import logging
from typing import Any, Callable

from sqlalchemy import func, text
from tabulate import tabulate
from telegram import Bot, ParseMode, ReplyKeyboardMarkup, Update
from telegram.error import NetworkError, TelegramError
from telegram.ext import CommandHandler, Updater

from freqtrade.rpc.__init__ import (rpc_status_table,
                                    rpc_trade_status,
                                    rpc_daily_profit,
                                    rpc_trade_statistics,
                                    rpc_balance,
                                    rpc_start,
                                    rpc_stop,
                                    rpc_forcesell,
                                    )

from freqtrade import __version__, exchange
from freqtrade.fiat_convert import CryptoToFiatConverter
from freqtrade.persistence import Trade
from freqtrade.misc import State, get_state


# Remove noisy log messages
logging.getLogger('requests.packages.urllib3').setLevel(logging.INFO)
logging.getLogger('telegram').setLevel(logging.INFO)
logger = logging.getLogger(__name__)

_UPDATER: Updater = None
_CONF = {}
_FIAT_CONVERT = CryptoToFiatConverter()


def init(config: dict) -> None:
    """
    Initializes this module with the given config,
    registers all known command handlers
    and starts polling for message updates
    :param config: config to use
    :return: None
    """
    global _UPDATER

    _CONF.update(config)
    if not is_enabled():
        return

    _UPDATER = Updater(token=config['telegram']['token'], workers=0)

    # Register command handler and start telegram message polling
    handles = [
        CommandHandler('status', _status),
        CommandHandler('profit', _profit),
        CommandHandler('balance', _balance),
        CommandHandler('start', _start),
        CommandHandler('stop', _stop),
        CommandHandler('forcesell', _forcesell),
        CommandHandler('performance', _performance),
        CommandHandler('daily', _daily),
        CommandHandler('count', _count),
        CommandHandler('help', _help),
        CommandHandler('version', _version),
    ]
    for handle in handles:
        _UPDATER.dispatcher.add_handler(handle)
    _UPDATER.start_polling(
        clean=True,
        bootstrap_retries=-1,
        timeout=30,
        read_latency=60,
    )
    logger.info(
        'rpc.telegram is listening for following commands: %s',
        [h.command for h in handles]
    )


def cleanup() -> None:
    """
    Stops all running telegram threads.
    :return: None
    """
    if not is_enabled():
        return
    _UPDATER.stop()


def is_enabled() -> bool:
    """
    Returns True if the telegram module is activated, False otherwise
    """
    return bool(_CONF['telegram'].get('enabled', False))


def authorized_only(command_handler: Callable[[Bot, Update], None]) -> Callable[..., Any]:
    """
    Decorator to check if the message comes from the correct chat_id
    :param command_handler: Telegram CommandHandler
    :return: decorated function
    """
    def wrapper(*args, **kwargs):
        update = kwargs.get('update') or args[1]

        # Reject unauthorized messages
        chat_id = int(_CONF['telegram']['chat_id'])
        if int(update.message.chat_id) != chat_id:
            logger.info('Rejected unauthorized message from: %s', update.message.chat_id)
            return wrapper

        logger.info('Executing handler: %s for chat_id: %s', command_handler.__name__, chat_id)
        try:
            return command_handler(*args, **kwargs)
        except BaseException:
            logger.exception('Exception occurred within Telegram module')
    return wrapper


@authorized_only
def _status(bot: Bot, update: Update) -> None:
    """
    Handler for /status.
    Returns the current TradeThread status
    :param bot: telegram bot
    :param update: message update
    :return: None
    """

    # Check if additional parameters are passed
    params = update.message.text.replace('/status', '').split(' ') \
        if update.message.text else []
    if 'table' in params:
        _status_table(bot, update)
        return

    # Fetch open trade
    (error, trades) = rpc_trade_status()
    if error:
        send_msg(trades, bot=bot)
    else:
        for trademsg in trades:
            send_msg(trademsg, bot=bot)


@authorized_only
def _status_table(bot: Bot, update: Update) -> None:
    """
    Handler for /status table.
    Returns the current TradeThread status in table format
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    # Fetch open trade
    (err, df_statuses) = rpc_status_table()
    if err:
        send_msg(df_statuses, bot=bot)
    else:
        message = tabulate(df_statuses, headers='keys', tablefmt='simple')
        message = "<pre>{}</pre>".format(message)

        send_msg(message, parse_mode=ParseMode.HTML)


