import contextlib
import json
import logging
import os
import re
import tempfile
import time
from datetime import datetime, timedelta
from html import escape

import redis
from playwright.async_api import async_playwright
from telegram import ChatMember, InlineKeyboardButton, InlineKeyboardMarkup, Update
from telegram.constants import ChatType
from telegram.ext import Application, CallbackQueryHandler, CommandHandler, ContextTypes

# Logger
logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
logger = logging.getLogger(__name__)

# Suppress HTTP request logs
logging.getLogger('urllib3').setLevel(logging.WARNING)
logging.getLogger('httpx').setLevel(logging.WARNING)
logging.getLogger('telegram.ext._application').setLevel(logging.WARNING)


# Load environment variables
def _env(key, default=None):
    v = os.getenv(key, default)
    if isinstance(v, str) and len(v) >= 2 and ((v[0] == '"' and v[-1] == '"') or (v[0] == "'" and v[-1] == "'")):
        return v[1:-1]
    return v


EDU_BASE = _env('EDU_URL_BASE', 'https://edu.edu.vn.ua')
EDU_WEBINAR_PATH = _env('EDU_URL_WEBINAR', '/webinar/useractive')
WEBINAR_URL = f'{EDU_BASE.rstrip("/")}/{EDU_WEBINAR_PATH.lstrip("/")}'
DIARY_URL = f'{EDU_BASE.rstrip("/")}/user/diary'
SCHEDULE_URL = f'{EDU_BASE.rstrip("/")}/lessons/table'

WEBINAR_CHECK_INTERVAL = int(_env('WEBINAR_CHECK_INTERVAL', 60))
REDIS_HOST = _env('REDIS_HOST', 'redis')
REDIS_PORT = int(_env('REDIS_PORT', 6379))
PLAYWRIGHT_WS = _env('PLAYWRIGHT_WS', 'ws://playwright-service:3000/ws')
USER_AGENT = _env(
    'USER_AGENT',
    'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36',
)
WEBINAR_TELEGRAM_TOKEN = _env('WEBINAR_TELEGRAM_TOKEN')
ADMIN_ID = int(_env('WEBINAR_ADMIN_ID', '0'))

# Redis Keys
KEY_WHITELIST = 'bot:whitelist'
KEY_WHITELIST_ENABLED = 'bot:whitelist_enabled'
KEY_SUBSCRIBERS = 'bot:subscribers'
KEY_PHPSESSID = 'EDU_PHPSESSID'
KEY_WEBINAR_HISTORY = 'bot:webinar_history'  # Stores last 3 webinars

# Marker shown by the site when there are no active online lessons
NO_WEBINAR_MARKER = 'Жодного онлайн уроку зараз'

# Initialize Redis
try:
    redis_client = redis.Redis(host=REDIS_HOST, port=REDIS_PORT, decode_responses=True)
    redis_client.ping()
    logger.info(f'Connected to Redis at {REDIS_HOST}:{REDIS_PORT}')
except Exception as e:
    logger.error(f'Failed to connect to Redis: {e}')
    exit(1)

