/*

 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.incubator.http;

import jdk.incubator.http.internal.common.Demand;

import jdk.incubator.http.internal.common.FlowTube;

import jdk.incubator.http.internal.common.SSLFlowDelegate;

import jdk.incubator.http.internal.common.SSLTube;

import jdk.incubator.http.internal.common.SequentialScheduler;

import jdk.incubator.http.internal.common.Utils;

import org.testng.annotations.Test;

import javax.net.ssl.KeyManagerFactory;

import javax.net.ssl.SSLContext;

import javax.net.ssl.SSLEngine;

import javax.net.ssl.SSLParameters;

import javax.net.ssl.SSLServerSocket;

import javax.net.ssl.SSLServerSocketFactory;

import javax.net.ssl.SSLSocket;

import javax.net.ssl.TrustManagerFactory;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.net.Socket;

import java.nio.ByteBuffer;

import java.security.KeyManagementException;

import java.security.KeyStore;

import java.security.KeyStoreException;

import java.security.NoSuchAlgorithmException;

import java.security.UnrecoverableKeyException;

import java.security.cert.CertificateException;

import java.util.List;

import java.util.Queue;

import java.util.StringTokenizer;

import java.util.concurrent.BlockingQueue;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.ConcurrentLinkedQueue;

import java.util.concurrent.Executor;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Flow;

import java.util.concurrent.ForkJoinPool;

import java.util.concurrent.LinkedBlockingQueue;

import java.util.concurrent.SubmissionPublisher;

import java.util.concurrent.atomic.AtomicBoolean;

import java.util.concurrent.atomic.AtomicInteger;

import java.util.concurrent.atomic.AtomicLong;

@Test

public class SSLTubeTest {

    private static final long COUNTER = 600;

    private static final int LONGS_PER_BUF = 800;

    private static final long TOTAL_LONGS = COUNTER * LONGS_PER_BUF;

    private static ByteBuffer getBuffer(long startingAt) {

        ByteBuffer buf = ByteBuffer.allocate(LONGS_PER_BUF * 8);

        for (int j = 0; j < LONGS_PER_BUF; j++) {

            buf.putLong(startingAt++);

        }

        buf.flip();

        return buf;

    }

        ExecutorService sslExecutor = Executors.newCachedThreadPool();

        /* Emulates an echo server */

        SSLLoopbackSubscriber server =

                new SSLLoopbackSubscriber((new SimpleSSLContext()).get(), sslExecutor);

        server.start();

        FlowTube client = new SSLTube(createSSLEngine(true),

                                      sslExecutor,

                                      server);

        SubmissionPublisher<List<ByteBuffer>> p =

                new SubmissionPublisher<>(ForkJoinPool.commonPool(),

                                          Integer.MAX_VALUE);

        FlowTube.TubePublisher begin = p::subscribe;

        CompletableFuture<Void> completion = new CompletableFuture<>();

        EndSubscriber end = new EndSubscriber(TOTAL_LONGS, completion);

        client.connectFlows(begin, end);

        /* End of wiring */

        long count = 0;

        System.out.printf("Submitting %d buffer arrays\n", COUNTER);

        System.out.printf("LoopCount should be %d\n", TOTAL_LONGS);

        for (long i = 0; i < COUNTER; i++) {

            ByteBuffer b = getBuffer(count);

            count += LONGS_PER_BUF;

            p.submit(List.of(b));

        }

        System.out.println("Finished submission. Waiting for loopback");

        p.close();

        try {

            completion.join();

            System.out.println("OK");

        } finally {

            sslExecutor.shutdownNow();

        }

    }

    static class SSLLoopbackSubscriber implements FlowTube {

        private final BlockingQueue<ByteBuffer> buffer;

        private final Socket clientSock;

        private final SSLSocket serverSock;

        private final Thread thread1, thread2, thread3;

        private volatile Flow.Subscription clientSubscription;

        private final SubmissionPublisher<List<ByteBuffer>> publisher;

        SSLLoopbackSubscriber(SSLContext ctx, ExecutorService exec) throws IOException {

            SSLServerSocketFactory fac = ctx.getServerSocketFactory();

            SSLServerSocket serv = (SSLServerSocket) fac.createServerSocket(0);

            SSLParameters params = serv.getSSLParameters();

            params.setApplicationProtocols(new String[]{"proto2"});

            serv.setSSLParameters(params);

            int serverPort = serv.getLocalPort();

            clientSock = new Socket("127.0.0.1", serverPort);

            serverSock = (SSLSocket) serv.accept();

            this.buffer = new LinkedBlockingQueue<>();

            thread1 = new Thread(this::clientWriter, "clientWriter");

            thread2 = new Thread(this::serverLoopback, "serverLoopback");

            thread3 = new Thread(this::clientReader, "clientReader");

            publisher = new SubmissionPublisher<>(exec, Flow.defaultBufferSize(),

                    this::handlePublisherException);