@authorized_only
def _daily(bot: Bot, update: Update) -> None:
    """
    Handler for /daily <n>
    Returns a daily profit (in BTC) over the last n days.
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    try:
        timescale = int(update.message.text.replace('/daily', '').strip())
    except (TypeError, ValueError):
        timescale = 7
    (error, stats) = rpc_daily_profit(timescale,
                                      _CONF['stake_currency'],
                                      _CONF['fiat_display_currency'])
    if error:
        send_msg(stats, bot=bot)
    else:
        stats = tabulate(stats,
                         headers=[
                             'Day',
                             'Profit {}'.format(_CONF['stake_currency']),
                             'Profit {}'.format(_CONF['fiat_display_currency'])
                         ],
                         tablefmt='simple')
        message = '<b>Daily Profit over the last {} days</b>:\n<pre>{}</pre>'.format(
                  timescale, stats)
        send_msg(message, bot=bot, parse_mode=ParseMode.HTML)


@authorized_only
def _profit(bot: Bot, update: Update) -> None:
    """
    Handler for /profit.
    Returns a cumulative profit statistics.
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    (error, stats) = rpc_trade_statistics(_CONF['stake_currency'],
                                          _CONF['fiat_display_currency'])
    if error:
        send_msg(stats, bot=bot)
        return

    markdown_msg = """
*ROI:* Close trades
  ∙ `{profit_closed_coin:.8f} {coin} ({profit_closed_percent:.2f}%)`
  ∙ `{profit_closed_fiat:.3f} {fiat}`
*ROI:* All trades
  ∙ `{profit_all_coin:.8f} {coin} ({profit_all_percent:.2f}%)`
  ∙ `{profit_all_fiat:.3f} {fiat}`

*Total Trade Count:* `{trade_count}`
*First Trade opened:* `{first_trade_date}`
*Latest Trade opened:* `{latest_trade_date}`
*Avg. Duration:* `{avg_duration}`
*Best Performing:* `{best_pair}: {best_rate:.2f}%`
    """.format(
        coin=_CONF['stake_currency'],
        fiat=_CONF['fiat_display_currency'],
        profit_closed_coin=stats['profit_closed_coin'],
        profit_closed_percent=stats['profit_closed_percent'],
        profit_closed_fiat=stats['profit_closed_fiat'],
        profit_all_coin=stats['profit_all_coin'],
        profit_all_percent=stats['profit_all_percent'],
        profit_all_fiat=stats['profit_all_fiat'],
        trade_count=stats['trade_count'],
        first_trade_date=stats['first_trade_date'],
        latest_trade_date=stats['latest_trade_date'],
        avg_duration=stats['avg_duration'],
        best_pair=stats['best_pair'],
        best_rate=stats['best_rate']
    )
    send_msg(markdown_msg, bot=bot)


@authorized_only
def _balance(bot: Bot, update: Update) -> None:
    """
    Handler for /balance
    Returns current account balance per crypto
    """
    (error, result) = rpc_balance(_CONF['fiat_display_currency'])
    if error:
        send_msg('`All balances are zero.`')
        return

    (currencys, total, symbol, value) = result
    output = ''
    for currency in currencys:
        output += """*Currency*: {currency}
*Available*: {available}
*Balance*: {balance}
*Pending*: {pending}
*Est. BTC*: {est_btc: .8f}

""".format(**currency)

    output += """*Estimated Value*:
*BTC*: {0: .8f}
*{1}*: {2: .2f}
""".format(total, symbol, value)
    send_msg(output)


@authorized_only
def _start(bot: Bot, update: Update) -> None:
    """
    Handler for /start.
    Starts TradeThread
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    (error, msg) = rpc_start()
    if error:
        send_msg(msg, bot=bot)


@authorized_only
def _stop(bot: Bot, update: Update) -> None:
    """
    Handler for /stop.
    Stops TradeThread
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    (error, msg) = rpc_stop()
    send_msg(msg, bot=bot)


# FIX: no test for this!!!!
@authorized_only
def _forcesell(bot: Bot, update: Update) -> None:
    """
    Handler for /forcesell <id>.
    Sells the given trade at current price
    :param bot: telegram bot
    :param update: message update
    :return: None
    """

    trade_id = update.message.text.replace('/forcesell', '').strip()
    (error, message) = rpc_forcesell(trade_id)
    if error:
        send_msg(message, bot=bot)
        return


