import telebot
from telebot.types import Message


class CommandProcessor:
    """Processes user input and dispatches the data to other services."""

    bot: telebot.TeleBot

    def __init__(self, token: str):
        if token is None or len(token) == 0:
            raise ValueError("Token should not be empty")
        self.bot = telebot.TeleBot(token)

    def run(self):
        """Runs a bot and polls for new messages indefinitely."""
        self.bot.register_message_handler(commands=['help', 'start'], callback=self.__command_help)
        self.bot.register_message_handler(commands=['add'], callback=self.__add_feed)
        self.bot.register_message_handler(commands=['list'], callback=self.__list_feeds)
        self.bot.register_message_handler(commands=['del'], callback=self.__delete_feed)

        self.bot.infinity_polling()

    def __command_help(self, message: Message):
        self.bot.reply_to(message, 'Commands: "/add", "/list", "/del", "/help".')

    def __add_feed(self, message: Message):
        self.bot.reply_to(message, 'Feed added (stub)')

    def __list_feeds(self, message: Message):
        self.bot.reply_to(message, 'Your feeds: (stub)')

    def __delete_feed(self, message: Message):
        self.bot.reply_to(message, 'Feed deleted: (stub)')


class Notifier:
    """Sends notifications to users about new RSS feed items."""

    bot: telebot.TeleBot

    def __init__(self, token: str):
        self.bot = telebot.TeleBot(token)

    def send_updates(self, chat_id: int, updates: list):
        """Send notification about new items to the user"""
        for update in updates:
            self.__send_update(chat_id, update)

    def __send_update(self, chat_id: int, update):
        self.bot.send_message(
            chat_id=chat_id,
            text=self.__format_message(),
            parse_mode='MarkdownV2'
        )

    def __format_message(self) -> str:
        update = {
            'title': 'Item Title',
            'text': 'Short item text here...',
            'url': 'https://fediland.github.io/',
        }

        return (
            f"**[{update['title']}]({update['url']})**\n\n"
            f"{update['text']}"
        )