imaginaryfriend/src/service/reply_generator.py

71 lines
2.5 KiB
Python

from src.config import config, redis, tokenizer, trigram_repository
from src.utils import strings_has_equal_letters, capitalize
class ReplyGenerator:
"""
Handles generation of responses for user message
"""
def __init__(self):
self.redis = redis
self.tokenizer = tokenizer
self.trigram_repository = trigram_repository
self.max_words = config.getint('grammar', 'max_words')
self.max_messages = config.getint('grammar', 'max_messages')
self.stop_word = config['grammar']['stop_word']
self.separator = config['grammar']['separator']
self.end_sentence = config['grammar']['end_sentence']
def generate(self, message):
"""
Generates response based on message words
:param message: Message
:return: Response or empty string, if generated response equals to user message
"""
words = self.tokenizer.extract_words(message)
pairs = [trigram[:-1] for trigram in self.tokenizer.split_to_trigrams(words)]
messages = [self.__generate_best_message(chat_id=message.chat_id, pair=pair) for pair in pairs]
longest_message = max(messages, key=len) if len(messages) else ''
if longest_message and strings_has_equal_letters(longest_message, ''.join(words)):
return ''
return longest_message
def __generate_best_message(self, chat_id, pair):
best_message = ''
for _ in range(self.max_messages):
generated = self.__generate_sentence(chat_id=chat_id, pair=pair)
if len(generated) > len(best_message):
best_message = generated
return best_message
def __generate_sentence(self, chat_id, pair):
gen_words = []
key = self.separator.join(pair)
for _ in range(self.max_words):
words = key.split(self.separator)
gen_words.append(words[1] if len(gen_words) == 0 else words[1])
next_word = self.trigram_repository.get_random_reply(chat_id, key)
if next_word is None:
break
key = self.separator.join(words[1:] + [next_word])
last_word = key.split(self.separator)[-1]
if last_word not in gen_words:
gen_words.append(last_word)
gen_words = list(filter(lambda w: w != self.stop_word, gen_words))
sentence = ' '.join(gen_words).strip()
if sentence[-1:] not in self.end_sentence:
sentence += self.tokenizer.random_end_sentence_token()
return capitalize(sentence)