"""
This module contains class to define a RPC communications
"""
import logging
from datetime import datetime, timedelta, date
from decimal import Decimal
from typing import Dict, Tuple, Any, Optional

import arrow
import sqlalchemy as sql
from pandas import DataFrame

from freqtrade import exchange
from freqtrade.misc import shorten_date
from freqtrade.persistence import Trade
from freqtrade.state import State


logger = logging.getLogger(__name__)


class RPC(object):
    """
    RPC class can be used to have extra feature, like bot data, and access to DB data
    """
    def __init__(self, freqtrade) -> None:
        """
        Initializes all enabled rpc modules
        :param freqtrade: Instance of a freqtrade bot
        :return: None
        """
        self.freqtrade = freqtrade

    def rpc_trade_status(self) -> Tuple[bool, Any]:
        """
        Below follows the RPC backend it is prefixed with rpc_ to raise awareness that it is
        a remotely exposed function
        :return:
        """
        # Fetch open trade
        trades = Trade.query.filter(Trade.is_open.is_(True)).all()
        if self.freqtrade.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, trade.pair)
                # 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}`\n" \
                          "*Current Pair:* [{pair}]({market_url})\n" \
                          "*Open Since:* `{date}`\n" \
                          "*Amount:* `{amount}`\n" \
                          "*Open Rate:* `{open_rate:.8f}`\n" \
                          "*Close Rate:* `{close_rate}`\n" \
                          "*Current Rate:* `{current_rate:.8f}`\n" \
                          "*Close Profit:* `{close_profit}`\n" \
                          "*Current Profit:* `{current_profit:.2f}%`\n" \
                          "*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['side'], order['remaining']
                              ) if order else None,
                          )
                result.append(message)
            return False, result

    def rpc_status_table(self) -> Tuple[bool, Any]:
        trades = Trade.query.filter(Trade.is_open.is_(True)).all()
        if self.freqtrade.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(
            self, timescale: int,
            stake_currency: str, fiat_display_currency: str) -> Tuple[bool, Any]:
        today = datetime.utcnow().date()
        profit_days: Dict[date, Dict] = {}

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

        fiat = self.freqtrade.fiat_converter
        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(
            self, stake_currency: str, fiat_display_currency: str) -> Tuple[bool, Any]:
        """
        :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: float = 0.0

            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 = self.freqtrade.fiat_converter
        # 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(self, fiat_display_currency: str) -> Tuple[bool, Any]:
        """
        :return: current account balance per crypto
        """
        output = []
        total = 0.0
        for coin, balance in exchange.get_balances().items():
            if not balance['total']:
                continue

            rate = None
            if coin == 'BTC':
                rate = 1.0
            else:
                if coin == 'USDT':
                    rate = 1.0 / exchange.get_ticker('BTC/USDT', False)['bid']
                else:
                    rate = exchange.get_ticker(coin + '/BTC', False)['bid']
            est_btc: float = rate * balance['total']
            total = total + est_btc
            output.append(
                {
                    'currency': coin,
                    'available': balance['free'],
                    'balance': balance['total'],
                    'pending': balance['used'],
                    'est_btc': est_btc
                }
            )
        if total == 0.0:
            return True, '`All balances are zero.`'

        fiat = self.freqtrade.fiat_converter
        symbol = fiat_display_currency
        value = fiat.convert_amount(total, 'BTC', symbol)
        return False, (output, total, symbol, value)

    def rpc_start(self) -> Tuple[bool, str]:
        """
        Handler for start.
        """
        if self.freqtrade.state == State.RUNNING:
            return True, '*Status:* `already running`'

        self.freqtrade.state = State.RUNNING
        return False, '`Starting trader ...`'

    def rpc_stop(self) -> Tuple[bool, str]:
        """
        Handler for stop.
        """
        if self.freqtrade.state == State.RUNNING:
            self.freqtrade.state = State.STOPPED
            return False, '`Stopping trader ...`'

        return True, '*Status:* `already stopped`'

    # FIX: no test for this!!!!
    def rpc_forcesell(self, trade_id) -> Tuple[bool, Any]:
        """
        Handler for forcesell <id>.
        Sells the given trade at current price
        :return: error or None
        """
        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, trade.pair)

                # Cancel open LIMIT_BUY orders and close trade
                if order and order['status'] == 'open' \
                        and order['type'] == 'limit' \
                        and order['side'] == 'buy':
                    exchange.cancel_order(trade.open_order_id, trade.pair)
                    trade.close(order.get('price') or trade.open_rate)
                    # TODO: sell amount which has been bought already
                    return

                # Ignore trades with an attached LIMIT_SELL order
                if order and order['status'] == 'open' \
                        and order['type'] == 'limit' \
                        and order['side'] == 'sell':
                    return

            # Get current rate and execute sell
            current_rate = exchange.get_ticker(trade.pair, False)['bid']
            self.freqtrade.execute_sell(trade, current_rate)
        # ---- EOF def _exec_forcesell ----

        if self.freqtrade.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(self) -> Tuple[bool, Any]:
        """
        Handler for performance.
        Shows a performance statistic from finished trades
        """
        if self.freqtrade.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(self) -> Tuple[bool, Any]:
        """
        Returns the number of trades running
        :return: None
        """
        if self.freqtrade.state != State.RUNNING:
            return True, '`trader is not running`'

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