/*
 * Copyright 2015 Christian Basler
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package ch.dissem.bitmessage.networking;

import ch.dissem.bitmessage.BitmessageContext;
import ch.dissem.bitmessage.cryptography.bc.BouncyCryptography;
import ch.dissem.bitmessage.entity.CustomMessage;
import ch.dissem.bitmessage.entity.MessagePayload;
import ch.dissem.bitmessage.entity.valueobject.NetworkAddress;
import ch.dissem.bitmessage.exception.NodeException;
import ch.dissem.bitmessage.networking.nio.NioNetworkHandler;
import ch.dissem.bitmessage.ports.*;
import ch.dissem.bitmessage.utils.Property;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.DisableOnDebug;
import org.junit.rules.TestRule;
import org.junit.rules.Timeout;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Arrays;
import java.util.List;
import java.util.concurrent.Future;

import static ch.dissem.bitmessage.utils.Singleton.cryptography;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.mock;

/**
 * Tests network handlers. This test is parametrized, so it can test both the nio and classic implementation
 * as well as their combinations. It might be slightly over the top and will most probably be cleaned up once
 * the nio implementation is deemed stable.
 */
@RunWith(Parameterized.class)
public class NetworkHandlerTest {
    private static final Logger LOG = LoggerFactory.getLogger(NetworkHandlerTest.class);
    private static NetworkAddress peerAddress = new NetworkAddress.Builder().ipv4(127, 0, 0, 1).port(6001).build();

    private TestInventory peerInventory;
    private TestInventory nodeInventory;

    private BitmessageContext peer;
    private BitmessageContext node;

    private final NetworkHandler peerNetworkHandler;
    private final NetworkHandler nodeNetworkHandler;

    @Rule
    public final TestRule timeout = new DisableOnDebug(Timeout.seconds(60));

    public NetworkHandlerTest(NetworkHandler peer, NetworkHandler node) {
        this.peerNetworkHandler = peer;
        this.nodeNetworkHandler = node;
    }

    @Parameterized.Parameters
    public static List<Object[]> parameters() {
        return Arrays.asList(new Object[][]{
            {new DefaultNetworkHandler(), new DefaultNetworkHandler()},
            {new DefaultNetworkHandler(), new NioNetworkHandler()},
            {new NioNetworkHandler(), new DefaultNetworkHandler()},
            {new NioNetworkHandler(), new NioNetworkHandler()}
        });
    }

    @Before
    public void setUp() {
        peerInventory = new TestInventory();
        peer = new BitmessageContext.Builder()
            .addressRepo(mock(AddressRepository.class))
            .inventory(peerInventory)
            .messageRepo(mock(MessageRepository.class))
            .powRepo(mock(ProofOfWorkRepository.class))
            .port(peerAddress.getPort())
            .nodeRegistry(new TestNodeRegistry())
            .networkHandler(peerNetworkHandler)
            .cryptography(new BouncyCryptography())
            .listener(mock(BitmessageContext.Listener.class))
            .customCommandHandler(new CustomCommandHandler() {
                @Override
                public MessagePayload handle(CustomMessage request) {
                    byte[] data = request.getData();
                    if (data.length > 0) {
                        switch (data[0]) {
                            case 0:
                                return null;
                            case 1:
                                break;
                            case 3:
                                data[0] = 0;
                                break;
                            default:
                                break;
                        }
                    }
                    return new CustomMessage("test response", request.getData());
                }
            })
            .build();
        peer.startup();

        nodeInventory = new TestInventory();
        node = new BitmessageContext.Builder()
            .addressRepo(mock(AddressRepository.class))
            .inventory(nodeInventory)
            .messageRepo(mock(MessageRepository.class))
            .powRepo(mock(ProofOfWorkRepository.class))
            .port(6002)
            .nodeRegistry(new TestNodeRegistry(peerAddress))
            .networkHandler(nodeNetworkHandler)
            .cryptography(new BouncyCryptography())
            .listener(mock(BitmessageContext.Listener.class))
            .build();
    }

