#!/usr/bin/env python

###
# Copyright (c) 2002, Jeremiah Fincher
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
#   * Redistributions of source code must retain the above copyright notice,
#     this list of conditions, and the following disclaimer.
#   * Redistributions in binary form must reproduce the above copyright notice,
#     this list of conditions, and the following disclaimer in the
#     documentation and/or other materials provided with the distribution.
#   * Neither the name of the author of this software nor the name of
#     contributors to this software may be used to endorse or promote products
#     derived from this software without specific prior written consent.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
###

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

__revision__ = "$Id$"

import plugins

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

import unum.units

import utils
import privmsgs
import callbacks


def configure(onStart, afterConnect, advanced):
    # This will be called by setup.py to configure this module.  onStart and
    # afterConnect are both lists.  Append to onStart the commands you would
    # like to be run when the bot is started; append to afterConnect the
    # commands you would like to be run when the bot has finished connecting.
    from questions import expect, anything, something, yn
    onStart.append('load Math')

class Math(callbacks.Privmsg):
    ###
    # 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.
    ###
    _mathEnv = {'__builtins__': types.ModuleType('__builtins__'), 'i': 1j}
    _mathEnv.update(math.__dict__)
    _mathEnv.update(cmath.__dict__)
    _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 _complexToString(self, x):
        real = x.real
        imag = x.imag
        if -1e-12 < real < 1e-12 and -1e-12 < imag < 1e-12:
            return '0'
        if int(real) == real:
            real = int(real)
        if int(imag) == imag:
            imag = int(imag)
        if -1e-12 < real < 1e-12:
            real = 0
        if -1e-12 < imag < 1e-12:
            imag = 0
        if imag == 0:
            return str(real)
        elif imag == 1:
            imag = '+i'
        elif imag == -1:
            imag = '-i'
        elif imag < 0:
            imag = '%si' % imag
        elif imag > 0:
            imag = '+%si' % imag
        if real == 0:
            return imag.lstrip('+')
        else:
            return '%s%s' % (real, imag)

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

        Returns the value of the evaluted <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.
        """
        text = privmsgs.getArgs(args)
        text = text.translate(string.ascii, '_[] \t')
        text = text.replace('lambda', '')
        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 %r from %s' % (text, msg.prefix))
            x = complex(eval(text, self._mathEnv, self._mathEnv))
            irc.reply(msg, self._complexToString(x))
        except OverflowError:
            maxFloat = math.ldexp(0.9999999999999999, 1024)
            irc.error(msg, 'The answer exceeded %s or so.' % maxFloat)
        except TypeError:
            irc.error(msg, 'Something in there wasn\'t a valid number.')
        except NameError, e:
            irc.error(msg, '%s is not a defined function.' % str(e).split()[1])
        except Exception, e:
            irc.error(msg, utils.exnToString(e))

    _rpnEnv = {
        'dup': lambda s: s.extend([s.pop()]*2),
        }
    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(msg, '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(msg, '%r is not a defined function.' % arg)
                        return
        if len(stack) == 1:
            irc.reply(msg, str(self._complexToString(complex(stack[0]))))
        else:
            s = ', '.join(imap(self._complexToString, imap(complex, stack)))
            irc.reply(msg, 'Stack: [%s]' % s)

    _convertEnv = {'__builtins__': types.ModuleType('__builtins__')}
    for (k, v) in unum.units.__dict__.iteritems():
        if isinstance(v, unum.Unum):
            _convertEnv[k.lower()] = v
    def convert(self, irc, msg, args):
        """[<number>] <units> to <other units>

        Converts the first number of <units> to the <other units>.  Valid units
        expressions include the standard Python math operators applied to valid
        units.  If <number> isn't given, it defaults to 1.
        """
        if args and args[0].isdigit():
            n = args.pop(0)
        else:
            n = 1
        (unit1, to, unit2) = privmsgs.getArgs(args, required=3)
        if to != 'to':
            raise callbacks.ArgumentError
        try:
            n = float(n)
        except ValueError:
            irc.error(msg, '%s is not a valid number.' % n)
            return
        try:
            unit1 = unit1.lower()
            self.log.info('evaluating %r from %s' % (unit1, msg.prefix))
            u1 = eval(unit1, self._convertEnv, self._convertEnv)
        except:
            irc.error(msg, '%s is not a valid units expression.' % unit1)
            return
        try:
            unit2 = unit2.lower()
            self.log.info('evaluating %r from %s' % (unit2, msg.prefix))
            u2 = eval(unit2, self._convertEnv, self._convertEnv)
        except:
            irc.error(msg, '%s is not a valid units expression.' % unit2)
            return
        try:
            irc.reply(msg, str((n*u1).as(u2)))
        except Exception, e:
            irc.error(msg, str(e))

    def units(self, irc, msg, args):
        """takes no arguments

        Returns all the valid units.
        """
        L = self._convertEnv.keys()
        L.remove('__builtins__')
        L.sort()
        irc.reply(msg, utils.commaAndify(L))
        
        
Class = Math

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