# --- Translations ---

TRANSLATIONS = {
    'ru': {
        'welcome': '👋 Привет, {name}!\n\nЯ бот-уведомитель о вебинарах. Я буду сообщать вам, когда появится новый вебинар.\nВы подписаны на уведомления.',
        'welcome_admin': '\n\n👑 <b>Режим администратора активен</b>',
        'access_denied': '⛔ Доступ запрещен. Вас нет в белом списке.',
        'help_title': '🤖 <b>Помощь по боту</b>\n\n',
        'help_commands': '/start - Подписаться на уведомления\n/stop - Отписаться от уведомлений\n/help - Показать это сообщение\n/language - Сменить язык',
        'help_admin': '\n<b>Команды администратора:</b>\n/adduser [user_id] - Добавить пользователя в белый список\n/removeuser [user_id] - Удалить пользователя из белого списка\nИли используйте панель ниже для управления настройками.',
        'admin_only': '⛔ Только для администратора!',
        'user_added': '✅ Пользователь {user_id} добавлен в белый список',
        'user_removed': '✅ Пользователь {user_id} удален из белого списка',
        'user_not_in_whitelist': '⚠️ Пользователь {user_id} не был в белом списке',
        'cannot_remove_admin': '❌ Невозможно удалить администратора из белого списка',
        'invalid_user_id': '❌ Неверный ID пользователя. Должно быть число.',
        'usage_adduser': 'Использование: /adduser [user_id]',
        'usage_removeuser': 'Использование: /removeuser [user_id]',
        'whitelist_enabled': '✅ Белый список включен',
        'whitelist_disabled': '🚫 Белый список отключен',
        'whitelist_title': '📋 <b>Белый список:</b>\n',
        'subscribers_title': '👥 <b>Подписчики:</b>\n',
        'empty': 'Пусто',
        'force_check_running': '🔄 Запускаю проверку...',
        'check_failed': '❌ Проверка не удалась. Смотрите логи.',
        'check_completed_none': '✅ Проверка завершена. Вебинаров не найдено.',
        'check_completed': '✅ Проверка завершена. Найдено {count} вебинар(ов)!',
        'toggle_whitelist_disable': '🔒 Отключить белый список',
        'toggle_whitelist_enable': '🔓 Включить белый список',
        'view_whitelist': '📋 Посмотреть белый список',
        'view_subscribers': '👥 Посмотреть подписчиков',
        'force_check': '🔄 Принудительная проверка',
        'webinar_found': '🎓 <b>Новый вебинар!</b>\n\n',
        'webinar_item': '📌 <b>{name}</b>\n🔗 https://edu.edu.vn.ua{url}',
        'select_language': '🌐 <b>Выберите язык / Оберіть мову / Select language:</b>',
        'language_changed': '✅ Язык изменен на {lang}',
        'flag_ru': '🇷🇺 Русский',
        'flag_uk': '🇺🇦 Українська',
        'flag_en': '🇬🇧 English',
        'history_cleared': '✅ История вебинаров очищена',
        'history_clear_failed': '❌ Ошибка при очистке истории',
        'today': '📌 Сегодня',
        'tomorrow': '📌 Завтра',
        'week': '📅 Эта неделя',
        'month': '📅 Весь месяц',
        'no_events': 'Нет событий',
        'no_lessons': 'Нет уроков',
        'free_period': 'Свободно',
        'unsubscribed': '🔕 Вы отписались от уведомлений.',
        'diary_title': '📅 <b>Дневник</b> — выберите период:',
        'diary_week_title': '📅 <b>Неделя {start} – {end}</b>',
        'schedule_title': '📅 <b>{weekday} — {class_num} класс</b>',
        'loading_diary': '🔄 Загружаю дневник...',
        'diary_load_failed': '❌ Не удалось загрузить дневник.',
        'diary_no_session': '❌ Не удалось загрузить дневник. Нет сессии или ошибка.',
        'diary_next_month': '❌ Данные за следующий месяц недоступны. Перейдите на сайт.',
        'schedule_load_failed': '❌ Не удалось загрузить расписание.',
        'class_not_set': '❌ Класс не настроен. Используйте /setclass.',
        'class_not_found': '❌ Классы не найдены в расписании.',
        'select_class': '🎒 <b>Выберите класс</b> — сохранится и больше не спросится:',
        'admin_class_not_set': '⚠️ Администратор еще не настроил класс для этой группы. Используйте /setclass 11',
        'loading_schedule': '🔄 Загружаю расписание...',
        'invalid_class_num': '❌ Неверный номер класса.',
        'class_saved': '✅ Класс <b>{class_num}</b> сохранен.',
        'admin_only_msg': '⚠️ Только администратор может настроить класс для группы.',
        'truncation': '\n\n✂️ ...(обрезано)',
        'day_mon': 'Пн',
        'day_tue': 'Вт',
        'day_wed': 'Ср',
        'day_thu': 'Чт',
        'day_fri': 'Пт',
        'day_sat': 'Сб',
        'day_sun': 'Вс',
    },
    'uk': {
        'welcome': "👋 Привіт, {name}!\n\nЯ бот-сповіщувач про вебінари. Я повідомлятиму вас, коли з'явиться новий вебінар.\nВи підписані на сповіщення.",
        'welcome_admin': '\n\n👑 <b>Режим адміністратора активний</b>',
        'access_denied': '⛔ Доступ заборонено. Вас немає в білому списку.',
        'help_title': '🤖 <b>Довідка по боту</b>\n\n',
        'help_commands': '/start - Підписатися на сповіщення\n/stop - Відписатися від сповіщень\n/help - Показати це повідомлення\n/language - Змінити мову',
        'help_admin': '\n<b>Команди адміністратора:</b>\n/adduser [user_id] - Додати користувача до білого списку\n/removeuser [user_id] - Видалити користувача з білого списку\nАбо використовуйте панель нижче для керування налаштуваннями.',
        'admin_only': '⛔ Тільки для адміністратора!',
        'user_added': '✅ Користувач {user_id} доданий до білого списку',
        'user_removed': '✅ Користувач {user_id} видалений з білого списку',
        'user_not_in_whitelist': '⚠️ Користувач {user_id} не був у білому списку',
        'cannot_remove_admin': '❌ Неможливо видалити адміністратора з білого списку',
        'invalid_user_id': '❌ Невірний ID користувача. Має бути число.',
        'usage_adduser': 'Використання: /adduser [user_id]',
        'usage_removeuser': 'Використання: /removeuser [user_id]',
        'whitelist_enabled': '✅ Білий список увімкнено',
        'whitelist_disabled': '🚫 Білий список вимкнено',
        'whitelist_title': '📋 <b>Білий список:</b>\n',
        'subscribers_title': '👥 <b>Підписники:</b>\n',
        'empty': 'Порожньо',
        'force_check_running': '🔄 Запускаю перевірку...',
        'check_failed': '❌ Перевірка не вдалася. Дивіться логи.',
        'check_completed_none': '✅ Перевірка завершена. Вебінарів не знайдено.',
        'check_completed': '✅ Перевірка завершена. Знайдено {count} вебінар(ів)!',
        'toggle_whitelist_disable': '🔒 Вимкнути білий список',
        'toggle_whitelist_enable': '🔓 Увімкнути білий список',
        'view_whitelist': '📋 Переглянути білий список',
        'view_subscribers': '👥 Переглянути підписників',
        'force_check': '🔄 Примусова перевірка',
        'webinar_found': '🎓 <b>Новий вебінар!</b>\n\n',
        'webinar_item': '📌 <b>{name}</b>\n🔗 https://edu.edu.vn.ua{url}',
        'select_language': '🌐 <b>Виберіть мову / Выберите язык / Select language:</b>',
        'language_changed': '✅ Мову змінено на {lang}',
        'flag_ru': '🇷🇺 Русский',
        'flag_uk': '🇺🇦 Українська',
        'flag_en': '🇬🇧 English',
        'history_cleared': '✅ Історія вебінарів очищена',
        'history_clear_failed': '❌ Помилка при очищенні історії',
        'today': '📌 Сьогодні',
        'tomorrow': '📌 Завтра',
        'week': '📅 Цей тиждень',
        'month': '📅 Весь місяць',
        'no_events': 'Немає подій',
        'no_lessons': 'Немає уроків',
        'free_period': 'Вільно',
        'unsubscribed': '🔕 Ви відписалися від сповіщень.',
        'diary_title': '📅 <b>Щоденник</b> — виберіть період:',
        'diary_week_title': '📅 <b>Тиждень {start} – {end}</b>',
        'schedule_title': '📅 <b>{weekday} — {class_num} клас</b>',
        'loading_diary': '🔄 Завантажую щоденник...',
        'diary_load_failed': '❌ Не вдалося завантажити щоденник.',
        'diary_no_session': '❌ Не вдалося завантажити щоденник. Немає сесії або помилка.',
        'diary_next_month': '❌ Дані за наступний місяць недоступні. Перейдіть на сайт.',
        'schedule_load_failed': '❌ Не вдалося завантажити розклад.',
        'class_not_set': '❌ Клас не налаштовано. Використайте /setclass.',
        'class_not_found': '❌ Класи не знайдені в розкладі.',
        'select_class': '🎒 <b>Оберіть клас</b> — збережеться і більше не питатиметься:',
        'admin_class_not_set': '⚠️ Адміністратор ще не налаштував клас для цієї групи. Використайте /setclass 11',
        'loading_schedule': '🔄 Завантажую розклад...',
        'invalid_class_num': '❌ Невірний номер класу.',
        'class_saved': '✅ Клас <b>{class_num}</b> збережено.',
        'admin_only_msg': '⚠️ Тільки адміністратор може налаштувати клас для групи.',
        'truncation': '\n\n✂️ ...(обрізано)',
        'day_mon': 'Пн',
        'day_tue': 'Вт',
        'day_wed': 'Ср',
        'day_thu': 'Чт',
        'day_fri': 'Пт',
        'day_sat': 'Сб',
        'day_sun': 'Нд',
    },
    'en': {
        'welcome': '👋 Hello, {name}!\n\nI am the Webinar Checker Bot. I will notify you when a new webinar appears.\nYou have been subscribed to notifications.',
        'welcome_admin': '\n\n👑 <b>Admin Mode Active</b>',
        'access_denied': '⛔ Access denied. You are not on the whitelist.',
        'help_title': '🤖 <b>Bot Help</b>\n\n',
        'help_commands': '/start - Subscribe to notifications\n/stop - Unsubscribe from notifications\n/help - Show this message\n/language - Change language',
        'help_admin': '\n<b>Admin Commands:</b>\n/adduser [user_id] - Add user to whitelist\n/removeuser [user_id] - Remove user from whitelist\nOr use the panel below to manage settings.',
        'admin_only': '⛔ Admin only!',
        'user_added': '✅ User {user_id} added to whitelist',
        'user_removed': '✅ User {user_id} removed from whitelist',
        'user_not_in_whitelist': '⚠️ User {user_id} was not in whitelist',
        'cannot_remove_admin': '❌ Cannot remove admin from whitelist',
        'invalid_user_id': '❌ Invalid user ID. Must be a number.',
        'usage_adduser': 'Usage: /adduser [user_id]',
        'usage_removeuser': 'Usage: /removeuser [user_id]',
        'whitelist_enabled': '✅ Whitelist Enabled',
        'whitelist_disabled': '🚫 Whitelist Disabled',
        'whitelist_title': '📋 <b>Whitelist:</b>\n',
        'subscribers_title': '👥 <b>Subscribers:</b>\n',
        'empty': 'Empty',
        'force_check_running': '🔄 Running immediate check...',
        'check_failed': '❌ Check failed. See logs for details.',
        'check_completed_none': '✅ Check completed. No webinars found.',
        'check_completed': '✅ Check completed. Found {count} webinar(s)!',
        'toggle_whitelist_disable': '🔒 Disable Whitelist',
        'toggle_whitelist_enable': '🔓 Enable Whitelist',
        'view_whitelist': '📋 View Whitelist',
        'view_subscribers': '👥 View Subscribers',
        'force_check': '🔄 Force Check',
        'webinar_found': '🎓 <b>New webinar found!</b>\n\n',
        'webinar_item': '📌 <b>{name}</b>\n🔗 https://edu.edu.vn.ua{url}',
        'select_language': '🌐 <b>Select language / Виберіть мову / Выберите язык:</b>',
        'language_changed': '✅ Language changed to {lang}',
        'flag_ru': '🇷🇺 Русский',
        'flag_uk': '🇺🇦 Українська',
        'flag_en': '🇬🇧 English',
        'history_cleared': '✅ Webinar history cleared',
        'history_clear_failed': '❌ Error clearing history',
        'today': '📌 Today',
        'tomorrow': '📌 Tomorrow',
        'week': '📅 This week',
        'month': '📅 Whole month',
        'no_events': 'No events',
        'no_lessons': 'No lessons',
        'free_period': 'Free',
        'unsubscribed': '🔕 You have unsubscribed from notifications.',
        'diary_title': '📅 <b>Diary</b> — choose a period:',
        'diary_week_title': '📅 <b>Week {start} – {end}</b>',
        'schedule_title': '📅 <b>{weekday} — {class_num} class</b>',
        'loading_diary': '🔄 Loading diary...',
        'diary_load_failed': '❌ Failed to load diary.',
        'diary_no_session': '❌ Failed to load diary. No session or error.',
        'diary_next_month': '❌ Next month data is not available. Please visit the website.',
        'schedule_load_failed': '❌ Failed to load schedule.',
        'class_not_set': '❌ Class is not set. Use /setclass.',
        'class_not_found': '❌ No classes found in the schedule.',
        'select_class': '🎒 <b>Choose a class</b> — it will be saved and not asked again:',
        'admin_class_not_set': '⚠️ Admin has not set a class for this group yet. Use /setclass 11',
        'loading_schedule': '🔄 Loading schedule...',
        'invalid_class_num': '❌ Invalid class number.',
        'class_saved': '✅ Class <b>{class_num}</b> saved.',
        'admin_only_msg': '⚠️ Only an admin can set the class for this group.',
        'truncation': '\n\n✂️ ...(truncated)',
        'day_mon': 'Mon',
        'day_tue': 'Tue',
        'day_wed': 'Wed',
        'day_thu': 'Thu',
        'day_fri': 'Fri',
        'day_sat': 'Sat',
        'day_sun': 'Sun',
    },
}