    @After
    public void cleanUp() {
        shutdown(peer);
        shutdown(node);
        shutdown(nodeNetworkHandler);
    }

    private static void shutdown(BitmessageContext ctx) {
        if (!ctx.isRunning()) return;

        ctx.shutdown();
        do {
            try {
                Thread.sleep(100);
            } catch (InterruptedException ignore) {
            }
        } while (ctx.isRunning());
    }

    private static void shutdown(NetworkHandler networkHandler) {
        if (!networkHandler.isRunning()) return;

        networkHandler.stop();
        do {
            try {
                Thread.sleep(100);
            } catch (InterruptedException ignore) {
                if (networkHandler.isRunning()) {
                    LOG.warn("Thread interrupted while waiting for network shutdown - " +
                        "this could cause problems in subsequent tests.");
                }
                return;
            }
        } while (networkHandler.isRunning());
    }

    private Property waitForNetworkStatus(BitmessageContext ctx) throws InterruptedException {
        Property status;
        do {
            Thread.sleep(100);
            status = ctx.status().getProperty("network", "connections", "stream 1");
        } while (status == null);
        return status;
    }

    @Test
    public void ensureNodesAreConnecting() throws Exception {
        node.startup();

        Property nodeStatus = waitForNetworkStatus(node);
        Property peerStatus = waitForNetworkStatus(peer);

        assertEquals(1, nodeStatus.getProperty("outgoing").getValue());
        assertEquals(1, peerStatus.getProperty("incoming").getValue());
    }

    @Test
    public void ensureCustomMessageIsSentAndResponseRetrieved() throws Exception {
        byte[] data = cryptography().randomBytes(8);
        data[0] = (byte) 1;
        CustomMessage request = new CustomMessage("test request", data);
        node.startup();

        CustomMessage response = nodeNetworkHandler.send(peerAddress.toInetAddress(), peerAddress.getPort(), request);

        assertThat(response, notNullValue());
        assertThat(response.getCustomCommand(), is("test response"));
        assertThat(response.getData(), is(data));
    }

    @Test(expected = NodeException.class)
    public void ensureCustomMessageWithoutResponseYieldsException() throws Exception {
        byte[] data = cryptography().randomBytes(8);
        data[0] = (byte) 0;
        CustomMessage request = new CustomMessage("test request", data);

        CustomMessage response = nodeNetworkHandler.send(peerAddress.toInetAddress(), peerAddress.getPort(), request);

        assertThat(response, notNullValue());
        assertThat(response.getCustomCommand(), is("test response"));
        assertThat(response.getData(), is(request.getData()));
    }

    @Test
    public void ensureObjectsAreSynchronizedIfBothHaveObjects() throws Exception {
        peerInventory.init(
            "V4Pubkey.payload",
            "V5Broadcast.payload"
        );

        nodeInventory.init(
            "V1Msg.payload",
            "V4Pubkey.payload"
        );

        Future<?> future = nodeNetworkHandler.synchronize(peerAddress.toInetAddress(), peerAddress.getPort(), 10);
        future.get();
        assertInventorySize(3, nodeInventory);
        assertInventorySize(3, peerInventory);
    }

    @Test
    public void ensureObjectsAreSynchronizedIfOnlyPeerHasObjects() throws Exception {
        peerInventory.init(
            "V4Pubkey.payload",
            "V5Broadcast.payload"
        );

        nodeInventory.init();

        Future<?> future = nodeNetworkHandler.synchronize(peerAddress.toInetAddress(), peerAddress.getPort(), 10);
        future.get();
        assertInventorySize(2, nodeInventory);
        assertInventorySize(2, peerInventory);
    }

    @Test
    public void ensureObjectsAreSynchronizedIfOnlyNodeHasObjects() throws Exception {
        peerInventory.init();

        nodeInventory.init(
            "V1Msg.payload"
        );

        Future<?> future = nodeNetworkHandler.synchronize(peerAddress.toInetAddress(), peerAddress.getPort(), 10);
        future.get();
        assertInventorySize(1, nodeInventory);
        assertInventorySize(1, peerInventory);
    }

    private void assertInventorySize(int expected, TestInventory inventory) throws InterruptedException {
        long timeout = System.currentTimeMillis() + 1000;
        while (expected != inventory.getInventory().size() && System.currentTimeMillis() < timeout) {
            Thread.sleep(10);
        }
        assertEquals(expected, inventory.getInventory().size());
    }

}