import logging
import re
import arrow
from decimal import Decimal
from datetime import datetime, timedelta
from pandas import DataFrame
import sqlalchemy as sql
# from sqlalchemy import and_, func, text

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

logger = logging.getLogger(__name__)

_FIAT_CONVERT = CryptoToFiatConverter()
REGISTERED_MODULES = []


def init(config: dict) -> None:
    """
    Initializes all enabled rpc modules
    :param config: config to use
    :return: None
    """

    if config['telegram'].get('enabled', False):
        logger.info('Enabling rpc.telegram ...')
        REGISTERED_MODULES.append('telegram')
        telegram.init(config)


def cleanup() -> None:
    """
    Stops all enabled rpc modules
    :return: None
    """
    if 'telegram' in REGISTERED_MODULES:
        logger.debug('Cleaning up rpc.telegram ...')
        telegram.cleanup()


def send_msg(msg: str) -> None:
    """
    Send given markdown message to all registered rpc modules
    :param msg: message
    :return: None
    """
    logger.info(msg)
    if 'telegram' in REGISTERED_MODULES:
        telegram.send_msg(msg)


def shorten_date(_date):
    """
    Trim the date so it fits on small screens
    """
    new_date = re.sub('seconds?', 'sec', _date)
    new_date = re.sub('minutes?', 'min', new_date)
    new_date = re.sub('hours?', 'h', new_date)
    new_date = re.sub('days?', 'd', new_date)
    new_date = re.sub('^an?', '1', new_date)
    return new_date


#
# Below follows the RPC backend
# it is prefixed with rpc_
# to raise awareness that it is
# a remotely exposed function


def rpc_trade_status():
    # Fetch open trade
    trades = Trade.query.filter(Trade.is_open.is_(True)).all()
    if get_state() != State.RUNNING:
        return (True, '*Status:* `trader is not running`')
    elif not trades:
        return (True, '*Status:* `no active trade`')
    else:
        result = []
        for trade in trades:
            order = None
            if trade.open_order_id:
                order = exchange.get_order(trade.open_order_id)
            # calculate profit and send message to user
            current_rate = exchange.get_ticker(trade.pair, False)['bid']
            current_profit = trade.calc_profit_percent(current_rate)
            fmt_close_profit = '{:.2f}%'.format(
                round(trade.close_profit * 100, 2)
            ) if trade.close_profit else None
            message = """
*Trade ID:* `{trade_id}`
*Current Pair:* [{pair}]({market_url})
*Open Since:* `{date}`
*Amount:* `{amount}`
*Open Rate:* `{open_rate:.8f}`
*Close Rate:* `{close_rate}`
*Current Rate:* `{current_rate:.8f}`
*Close Profit:* `{close_profit}`
*Current Profit:* `{current_profit:.2f}%`
*Open Order:* `{open_order}`
            """.format(
                trade_id=trade.id,
                pair=trade.pair,
                market_url=exchange.get_pair_detail_url(trade.pair),
                date=arrow.get(trade.open_date).humanize(),
                open_rate=trade.open_rate,
                close_rate=trade.close_rate,
                current_rate=current_rate,
                amount=round(trade.amount, 8),
                close_profit=fmt_close_profit,
                current_profit=round(current_profit * 100, 2),
                open_order='({} rem={:.8f})'.format(
                    order['type'], order['remaining']
                ) if order else None,
            )
            result.append(message)
        return (False, result)


def rpc_status_table():
    trades = Trade.query.filter(Trade.is_open.is_(True)).all()
    if get_state() != State.RUNNING:
        return (True, '*Status:* `trader is not running`')
    elif not trades:
        return (True, '*Status:* `no active order`')
    else:
        trades_list = []
        for trade in trades:
            # calculate profit and send message to user
            current_rate = exchange.get_ticker(trade.pair, False)['bid']
            trades_list.append([
                trade.id,
                trade.pair,
                shorten_date(arrow.get(trade.open_date).humanize(only_distance=True)),
                '{:.2f}%'.format(100 * trade.calc_profit_percent(current_rate))
            ])