# --- Language Helper Functions ---


LANG_NAME_MAP = {'ru': 'Русский', 'uk': 'Українська', 'en': 'English'}


def get_user_language(user_id: int) -> str:
    """Get user's preferred language from Redis. Default: English."""
    lang = redis_client.get(f'user:{user_id}:language')
    return lang if lang in ['ru', 'uk', 'en'] else 'en'


def set_user_language(user_id: int, lang: str):
    """Save user's language preference to Redis."""
    if lang in ['ru', 'uk', 'en']:
        redis_client.set(f'user:{user_id}:language', lang)
        logger.info(f'User {user_id} language set to {lang}')


def t(user_id: int, key: str, **kwargs) -> str:
    """Translate message for user with optional formatting.

    Fallback chain: user lang → en → uk → ru, otherwise return the key.
    """
    lang = get_user_language(user_id)
    message = None
    for fallback in (lang, 'en', 'uk', 'ru'):
        message = TRANSLATIONS.get(fallback, {}).get(key)
        if message is not None:
            break
    if message is None:
        return key
    if kwargs:
        return message.format(**kwargs)
    return message


def _tr(lang: str, key: str, **kwargs) -> str:
    """Translate by explicit lang code (for format_* helpers).

    Fallback chain: lang → en → uk → ru, otherwise return the key.
    """
    message = None
    for fallback in (lang, 'en', 'uk', 'ru'):
        message = TRANSLATIONS.get(fallback, {}).get(key)
        if message is not None:
            break
    if message is None:
        return key
    if kwargs:
        return message.format(**kwargs)
    return message


def get_chat_language(chat_id: int) -> str:
    """Get group chat language from Redis. Default: Ukrainian."""
    lang = redis_client.get(f'chat:{chat_id}:language')
    return lang if lang in ['ru', 'uk', 'en'] else 'uk'


def set_chat_language(chat_id: int, lang: str):
    """Save group chat language preference to Redis."""
    if lang in ['ru', 'uk', 'en']:
        redis_client.set(f'chat:{chat_id}:language', lang)
        logger.info(f'Chat {chat_id} language set to {lang}')


def resolve_lang(chat, user_id=None) -> str:
    """Resolve effective language: private → user lang, groups → chat lang (default 'uk')."""
    chat_id = getattr(chat, 'id', chat)
    chat_type = getattr(chat, 'type', None)
    if chat_type is None:
        try:
            is_private = int(chat_id) > 0
        except (TypeError, ValueError):
            is_private = True
        if is_private:
            uid = user_id if user_id is not None else chat_id
            return get_user_language(int(uid))
        return get_chat_language(int(chat_id))
    if chat_type in (ChatType.PRIVATE, 'private'):
        uid = user_id if user_id is not None else chat_id
        return get_user_language(int(uid))
    return get_chat_language(chat_id)


def t_chat(chat, user_id, key: str, **kwargs) -> str:
    """Translate using chat-resolved language (private → user, groups → chat 'uk' default)."""
    return _tr(resolve_lang(chat, user_id), key, **kwargs)


def get_language_keyboard(user_id: int | None = None):
    """Generate language selection keyboard."""
    lang = get_user_language(user_id) if user_id is not None else 'en'
    keyboard = [
        [
            InlineKeyboardButton(_tr(lang, 'flag_ru'), callback_data='lang_ru'),
            InlineKeyboardButton(_tr(lang, 'flag_uk'), callback_data='lang_uk'),
        ],
        [
            InlineKeyboardButton(_tr(lang, 'flag_en'), callback_data='lang_en'),
        ],
    ]
    return InlineKeyboardMarkup(keyboard)


# --- Helper Functions ---


def is_whitelisted(user_id: int) -> bool:
    """Check if user is allowed to use the bot."""
    if user_id == ADMIN_ID:
        return True

    enabled = redis_client.get(KEY_WHITELIST_ENABLED)
    if enabled == '0':  # Whitelist disabled
        return True

    return redis_client.sismember(KEY_WHITELIST, str(user_id))


async def is_group_admin(update: Update, context: ContextTypes.DEFAULT_TYPE) -> bool:
    """Check if the user is an administrator in the group."""
    user = update.effective_user
    chat = update.effective_chat

    if chat.type in [ChatType.PRIVATE, 'private']:
        return True

    try:
        member = await context.bot.get_chat_member(chat.id, user.id)
        return member.status in [ChatMember.OWNER, ChatMember.ADMINISTRATOR]
    except Exception as e:
        logger.error(f'Failed to check admin status: {e}')
        return False


def get_admin_keyboard(user_id: int):
    """Generate admin panel keyboard."""
    whitelist_enabled = redis_client.get(KEY_WHITELIST_ENABLED) != '0'
    toggle_text = t(user_id, 'toggle_whitelist_disable') if whitelist_enabled else t(user_id, 'toggle_whitelist_enable')

    keyboard = [
        [InlineKeyboardButton(toggle_text, callback_data='toggle_whitelist')],
        [InlineKeyboardButton(t(user_id, 'view_whitelist'), callback_data='view_whitelist')],
        [InlineKeyboardButton(t(user_id, 'view_subscribers'), callback_data='view_subscribers')],
        [InlineKeyboardButton(t(user_id, 'force_check'), callback_data='force_check')],
    ]
    return InlineKeyboardMarkup(keyboard)


# --- Diary Functions ---

SCHEDULE_WEEKDAYS_FULL = {
    'uk': ['Понеділок', 'Вівторок', 'Середа', 'Четвер', "П'ятниця", 'Субота', 'Неділя'],
    'ru': ['Понедельник', 'Вторник', 'Среда', 'Четверг', 'Пятница', 'Суббота', 'Воскресенье'],
    'en': ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'],
}
# Canonical weekday names used in callback_data and schedule lookup (site language).
SCHEDULE_WEEKDAYS_CANONICAL = SCHEDULE_WEEKDAYS_FULL['uk']
SCHEDULE_CACHE_TTL = 18000  # 5 hours


def _norm_day(s):
    """Normalize weekday name for tolerant matching (case, spaces, apostrophes)."""
    if not isinstance(s, str):
        return ''
    s = s.strip().casefold()
    for _q in ('\u2019', '\u2018', '\u02bc', '`'):
        s = s.replace(_q, "'")
    s = re.sub(r'\s+', ' ', s)
    return s.strip()


_SCHEDULE_WEEKDAYS_CANONICAL_NORM = [_norm_day(d) for d in SCHEDULE_WEEKDAYS_CANONICAL]

