JavaAdventureRepo/test/cz/davza/studentadventure/commands/BuyCommandTest.java

package cz.davza.studentadventure.commands;

import cz.davza.studentadventure.Items.EnergyDrink;
import cz.davza.studentadventure.TestHelpers;
import cz.davza.studentadventure.enums.CommandState;
import cz.davza.studentadventure.objects.CommandResult;
import cz.davza.studentadventure.objects.GameData;
import cz.davza.studentadventure.objects.Player;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import static cz.davza.studentadventure.TestHelpers.execute;
import static org.junit.jupiter.api.Assertions.*;

class BuyCommandTest {

    private GameData context;
    private Player player;

    @BeforeEach
    void setUp() {
        context = TestHelpers.buildGameData();
        player  = context.getPlayer();
    }

    @Test
    void buyEnergyDrinkDeductsCost() {
        int before = player.getWallet().getMoney();
        execute("buy energy_drink", context);
        assertEquals(before - EnergyDrink.COST, player.getWallet().getMoney());
    }

    @Test
    void buyEnergyDrinkAddsToInventory() {
        execute("buy energy_drink", context);
        assertNotNull(player.getInventory().GetByItemCode("energy_drink"));
    }

    @Test
    void buyReturnsSuccessState() {
        CommandResult result = execute("buy energy_drink", context);
        assertEquals(CommandState.SUCCESS, result.getResultState());
    }

    @Test
    void buyWithInsufficientFundsReturnsFailed() {
        player.getWallet().spendMoney(player.getWallet().getMoney()); // drain wallet
        CommandResult result = execute("buy energy_drink", context);
        assertEquals(CommandState.FAILED, result.getResultState());
    }

    @Test
    void buyWithInsufficientFundsDoesNotAddItem() {
        player.getWallet().spendMoney(player.getWallet().getMoney());
        execute("buy energy_drink", context);
        assertNull(player.getInventory().GetByItemCode("energy_drink"));
    }

    @Test
    void buyUnknownItemReturnsFailed() {
        CommandResult result = execute("buy sandwich", context);
        assertEquals(CommandState.FAILED, result.getResultState());
    }

    @Test
    void buyWithNoParamsReturnsInvalidParams() {
        CommandResult result = execute("buy", context);
        assertEquals(CommandState.INVALID_PARAMS, result.getResultState());
    }

    @Test
    void buyWhenInventoryFullReturnsInventoryFull() {
        // Fill inventory: capacity 20, drink bulk 2 → 10 drinks = 20 bulk
        player.getInventory().Add(new EnergyDrink(), 10);
        CommandResult result = execute("buy energy_drink", context);
        assertEquals(CommandState.INVENTORY_FULL, result.getResultState());
    }

    @Test
    void buyDoesNotSpendMoneyWhenInventoryFull() {
        player.getInventory().Add(new EnergyDrink(), 10);
        int moneyBefore = player.getWallet().getMoney();
        execute("buy energy_drink", context);
        assertEquals(moneyBefore, player.getWallet().getMoney());
    }
}