        columns = ['ID', 'Pair', 'Since', 'Profit']
        df_statuses = DataFrame.from_records(trades_list, columns=columns)
        df_statuses = df_statuses.set_index(columns[0])
        # The style used throughout is to return a tuple
        # consisting of (error_occured?, result)
        # Another approach would be to just return the
        # result, or raise error
        return (False, df_statuses)


def rpc_daily_profit(timescale, stake_currency, fiat_display_currency):
    today = datetime.utcnow().date()
    profit_days = {}

    if not (isinstance(timescale, int) and timescale > 0):
        return (True, '*Daily [n]:* `must be an integer greater than 0`')

    fiat = _FIAT_CONVERT
    for day in range(0, timescale):
        profitday = today - timedelta(days=day)
        trades = Trade.query \
            .filter(Trade.is_open.is_(False)) \
            .filter(Trade.close_date >= profitday)\
            .filter(Trade.close_date < (profitday + timedelta(days=1)))\
            .order_by(Trade.close_date)\
            .all()
        curdayprofit = sum(trade.calc_profit() for trade in trades)
        profit_days[profitday] = {
            'amount': format(curdayprofit, '.8f'),
            'trades': len(trades)
        }

    stats = [
        [
            key,
            '{value:.8f} {symbol}'.format(
                value=float(value['amount']),
                symbol=stake_currency
            ),
            '{value:.3f} {symbol}'.format(
                value=fiat.convert_amount(
                    value['amount'],
                    stake_currency,
                    fiat_display_currency
                ),
                symbol=fiat_display_currency
            ),
            '{value} trade{s}'.format(value=value['trades'], s='' if value['trades'] < 2 else 's'),
        ]
        for key, value in profit_days.items()
    ]
    return (False, stats)


def rpc_trade_statistics(stake_currency, fiat_display_currency) -> None:
    """
    :return: cumulative profit statistics.
    """
    trades = Trade.query.order_by(Trade.id).all()

    profit_all_coin = []
    profit_all_percent = []
    profit_closed_coin = []
    profit_closed_percent = []
    durations = []

    for trade in trades:
        current_rate = None

        if not trade.open_rate:
            continue
        if trade.close_date:
            durations.append((trade.close_date - trade.open_date).total_seconds())

        if not trade.is_open:
            profit_percent = trade.calc_profit_percent()
            profit_closed_coin.append(trade.calc_profit())
            profit_closed_percent.append(profit_percent)
        else:
            # Get current rate
            current_rate = exchange.get_ticker(trade.pair, False)['bid']
            profit_percent = trade.calc_profit_percent(rate=current_rate)

        profit_all_coin.append(trade.calc_profit(rate=Decimal(trade.close_rate or current_rate)))
        profit_all_percent.append(profit_percent)

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

    if not best_pair:
        return (True, '*Status:* `no closed trade`')

    bp_pair, bp_rate = best_pair

    # FIX: we want to keep fiatconverter in a state/environment,
    #      doing this will utilize its caching functionallity, instead we reinitialize it here
    fiat = _FIAT_CONVERT
    # Prepare data to display
    profit_closed_coin = round(sum(profit_closed_coin), 8)
    profit_closed_percent = round(sum(profit_closed_percent) * 100, 2)
    profit_closed_fiat = fiat.convert_amount(
        profit_closed_coin,
        stake_currency,
        fiat_display_currency
    )
    profit_all_coin = round(sum(profit_all_coin), 8)
    profit_all_percent = round(sum(profit_all_percent) * 100, 2)
    profit_all_fiat = fiat.convert_amount(
        profit_all_coin,
        stake_currency,
        fiat_display_currency
    )
    num = float(len(durations) or 1)
    return (False,
            {'profit_closed_coin': profit_closed_coin,
             'profit_closed_percent': profit_closed_percent,
             'profit_closed_fiat': profit_closed_fiat,
             'profit_all_coin': profit_all_coin,
             'profit_all_percent': profit_all_percent,
             'profit_all_fiat': profit_all_fiat,
             'trade_count': len(trades),
             'first_trade_date': arrow.get(trades[0].open_date).humanize(),
             'latest_trade_date': arrow.get(trades[-1].open_date).humanize(),
             'avg_duration': str(timedelta(seconds=sum(durations) /
                                           num)).split('.')[0],
             'best_pair': bp_pair,
             'best_rate': round(bp_rate * 100, 2)
             })