DIARY_WEEKDAYS_SHORT = {
    'uk': ['Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб', 'Нд'],
    'ru': ['Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб', 'Вс'],
    'en': ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'],
}


def get_diary_keyboard(user_id: int | None = None):
    today = datetime.now()
    lang = get_user_language(user_id) if user_id is not None else 'en'
    today_label = _tr(lang, 'today')
    tomorrow_label = _tr(lang, 'tomorrow')
    week_label = _tr(lang, 'week')
    month_label = _tr(lang, 'month')
    keyboard = [
        [
            InlineKeyboardButton(f'{today_label} ({today.day}.{today.month:02d})', callback_data='diary_today'),
            InlineKeyboardButton(tomorrow_label, callback_data='diary_tomorrow'),
        ],
        [
            InlineKeyboardButton(week_label, callback_data='diary_week'),
            InlineKeyboardButton(month_label, callback_data='diary_month'),
        ],
    ]
    return InlineKeyboardMarkup(keyboard)


def _parse_calendar_html(table_html: str) -> tuple:
    """Parse calendar HTML table into (month_text, {day_num: {weekday, events}})."""
    days = {}
    weekdays = []
    rows = re.findall(r'<tr[^>]*>(.*?)</tr>', table_html, re.DOTALL)

    month_text = ''
    for r_idx, row in enumerate(rows):
        cells = re.findall(r'<t[dh][^>]*>(.*?)</t[dh]>', row, re.DOTALL)

        if r_idx == 0:
            # Month navigation row: extract "Травень 2026" from nav text
            raw = re.sub(r'<[^>]+>', ' ', row).strip()
            raw = re.sub(r'\s+', ' ', raw)
            m = re.search(r'([А-Яа-яіїєґ\']+\s*:?\s*\d{4})', raw)
            month_text = m.group(1).replace(' : ', ' ').strip() if m else raw
        elif r_idx == 1:
            # Day names row
            for cell in cells:
                name = re.sub(r'<[^>]+>', '', cell).strip()
                if name:
                    weekdays.append(name)
        else:
            # Data rows: each cell = a day
            for col_idx, cell in enumerate(cells):
                # Extract day number — first number in the cell text
                text = re.sub(r'<[^>]+>', ' ', cell).strip()
                text = re.sub(r'\s+', ' ', text)
                dm = re.match(r'(\d+)', text)
                if not dm:
                    continue
                day_num = dm.group(1)

                # Extract events: title attribute (full name) of ALL <a> tags inside the cell
                events = []
                for a_match in re.finditer(r'<a[^>]*>(.*?)</a>', cell, re.DOTALL):
                    a_tag = a_match.group(0)
                    # Prefer the title attribute (contains full name, not truncated)
                    title_m = re.search(r'title\s*=\s*"([^"]*)"', a_tag)
                    et = title_m.group(1).strip() if title_m else re.sub(r'<[^>]+>', '', a_match.group(1)).strip()
                    if et:
                        events.append(et)

                weekday = weekdays[col_idx] if col_idx < len(weekdays) else ''
                days[day_num] = {'weekday': weekday, 'events': events}

    return month_text, days


async def fetch_diary_data(phpsessid: str) -> dict | None:
    logger.info('Fetching diary data via Playwright...')
    try:
        async with async_playwright() as p:
            browser = await p.chromium.connect(PLAYWRIGHT_WS)
            try:
                context_browser = await browser.new_context(user_agent=USER_AGENT)
                await context_browser.add_cookies(
                    [{'name': 'PHPSESSID', 'value': phpsessid, 'domain': 'edu.edu.vn.ua', 'path': '/'}]
                )
                page = await context_browser.new_page()

                try:
                    await page.goto(DIARY_URL, wait_until='domcontentloaded')
                    await page.wait_for_selector('table.calendar', timeout=10000)
                    await page.wait_for_timeout(1500)

                    table_html = await page.evaluate("""
                        () => {
                            const t = document.querySelector('table.calendar');
                            return t ? t.outerHTML : null;
                        }
                    """)
                    if not table_html:
                        logger.error('table.calendar not found in DOM')
                        return None

                    # Debug: save HTML for troubleshooting
                    with contextlib.suppress(Exception), open('/tmp/diary_debug.html', 'w', encoding='utf-8') as f:  # noqa: S108
                        f.write(table_html)

                    month_text, days = _parse_calendar_html(table_html)
                    logger.info(
                        f'Diary parsed: month={month_text!r}, days_with_events={sum(1 for d in days.values() if d["events"])}/{len(days)}'
                    )

                    return {'monthFullText': month_text, 'days': days}

                except Exception as e:
                    logger.error(f'Error parsing diary: {e}')
                    return None
                finally:
                    await page.close()
                    await context_browser.close()
            finally:
                await browser.close()
    except Exception as e:
        logger.error(f'Playwright error in diary fetch: {e}')
        return None


def _parse_diary_month(text: str) -> str:
    match = re.search(r'([А-Яа-яіїєґ\']+\s*:\s*\d{4})', text)
    if match:
        return match.group(1).replace(' : ', ' ').strip()
    return text.strip()


def format_diary_day(data: dict, day_num: int, lang: str = 'en') -> str:
    days = data.get('days', {})
    month_str = _parse_diary_month(data.get('monthFullText', ''))
    day_data = days.get(str(day_num))
    lines = [f'📅 <b>{day_num} {month_str}</b>', '─' * 18]
    if not day_data or not day_data.get('events'):
        lines.append(_tr(lang, 'no_events'))
    else:
        for e in day_data['events']:
            lines.append(f'📌 {escape(e)}')
    lines.append(f'\n🔗 {DIARY_URL}')
    return '\n'.join(lines)


def format_diary_week(data: dict, today: datetime, lang: str = 'en') -> str:
    days = data.get('days', {})
    _parse_diary_month(data.get('monthFullText', ''))
    monday = today - timedelta(days=today.weekday())
    sunday = monday + timedelta(days=6)
    start = f'{monday.day}.{monday.month}'
    end = f'{sunday.day}.{sunday.month}'
    short = DIARY_WEEKDAYS_SHORT.get(lang, DIARY_WEEKDAYS_SHORT['en'])
    lines = [_tr(lang, 'diary_week_title', start=start, end=end) + '\n']
    for i in range(7):
        d = monday + timedelta(days=i)
        day_data = days.get(str(d.day))
        lines.append(f'─ <b>{short[i]} {d.day}.{d.month}</b> ─')
        if not day_data or not day_data.get('events'):
            lines.append(_tr(lang, 'no_events') + '\n')
        else:
            for e in day_data['events']:
                lines.append(f'📌 {escape(e)}')
            lines.append('')
    lines.append(f'🔗 {DIARY_URL}')
    return '\n'.join(lines)


def format_diary_month(data: dict, lang: str = 'en') -> str:
    days = data.get('days', {})
    month_str = _parse_diary_month(data.get('monthFullText', ''))
    lines = [f'📅 <b>{month_str}</b>\n']
    for day_num in sorted(days.keys(), key=int):
        day_data = days[day_num]
        events = day_data.get('events', [])
        weekday = day_data.get('weekday', '')
        lines.append(f'─ <b>{weekday} {day_num}</b> ─')
        if not events:
            lines.append(_tr(lang, 'no_events') + '\n')
        else:
            for e in events:
                lines.append(f'📌 {escape(e)}')
            lines.append('')
    lines.append(f'🔗 {DIARY_URL}')
    return '\n'.join(lines)


async def _get_diary_data(context: ContextTypes.DEFAULT_TYPE) -> dict | None:
    cached = context.user_data.get('diary_cache')
    now_ts = time.time()
    if cached and (now_ts - cached.get('timestamp', 0)) < 300:
        return cached['data']
    phpsessid = redis_client.get(KEY_PHPSESSID)
    if not phpsessid:
        return None
    data = await fetch_diary_data(phpsessid)
    if data:
        context.user_data['diary_cache'] = {'data': data, 'timestamp': now_ts}
    return data


