Add cities game to avoid rambling responses

app/features/cities_game.py

@@ -0,0 +1,325 @@
+"""
+Cities game feature (RU).
+Plays the classic "города" game: each next city starts with the last valid letter.
+"""
+
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass, field
+from typing import Optional
+
+
+_EXCLUDED_LAST_LETTERS = {"ь", "ъ", "ы", "й"}
+_CITY_TOKEN_RE = re.compile(r"[a-zа-яё]+", re.IGNORECASE)
+_NON_CITY_TOKENS = {"город", "города", "игра", "игру", "сыграем", "сыграть"}
+
+# Core city list (RU + a few common international cities in RU spelling).
+# Keep it curated and deterministic to avoid "rambling" responses.
+_CITIES = [
+    "Абакан",
+    "Анапа",
+    "Апатиты",
+    "Архангельск",
+    "Астрахань",
+    "Барнаул",
+    "Белгород",
+    "Бердск",
+    "Бийск",
+    "Благовещенск",
+    "Брянск",
+    "Великий Новгород",
+    "Великий Устюг",
+    "Владивосток",
+    "Владикавказ",
+    "Владимир",
+    "Волгоград",
+    "Волгодонск",
+    "Вологда",
+    "Воронеж",
+    "Выборг",
+    "Гатчина",
+    "Геленджик",
+    "Екатеринбург",
+    "Елабуга",
+    "Ессентуки",
+    "Жуковский",
+    "Зеленоград",
+    "Иваново",
+    "Ижевск",
+    "Иркутск",
+    "Йошкар-Ола",
+    "Казань",
+    "Калининград",
+    "Калуга",
+    "Каменск-Уральский",
+    "Кемерово",
+    "Киров",
+    "Кисловодск",
+    "Клин",
+    "Кострома",
+    "Краснодар",
+    "Красноярск",
+    "Курган",
+    "Курск",
+    "Липецк",
+    "Магадан",
+    "Магнитогорск",
+    "Майкоп",
+    "Махачкала",
+    "Минеральные Воды",
+    "Москва",
+    "Мурманск",
+    "Муром",
+    "Мытищи",
+    "Набережные Челны",
+    "Нальчик",
+    "Находка",
+    "Невинномысск",
+    "Нижний Новгород",
+    "Нижний Тагил",
+    "Новороссийск",
+    "Новосибирск",
+    "Новочеркасск",
+    "Новокузнецк",
+    "Норильск",
+    "Обнинск",
+    "Омск",
+    "Орёл",
+    "Оренбург",
+    "Орск",
+    "Пенза",
+    "Пермь",
+    "Петрозаводск",
+    "Петропавловск-Камчатский",
+    "Псков",
+    "Пятигорск",
+    "Ростов-на-Дону",
+    "Рязань",
+    "Самара",
+    "Санкт-Петербург",
+    "Саратов",
+    "Саров",
+    "Севастополь",
+    "Северодвинск",
+    "Смоленск",
+    "Сочи",
+    "Ставрополь",
+    "Старый Оскол",
+    "Стерлитамак",
+    "Сургут",
+    "Сызрань",
+    "Сыктывкар",
+    "Таганрог",
+    "Тамбов",
+    "Тверь",
+    "Тольятти",
+    "Томск",
+    "Туапсе",
+    "Тула",
+    "Тюмень",
+    "Улан-Удэ",
+    "Ульяновск",
+    "Уфа",
+    "Хабаровск",
+    "Ханты-Мансийск",
+    "Химки",
+    "Чебоксары",
+    "Челябинск",
+    "Череповец",
+    "Чита",
+    "Элиста",
+    "Южно-Сахалинск",
+    "Якутск",
+    "Ялта",
+    "Ярославль",
+    # International cities in Russian spelling (optional but handy).
