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 * Copyright (c) 2018, 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

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import com.sun.net.httpserver.HttpServer;

import com.sun.net.httpserver.HttpsConfigurator;

import com.sun.net.httpserver.HttpsServer;

import jdk.test.lib.net.SimpleSSLContext;

import org.testng.annotations.AfterClass;

import org.testng.annotations.AfterTest;

import org.testng.annotations.BeforeTest;

import org.testng.annotations.DataProvider;

import org.testng.annotations.Test;

import javax.net.ssl.SSLContext;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.UncheckedIOException;

import java.net.InetAddress;

import java.net.InetSocketAddress;

import java.net.URI;

import java.net.http.HttpClient;

import java.net.http.HttpRequest;

import java.net.http.HttpRequest.BodyPublisher;

import java.net.http.HttpRequest.BodyPublishers;

import java.net.http.HttpResponse;

import java.net.http.HttpResponse.BodyHandler;

import java.net.http.HttpResponse.BodyHandlers;

import java.nio.ByteBuffer;

import java.nio.charset.StandardCharsets;

import java.util.EnumSet;

import java.util.List;

import java.util.Set;

import java.util.concurrent.CompletableFuture;

import java.util.concurrent.CompletionException;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.ConcurrentMap;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.Executor;

import java.util.concurrent.Executors;

import java.util.concurrent.Flow;

import java.util.concurrent.SubmissionPublisher;

import java.util.concurrent.atomic.AtomicLong;

import java.util.function.BiPredicate;

import java.util.function.Consumer;

import java.util.function.Supplier;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import static java.lang.String.format;

import static java.lang.System.out;

import static java.nio.charset.StandardCharsets.UTF_8;

import static org.testng.Assert.assertEquals;

import static org.testng.Assert.assertTrue;

public abstract class AbstractThrowingPublishers implements HttpServerAdapters {

    SSLContext sslContext;

    HttpTestServer httpTestServer;    // HTTP/1.1    [ 4 servers ]

    HttpTestServer httpsTestServer;   // HTTPS/1.1

    HttpTestServer http2TestServer;   // HTTP/2 ( h2c )

    HttpTestServer https2TestServer;  // HTTP/2 ( h2  )

    String httpURI_fixed;

    String httpURI_chunk;

    String httpsURI_fixed;

    String httpsURI_chunk;

    String http2URI_fixed;

    String http2URI_chunk;

    String https2URI_fixed;

    String https2URI_chunk;

    static final int ITERATION_COUNT = 1;

    // a shared executor helps reduce the amount of threads created by the test

    static final Executor executor = new TestExecutor(Executors.newCachedThreadPool());

    static final ConcurrentMap<String, Throwable> FAILURES = new ConcurrentHashMap<>();

    static volatile boolean tasksFailed;

    static final AtomicLong serverCount = new AtomicLong();

    static final AtomicLong clientCount = new AtomicLong();

    static final long start = System.nanoTime();

    public static String now() {

        long now = System.nanoTime() - start;

        long secs = now / 1000_000_000;

        long mill = (now % 1000_000_000) / 1000_000;

        long nan = now % 1000_000;

        return String.format("[%d s, %d ms, %d ns] ", secs, mill, nan);

    }

    final ReferenceTracker TRACKER = ReferenceTracker.INSTANCE;

    private volatile HttpClient sharedClient;

    static class TestExecutor implements Executor {

        final AtomicLong tasks = new AtomicLong();

        Executor executor;

        TestExecutor(Executor executor) {

            this.executor = executor;

        }

        @Override

        public void execute(Runnable command) {

            long id = tasks.incrementAndGet();

            executor.execute(() -> {

                try {

                    command.run();

                } catch (Throwable t) {

                    tasksFailed = true;

                    System.out.printf(now() + "Task %s failed: %s%n", id, t);

                    System.err.printf(now() + "Task %s failed: %s%n", id, t);

                    FAILURES.putIfAbsent("Task " + id, t);

                    throw t;

                }

            });

        }

    }

    @AfterClass

    static final void printFailedTests() {

        out.println("\n=========================");

        try {

            out.printf("%n%sCreated %d servers and %d clients%n",

                    now(), serverCount.get(), clientCount.get());

            if (FAILURES.isEmpty()) return;

            out.println("Failed tests: ");