# --- Schedule Functions ---


def get_schedule_day_keyboard(user_id: int | None = None):
    lang = get_user_language(user_id) if user_id is not None else 'en'
    full = SCHEDULE_WEEKDAYS_FULL.get(lang, SCHEDULE_WEEKDAYS_FULL['en'])
    today = datetime.now()
    tomorrow = today + timedelta(days=1)
    today_label = _tr(lang, 'today')
    tomorrow_label = _tr(lang, 'tomorrow')
    short_keys = ['day_mon', 'day_tue', 'day_wed', 'day_thu', 'day_fri', 'day_sat', 'day_sun']
    keyboard = [
        [
            InlineKeyboardButton(
                f'{today_label} ({full[today.weekday()]})',
                callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[today.weekday()]}',
            ),
            InlineKeyboardButton(
                f'{tomorrow_label} ({full[tomorrow.weekday()]})',
                callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[tomorrow.weekday()]}',
            ),
        ],
        [
            InlineKeyboardButton(
                _tr(lang, short_keys[0]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[0]}'
            ),
            InlineKeyboardButton(
                _tr(lang, short_keys[1]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[1]}'
            ),
            InlineKeyboardButton(
                _tr(lang, short_keys[2]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[2]}'
            ),
        ],
        [
            InlineKeyboardButton(
                _tr(lang, short_keys[3]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[3]}'
            ),
            InlineKeyboardButton(
                _tr(lang, short_keys[4]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[4]}'
            ),
            InlineKeyboardButton(
                _tr(lang, short_keys[5]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[5]}'
            ),
        ],
        [
            InlineKeyboardButton(
                _tr(lang, short_keys[6]), callback_data=f'schedule_day_{SCHEDULE_WEEKDAYS_CANONICAL[6]}'
            ),
        ],
    ]
    return InlineKeyboardMarkup(keyboard)


def get_schedule_class_keyboard(classes: list):
    rows = []
    for i in range(0, len(classes), 4):
        row = [InlineKeyboardButton(str(c), callback_data=f'schedule_class_{c}') for c in classes[i : i + 4]]
        rows.append(row)
    return InlineKeyboardMarkup(rows)


def _get_chat_class(chat, user_id) -> str | None:
    """Get stored schedule class for a private user or a group chat."""
    if chat.type == 'private':
        return redis_client.get(f'user:{user_id}:schedule_class')
    return redis_client.get(f'chat:{chat.id}:schedule_class')


def _set_chat_class(chat, user_id, class_num) -> None:
    """Save schedule class for a private user or a group chat."""
    if chat.type == 'private':
        redis_client.set(f'user:{user_id}:schedule_class', str(class_num))
    else:
        redis_client.set(f'chat:{chat.id}:schedule_class', str(class_num))


def _parse_schedule_cell(cell_html: str) -> list:
    """Parse a single schedule cell, returning list of {subject, note, teacher}."""
    lessons = []
    parts = re.split(r'<hr\s*/?>', cell_html, flags=re.IGNORECASE)
    for part in parts:
        part = re.sub(r'<!--.*?-->', '', part, flags=re.DOTALL)
        part = re.sub(r'<!--', '', part)
        text = re.sub(r'<[^>]+>', '\n', part)
        text = re.sub(r'&nbsp;', ' ', text)
        text = text.strip()
        if not text:
            continue
        lines = [ln.strip() for ln in text.split('\n') if ln.strip()]
        if not lines:
            continue
        subject = lines[0] if lines else ''
        note = ''
        teacher = ''
        for line in lines[1:]:
            if (
                line in ('вебінар', 'онлайн', 'асинхрон', 'асинхронно')
                or 'Вебінар' in line
                or 'Асинхронн' in line
                or 'вебінар' in line.lower()
                or 'онлайн' in line.lower()
                or 'асинхрон' in line.lower()
                or 'А/С урок' in line
                or 'Онлайн' in line
            ):
                note = line
            else:
                teacher = line
        lessons.append({'subject': subject, 'note': note, 'teacher': teacher})
    return lessons


def _parse_schedule_html(table_html: str) -> dict:
    """Parse schedule HTML table into {classes: [...], weekdays: {day: [...]}}."""
    result = {'classes': [], 'weekdays': {}, 'weekday_norm': {}}
    row_matches = re.finditer(r'<tr([^>]*)>(.*?)</tr>', table_html, re.DOTALL)

    current_day = None
    classes_header = []

    for match in row_matches:
        tr_attrs, row = match.group(1), match.group(2)

        if 'first-row' in tr_attrs:
            cells = re.findall(r'<td[^>]*>(.*?)</td>', row, re.DOTALL)
            if cells:
                day_text = re.sub(r'<[^>]+>', '', cells[0]).strip()
                current_day = day_text
                result['weekdays'][current_day] = []
                result['weekday_norm'][_norm_day(day_text)] = current_day
                classes_header = []
                for cell in cells[1:]:
                    cls = re.sub(r'<[^>]+>', '', cell).strip()
                    if cls:
                        try:
                            classes_header.append(int(cls))
                        except ValueError:
                            classes_header.append(cls)
                result['classes'] = classes_header
            continue

        if 'second-row' in tr_attrs:
            continue

        if current_day is None:
            continue

        cells = re.findall(r'<td[^>]*>(.*?)</td>', row, re.DOTALL)
        if len(cells) < 3:
            continue

        first_cell_text = re.sub(r'<[^>]+>', '', cells[0]).strip()
        if not re.match(r'^\d+\.', first_cell_text) and (
            'Позакласне' in first_cell_text or re.search(r'colspan\s*=\s*"?(\d+)"?', row)
        ):
            continue

        lesson_num_match = re.match(r'^(\d+)\.', first_cell_text)
        lesson_num = lesson_num_match.group(1) if lesson_num_match else ''
        time_text = re.sub(r'<[^>]+>', '', cells[1]).strip()

        entry = {'lesson_num': lesson_num, 'time': time_text, 'classes': {}}

        data_cells = cells[2:]
        for idx, cell in enumerate(data_cells):
            cls = classes_header[idx] if idx < len(classes_header) else idx
            lessons = _parse_schedule_cell(cell)
            entry['classes'][cls] = lessons

        result['weekdays'][current_day].append(entry)

    return result


async def fetch_schedule_data(phpsessid: str) -> dict | None:
    logger.info('Fetching schedule data via Playwright...')
    try:
        async with async_playwright() as p:
            browser = await p.chromium.connect(PLAYWRIGHT_WS)
            try:
                context_browser = await browser.new_context(user_agent=USER_AGENT)
                await context_browser.add_cookies(
                    [{'name': 'PHPSESSID', 'value': phpsessid, 'domain': 'edu.edu.vn.ua', 'path': '/'}]
                )
                page = await context_browser.new_page()

                try:
                    await page.goto(SCHEDULE_URL, wait_until='domcontentloaded')
                    await page.wait_for_selector('table.schedule-table', timeout=10000)
                    await page.wait_for_timeout(1500)

                    table_html = await page.evaluate("""
                        () => {
                            const t = document.querySelector('table.schedule-table');
                            return t ? t.outerHTML : null;
                        }
                    """)
                    if not table_html:
                        logger.error('table.schedule-table not found in DOM')
                        return None

                    debug_path = os.path.join(tempfile.gettempdir(), 'schedule_debug.html')
                    with contextlib.suppress(Exception), open(debug_path, 'w', encoding='utf-8') as f:
                        f.write(table_html)

                    data = _parse_schedule_html(table_html)
                    logger.info(list(data['weekdays'].keys()))
                    logger.info(f'Schedule parsed: {len(data["weekdays"])} days, classes={data["classes"]}')

                    return data

                except Exception as e:
                    logger.error(f'Error parsing schedule: {e}')
                    return None
                finally:
                    await page.close()
                    await context_browser.close()
            finally:
                await browser.close()
    except Exception as e:
        logger.error(f'Playwright error in schedule fetch: {e}')
        return None


async def _get_schedule_data(context: ContextTypes.DEFAULT_TYPE) -> dict | None:
    cached = context.user_data.get('schedule_cache')
    now_ts = time.time()
    if cached and (now_ts - cached.get('timestamp', 0)) < SCHEDULE_CACHE_TTL:
        return cached['data']
    phpsessid = redis_client.get(KEY_PHPSESSID)
    if not phpsessid:
        return None
    data = await fetch_schedule_data(phpsessid)
    if data:
        context.user_data['schedule_cache'] = {'data': data, 'timestamp': now_ts}
    return data


