fd.write(r'[}\]]')
            elif c in '|\\':
                fd.write(r'[|\\]')
            elif c in '^~':
                fd.write('[~^]')
            else:
                fd.write(re.escape(c))
        fd.write('$')
        f = re.compile(fd.getvalue(), re.I).match
        _patternCache[pattern] = f
        return f(hostmask) is not None

_hostmaskPatternEqualCache = {}
def hostmaskPatternEqual(pattern, hostmask):
    try:
        return _hostmaskPatternEqualCache[(pattern, hostmask)]
    except KeyError:
        b = _hostmaskPatternEqual(pattern, hostmask)
        _hostmaskPatternEqualCache[(pattern, hostmask)] = b
        return b

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 utils.isIP(host):
        L = host.split('.')
        L[-1] = '*'
        return '*!*@' + '.'.join(L)
    elif utils.isIPV6(host):
        L = host.split(':')
        L[-1] = '*'
        return '*!*@' + ':'.join(L)
    else:
        if '.' in host:
            return '*!*@*%s' % host[host.find('.'):]
        else:
            return '*!*@'  + host

_plusRequireArguments = 'ovhblkqe'
_minusRequireArguments = 'ovhbkqe'
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)]
    """
    if not args:
        return []
    modes = args[0]
    assert modes[0] in '+-', 'Invalid args: %r' % args
    args = list(args[1:])
    ret = []
    length = len(modes)
    for c in modes:
        if c in '+-':
            last = c
        else:
            if last == '+':
                requireArguments = _plusRequireArguments
            else:
                requireArguments = _minusRequireArguments
            if c in requireArguments:
                arg = args.pop(0)
                try:
                    arg = int(arg)
                except ValueError:
                    pass
                ret.append((last + c, arg))
            else:
                ret.append((last + c, None))
    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\x02' % s

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

def underline(s):
    """Returns the string s, underlined."""
    return '\x1F%s\x1F' % 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 isinstance(fg, int):
        fg = mircColors[fg] # Convert to string, just in case.
    if isinstance(bg, int):
        bg = mircColors[bg] # Convert to string, just in case.
    if fg is None or isinstance(fg, str):
        fg = mircColors[fg]
    if bg is None:
        return '\x03%s%s\x03' % (fg, s)
    else:
        if isinstance(bg, str):
            bg = mircColors[bg]
        return '\x03%s,%s%s\x03' % (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)

def stripBold(s):
    """Returns the string s, with bold removed."""
    return s.replace('\x02', '')

_stripColorRe = re.compile(r'\x03(?:\d{1,2},\d{1,2}|\d{1,2}|,\d{1,2}|)')
def stripColor(s):
    """Returns the string s, with color removed."""
    return _stripColorRe.sub('', s)

def stripReverse(s):
    """Returns the string s, with reverse-video removed."""
    return s.replace('\x16', '')

def stripUnderline(s):
    """Returns the string s, with underlining removed."""
    return s.replace('\x1f', '').replace('\x1F', '')

def stripFormatting(s):
    """Returns the string s, with all formatting removed."""
    s = stripBold(s)
    s = stripColor(s)
    s = stripReverse(s)
    s = stripUnderline(s)
    return s.replace('\x0f', '').replace('\x0F', '')

def isValidArgument(s):
    """Returns whether 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

def safeArgument(s):
    """If s is unsafe for IRC, returns a safe version."""
    if isinstance(s, unicode):
        s = s.encode('utf-8')
    if isValidArgument(s):
        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 dccIP(ip):
    """Returns in IP in the proper for DCC."""
    assert utils.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.append(i % 256)
        i /= 256
    L.reverse()
    return '.'.join(imap(str, L))

class IrcString(str):
    """This class does case-insensitive comparison and hashing of nicks."""
    def __init__(self, s):
        assert isinstance(s, basestring), \
               'Cannot make an IrcString from %s' % type(s)
        str.__init__(self, intern(s)) # This does nothing, I fear.
        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(utils.InsensitivePreservingDict):
    """Subclass of dict to make key comparison IRC-case insensitive."""
    key = staticmethod(toLower)


class IrcSet(sets.Set):
    """A sets.Set using IrcStrings instead of regular strings."""
    def __init__(self, seq=()):
        self.__parent = super(IrcSet, self)
        self.__parent.__init__()
        for elt in seq:
            self.add(elt)
        
    def add(self, s):
        return self.__parent.add(IrcString(s))

    def remove(self, s):
        return self.__parent.remove(IrcString(s))

    def discard(self, s):
        return self.__parent.discard(IrcString(s))

    def __contains__(self, s):
        return self.__parent.__contains__(IrcString(s))
    has_key = __contains__

    def __reduce__(self):
        return (self.__class__, (list(self),))


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