            FAILURES.entrySet().forEach((e) -> {

                out.printf("\t%s: %s%n", e.getKey(), e.getValue());

                e.getValue().printStackTrace(out);

            });

            if (tasksFailed) {

                System.out.println("WARNING: Some tasks failed");

            }

        } finally {

            out.println("\n=========================\n");

        }

    }

    private String[] uris() {

        return new String[] {

                httpURI_fixed,

                httpURI_chunk,

                httpsURI_fixed,

                httpsURI_chunk,

                http2URI_fixed,

                http2URI_chunk,

                https2URI_fixed,

                https2URI_chunk,

        };

    }

    @DataProvider(name = "sanity")

    public Object[][] sanity() {

        String[] uris = uris();

        Object[][] result = new Object[uris.length * 2][];

        //Object[][] result = new Object[uris.length][];

        int i = 0;

        for (boolean sameClient : List.of(false, true)) {

            //if (!sameClient) continue;

            for (String uri: uris()) {

                result[i++] = new Object[] {uri + "/sanity", sameClient};

            }

        }

        assert i == uris.length * 2;

        // assert i == uris.length ;

        return result;

    }

    enum Where {

        BEFORE_SUBSCRIBE, BEFORE_REQUEST, BEFORE_NEXT_REQUEST, BEFORE_CANCEL,

        AFTER_SUBSCRIBE, AFTER_REQUEST, AFTER_NEXT_REQUEST, AFTER_CANCEL;

        public Consumer<Where> select(Consumer<Where> consumer) {

            return new Consumer<Where>() {

                @Override

                public void accept(Where where) {

                    if (Where.this == where) {

                        consumer.accept(where);

                    }

                }

            };

        }

    }

    private Object[][] variants(List<Thrower> throwers, Set<Where> whereValues) {

        String[] uris = uris();

        Object[][] result = new Object[uris.length * 2 * throwers.size()][];

        //Object[][] result = new Object[(uris.length/2) * 2 * 2][];

        int i = 0;

        for (Thrower thrower : throwers) {

            for (boolean sameClient : List.of(false, true)) {

                for (String uri : uris()) {

                    // if (uri.contains("http2") || uri.contains("https2")) continue;

                    // if (!sameClient) continue;

                    result[i++] = new Object[]{uri, sameClient, thrower, whereValues};

                }

            }

        }

        assert i == uris.length * 2 * throwers.size();

        //assert Stream.of(result).filter(o -> o != null).count() == result.length;

        return result;

    }

    @DataProvider(name = "subscribeProvider")

    public Object[][] subscribeProvider() {

        return  variants(List.of(

                new UncheckedCustomExceptionThrower(),

                new UncheckedIOExceptionThrower()),

                EnumSet.of(Where.BEFORE_SUBSCRIBE, Where.AFTER_SUBSCRIBE));

    }

    @DataProvider(name = "requestProvider")

    public Object[][] requestProvider() {

        return  variants(List.of(

                new UncheckedCustomExceptionThrower(),

                new UncheckedIOExceptionThrower()),

                EnumSet.of(Where.BEFORE_REQUEST, Where.AFTER_REQUEST));

    }

    @DataProvider(name = "nextRequestProvider")

    public Object[][] nextRequestProvider() {

        return  variants(List.of(

                new UncheckedCustomExceptionThrower(),

                new UncheckedIOExceptionThrower()),

                EnumSet.of(Where.BEFORE_NEXT_REQUEST, Where.AFTER_NEXT_REQUEST));

    }

    @DataProvider(name = "beforeCancelProviderIO")

    public Object[][] beforeCancelProviderIO() {

        return  variants(List.of(

                new UncheckedIOExceptionThrower()),

                EnumSet.of(Where.BEFORE_CANCEL));

    }

    @DataProvider(name = "afterCancelProviderIO")

    public Object[][] afterCancelProviderIO() {

        return  variants(List.of(

                new UncheckedIOExceptionThrower()),

                EnumSet.of(Where.AFTER_CANCEL));

    }

    @DataProvider(name = "beforeCancelProviderCustom")

    public Object[][] beforeCancelProviderCustom() {

        return  variants(List.of(

                new UncheckedCustomExceptionThrower()),

                EnumSet.of(Where.BEFORE_CANCEL));