def format_schedule_day(data: dict, weekday: str, class_num, lang: str = 'en') -> str:
    days = data.get('weekdays', {})
    norm_map = data.get('weekday_norm') or {_norm_day(k): k for k in days}
    norm = _norm_day(weekday)
    day_key = norm_map.get(norm)
    if day_key is None:
        logger.warning(f'Schedule weekday not matched: {weekday!r}')
    entries = days.get(day_key, []) if day_key is not None else []
    try:
        class_key = int(class_num)
    except (TypeError, ValueError):
        class_key = class_num
    try:
        idx = _SCHEDULE_WEEKDAYS_CANONICAL_NORM.index(norm)
        display_weekday = SCHEDULE_WEEKDAYS_FULL.get(lang, SCHEDULE_WEEKDAYS_FULL['en'])[idx]
    except ValueError:
        logger.warning(f'Schedule weekday not in canonical list: {weekday!r}')
        display_weekday = weekday
    lines = [_tr(lang, 'schedule_title', weekday=display_weekday, class_num=class_num), '─' * 20]

    if not entries:
        lines.append(_tr(lang, 'no_lessons'))
    else:
        for entry in entries:
            time_str = entry.get('time', '').replace(' ', '–')
            lines.append(f'\n<b>{entry["lesson_num"]}. </b>({time_str})')

            lessons = entry.get('classes', {}).get(class_key, [])
            if not lessons:
                lines.append(f'  {_tr(lang, "free_period")}')
            else:
                for i, lesson in enumerate(lessons):
                    note_part = f' ({escape(lesson["note"])})' if lesson.get('note') else ''
                    lines.append(f'  📌 <b>{escape(lesson["subject"])}</b>{note_part}')
                    if lesson.get('teacher'):
                        lines.append(f'  {escape(lesson["teacher"])}')
                    if i < len(lessons) - 1:
                        lines.append('  ──')

    lines.append(f'\n🔗 {SCHEDULE_URL}')
    return '\n'.join(lines)


# --- Command Handlers ---


async def start(update: Update, _context: ContextTypes.DEFAULT_TYPE):
    """Handle /start command."""
    user = update.effective_user
    chat = update.effective_chat
    logger.info(f'User {user.id} ({user.username}) started the bot in chat {chat.id} ({chat.type}).')

    # Check whitelist - MUST be the user executing the command
    if not is_whitelisted(user.id):
        await update.message.reply_text(t(user.id, 'access_denied'))
        return

    # Add to subscribers (Chat ID!)
    redis_client.sadd(KEY_SUBSCRIBERS, chat.id)

    msg = t_chat(chat, user.id, 'welcome', name=escape(user.first_name))

    if user.id == ADMIN_ID and chat.type == 'private':
        msg += t_chat(chat, user.id, 'welcome_admin')
        await update.message.reply_text(msg, parse_mode='HTML', reply_markup=get_admin_keyboard(user.id))
    else:
        await update.message.reply_text(msg, parse_mode='HTML')


async def help_command(update: Update, _context: ContextTypes.DEFAULT_TYPE):
    """Handle /help command."""
    user_id = update.effective_user.id
    chat = update.effective_chat
    msg = t_chat(chat, user_id, 'help_title') + t_chat(chat, user_id, 'help_commands')

    if user_id == ADMIN_ID and update.effective_chat.type == 'private':
        msg += t_chat(chat, user_id, 'help_admin')
        await update.message.reply_text(msg, parse_mode='HTML', reply_markup=get_admin_keyboard(user_id))
    else:
        await update.message.reply_text(msg, parse_mode='HTML')


async def stop_command(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Handle /stop command (unsubscribe)."""
    user = update.effective_user
    chat = update.effective_chat

    # Permission check: Whitelisted user OR Group Admin
    lang = resolve_lang(chat, user.id)
    if not (is_whitelisted(user.id) or await is_group_admin(update, context)):
        await update.message.reply_text(_tr(lang, 'access_denied'))  # Or specific "admin only" message
        return

    redis_client.srem(KEY_SUBSCRIBERS, chat.id)
    await update.message.reply_text(_tr(lang, 'unsubscribed'))


async def language_command(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Handle /language command."""
    user = update.effective_user
    chat = update.effective_chat

    # Permission check for groups
    if not (is_whitelisted(user.id) or await is_group_admin(update, context)):
        return

    await update.message.reply_text(
        t_chat(chat, user.id, 'select_language'), parse_mode='HTML', reply_markup=get_language_keyboard()
    )


async def add_user(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Add user to whitelist (admin only)."""
    admin_id = update.effective_user.id
    if admin_id != ADMIN_ID:
        await update.message.reply_text(t(admin_id, 'admin_only'))
        return

    if not context.args:
        await update.message.reply_text(t(admin_id, 'usage_adduser'))
        return

    try:
        user_id = int(context.args[0])
        redis_client.sadd(KEY_WHITELIST, str(user_id))
        await update.message.reply_text(t(admin_id, 'user_added', user_id=user_id))
        logger.info(f'Admin added user {user_id} to whitelist')
    except ValueError:
        await update.message.reply_text(t(admin_id, 'invalid_user_id'))


async def remove_user(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Remove user from whitelist (admin only)."""
    admin_id = update.effective_user.id
    if admin_id != ADMIN_ID:
        await update.message.reply_text(t(admin_id, 'admin_only'))
        return

    if not context.args:
        await update.message.reply_text(t(admin_id, 'usage_removeuser'))
        return

    try:
        user_id = int(context.args[0])
        if str(user_id) == str(ADMIN_ID):
            await update.message.reply_text(t(admin_id, 'cannot_remove_admin'))
            return

        removed = redis_client.srem(KEY_WHITELIST, str(user_id))
        if removed:
            await update.message.reply_text(t(admin_id, 'user_removed', user_id=user_id))
            logger.info(f'Admin removed user {user_id} from whitelist')
        else:
            await update.message.reply_text(t(admin_id, 'user_not_in_whitelist', user_id=user_id))
    except ValueError:
        await update.message.reply_text(t(admin_id, 'invalid_user_id'))


async def clear_history(update: Update, _context: ContextTypes.DEFAULT_TYPE):
    """Clear webinar history (admin only)."""
    admin_id = update.effective_user.id
    if admin_id != ADMIN_ID:
        await update.message.reply_text(t(admin_id, 'admin_only'))
        return

    try:
        redis_client.delete(KEY_WEBINAR_HISTORY)
        await update.message.reply_text(t(admin_id, 'history_cleared'))
        logger.info('Admin cleared webinar history')
    except Exception as e:
        logger.error(f'Failed to clear history: {e}')
        await update.message.reply_text(t(admin_id, 'history_clear_failed'))


async def diary_command(update: Update, _context: ContextTypes.DEFAULT_TYPE):
    user = update.effective_user
    if not is_whitelisted(user.id):
        await update.message.reply_text(t(user.id, 'access_denied'))
        return
    await update.message.reply_text(
        t(user.id, 'diary_title'), parse_mode='HTML', reply_markup=get_diary_keyboard(user.id)
    )


async def diary_callback(update: Update, context: ContextTypes.DEFAULT_TYPE):
    query = update.callback_query
    user_id = query.from_user.id
    await query.answer()

    if user_id != ADMIN_ID and not is_whitelisted(user_id):
        await query.edit_message_text(t(user_id, 'access_denied'))
        return

    data = query.data
    if data == 'diary_refresh':
        context.user_data.pop('diary_cache', None)
        await query.edit_message_text(t(user_id, 'loading_diary'))
        diary_data = await _get_diary_data(context)
        if not diary_data:
            await query.edit_message_text(t(user_id, 'diary_no_session'))
            return
        await query.edit_message_text(
            t(user_id, 'diary_title'), parse_mode='HTML', reply_markup=get_diary_keyboard(user_id)
        )
        return

    await query.edit_message_text(t(user_id, 'loading_diary'))
    diary_data = await _get_diary_data(context)
    if not diary_data:
        await query.edit_message_text(t(user_id, 'diary_load_failed'))
        return

    today = datetime.now()
    lang = get_user_language(user_id)
    if data == 'diary_today':
        text = format_diary_day(diary_data, today.day, lang=lang)
    elif data == 'diary_tomorrow':
        tomorrow = today + timedelta(days=1)
        if tomorrow.day < today.day:
            text = t(user_id, 'diary_next_month')
        else:
            text = format_diary_day(diary_data, tomorrow.day, lang=lang)
    elif data == 'diary_week':
        text = format_diary_week(diary_data, today, lang=lang)
    elif data == 'diary_month':
        text = format_diary_month(diary_data, lang=lang)
    else:
        return

    if len(text) > 4096:
        text = text[:4090] + t(user_id, 'truncation')

    await query.edit_message_text(text, parse_mode='HTML', reply_markup=get_diary_keyboard(user_id))