+    "Амстердам",
+    "Афины",
+    "Баку",
+    "Белград",
+    "Берлин",
+    "Варшава",
+    "Вена",
+    "Вильнюс",
+    "Дели",
+    "Дублин",
+    "Женева",
+    "Иерусалим",
+    "Каир",
+    "Киев",
+    "Лиссабон",
+    "Лондон",
+    "Мадрид",
+    "Минск",
+    "Монако",
+    "Нью-Йорк",
+    "Осака",
+    "Осло",
+    "Париж",
+    "Прага",
+    "Рига",
+    "Рим",
+    "Стамбул",
+    "Таллин",
+    "Тбилиси",
+    "Токио",
+    "Хельсинки",
+    "Цюрих",
+]
+
+
+def _normalize(text: str) -> str:
+    text = text.lower().replace("ё", "е")
+    text = re.sub(r"[^a-zа-я\s-]+", " ", text, flags=re.IGNORECASE)
+    text = text.replace("-", " ")
+    text = re.sub(r"\s+", " ", text).strip()
+    return text
+
+
+def _first_letter(text: str) -> Optional[str]:
+    for ch in text:
+        if ch.isalpha():
+            return ch
+    return None
+
+
+def _last_letter(text: str) -> Optional[str]:
+    for ch in reversed(text):
+        if not ch.isalpha():
+            continue
+        if ch in _EXCLUDED_LAST_LETTERS:
+            continue
+        return ch
+    return None
+
+
+def _tokenize(text: str) -> list[str]:
+    return [m.group(0).lower().replace("ё", "е") for m in _CITY_TOKEN_RE.finditer(text)]
+
+
+_CITY_MAP = {}
+for city in _CITIES:
+    norm = _normalize(city)
+    if norm not in _CITY_MAP:
+        _CITY_MAP[norm] = city
+
+_CITY_NORMS = sorted(_CITY_MAP.keys(), key=lambda s: (len(s), s))
+
+_CITY_BY_FIRST = {}
+for norm, display in _CITY_MAP.items():
+    letter = _first_letter(norm)
+    if not letter:
+        continue
+    _CITY_BY_FIRST.setdefault(letter, []).append((norm, display))
+
+for letter in _CITY_BY_FIRST:
+    _CITY_BY_FIRST[letter].sort(key=lambda pair: pair[0])
+
+
+_START_PATTERNS = [
+    r"\b(игра|сыграем|сыграть|давай|хочу|можем)\b.*\bгорода\b",
+    r"\bв\s+города\b",
+    r"^города$",
+]
+_STOP_PATTERNS = [
+    r"\b(стоп|хватит|выход|конец|закончим|останови)\b.*\b(игру|игра|города)?\b",
+    r"\bсдаюсь\b",
+]
+
+
+def _is_start_command(text: str) -> bool:
+    return any(re.search(p, text, flags=re.IGNORECASE) for p in _START_PATTERNS)
+
+
+def _is_stop_command(text: str) -> bool:
+    return any(re.search(p, text, flags=re.IGNORECASE) for p in _STOP_PATTERNS)
+
+
+def _extract_city(text: str) -> Optional[str]:
+    tokens = _tokenize(text)
+    if not tokens:
+        return None
+
+    # Try to find the longest matching city name among tokens.
+    max_len = min(4, len(tokens))
+    for span in range(max_len, 0, -1):
+        for i in range(len(tokens) - span + 1):
+            candidate = " ".join(tokens[i : i + span])
+            if candidate in _CITY_MAP:
+                return candidate
+
+    # Fallback: treat the last token as a city if it looks plausible.
+    candidate = tokens[-1]
+    if candidate in _NON_CITY_TOKENS:
+        return None
+    if len(candidate) >= 3:
+        return candidate
+    return None
+
+
+@dataclass
+class CitiesGame:
+    active: bool = False
+    required_letter: Optional[str] = None
+    used: set[str] = field(default_factory=set)
+
+    def start(self) -> str:
+        self.active = True
+        self.required_letter = None
+        self.used.clear()
+        return "Давай сыграем в города. Назови город."
+
+    def stop(self) -> str:
+        self.active = False
+        self.required_letter = None
+        self.used.clear()
+        return "Хорошо, заканчиваем игру в города."
+
+    def handle(self, text: str) -> Optional[str]:
+        normalized = _normalize(text)
+
+        if not self.active:
+            if _is_start_command(normalized):
+                return self.start()
+            return None
+
+        if _is_stop_command(normalized):
+            return self.stop()
+
+        city_norm = _extract_city(normalized)
+        if not city_norm:
+            return "Назови город."
+
+        if self.required_letter and not city_norm.startswith(self.required_letter):
+            return f"Нужно на букву {self.required_letter.upper()}."
+
+        if city_norm in self.used:
+            return "Этот город уже был. Назови другой."
+
+        self.used.add(city_norm)
+
+        next_letter = _last_letter(city_norm)
+        if not next_letter:
+            return "Не могу определить следующую букву. Назови другой город."
+
+        candidates = _CITY_BY_FIRST.get(next_letter, [])
+        for candidate_norm, candidate_display in candidates:
+            if candidate_norm not in self.used:
+                self.used.add(candidate_norm)
+                self.required_letter = _last_letter(candidate_norm)
+                return candidate_display
+
+        self.active = False
+        self.required_letter = None
+        return f"Не знаю город на букву {next_letter.upper()}. Ты победил."
+
+
+_game = None
+
+
+def get_cities_game() -> CitiesGame:
+    global _game
+    if _game is None:
+        _game = CitiesGame()
+    return _game