    }

    @DataProvider(name = "afterCancelProviderCustom")

    public Object[][] afterCancelProvider() {

        return  variants(List.of(

                new UncheckedCustomExceptionThrower()),

                EnumSet.of(Where.AFTER_CANCEL));

    }

    private HttpClient makeNewClient() {

        clientCount.incrementAndGet();

        return TRACKER.track(HttpClient.newBuilder()

                .proxy(HttpClient.Builder.NO_PROXY)

                .executor(executor)

                .sslContext(sslContext)

                .build());

    }

    HttpClient newHttpClient(boolean share) {

        if (!share) return makeNewClient();

        HttpClient shared = sharedClient;

        if (shared != null) return shared;

        synchronized (this) {

            shared = sharedClient;

            if (shared == null) {

                shared = sharedClient = makeNewClient();

            }

            return shared;

        }

    }

    final String BODY = "Some string | that ? can | be split ? several | ways.";

    //@Test(dataProvider = "sanity")

    protected void testSanityImpl(String uri, boolean sameClient)

            throws Exception {

        HttpClient client = null;

        out.printf("%n%s testSanity(%s, %b)%n", now(), uri, sameClient);

        for (int i=0; i< ITERATION_COUNT; i++) {

            if (!sameClient || client == null)

                client = newHttpClient(sameClient);

            SubmissionPublisher<ByteBuffer> publisher

                    = new SubmissionPublisher<>(executor,10);

            ThrowingBodyPublisher bodyPublisher = new ThrowingBodyPublisher((w) -> {},

                    BodyPublishers.fromPublisher(publisher));

            CompletableFuture<Void> subscribedCF = bodyPublisher.subscribedCF();

            subscribedCF.whenComplete((r,t) -> System.out.println(now() + " subscribe completed " + t))

                    .thenAcceptAsync((v) -> {

                                Stream.of(BODY.split("\\|"))

                                        .forEachOrdered(s -> {

                                                System.out.println("submitting \"" + s +"\"");

                                                publisher.submit(ByteBuffer.wrap(s.getBytes(StandardCharsets.UTF_8)));

                                        });

                                System.out.println("publishing done");

                                publisher.close();

                            },

                    executor);

            HttpRequest req = HttpRequest.newBuilder(URI.create(uri))

                    .POST(bodyPublisher)

                    .build();

            BodyHandler<String> handler = BodyHandlers.ofString();

            CompletableFuture<HttpResponse<String>> response = client.sendAsync(req, handler);

            String body = response.join().body();

            assertEquals(body, Stream.of(BODY.split("\\|")).collect(Collectors.joining()));

        }

    }

    // @Test(dataProvider = "variants")

    protected void testThrowingAsStringImpl(String uri,

                                     boolean sameClient,

                                     Thrower thrower,

                                     Set<Where> whereValues)

            throws Exception

    {

        String test = format("testThrowingAsString(%s, %b, %s, %s)",

                             uri, sameClient, thrower, whereValues);

        List<byte[]> bytes = Stream.of(BODY.split("|"))

                .map(s -> s.getBytes(UTF_8))

                .collect(Collectors.toList());

        testThrowing(test, uri, sameClient, () -> BodyPublishers.ofByteArrays(bytes),

                this::shouldNotThrowInCancel, thrower,false, whereValues);

    }

    private <T,U> void testThrowing(String name, String uri, boolean sameClient,

                                    Supplier<BodyPublisher> publishers,

                                    Finisher finisher, Thrower thrower,

                                    boolean async, Set<Where> whereValues)

            throws Exception

    {

        out.printf("%n%s%s%n", now(), name);

        try {

            testThrowing(uri, sameClient, publishers, finisher, thrower, async, whereValues);

        } catch (Error | Exception x) {

            FAILURES.putIfAbsent(name, x);

            throw x;

        }

    }

    private void testThrowing(String uri, boolean sameClient,

                                    Supplier<BodyPublisher> publishers,

                                    Finisher finisher, Thrower thrower,

                                    boolean async, Set<Where> whereValues)

            throws Exception

    {

        HttpClient client = null;

        for (Where where : whereValues) {

            //if (where == Where.ON_SUBSCRIBE) continue;

            //if (where == Where.ON_ERROR) continue;

            if (!sameClient || client == null)

                client = newHttpClient(sameClient);

            ThrowingBodyPublisher bodyPublisher =

                    new ThrowingBodyPublisher(where.select(thrower), publishers.get());