# --- Schedule Command Handlers ---


async def _schedule_text_for(context, chat, user_id, weekday) -> tuple:
    """Load schedule data and render one weekday for the stored class."""
    schedule_data = await _get_schedule_data(context)
    if not schedule_data:
        return None, t(user_id, 'schedule_load_failed')
    class_num = _get_chat_class(chat, user_id)
    if not class_num:
        return None, t(user_id, 'class_not_set')
    text = format_schedule_day(schedule_data, weekday, class_num, lang=get_user_language(user_id))
    if len(text) > 4096:
        text = text[:4090] + t(user_id, 'truncation')
    return text, None


async def _show_class_picker(update, context) -> bool:
    """Fetch classes from schedule and render the class-picker keyboard."""
    user_id = update.effective_user.id
    schedule_data = await _get_schedule_data(context)
    if not schedule_data:
        await update.message.reply_text(t(user_id, 'schedule_load_failed'))
        return False
    classes = schedule_data.get('classes', [])
    if not classes:
        await update.message.reply_text(t(user_id, 'class_not_found'))
        return False
    await update.message.reply_text(
        t(user_id, 'select_class'),
        parse_mode='HTML',
        reply_markup=get_schedule_class_keyboard(classes),
    )
    return True


async def schedule_command(update: Update, context: ContextTypes.DEFAULT_TYPE):
    user = update.effective_user
    if not is_whitelisted(user.id):
        await update.message.reply_text(t(user.id, 'access_denied'))
        return

    chat = update.effective_chat
    stored_class = _get_chat_class(chat, user.id)

    if not stored_class:
        if chat.type != 'private' and not await is_group_admin(update, context):
            await update.message.reply_text(t(user.id, 'admin_class_not_set'))
            return
        await _show_class_picker(update, context)
        return

    await update.message.reply_text(t(user.id, 'loading_schedule'))
    today = datetime.now()
    weekday = SCHEDULE_WEEKDAYS_CANONICAL[today.weekday()]
    text, err = await _schedule_text_for(context, chat, user.id, weekday)
    if err:
        await update.message.reply_text(err)
        return
    await update.message.reply_text(text, parse_mode='HTML', reply_markup=get_schedule_day_keyboard(user.id))


async def setclass_command(update: Update, context: ContextTypes.DEFAULT_TYPE):
    user = update.effective_user
    if not is_whitelisted(user.id):
        await update.message.reply_text(t(user.id, 'access_denied'))
        return

    chat = update.effective_chat
    if chat.type != 'private' and not await is_group_admin(update, context):
        await update.message.reply_text(t(user.id, 'admin_only'))
        return

    if context.args:
        try:
            class_num = int(context.args[0])
        except ValueError:
            await update.message.reply_text(t(user.id, 'invalid_class_num'))
            return
        _set_chat_class(chat, user.id, class_num)
        await update.message.reply_text(t(user.id, 'class_saved', class_num=class_num), parse_mode='HTML')
        return

    await _show_class_picker(update, context)


async def schedule_callback(update: Update, context: ContextTypes.DEFAULT_TYPE):
    query = update.callback_query
    user_id = query.from_user.id
    await query.answer()

    if user_id != ADMIN_ID and not is_whitelisted(user_id):
        await query.edit_message_text(t(user_id, 'access_denied'))
        return

    data = query.data

    if data.startswith('schedule_class_'):
        class_num_str = data[len('schedule_class_') :]
        try:
            class_num = int(class_num_str)
        except ValueError:
            await query.edit_message_text(t(user_id, 'invalid_class_num'))
            return

        chat = update.effective_chat
        if chat.type != 'private' and not await is_group_admin(update, context):
            await query.edit_message_text(t(user_id, 'admin_only_msg'))
            return

        _set_chat_class(chat, user_id, class_num)
        await query.edit_message_text(t(user_id, 'loading_schedule'))

        today = datetime.now()
        weekday = SCHEDULE_WEEKDAYS_CANONICAL[today.weekday()]
        text, err = await _schedule_text_for(context, chat, user_id, weekday)
        if err:
            await query.edit_message_text(err)
            return
        await query.edit_message_text(text, parse_mode='HTML', reply_markup=get_schedule_day_keyboard(user_id))
        return

    if data.startswith('schedule_day_'):
        weekday = data[len('schedule_day_') :]
        try:
            _SCHEDULE_WEEKDAYS_CANONICAL_NORM.index(_norm_day(weekday))
        except ValueError:
            logger.warning(f'Schedule callback weekday not in canonical list: {weekday!r}')
        await query.edit_message_text(t(user_id, 'loading_schedule'))
        text, err = await _schedule_text_for(context, query.message.chat, user_id, weekday)
        if err:
            await query.edit_message_text(err)
            return
        await query.edit_message_text(text, parse_mode='HTML', reply_markup=get_schedule_day_keyboard(user_id))
        return

    if data == 'schedule_refresh':
        context.user_data.pop('schedule_cache', None)
        await query.edit_message_text(t(user_id, 'loading_schedule'))
        today = datetime.now()
        weekday = SCHEDULE_WEEKDAYS_CANONICAL[today.weekday()]
        text, err = await _schedule_text_for(context, query.message.chat, user_id, weekday)
        if err:
            await query.edit_message_text(err)
            return
        await query.edit_message_text(text, parse_mode='HTML', reply_markup=get_schedule_day_keyboard(user_id))
        return


# --- Admin Callbacks ---


async def admin_callback(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Handle admin panel button clicks."""
    query = update.callback_query
    user_id = query.from_user.id

    if user_id != ADMIN_ID:
        await query.answer(t(user_id, 'admin_only'), show_alert=True)
        return

    await query.answer()
    data = query.data

    if data == 'toggle_whitelist':
        current = redis_client.get(KEY_WHITELIST_ENABLED)
        new_state = '0' if current != '0' else '1'
        redis_client.set(KEY_WHITELIST_ENABLED, new_state)
        state_text = t(user_id, 'whitelist_disabled') if new_state == '0' else t(user_id, 'whitelist_enabled')
        await query.edit_message_reply_markup(reply_markup=get_admin_keyboard(user_id))
        await query.message.reply_text(state_text)

    elif data == 'view_whitelist':
        members = redis_client.smembers(KEY_WHITELIST)
        msg = t(user_id, 'whitelist_title') + ('\n'.join(members) if members else t(user_id, 'empty'))
        await query.message.reply_text(msg, parse_mode='HTML')

    elif data == 'view_subscribers':
        subs = redis_client.smembers(KEY_SUBSCRIBERS)
        msg = t(user_id, 'subscribers_title') + ('\n'.join(subs) if subs else t(user_id, 'empty'))
        await query.message.reply_text(msg, parse_mode='HTML')

    elif data == 'force_check':
        await query.message.reply_text(t(user_id, 'force_check_running'))
        result = await check_webinars_job(context)

        if result is None:
            await query.message.reply_text(t(user_id, 'check_failed'))
        elif result == 0:
            await query.message.reply_text(t(user_id, 'check_completed_none'))
        else:
            await query.message.reply_text(t(user_id, 'check_completed', count=result))


async def language_callback(update: Update, context: ContextTypes.DEFAULT_TYPE):
    """Handle language selection button clicks."""
    query = update.callback_query
    user_id = query.from_user.id
    chat = update.effective_chat
    data = query.data

    if data.startswith('lang_'):
        lang = data.split('_')[1]
        is_private = chat is None or getattr(chat, 'type', 'private') in (ChatType.PRIVATE, 'private')
        if is_private:
            set_user_language(user_id, lang)
            await query.answer()
            await query.edit_message_text(
                t(user_id, 'language_changed', lang=LANG_NAME_MAP.get(lang, lang)), parse_mode='HTML'
            )
        else:
            if not await is_group_admin(update, context):
                await query.answer(t_chat(chat, user_id, 'admin_only'), show_alert=True)
                return
            set_chat_language(chat.id, lang)
            await query.answer()
            await query.edit_message_text(
                _tr(lang, 'language_changed', lang=LANG_NAME_MAP.get(lang, lang)), parse_mode='HTML'
            )


# --- Webinar Checking Job ---


def get_webinar_key(url: str) -> str:
    """Generate unique key for a webinar based on URL."""
    return url


def get_stored_webinars() -> list:
    """Get list of stored webinar keys from Redis."""
    data = redis_client.get(KEY_WEBINAR_HISTORY)
    if data:
        try:
            return json.loads(data)
        except Exception as e:
            logger.error(f'Failed to parse webinar history: {e}')
    return []


def store_webinars(webinar_keys: list):
    """Store up to 3 most recent webinar keys in Redis."""
    # Keep only last 3
    webinar_keys = webinar_keys[-3:]
    try:
        redis_client.set(KEY_WEBINAR_HISTORY, json.dumps(webinar_keys))
        logger.info(f'Stored {len(webinar_keys)} webinar(s) in history')
    except Exception as e:
        logger.error(f'Failed to store webinar history: {e}')


async def check_webinars_job(context: ContextTypes.DEFAULT_TYPE):
    """Background job to check for webinars using Async Playwright.

