package banking;

import dev.banking.model.BankAccount;
import org.junit.jupiter.api.Test;

import java.util.concurrent.*;

import static org.junit.jupiter.api.Assertions.assertTimeoutPreemptively;

import java.time.Duration;

public class BankAccountTransferDeadlockTest {

    @Test
    void deadlockFreeTransfers() {

        assertTimeoutPreemptively(Duration.ofSeconds(5), () -> {

            BankAccount a = new BankAccount(1, 1_000_000);
            BankAccount b = new BankAccount(2, 1_000_000);

            ExecutorService executor = Executors.newFixedThreadPool(50);

            for (int i = 0; i < 50_000; i++) {

                executor.submit(() -> a.transfer(b, 1));
                executor.submit(() -> b.transfer(a, 1));
            }

            executor.shutdown();

            executor.awaitTermination(5, TimeUnit.SECONDS);
        });
    }
}