import unittest
from decimal import Decimal

from trade import PriceAdaption, Trade


class TestTrade(unittest.TestCase):
    def setUp(self) -> None:
        """
        Set up a Trade instance for testing.
        """
        self.trade = Trade(amount=Decimal(10.0), total_cost=Decimal(100.0), timestamp="2025-04-14 00:00:00", refid="abcd1234")

    def test_initialization(self):
        """
        Test that the Trade instance initializes correctly.
        """
        self.assertEqual(self.trade.amount, 10.0)
        self.assertEqual(self.trade.total_cost, 100.0)
        self.assertEqual(self.trade.date, "2025-04-14")
        self.assertEqual(self.trade.price_per_coin, 10.0)

    def test_remove_coins_ppc_valid(self):
        """
        Test removing a valid amount of coins. (PPC const).
        """
        coin_price_before = self.trade.price_per_coin
        self.trade.remove_coins(4.0, PriceAdaption.KeepPricePerCoin)
        coin_price_after = self.trade.price_per_coin

        self.assertEqual(coin_price_before, coin_price_after)

        self.assertEqual(self.trade.amount, 6.0)
        self.assertEqual(self.trade.total_cost, 60.0)
        self.assertEqual(self.trade.price_per_coin, 10.0)

    def test_remove_coins_tc_valid(self):
        """
        Test removing a valid amount of coins. (TC const).
        """
        coin_price_before = self.trade.price_per_coin
        self.trade.remove_coins(4.0, PriceAdaption.KeepTotalCost)
        coin_price_after = self.trade.price_per_coin

        self.assertNotEqual(coin_price_before, coin_price_after)

        self.assertEqual(self.trade.amount, 6.0)
        self.assertEqual(self.trade.total_cost, 100.0)
        self.assertEqual(self.trade.price_per_coin, Decimal("100.0") / Decimal("6.0"))

    def test_remove_coins_exceeds_amount(self):
        """
        Test removing more coins than available.
        """
        with self.assertRaises(ValueError):
            self.trade.remove_coins(15.0)

    def test_price_per_coin_division_by_zero(self):
        """
        Test the price_per_coin property when the amount is zero.
        """
        self.trade.remove_coins(10.0)  # Reduce amount to zero
        with self.assertRaises(ZeroDivisionError):
            _ = self.trade.price_per_coin

    def test_repr(self):
        """
        Test the __repr__ method for correct string representation.
        """
        expected_repr = "Trade(amount=10.00, price_per_coin=10.00, total_cost=100.00, date=2025-04-14, refid=abcd1234)"
        self.assertEqual(repr(self.trade), expected_repr)


if __name__ == "__main__":
    unittest.main()