            HttpRequest req = HttpRequest.

                    newBuilder(URI.create(uri))

                    .header("X-expect-exception", "true")

                    .POST(bodyPublisher)

                    .build();

            BodyHandler<String> handler = BodyHandlers.ofString();

            System.out.println("try throwing in " + where);

            HttpResponse<String> response = null;

            if (async) {

                try {

                    response = client.sendAsync(req, handler).join();

                } catch (Error | Exception x) {

                    Throwable cause = findCause(where, x, thrower);

                    if (cause == null) throw causeNotFound(where, x);

                    System.out.println(now() + "Got expected exception: " + cause);

                }

            } else {

                try {

                    response = client.send(req, handler);

                } catch (Error | Exception t) {

                    // synchronous send will rethrow exceptions

                    Throwable throwable = t.getCause();

                    assert throwable != null;

                    if (thrower.test(where, throwable)) {

                        System.out.println(now() + "Got expected exception: " + throwable);

                    } else throw causeNotFound(where, t);

                }

            }

            if (response != null) {

                finisher.finish(where, response, thrower);

            }

        }

    }

    // can be used to reduce the surface of the test when diagnosing

    // some failure

    Set<Where> whereValues() {

        //return EnumSet.of(Where.BEFORE_CANCEL, Where.AFTER_CANCEL);

        return EnumSet.allOf(Where.class);

    }

    interface Thrower extends Consumer<Where>, BiPredicate<Where,Throwable> {

    }

    interface Finisher<T,U> {

        U finish(Where w, HttpResponse<T> resp, Thrower thrower) throws IOException;

    }

    final <T,U> U shouldNotThrowInCancel(Where w, HttpResponse<T> resp, Thrower thrower) {

        switch (w) {

            case BEFORE_CANCEL: return null;

            case AFTER_CANCEL: return null;

            default: break;

        }

        return shouldHaveThrown(w, resp, thrower);

    }

    final <T,U> U shouldHaveThrown(Where w, HttpResponse<T> resp, Thrower thrower) {

        String msg = "Expected exception not thrown in " + w

                + "\n\tReceived: " + resp

                + "\n\tWith body: " + resp.body();

        System.out.println(msg);

        throw new RuntimeException(msg);

    }

    private static Throwable findCause(Where w,

                                       Throwable x,

                                       BiPredicate<Where, Throwable> filter) {

        while (x != null && !filter.test(w,x)) x = x.getCause();

        return x;

    }

    static AssertionError causeNotFound(Where w, Throwable t) {

        return new AssertionError("Expected exception not found in " + w, t);

    }

    static boolean isConnectionClosedLocally(Throwable t) {

        if (t instanceof CompletionException) t = t.getCause();

        if (t instanceof ExecutionException) t = t.getCause();

        if (t instanceof IOException) {

            String msg = t.getMessage();

            return msg == null ? false

                    : msg.contains("connection closed locally");

        }

        return false;

    }

    static final class UncheckedCustomExceptionThrower implements Thrower {

        @Override

        public void accept(Where where) {

            out.println(now() + "Throwing in " + where);

            throw new UncheckedCustomException(where.name());

        }

        @Override

        public boolean test(Where w, Throwable throwable) {

            switch (w) {

                case AFTER_REQUEST:

                case BEFORE_NEXT_REQUEST:

                case AFTER_NEXT_REQUEST:

                    if (isConnectionClosedLocally(throwable)) return true;

                    break;

                default:

                    break;

            }

            return UncheckedCustomException.class.isInstance(throwable);

        }

        @Override

        public String toString() {

            return "UncheckedCustomExceptionThrower";

        }

    }

    static final class UncheckedIOExceptionThrower implements Thrower {

        @Override

        public void accept(Where where) {

            out.println(now() + "Throwing in " + where);

            throw new UncheckedIOException(new CustomIOException(where.name()));

        }

        @Override

        public boolean test(Where w, Throwable throwable) {

            switch (w) {

                case AFTER_REQUEST:

                case BEFORE_NEXT_REQUEST:

                case AFTER_NEXT_REQUEST:

                    if (isConnectionClosedLocally(throwable)) return true;

                    break;

                default:

                    break;

            }

            return UncheckedIOException.class.isInstance(throwable)

                    && CustomIOException.class.isInstance(throwable.getCause());

        }

        @Override

        public String toString() {