###
# Copyright (c) 2002-2004, Jeremiah Fincher
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# modification, are permitted provided that the following conditions are met:
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#   * Redistributions of source code must retain the above copyright notice,
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###

"""
Various math-related commands.
"""

__revision__ = "$Id$"

from __future__ import division

import supybot.plugins as plugins

import re
import math
import cmath
import types
import string
from itertools import imap

import supybot.utils as utils
from supybot.commands import *
import supybot.callbacks as callbacks

import convertcore

baseArg = ('int', 'base', lambda i: i <= 36)

class Math(callbacks.Privmsg):
    def base(self, irc, msg, args, frm, to, number):
        """<fromBase> [<toBase>] <number>

        Converts <number> from base <fromBase> to base <toBase>.
        If <toBase> is left out, it converts to decimal.
        """
        if not number:
            number = str(to)
            to = 10
        try:
            irc.reply(self._convertBaseToBase(number, to, frm))
        except ValueError:
            irc.error('Invalid <number> for base %s: %s' % (frm, number))
    base = wrap(base, [('int', 'base', lambda i: 2 <= i <= 36),
                       optional(('int', 'base', lambda i: 2 <= i <= 36), 10),
                       additional('something')])

    def _convertDecimalToBase(self, number, base):
        """Convert a decimal number to another base; returns a string."""
        if number == 0:
            return '0'
        elif number < 0:
            negative = True
            number = -number
        else:
            negative = False
        digits = []
        while number != 0:
            digit = number % base
            if digit >= 10:
                digit = string.uppercase[digit - 10]
            else:
                digit = str(digit)
            digits.append(digit)
            number = number // base
        digits.reverse()
        return '-'*negative + ''.join(digits)

    def _convertBaseToBase(self, number, toBase, fromBase):
        """Convert a number from any base, 2 through 36, to any other
        base, 2 through 36. Returns a string."""
        number = long(str(number), fromBase)
        if toBase == 10:
            return str(number)
        return self._convertDecimalToBase(number, toBase)

    _mathEnv = {'__builtins__': types.ModuleType('__builtins__'), 'i': 1j}
    _mathEnv.update(math.__dict__)
    _mathEnv.update(cmath.__dict__)
    def _sqrt(x):
        if isinstance(x, complex) or x < 0:
            return cmath.sqrt(x)
        else:
            return math.sqrt(x)
    _mathEnv['sqrt'] = _sqrt
    _mathEnv['abs'] = abs
    _mathEnv['max'] = max
    _mathEnv['min'] = min
    _mathRe = re.compile(r'((?:(?<![A-Fa-f\d)])-)?'
                         r'(?:0x[A-Fa-f\d]+|'
                         r'0[0-7]+|'
                         r'\d+\.\d+|'
                         r'\.\d+|'
                         r'\d+\.|'
                         r'\d+))')
    def _floatToString(self, x):
        if -1e-10 < x < 1e-10:
            return '0'
        elif -1e-10 < int(x) - x < 1e-10:
            return str(int(x))
        else:
            return str(x)

    def _complexToString(self, x):
        realS = self._floatToString(x.real)
        imagS = self._floatToString(x.imag)
        if imagS == '0':
            return realS
        elif imagS == '1':
            imagS = '+i'
        elif imagS == '-1':
            imagS = '-i'
        elif x.imag < 0:
            imagS = '%si' % imagS
        else:
            imagS = '+%si' % imagS
        if realS == '0' and imagS == '0':
            return '0'
        elif realS == '0':
            return imagS.lstrip('+')
        elif imagS == '0':
            return realS
        else:
            return '%s%s' % (realS, imagS)

    ###
    # So this is how the 'calc' command works:
    # First, we make a nice little safe environment for evaluation; basically,
    # the names in the 'math' and 'cmath' modules.  Then, we remove the ability
    # of a random user to get ints evaluated: this means we have to turn all
    # int literals (even octal numbers and hexadecimal numbers) into floats.
    # Then we delete all square brackets, underscores, and whitespace, so no
    # one can do list comprehensions or call __...__ functions.
    ###
    def calc(self, irc, msg, args, text):
        """<math expression>

