# Copyright 2016 Mycroft AI, Inc.
#
# This file is part of Mycroft Core.
#
# Mycroft Core 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.
#
# Mycroft Core 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 Mycroft Core.  If not, see <http://www.gnu.org/licenses/>.


from adapt.engine import IntentDeterminationEngine

from mycroft.messagebus.message import Message
from mycroft.skills.core import open_intent_envelope
from mycroft.util.log import getLogger
from mycroft.util.parse import normalize

__author__ = 'seanfitz'

logger = getLogger(__name__)


class IntentService(object):
    def __init__(self, emitter):
        self.engine = IntentDeterminationEngine()
        self.emitter = emitter
        self.emitter.on('register_vocab', self.handle_register_vocab)
        self.emitter.on('register_intent', self.handle_register_intent)
        self.emitter.on('recognizer_loop:utterance', self.handle_utterance)
        self.emitter.on('detach_intent', self.handle_detach_intent)
        self.emitter.on('detach_skill', self.handle_detach_skill)

    def handle_utterance(self, message):
        # Get language of the utterance
        lang = message.data.get('lang', None)
        if not lang:
            lang = "en-us"

        utterances = message.data.get('utterances', '')

        best_intent = None
        for utterance in utterances:
            try:
                # normalize() changes "it's a boy" to "it is boy", etc.
                best_intent = next(self.engine.determine_intent(
                    normalize(utterance, lang), 100))

                # TODO - Should Adapt handle this?
                best_intent['utterance'] = utterance
            except StopIteration, e:
                logger.exception(e)
                continue

        if best_intent and best_intent.get('confidence', 0.0) > 0.0:
            reply = message.reply(
                best_intent.get('intent_type'), best_intent)
            self.emitter.emit(reply)
        else:
            self.emitter.emit(Message("intent_failure", {
                "utterance": utterances[0],
                "lang": lang
            }))

    def handle_register_vocab(self, message):
        start_concept = message.data.get('start')
        end_concept = message.data.get('end')
        regex_str = message.data.get('regex')
        alias_of = message.data.get('alias_of')
        if regex_str:
            self.engine.register_regex_entity(regex_str)
        else:
            self.engine.register_entity(
                start_concept, end_concept, alias_of=alias_of)

    def handle_register_intent(self, message):
        intent = open_intent_envelope(message)
        self.engine.register_intent_parser(intent)

    def handle_detach_intent(self, message):
        intent_name = message.data.get('intent_name')
        new_parsers = [
            p for p in self.engine.intent_parsers if p.name != intent_name]
        self.engine.intent_parsers = new_parsers

    def handle_detach_skill(self, message):
        skill_name = message.data.get('skill_name')
        new_parsers = [
            p for p in self.engine.intent_parsers if
            not p.name.startswith(skill_name)]
        self.engine.intent_parsers = new_parsers