            SSLFlowDelegate.Monitor.add(this::monitor);

        }

        public void start() {

            thread1.start();

            thread2.start();

            thread3.start();

        }

        private void handlePublisherException(Object o, Throwable t) {

            System.out.println("Loopback Publisher exception");

            t.printStackTrace(System.out);

        }

        private final AtomicInteger readCount = new AtomicInteger();

        // reads off the SSLSocket the data from the "server"

        private void clientReader() {

            try {

                InputStream is = clientSock.getInputStream();

                System.out.println("clientReader: bufsize = " + bufsize);

                while (true) {

                    byte[] buf = new byte[bufsize];

                    int n = is.read(buf);

                    if (n == -1) {

                        System.out.println("clientReader close: read "

                                + readCount.get() + " bytes");

                        publisher.close();

                        sleep(2000);

                        Utils.close(is, clientSock);

                        return;

                    }

                    ByteBuffer bb = ByteBuffer.wrap(buf, 0, n);

                    readCount.addAndGet(n);

                    publisher.submit(List.of(bb));

                }

            } catch (Throwable e) {

                e.printStackTrace();

                Utils.close(clientSock);

            }

        }

        // writes the encrypted data from SSLFLowDelegate to the j.n.Socket

        // which is connected to the SSLSocket emulating a server.

        private void clientWriter() {

            long nbytes = 0;

            try {

                OutputStream os =

                        new BufferedOutputStream(clientSock.getOutputStream());

                while (true) {

                    ByteBuffer buf = buffer.take();

                        // finished

                        //Utils.sleep(2000);

                        System.out.println("clientWriter close: " + nbytes + " written");

                        clientSock.shutdownOutput();

                        System.out.println("clientWriter close return");

                        return;

                    }

                    int len = buf.remaining();

                    int written = writeToStream(os, buf);

                    assert len == written;

                    nbytes += len;

                    assert !buf.hasRemaining()

                            : "buffer has " + buf.remaining() + " bytes left";

                    clientSubscription.request(1);

                }

            } catch (Throwable e) {

                e.printStackTrace();

            }

        }

        private int writeToStream(OutputStream os, ByteBuffer buf) throws IOException {

            byte[] b = buf.array();

            int offset = buf.arrayOffset() + buf.position();

            int n = buf.limit() - buf.position();

            os.write(b, offset, n);

            buf.position(buf.limit());

            os.flush();

            return n;

        }

        private final AtomicInteger loopCount = new AtomicInteger();

        public String monitor() {

            return "serverLoopback: loopcount = " + loopCount.toString()

                    + " clientRead: count = " + readCount.toString();

        }

        // thread2

        private void serverLoopback() {

            try {

                InputStream is = serverSock.getInputStream();

                OutputStream os = serverSock.getOutputStream();

                System.out.println("serverLoopback: bufsize = " + bufsize);

                byte[] bb = new byte[bufsize];

                while (true) {

                    int n = is.read(bb);

                    if (n == -1) {

                        sleep(2000);

                        is.close();

                        os.close();

                        serverSock.close();

                        return;

                    }

                    os.write(bb, 0, n);

                    os.flush();

                    loopCount.addAndGet(n);

                }

            } catch (Throwable e) {

                e.printStackTrace();

            }

        }

        /**

         * This needs to be called before the chain is subscribed. It can't be

         * supplied in the constructor.

         */

        public void setReturnSubscriber(Flow.Subscriber<List<ByteBuffer>> returnSubscriber) {

            publisher.subscribe(returnSubscriber);

        }

        @Override

        public void onSubscribe(Flow.Subscription subscription) {

            clientSubscription = subscription;

            clientSubscription.request(5);

        }

        @Override

        public void onNext(List<ByteBuffer> item) {

            try {

                for (ByteBuffer b : item)

                    buffer.put(b);

            } catch (InterruptedException e) {

                e.printStackTrace();

                Utils.close(clientSock);

            }

        }

        @Override

        public void onError(Throwable throwable) {

            throwable.printStackTrace();

            Utils.close(clientSock);

        }

        @Override

        public void onComplete() {

            try {

            } catch (InterruptedException e) {

                e.printStackTrace();

                Utils.close(clientSock);

            }

        }

        @Override

        public boolean isFinished() {

            return false;

        }

        @Override

        public void subscribe(Flow.Subscriber<? super List<ByteBuffer>> subscriber) {

            publisher.subscribe(subscriber);

        }

    }

    private static void sleep(long millis) {

        try {

            Thread.sleep(millis);

        } catch (InterruptedException e) {

        }

    }