        Returns the value of the evaluated <math expression>.  The syntax is
        Python syntax; the type of arithmetic is floating point.  Floating
        point arithmetic is used in order to prevent a user from being able to
        crash to the bot with something like 10**10**10**10.  One consequence
        is that large values such as 10**24 might not be exact.
        """
        if text != text.translate(string.ascii, '_[]'):
            irc.error('There\'s really no reason why you should have '
                           'underscores or brackets in your mathematical '
                           'expression.  Please remove them.')
            return
        #text = text.translate(string.ascii, '_[] \t')
        if 'lambda' in text:
            irc.error('You can\'t use lambda in this command.')
            return
        text = text.lower()
        def handleMatch(m):
            s = m.group(1)
            if s.startswith('0x'):
                i = int(s, 16)
            elif s.startswith('0') and '.' not in s:
                try:
                    i = int(s, 8)
                except ValueError:
                    i = int(s)
            else:
                i = float(s)
            x = complex(i)
            if x == abs(x):
                x = abs(x)
            return str(x)
        text = self._mathRe.sub(handleMatch, text)
        try:
            self.log.info('evaluating %s from %s' %
                          (utils.quoted(text), msg.prefix))
            x = complex(eval(text, self._mathEnv, self._mathEnv))
            irc.reply(self._complexToString(x))
        except OverflowError:
            maxFloat = math.ldexp(0.9999999999999999, 1024)
            irc.error('The answer exceeded %s or so.' % maxFloat)
        except TypeError:
            irc.error('Something in there wasn\'t a valid number.')
        except NameError, e:
            irc.error('%s is not a defined function.' % str(e).split()[1])
        except Exception, e:
            irc.error(str(e))
    calc = wrap(calc, ['text'])

    def icalc(self, irc, msg, args, text):
        """<math expression>

        This is the same as the calc command except that it allows integer
        math, and can thus cause the bot to suck up CPU.  Hence it requires
        the 'trusted' capability to use.
        """
        if text != text.translate(string.ascii, '_[]'):
            irc.error('There\'s really no reason why you should have '
                           'underscores or brackets in your mathematical '
                           'expression.  Please remove them.')
            return
        # This removes spaces, too, but we'll leave the removal of _[] for
        # safety's sake.
        text = text.translate(string.ascii, '_[] \t')
        if 'lambda' in text:
            irc.error('You can\'t use lambda in this command.')
            return
        text = text.replace('lambda', '')
        try:
            self.log.info('evaluating %s from %s' %
                          (utils.quoted(text), msg.prefix))
            irc.reply(str(eval(text, self._mathEnv, self._mathEnv)))
        except OverflowError:
            maxFloat = math.ldexp(0.9999999999999999, 1024)
            irc.error('The answer exceeded %s or so.' % maxFloat)
        except TypeError:
            irc.error('Something in there wasn\'t a valid number.')
        except NameError, e:
            irc.error('%s is not a defined function.' % str(e).split()[1])
        except Exception, e:
            irc.error(utils.exnToString(e))
    icalc = wrap(icalc, [('checkCapability', 'trusted'), 'text'])

    _rpnEnv = {
        'dup': lambda s: s.extend([s.pop()]*2),
        'swap': lambda s: s.extend([s.pop(), s.pop()])
        }
    def rpn(self, irc, msg, args):
        """<rpn math expression>

        Returns the value of an RPN expression.
        """
        stack = []
        for arg in args:
            try:
                x = complex(arg)
                if x == abs(x):
                    x = abs(x)
                stack.append(x)
            except ValueError: # Not a float.
                if arg in self._mathEnv:
                    f = self._mathEnv[arg]
                    if callable(f):
                        called = False
                        arguments = []
                        while not called and stack:
                            arguments.append(stack.pop())
                            try:
                                stack.append(f(*arguments))
                                called = True
                            except TypeError:
                                pass
                        if not called:
                            irc.error('Not enough arguments for %s' % arg)
                            return
                    else:
                        stack.append(f)
                elif arg in self._rpnEnv:
                    self._rpnEnv[arg](stack)
                else:
                    arg2 = stack.pop()
                    arg1 = stack.pop()
                    s = '%s%s%s' % (arg1, arg, arg2)
                    try:
                        stack.append(eval(s, self._mathEnv, self._mathEnv))
                    except SyntaxError:
                        irc.error('%s is not a defined function.' %
                                  utils.quoted(arg))
                        return
        if len(stack) == 1:
            irc.reply(str(self._complexToString(complex(stack[0]))))
        else:
            s = ', '.join(imap(self._complexToString, imap(complex, stack)))
            irc.reply('Stack: [%s]' % s)

    def convert(self, irc, msg, args, number, unit1, unit2):
        """[<number>] <unit> to <other unit>

        Converts from <unit> to <other unit>. If number isn't given, it
        defaults to 1. For unit information, see 'units' command.
        """
        try:
            newNum = convertcore.convert(number, unit1, unit2)
            newNum = self._floatToString(newNum)
            irc.reply(str(newNum))
        except convertcore.UnitDataError, ude:
            irc.error(str(ude))
    convert = wrap(convert, [optional('float', 1.0),'something','to','text'])

    def units(self, irc, msg, args, type):
        """ [<type>]

        With no arguments, returns a list of measurement types, which can be
        passed as arguments. When called with a type as an argument, returns
        the units of that type.
        """

        irc.reply(convertcore.units(type))
    units = wrap(units, [additional('text')])

Class = Math

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