@authorized_only
def _performance(bot: Bot, update: Update) -> None:
    """
    Handler for /performance.
    Shows a performance statistic from finished trades
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    if get_state() != State.RUNNING:
        send_msg('`trader is not running`', bot=bot)
        return

    pair_rates = Trade.session.query(Trade.pair, func.sum(Trade.close_profit).label('profit_sum'),
                                     func.count(Trade.pair).label('count')) \
        .filter(Trade.is_open.is_(False)) \
        .group_by(Trade.pair) \
        .order_by(text('profit_sum DESC')) \
        .all()

    stats = '\n'.join('{index}.\t<code>{pair}\t{profit:.2f}% ({count})</code>'.format(
        index=i + 1,
        pair=pair,
        profit=round(rate * 100, 2),
        count=count
    ) for i, (pair, rate, count) in enumerate(pair_rates))

    message = '<b>Performance:</b>\n{}'.format(stats)
    logger.debug(message)
    send_msg(message, parse_mode=ParseMode.HTML)


@authorized_only
def _count(bot: Bot, update: Update) -> None:
    """
    Handler for /count.
    Returns the number of trades running
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    if get_state() != State.RUNNING:
        send_msg('`trader is not running`', bot=bot)
        return

    trades = Trade.query.filter(Trade.is_open.is_(True)).all()

    message = tabulate({
        'current': [len(trades)],
        'max': [_CONF['max_open_trades']]
    }, headers=['current', 'max'], tablefmt='simple')
    message = "<pre>{}</pre>".format(message)
    logger.debug(message)
    send_msg(message, parse_mode=ParseMode.HTML)


@authorized_only
def _help(bot: Bot, update: Update) -> None:
    """
    Handler for /help.
    Show commands of the bot
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    message = """
*/start:* `Starts the trader`
*/stop:* `Stops the trader`
*/status [table]:* `Lists all open trades`
            *table :* `will display trades in a table`
*/profit:* `Lists cumulative profit from all finished trades`
*/forcesell <trade_id>|all:* `Instantly sells the given trade or all trades, regardless of profit`
*/performance:* `Show performance of each finished trade grouped by pair`
*/daily <n>:* `Shows profit or loss per day, over the last n days`
*/count:* `Show number of trades running compared to allowed number of trades`
*/balance:* `Show account balance per currency`
*/help:* `This help message`
*/version:* `Show version`
    """
    send_msg(message, bot=bot)


@authorized_only
def _version(bot: Bot, update: Update) -> None:
    """
    Handler for /version.
    Show version information
    :param bot: telegram bot
    :param update: message update
    :return: None
    """
    send_msg('*Version:* `{}`'.format(__version__), bot=bot)


def _exec_forcesell(trade: Trade) -> None:
    # Check if there is there is an open order
    if trade.open_order_id:
        order = exchange.get_order(trade.open_order_id)

        # Cancel open LIMIT_BUY orders and close trade
        if order and not order['closed'] and order['type'] == 'LIMIT_BUY':
            exchange.cancel_order(trade.open_order_id)
            trade.close(order.get('rate') or trade.open_rate)
            # TODO: sell amount which has been bought already
            return

        # Ignore trades with an attached LIMIT_SELL order
        if order and not order['closed'] and order['type'] == 'LIMIT_SELL':
            return

    # Get current rate and execute sell
    current_rate = exchange.get_ticker(trade.pair, False)['bid']
    from freqtrade.main import execute_sell
    execute_sell(trade, current_rate)


def send_msg(msg: str, bot: Bot = None, parse_mode: ParseMode = ParseMode.MARKDOWN) -> None:
    """
    Send given markdown message
    :param msg: message
    :param bot: alternative bot
    :param parse_mode: telegram parse mode
    :return: None
    """
    if not is_enabled():
        return

    bot = bot or _UPDATER.bot

    keyboard = [['/daily', '/profit', '/balance'],
                ['/status', '/status table', '/performance'],
                ['/count', '/start', '/stop', '/help']]

    reply_markup = ReplyKeyboardMarkup(keyboard)

    try:
        try:
            bot.send_message(
                _CONF['telegram']['chat_id'], msg,
                parse_mode=parse_mode, reply_markup=reply_markup
            )
        except NetworkError as network_err:
            # Sometimes the telegram server resets the current connection,
            # if this is the case we send the message again.
            logger.warning(
                'Got Telegram NetworkError: %s! Trying one more time.',
                network_err.message
            )
            bot.send_message(
                _CONF['telegram']['chat_id'], msg,
                parse_mode=parse_mode, reply_markup=reply_markup
            )
    except TelegramError as telegram_err:
        logger.warning('Got TelegramError: %s! Giving up on that message.', telegram_err.message)