from abc import ABC, abstractmethod
import datetime


class Position(ABC):

    def __init__(self, fee, nolog=False):
        self.nUnits = 0  # the position size in token units (in the price denominating unit)
        self.fee = fee  # fee for opening or closing a position (aka performing a swap)
        self.open = False
        self.ts_opened = None
        self.ts_closed = None
        self.opened_at_price = None
        self.closed_at_price = None
        self.performance = 0
        self.nolog = nolog

    def set_position_open(self, nUnits, current_price, current_reg_fun_vals: list):
        self.open = True
        self.ts_opened = datetime.datetime.now()
        self.opened_at_price = current_price
        self.nUnits = nUnits * (1 - self.fee)
        self.log_msg(self.to_str() +
                     "| Position opened. nUnits: " + str(round(self.nUnits, 4)) +
                     " opened at price: " + str(round(self.opened_at_price, 4)))
        self.set_tp_io(current_price, current_reg_fun_vals)

    def set_position_closed(self, current_price):
        self.ts_closed = datetime.datetime.now()
        self.closed_at_price = current_price
        self.nUnits = self.nUnits * self.closed_at_price/self.opened_at_price * (1-self.fee)
        self.performance = (current_price/self.opened_at_price - 1) * 100
        self.open = False

    @abstractmethod
    def update_position(self):
        """ check if position state needs to be changed. E.g. set to closed """
        # returns nUnits (size of position) if position is closed
        pass

    def get_performance(self):
        return self.performance

    def get_unrealized_profit(self, current_price):
        return (current_price / self.opened_at_price - 1) * 100

    def to_str(self):
        return "POS_" + self.ts_opened.strftime("%Y%m%d%H%M%S%f")

    def log_msg(self, msg):
        """ write message to log """
        if self.nolog:
            pass
        else:
            print(msg)