from datetime import datetime
from decimal import Decimal
from enum import Enum


class PriceAdaption(Enum):
    KeepTotalCost = 1
    KeepPricePerCoin = 2


class Trade:
    """
    Represents a cryptocurrency trade, including the amount traded, total cost, and the date of trade.
    Provides methods to modify the trade and access various attributes.
    """

    def __init__(
        self, amount: Decimal, total_cost: Decimal, timestamp: str, refid: str | None = None
    ) -> None:
        """
        Initialize a new Trade instance.

        Args:
            amount (Decimal): The amount of cryptocurrency traded.
            total_cost (Decimal): The total cost of the trade.
            timestamp (str): The date or timestamp of the trade, formatted as a string.
        """

        if amount < 0 and total_cost < 0:
            pass
        elif amount > 0 and total_cost > 0:
            pass
        else:
            raise ValueError("Amount and tota> cost must be same sign")

        # force timestamp
        try:
            datetime.strptime(timestamp, "%Y-%m-%d %H:%M:%S")
        except ValueError:
            datetime.strptime(timestamp, "%Y-%m-%d")
            timestamp = timestamp + " 00:00:00"


        self.__amount: Decimal = Decimal(amount)
        self.__total_cost: Decimal = Decimal(total_cost)
        self.__timestamp: str = timestamp
        self.__refid: str | None = refid

    def remove_coins(
        self,
        amount: float | Decimal,
        adapt: PriceAdaption = PriceAdaption.KeepPricePerCoin,
    ) -> None:
        """
        Reduce the amount of cryptocurrency in the trade by a specified amount.

        This effectively "loses" coins.

        Args:
            amount (Decimal): The amount of cryptocurrency to remove.

        Raises:
            ValueError: If the amount to remove exceeds the current amount in the trade.
        """
        if amount > self.__amount:
            raise ValueError(f"Can't remove more than {self.__amount}")

        if adapt == PriceAdaption.KeepPricePerCoin:
            amount = Decimal(amount)
            self.__total_cost -= amount * self.price_per_coin
            self.__amount -= amount
        elif adapt == PriceAdaption.KeepTotalCost:
            amount = Decimal(amount)
            self.__amount -= amount
        else:
            raise ValueError("Unknown adaptation strategy")

    @property
    def amount(self) -> Decimal:
        """
        Get the current amount of cryptocurrency in the trade.

        Returns:
            Decimal: The amount of cryptocurrency.
        """
        return self.__amount

    @property
    def total_cost(self) -> Decimal:
        """
        Get the total cost of the trade.

        Returns:
            Decimal: The total cost of the trade.
        """
        return self.__total_cost

    @property
    def date(self) -> str:
        """
        Get the date of the trade.

        Returns:
            str: The trade date as a string.
        """
        return self.__timestamp.split(" ")[0]

    @property
    def timestamp(self) -> str:
        """
        Get the timestamp of the trade.

        Returns:
            str: The trade timestamp as a string.
        """
        return self.__timestamp

    @property
    def price_per_coin(self) -> Decimal:
        """
        Calculate the price per coin based on the total cost and current amount.

        Returns:
            Decimal: The price per coin.

        Raises:
            ZeroDivisionError: If the current amount is zero.
        """
        if self.amount == 0:
            raise ZeroDivisionError(
                "Price per coin cannot be calculated when the amount is zero"
            )

        return self.total_cost / self.amount

    def __repr__(self) -> str:
        """
        Get a string representation of the Trade instance.

        Returns:
            str: A formatted string displaying the trade details.
        """
        rid = self.__refid or ""
        return f"Trade(amount={self.amount:.2f}, price_per_coin={self.price_per_coin:.2f}, total_cost={self.total_cost:.2f}, date={self.date}, refid={rid})"