stable/freqtrade/exchange/binance.py

""" Binance exchange subclass """
import logging
from typing import Dict, List, Optional, Tuple

import ccxt

from freqtrade.enums import Collateral, TradingMode
from freqtrade.exceptions import (DDosProtection, InsufficientFundsError, InvalidOrderException,
                                  OperationalException, TemporaryError)
from freqtrade.exchange import Exchange
from freqtrade.exchange.common import retrier


logger = logging.getLogger(__name__)


class Binance(Exchange):

    _ft_has: Dict = {
        "stoploss_on_exchange": True,
        "order_time_in_force": ['gtc', 'fok', 'ioc'],
        "time_in_force_parameter": "timeInForce",
        "ohlcv_candle_limit": 1000,
        "trades_pagination": "id",
        "trades_pagination_arg": "fromId",
        "l2_limit_range": [5, 10, 20, 50, 100, 500, 1000],
    }

    _supported_trading_mode_collateral_pairs: List[Tuple[TradingMode, Collateral]] = [
        # TradingMode.SPOT always supported and not required in this list
        # (TradingMode.MARGIN, Collateral.CROSS),  # TODO-lev: Uncomment once supported
        # (TradingMode.FUTURES, Collateral.CROSS),  # TODO-lev: Uncomment once supported
        # (TradingMode.FUTURES, Collateral.ISOLATED)  # TODO-lev: Uncomment once supported
    ]

    def stoploss_adjust(self, stop_loss: float, order: Dict, side: str) -> bool:
        """
        Verify stop_loss against stoploss-order value (limit or price)
        Returns True if adjustment is necessary.
        :param side: "buy" or "sell"
        """

        return order['type'] == 'stop_loss_limit' and (
            side == "sell" and stop_loss > float(order['info']['stopPrice']) or
            side == "buy" and stop_loss < float(order['info']['stopPrice'])
        )

    @retrier(retries=0)
    def stoploss(self, pair: str, amount: float,
                 stop_price: float, order_types: Dict, side: str) -> Dict:
        """
        creates a stoploss limit order.
        this stoploss-limit is binance-specific.
        It may work with a limited number of other exchanges, but this has not been tested yet.
        :param side: "buy" or "sell"
        """
        # Limit price threshold: As limit price should always be below stop-price
        limit_price_pct = order_types.get(
            'stoploss_on_exchange_limit_ratio',
            0.99 if side == 'sell' else 1.01
        )
        rate = stop_price * limit_price_pct

        ordertype = "stop_loss_limit"

        stop_price = self.price_to_precision(pair, stop_price)

        bad_stop_price = (stop_price <= rate) if side == "sell" else (stop_price >= rate)

        # Ensure rate is less than stop price
        if bad_stop_price:
            raise OperationalException(
                'In stoploss limit order, stop price should be better than limit price')

        if self._config['dry_run']:
            dry_order = self.create_dry_run_order(
                pair, ordertype, side, amount, stop_price)
            return dry_order

        try:
            params = self._params.copy()
            params.update({'stopPrice': stop_price})

            amount = self.amount_to_precision(pair, amount)

            rate = self.price_to_precision(pair, rate)

            order = self._api.create_order(symbol=pair, type=ordertype, side=side,
                                           amount=amount, price=rate, params=params)
            logger.info('stoploss limit order added for %s. '
                        'stop price: %s. limit: %s', pair, stop_price, rate)
            self._log_exchange_response('create_stoploss_order', order)
            return order
        except ccxt.InsufficientFunds as e:
            raise InsufficientFundsError(
                f'Insufficient funds to create {ordertype} {side} order on market {pair}. '
                f'Tried to {side} amount {amount} at rate {rate}. '
                f'Message: {e}') from e
        except ccxt.InvalidOrder as e:
            # Errors:
            # `binance Order would trigger immediately.`
            raise InvalidOrderException(
                f'Could not create {ordertype} {side} order on market {pair}. '
                f'Tried to {side} amount {amount} at rate {rate}. '
                f'Message: {e}') from e
        except ccxt.DDoSProtection as e:
            raise DDosProtection(e) from e
        except (ccxt.NetworkError, ccxt.ExchangeError) as e:
            raise TemporaryError(
                f'Could not place {side} order due to {e.__class__.__name__}. Message: {e}') from e
        except ccxt.BaseError as e:
            raise OperationalException(e) from e

    def _apply_leverage_to_stake_amount(self, stake_amount: float, leverage: float):
        return stake_amount / leverage

    @retrier
    def fill_leverage_brackets(self):
        """
            Assigns property _leverage_brackets to a dictionary of information about the leverage
            allowed on each pair
        """
        try:
            leverage_brackets = self._api.load_leverage_brackets()
            for pair, brackets in leverage_brackets.items():
                self._leverage_brackets[pair] = [
                    [
                        min_amount,
                        float(margin_req)
                    ] for [
                        min_amount,
                        margin_req
                    ] in brackets
                ]

        except ccxt.DDoSProtection as e:
            raise DDosProtection(e) from e
        except (ccxt.NetworkError, ccxt.ExchangeError) as e:
            raise TemporaryError(f'Could not fetch leverage amounts due to'
                                 f'{e.__class__.__name__}. Message: {e}') from e
        except ccxt.BaseError as e:
            raise OperationalException(e) from e

    def get_max_leverage(self, pair: Optional[str], nominal_value: Optional[float]) -> float:
        """
            Returns the maximum leverage that a pair can be traded at
            :param pair: The base/quote currency pair being traded
            :nominal_value: The total value of the trade in quote currency (collateral + debt)
        """
        pair_brackets = self._leverage_brackets[pair]
        max_lev = 1.0
        for [min_amount, margin_req] in pair_brackets:
            if nominal_value >= min_amount:
                max_lev = 1/margin_req
        return max_lev