#!/usr/bin/env python
# pylint: disable=missing-function-docstring, unused-argument
# This program is dedicated to the public domain under the CC0 license.

"""
First, a few callback functions are defined. Then, those functions are passed to
the Dispatcher and registered at their respective places.
Then, the bot is started and runs until we press Ctrl-C on the command line.

Usage:
Example of a bot-user conversation using ConversationHandler.
Send /start to initiate the conversation.
Press Ctrl-C on the command line or send a signal to the process to stop the
bot.
"""

import logging
from typing import Dict

from telegram import ReplyKeyboardMarkup, Update, ReplyKeyboardRemove
from telegram.ext import (
    CommandHandler,
    MessageHandler,
    filters,
    ConversationHandler,
    PicklePersistence,
    Updater,
    CallbackContext,
)


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

CHOOSING, TYPING_REPLY, TYPING_CHOICE = range(3)

reply_keyboard = [
    ['Age', 'Favourite colour'],
    ['Number of siblings', 'Something else...'],
    ['Done'],
]
markup = ReplyKeyboardMarkup(reply_keyboard, one_time_keyboard=True)


def facts_to_str(user_data: Dict[str, str]) -> str:
    """Helper function for formatting the gathered user info."""
    facts = [f'{key} - {value}' for key, value in user_data.items()]
    return "\n".join(facts).join(['\n', '\n'])


def start(update: Update, context: CallbackContext.DEFAULT_TYPE) -> int:
    """Start the conversation, display any stored data and ask user for input."""
    reply_text = "Hi! My name is Doctor Botter."
    if context.user_data:
        reply_text += (
            f" You already told me your {', '.join(context.user_data.keys())}. Why don't you "
            f"tell me something more about yourself? Or change anything I already know."
        )
    else:
        reply_text += (
            " I will hold a more complex conversation with you. Why don't you tell me "
            "something about yourself?"
        )
    update.message.reply_text(reply_text, reply_markup=markup)

    return CHOOSING


def regular_choice(update: Update, context: CallbackContext.DEFAULT_TYPE) -> int:
    """Ask the user for info about the selected predefined choice."""
    text = update.message.text.lower()
    context.user_data['choice'] = text
    if context.user_data.get(text):
        reply_text = (
            f'Your {text}? I already know the following about that: {context.user_data[text]}'
        )
    else:
        reply_text = f'Your {text}? Yes, I would love to hear about that!'
    update.message.reply_text(reply_text)

    return TYPING_REPLY


def custom_choice(update: Update, context: CallbackContext.DEFAULT_TYPE) -> int:
    """Ask the user for a description of a custom category."""
    update.message.reply_text(
        'Alright, please send me the category first, for example "Most impressive skill"'
    )

    return TYPING_CHOICE


def received_information(update: Update, context: CallbackContext.DEFAULT_TYPE) -> int:
    """Store info provided by user and ask for the next category."""
    text = update.message.text
    category = context.user_data['choice']
    context.user_data[category] = text.lower()
    del context.user_data['choice']

    update.message.reply_text(
        "Neat! Just so you know, this is what you already told me:"
        f"{facts_to_str(context.user_data)}"
        "You can tell me more, or change your opinion on something.",
        reply_markup=markup,
    )

    return CHOOSING


def show_data(update: Update, context: CallbackContext.DEFAULT_TYPE) -> None:
    """Display the gathered info."""
    update.message.reply_text(
        f"This is what you already told me: {facts_to_str(context.user_data)}"
    )


def done(update: Update, context: CallbackContext.DEFAULT_TYPE) -> int:
    """Display the gathered info and end the conversation."""
    if 'choice' in context.user_data:
        del context.user_data['choice']

    update.message.reply_text(
        f"I learned these facts about you: {facts_to_str(context.user_data)}Until next time!",
        reply_markup=ReplyKeyboardRemove(),
    )
    return ConversationHandler.END


def main() -> None:
    """Run the bot."""
    # Create the Updater and pass it your bot's token.
    persistence = PicklePersistence(filepath='conversationbot')
    updater = Updater.builder().token("TOKEN").persistence(persistence).build()

    # Get the dispatcher to register handlers
    dispatcher = updater.dispatcher

    # Add conversation handler with the states CHOOSING, TYPING_CHOICE and TYPING_REPLY
    conv_handler = ConversationHandler(
        entry_points=[CommandHandler('start', start)],
        states={
            CHOOSING: [
                MessageHandler(
                    filters.Regex('^(Age|Favourite colour|Number of siblings)$'), regular_choice
                ),
                MessageHandler(filters.Regex('^Something else...$'), custom_choice),
            ],
            TYPING_CHOICE: [
                MessageHandler(
                    filters.TEXT & ~(filters.COMMAND | filters.Regex('^Done$')), regular_choice
                )
            ],
            TYPING_REPLY: [
                MessageHandler(
                    filters.TEXT & ~(filters.COMMAND | filters.Regex('^Done$')),
                    received_information,
                )
            ],
        },
        fallbacks=[MessageHandler(filters.Regex('^Done$'), done)],
        name="my_conversation",
        persistent=True,
    )

    dispatcher.add_handler(conv_handler)

    show_data_handler = CommandHandler('show_data', show_data)
    dispatcher.add_handler(show_data_handler)

    # Start the Bot
    updater.start_polling()

    # Run the bot until you press Ctrl-C or the process receives SIGINT,
    # SIGTERM or SIGABRT. This should be used most of the time, since
    # start_polling() is non-blocking and will stop the bot gracefully.
    updater.idle()


if __name__ == '__main__':
    main()