private Leader leader;

private List<Node> system;

private final Random random = new Random();

@BeforeEach

void setUp() throws InterruptedException {

try {

leader = new Leader(Node.getLocalIp(), DEFAULT_LISTEN_PORT);

system = new ArrayList<>();

Node node = new Node(new TestConfiguration(DEFAULT_LISTEN_PORT, leader, system));

node.joinSystem();

system.add(node);

Thread.sleep(1000);

node = new Node(new TestConfiguration(11111, null, system));

node.joinSystem();

system.add(node);

Thread.sleep(1000);

} catch (IOException e) {

throw new RuntimeException(e);

}

}

@AfterEach

void tearDown() throws InterruptedException {

system.forEach(node -> {

try {

node.shutdown();

} catch (Exception e) {

throw new RuntimeException(e);

}

});

Thread.sleep(10_000); // let the system free resources

}

@Test

public void joinSystemTest() throws IOException {

Node node = new Node(new TestConfiguration(randomPort(), null, system));

node.joinSystem();

await().atMost(5, TimeUnit.SECONDS)

.until(() -> leader.equals(node.context.getLeader()));

}

@Test

public void healthcheckTest() throws IOException, InterruptedException {

TestConfiguration configuration = new TestConfiguration(randomPort(), null, system);

RemoteClient<DatagramPacket> remoteClient = configuration.getDefaultClient();

Node node = new Node(configuration);

node.joinSystem();

Thread.sleep(5000);

HealthPayloadConverter healthPayloadConverter = new HealthPayloadConverter();

verify(remoteClient, atLeastOnce())

.unicast(eq(healthPayloadConverter.encode(Command.HEALTH, new HealthMessage(new RemoteNode(Node.getLocalIp(), node.context.listenPort)))),

eq(leader.ip()), eq(leader.port()));

}

@Test

public void leaderElectionTest() throws IOException, InterruptedException {

Node node = new Node(new TestConfiguration(randomPort(), null, system));

node.joinSystem();

system.add(node);

system.get(0).shutdown();

await().atMost(20, TimeUnit.SECONDS)

.until(() -> system.get(1).context.isLeader() || system.get(2).context.isLeader());

System.out.println();

Thread.sleep(10_000);

}

@Test

public void neighboursAssignTest() throws IOException {

Node node = new Node(new TestConfiguration(randomPort(), null, system));

node.joinSystem();

system.add(node);

await().atMost(5, TimeUnit.SECONDS)

.until(() ->

system.get(1).context.getNeighbour() != null

&& system.get(1).context.getNeighbour().equals(new RemoteNode(Node.getLocalIp(), node.context.listenPort))

&& node.context.getNeighbour() != null

&& node.context.getNeighbour().equals(new RemoteNode(Node.getLocalIp(), system.get(1).context.listenPort)));

}

@Test

public void neighboursValidReassignTest() throws IOException, InterruptedException {

Node node = new Node(new TestConfiguration(randomPort(), null, system));

node.joinSystem();

system.add(node);

await().atMost(5, TimeUnit.SECONDS)

.until(() -> node.context.getNeighbour().equals(new RemoteNode(Node.getLocalIp(), system.get(1).context.listenPort)));

node.shutdown();

Thread.sleep(10_000);

await().atMost(15, TimeUnit.SECONDS).until(() -> system.get(1).context.getNeighbour() == null);

}

@Test

public void dataNodeCrashTest() throws IOException, InterruptedException {

int port = randomPort();

Node node = new Node(new TestConfiguration(port, null, system));

node.joinSystem();

node.shutdown();

await().atMost(15, TimeUnit.SECONDS).until(() ->

!system.get(0).context.getLeaderContext()

.aliveNodes.containsKey(new RemoteNode(Node.getLocalIp(), port)));

}

private int randomPort() {

return random.nextInt(55_535) + 10_000;

}