calculate

# HablarConSara.activity
# A simple hack to attach a chatterbot to speak activity
# Copyright (C) 2008 Sebastian Silva Fundacion FuenteLibre sebastian@fuentelibre.org
#
# Style and structure taken from Speak.activity Copyright (C) Joshua Minor
#
#     HablarConSara.activity is free software: you can redistribute it and/or modify
#     it under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     HablarConSara.activity is distributed in the hope that it will be useful,
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#     GNU General Public License for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with HablarConSara.activity.  If not, see <http://www.gnu.org/licenses/>.

import gtk
import gobject
from gettext import gettext as _

import logging
logger = logging.getLogger('speak')

from toolkit.combobox import ComboBox

import bot.aiml
import voice

import decimal

#
# relies on these two modules from the
# Calculate activity
#
try:
    from astparser import AstParser
    import rational
    MATHS_MODE='full'
except ImportError:
    MATHS_MODE='manual'

BOTS = {
    _('Spanish'): { 'name': 'Sara',
                    'brain': 'bot/sara.brn',
                    'predicates': { 'nombre_bot': 'Sara',
                                    'botmaster': 'la comunidad Azucar' } },
    _('English'): { 'name': 'Alice',
                    'brain': 'bot/alice.brn',
                    'predicates': { 'name': 'Alice',
                                    'master': 'the Sugar Community' } } }

# load Standard AIML set for restricted systems
if int([i for i in file('/proc/meminfo').readlines()
        if i.startswith('MemTotal:')][0].split()[1]) < 524288:
    BOTS[_('English')]['brain'] = 'bot/alisochka.brn'

_kernel = None
_kernel_voice = None


def get_default_voice():
    default_voice = voice.defaultVoice()
    if default_voice.friendlyname not in BOTS:
        return voice.allVoices()[_('English')]
    else:
        return default_voicem4ce751e0


def get_voices():
    voices = ComboBox()
    for lang in sorted(BOTS.keys()):
        voices.append_item(voice.allVoices()[lang], lang)
    return voices.get_model()


def respond(voice, text):
    if text.rstrip()[-1:] == '=':
        try:
            text = str(eval(text.rstrip()[:-1]))
        except:
            pass

    if _kernel is None:
        return text
    else:
        return _kernel.respond(text)

def calculate(equation):
    """
    Calculates the result of an equation represented as a
    string literal. We round the result down to 4 places
    of significance, so that we don't overload the face
    when it says the result

    >>> MATHS_MODE='full'
    >>> calculate('10/3')
    '3.3333'
    >>> MATHS_MODE='manual'
    >>> calculate('10/3')
    '3.3333'
    """
    parse_msg = 'MATHS_MODE=%s : "%s" couldn\'t be parsed.' % (
               MATHS_MODE, equation)
    except_msg = 'MATHS_MODE=%s : "%s" raised an unhandled exception' % (
               MATHS_MODE, equation)
    msg = _("I don't know how to answer this problem, sorry.")

    if MATHS_MODE is 'full':
        decimal.Decimal = D
        decimal.getcontext().prec = 4
        decimal.getcontext().rounding = decimal.ROUND_DOWN
        parsr = AstParser()
        try:
            res = parsr.evaluate(parsr.parse(equation))
        except ParseError:
            logger.exception(parse_msg)
            return equation
        except:
            logger.exception(except_msg)
            return equation

        #AstParser.evaluate() returns rational numbers sometimes
        if isinstance(res, rational.Rational):
            res = D(str(r.n))/D(str(r.d))

    ## FIXME think of a tricker way to do this
    #fallback to using eval, quick n dirty
    else:
        try:
            from __future__ import division
        except ImportError:
            pass
        try:
            res = eval(equation)
        except SyntaxError:
            logger.exception(parse_msg)
            return equation
        except:
            logger.exception(except_msg)
            return equation

    #round result, unless it's already rounded because of Decimal's context
    if not isinstance(res, D):
        ## FIXME InvalidOperation: quantize result has too many digits for current context
        ## res = D(str(res)).quantize(D('0.001'), decimal.ROUND_HALF_UP)

        #rely on string type coerion to deal with precision issues
        res = round(res, 4)

    res = str(res)
    if res[-2:] == '.0': return res[:-2]
    else: return res


def load(activity, voice, sorry=None):
    if voice == _kernel_voice:
        return False

    old_cursor = activity.get_cursor()
    activity.set_cursor(gtk.gdk.WATCH)

    def load_brain():
        global _kernel
        global _kernel_voice

        is_first_session = _kernel is None

        try:
            brain = BOTS[voice.friendlyname]
            logger.debug('Load bot: %s' % brain)

            kernel = bot.aiml.Kernel()
            kernel.loadBrain(brain['brain'])
            for name, value in brain['predicates'].items():
                kernel.setBotPredicate(name, value)

            if _kernel is not None:
                del _kernel
                _kernel = None
                import gc
                gc.collect()

            _kernel = kernel
            _kernel_voice = voice
        finally:
            activity.set_cursor(old_cursor)

        if is_first_session:
            hello = _("Hello, I'm a robot \"%s\". Ask me any question.") \
                    % BOTS[voice.friendlyname]['name']
            if sorry:
                hello += ' ' + sorry
            activity.face.say_notification(hello)
        elif sorry:
            activity.face.say_notification(sorry)

    gobject.idle_add(load_brain)
    return True