def rpc_balance(fiat_display_currency):
    """
    :return: current account balance per crypto
    """
    balances = [
        c for c in exchange.get_balances()
        if c['Balance'] or c['Available'] or c['Pending']
    ]
    if not balances:
        return (True, '`All balances are zero.`')

    output = []
    total = 0.0
    for currency in balances:
        coin = currency['Currency']
        if coin == 'BTC':
            currency["Rate"] = 1.0
        else:
            if coin == 'USDT':
                currency["Rate"] = 1.0 / exchange.get_ticker('USDT_BTC', False)['bid']
            else:
                currency["Rate"] = exchange.get_ticker('BTC_' + coin, False)['bid']
        currency['BTC'] = currency["Rate"] * currency["Balance"]
        total = total + currency['BTC']
        output.append({'currency': currency['Currency'],
                       'available': currency['Available'],
                       'balance': currency['Balance'],
                       'pending': currency['Pending'],
                       'est_btc': currency['BTC']
                       })
    fiat = _FIAT_CONVERT
    symbol = fiat_display_currency
    value = fiat.convert_amount(total, 'BTC', symbol)
    return (False, (output, total, symbol, value))


def rpc_start():
    """
    Handler for start.
    """
    if get_state() == State.RUNNING:
        return (True, '*Status:* `already running`')
    else:
        update_state(State.RUNNING)


def rpc_stop():
    """
    Handler for stop.
    """
    if get_state() == State.RUNNING:
        update_state(State.STOPPED)
        return (False, '`Stopping trader ...`')
    else:
        return (True, '*Status:* `already stopped`')


# FIX: no test for this!!!!
def rpc_forcesell(trade_id) -> None:
    """
    Handler for forcesell <id>.
    Sells the given trade at current price
    :return: error or None
    """
    def _exec_forcesell(trade: Trade) -> str:
        # 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)
    # ---- EOF def _exec_forcesell ----

    if get_state() != State.RUNNING:
        return (True, '`trader is not running`')

    if trade_id == 'all':
        # Execute sell for all open orders
        for trade in Trade.query.filter(Trade.is_open.is_(True)).all():
            _exec_forcesell(trade)
        return (False, '')

    # Query for trade
    trade = Trade.query.filter(sql.and_(
        Trade.id == trade_id,
        Trade.is_open.is_(True)
    )).first()
    if not trade:
        logger.warning('forcesell: Invalid argument received')
        return (True, 'Invalid argument.')

    _exec_forcesell(trade)
    return (False, '')


def rpc_performance() -> None:
    """
    Handler for performance.
    Shows a performance statistic from finished trades
    """
    if get_state() != State.RUNNING:
        return (True, '`trader is not running`')

    pair_rates = Trade.session.query(Trade.pair,
                                     sql.func.sum(Trade.close_profit).label('profit_sum'),
                                     sql.func.count(Trade.pair).label('count')) \
        .filter(Trade.is_open.is_(False)) \
        .group_by(Trade.pair) \
        .order_by(sql.text('profit_sum DESC')) \
        .all()
    trades = []
    for (pair, rate, count) in pair_rates:
        trades.append({'pair': pair, 'profit': round(rate * 100, 2), 'count': count})

    return (False, trades)


def rpc_count() -> None:
    """
    Returns the number of trades running
    :return: None
    """
    if get_state() != State.RUNNING:
        return (True, '`trader is not running`')

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