    Returns:
        int: Number of webinars found, or None if check failed
    """
    logger.info('Running webinar check...')

    phpsessid = redis_client.get(KEY_PHPSESSID)
    if not phpsessid:
        logger.warning('PHPSESSID missing. Skipping check.')
        # --- DEBUG LOGGING ---
        try:
            with open('phpsessid_missing.log', 'a') as f:
                f.write(f'[{os.getcwd()}] PHPSESSID missing at {context.job.last_run: %Y-%m-%d %H:%M:%S}\n')
        except Exception as e:
            logger.error(f'Failed to write PHPSESSID debug log: {e}')
        # ---------------------
        return None

    current_webinars = []  # List of dicts with name, url, and formatted text
    content = ''

    try:
        async with async_playwright() as p:
            # Connect to remote Playwright service
            browser = await p.chromium.connect(PLAYWRIGHT_WS)

            try:
                # Create browser context with user agent
                context_browser = await browser.new_context(user_agent=USER_AGENT)

                # Add PHPSESSID cookie
                await context_browser.add_cookies(
                    [{'name': 'PHPSESSID', 'value': phpsessid, 'domain': 'edu.edu.vn.ua', 'path': '/'}]
                )

                # Create new page
                page = await context_browser.new_page()

                try:
                    # Navigate to webinar page
                    await page.goto(WEBINAR_URL, wait_until='domcontentloaded')

                    # Wait for the table to load
                    await page.wait_for_selector('#meetings table', timeout=10000)
                    await page.wait_for_timeout(2000)

                    # Get page content
                    content = await page.content()

                    # Check if "no webinar" message is present
                    if NO_WEBINAR_MARKER not in content:
                        logger.info('!!! WEBINAR FOUND !!!')

                        # Extract webinar details from table rows
                        rows = page.locator('#meetings table tbody tr')
                        count = await rows.count()

                        for i in range(count):
                            row = rows.nth(i)
                            text = await row.inner_text()

                            if NO_WEBINAR_MARKER not in text:
                                # Extract name (topic) from first column
                                name_elem = row.locator('td').nth(0)
                                name = await name_elem.inner_text()
                                name = name.strip()

                                # Extract join URL from fourth column
                                url_elem = row.locator('td').nth(3).locator('a[href*="/webinar/join/"]').first
                                url = await url_elem.get_attribute('href')

                                if name and url:
                                    current_webinars.append({'name': name, 'url': url, 'text': text.strip()})
                                    logger.info(f'Found webinar: {name} -> {url}')
                    else:
                        logger.info('No webinars found (expected message present)')

                except Exception as e:
                    logger.error(f'Error checking page: {e}. Saving content for debug.')
                    # If page content is available, save it on error
                    with contextlib.suppress(Exception):
                        if page and not content:
                            content = await page.content()

                    return None
                finally:
                    await page.close()
                    await context_browser.close()

            finally:
                await browser.close()

    except Exception as e:
        logger.error(f'Playwright error: {e}')
        return None

    # --- DEBUG LOGGING (Saving last response content) ---
    if not current_webinars and content:  # if no webinars found, save the page content
        try:
            with open('response.html', 'w', encoding='utf-8') as f:
                f.write(content)
            logger.info('Saved page content to response.html for debug.')
        except Exception as e:
            logger.error(f'Failed to write debug HTML: {e}')
    # -----------------------------------------------------

    # Check for NEW webinars and notify
    if current_webinars:
        # Get stored webinar history
        stored_keys = get_stored_webinars()
        logger.info(f'Stored webinar keys: {stored_keys}')

        # Find new webinars (not in history)
        new_webinars = []
        current_keys = []

        for webinar in current_webinars:
            key = get_webinar_key(webinar['url'])
            current_keys.append(key)

            if key not in stored_keys:
                new_webinars.append(webinar)
                logger.info(f'NEW webinar detected: {webinar["name"]}')

        # Update stored history with current webinars
        # Merge old and new, keeping only last 5
        updated_keys = stored_keys + [k for k in current_keys if k not in stored_keys]
        store_webinars(updated_keys)

        # Notify subscribers ONLY about NEW webinars
        if new_webinars:
            subscribers = redis_client.smembers(KEY_SUBSCRIBERS)
            logger.info(
                f'Sending notification about {len(new_webinars)} new webinar(s) to {len(subscribers)} subscriber(s)'
            )

            for sub_id in subscribers:
                try:
                    # Build message in user's language
                    # sub_id comes from redis set as string, convert to int for translation lookup
                    webinar_items = '\n\n'.join(
                        [
                            t_chat(
                                int(sub_id), int(sub_id), 'webinar_item', name=escape(w['name']), url=escape(w['url'])
                            )
                            for w in new_webinars
                        ]
                    )
                    message = t_chat(int(sub_id), int(sub_id), 'webinar_found') + webinar_items

                    await context.bot.send_message(chat_id=sub_id, text=message, parse_mode='HTML')
                    logger.info(f'Notification sent to {sub_id}')
                except Exception as e:
                    logger.error(f'Failed to send to {sub_id}: {e}')
        else:
            logger.info(f'Found {len(current_webinars)} webinar(s), but all are already known')

    return len(current_webinars)


# --- Main ---


def main():
    if not WEBINAR_TELEGRAM_TOKEN:
        logger.error('WEBINAR_TELEGRAM_TOKEN is missing!')
        return

    # Set default whitelist state if not set
    if not redis_client.exists(KEY_WHITELIST_ENABLED):
        redis_client.set(KEY_WHITELIST_ENABLED, '1')  # Enabled by default

    # Add admin to whitelist
    if ADMIN_ID:
        redis_client.sadd(KEY_WHITELIST, str(ADMIN_ID))

    app = Application.builder().token(WEBINAR_TELEGRAM_TOKEN).build()

    # Handlers
    app.add_handler(CommandHandler('start', start))
    app.add_handler(CommandHandler('stop', stop_command))
    app.add_handler(CommandHandler('help', help_command))
    app.add_handler(CommandHandler('language', language_command))
    app.add_handler(CommandHandler('adduser', add_user))
    app.add_handler(CommandHandler('removeuser', remove_user))
    app.add_handler(CommandHandler('clearhistory', clear_history))
    app.add_handler(CommandHandler('diary', diary_command))
    app.add_handler(CommandHandler('schedule', schedule_command))
    app.add_handler(CommandHandler('setclass', setclass_command))

    # Callback handlers - diary/schedule first, then language selection, then admin panel
    app.add_handler(CallbackQueryHandler(diary_callback, pattern='^diary_'))
    app.add_handler(CallbackQueryHandler(schedule_callback, pattern='^schedule_'))
    app.add_handler(CallbackQueryHandler(language_callback, pattern='^lang_'))
    app.add_handler(CallbackQueryHandler(admin_callback))

    # Job Queue
    job_queue = app.job_queue
    job_queue.run_repeating(check_webinars_job, interval=WEBINAR_CHECK_INTERVAL, first=10)

    logger.info('Bot started polling...')
    app.run_polling()


if __name__ == '__main__':
    main()