#!/usr/bin/env python3
import logging

from argparse import ArgumentParser
import socket
from telegram import (
    Update,
    ParseMode,
    ReplyKeyboardMarkup
)
from telegram.ext import (
    Updater,
    Filters,
    CommandHandler,
    MessageHandler,
    CallbackContext
)
from telegram.error import TimedOut


class RelayClient:
    def __init__(self, port=8307, host='127.0.0.1'):
        self._host = host
        self._port = port
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    def __del__(self):
        self.sock.close()

    def connect(self):
        self.sock.connect((self._host, self._port))

    def _write(self, line):
        self.sock.sendall((line+'\r\n').encode())

    def _read(self):
        buf = bytearray()
        while True:
            buf.extend(self.sock.recv(256))
            if b'\r\n' in buf:
                break

        response = buf.decode().strip()
        return response

    def on(self):
        self._write('on')
        return self._read()

    def off(self):
        self._write('off')
        return self._read()

    def status(self):
        self._write('get')
        return self._read()


#
# helpers
#

def get_markup() -> ReplyKeyboardMarkup:
    button = [
        [
            'Включить',
            'Выключить'
        ],
        [
            'Статус'
        ]
    ]
    return ReplyKeyboardMarkup(button, one_time_keyboard=False)


def reply(update: Update, text: str) -> None:
    update.message.reply_text(text,
                              reply_markup=get_markup(),
                              parse_mode=ParseMode.HTML)


def handle_exc(update: Update, e) -> None:
    logging.exception(str(e))

    if not isinstance(e, TimedOut):
        reply(update, 'exception: ' + str(e))


#
# command/message handlers
#

def start(update: Update, context: CallbackContext) -> None:
    reply(update, 'Выберите команду на клавиатуре.')


def msg_status(update: Update, context: CallbackContext) -> None:
    try:
        relay = RelayClient()
        relay.connect()

        response = relay.status()
        status = 'Включен' if response == 'on' else 'Выключен'

        reply(update, status)
    except Exception as e:
        handle_exc(update, e)


def msg_on(update: Update, context: CallbackContext) -> None:
    try:
        relay = RelayClient()
        relay.connect()

        relay.on()
        reply(update, 'Готово')
    except Exception as e:
        handle_exc(update, e)


def msg_off(update: Update, context: CallbackContext) -> None:
    try:
        relay = RelayClient()
        relay.connect()

        relay.off()
        reply(update, 'Готово')
    except Exception as e:
        handle_exc(update, e)


def msg_all(update: Update, context: CallbackContext) -> None:
    reply(update, "Неизвестная команда.")


if __name__ == '__main__':
    # command-line arguments
    parser = ArgumentParser()
    parser.add_argument('--token', required=True, type=str,
                        help='Telegram bot token')
    parser.add_argument('--users-whitelist', nargs='+',
                        help='ID of users allowed to use the bot')
    parser.add_argument('--gpio-relayd-host', default='127.0.0.1', type=str)
    parser.add_argument('--gpio-relayd-port', default=8307, type=int)
    args = parser.parse_args()

    whitelist = list(map(lambda x: int(x), args.users_whitelist))

    # configure logging
    logging.basicConfig(format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
                        level=logging.INFO)

    # configure bot
    updater = Updater(args.token, request_kwargs={'read_timeout': 6, 'connect_timeout': 7})
    dispatcher = updater.dispatcher

    user_filter = Filters.user(whitelist)

    dispatcher.add_handler(CommandHandler('start', start))

    dispatcher.add_handler(MessageHandler(Filters.text('Включить') & user_filter, msg_on))
    dispatcher.add_handler(MessageHandler(Filters.text('Выключить') & user_filter, msg_off))
    dispatcher.add_handler(MessageHandler(Filters.text('Статус') & user_filter, msg_status))

    dispatcher.add_handler(MessageHandler(Filters.all & user_filter, msg_all))


    # start the bot
    updater.start_polling()

    # run the bot until the user presses Ctrl-C or the process receives SIGINT, SIGTERM or SIGABRT
    updater.idle()