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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
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import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.net.http.HttpClient.Builder;
import java.net.http.HttpClient.Version;
import java.nio.ByteBuffer;
import java.nio.MappedByteBuffer;
import java.util.Arrays;
import java.util.concurrent.Flow;
import java.util.concurrent.Flow.Publisher;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

import jdk.httpclient.test.lib.common.HttpServerAdapters;
import jdk.test.lib.net.SimpleSSLContext;
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 static java.util.stream.Collectors.joining;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.net.http.HttpRequest.BodyPublishers.fromPublisher;
import static java.net.http.HttpResponse.BodyHandlers.ofString;
import static org.testng.Assert.assertEquals;
import static org.testng.Assert.assertThrows;
import static org.testng.Assert.assertTrue;
import static org.testng.Assert.fail;

/*
 * @test
 * @summary Basic tests for Flow adapter Publishers
 * @library /test/lib /test/jdk/java/net/httpclient/lib
 * @build jdk.httpclient.test.lib.common.HttpServerAdapters
 *        jdk.test.lib.net.SimpleSSLContext
 * @run testng/othervm FlowAdapterPublisherTest
 */

public class FlowAdapterPublisherTest 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;
    String httpsURI;
    String http2URI;
    String https2URI;

    @DataProvider(name = "uris")
    public Object[][] variants() {
        return new Object[][]{
                { httpURI   },
                { httpsURI  },
                { http2URI  },
                { https2URI },
        };
    }

    static final Class<NullPointerException> NPE = NullPointerException.class;
    static final Class<IllegalArgumentException> IAE = IllegalArgumentException.class;

    private static Version version(String uri) {
        if (uri.contains("/http1/")) return Version.HTTP_1_1;
        if (uri.contains("/https1/")) return Version.HTTP_1_1;
        if (uri.contains("/http2/")) return Version.HTTP_2;
        if (uri.contains("/https2/")) return Version.HTTP_2;
        return null;
    }

    private HttpClient newHttpClient(String uri) {
        var builder = HttpClient.newBuilder();
        return builder.sslContext(sslContext).proxy(Builder.NO_PROXY).build();
    }

    private HttpRequest.Builder newRequestBuilder(String uri) {
        return HttpRequest.newBuilder(URI.create(uri));
    }

    @Test
    public void testAPIExceptions() {
        assertThrows(NPE, () -> fromPublisher(null));
        assertThrows(NPE, () -> fromPublisher(null, 1));
        assertThrows(IAE, () -> fromPublisher(new BBPublisher(), 0));
        assertThrows(IAE, () -> fromPublisher(new BBPublisher(), -1));
        assertThrows(IAE, () -> fromPublisher(new BBPublisher(), Long.MIN_VALUE));

        Publisher publisher = fromPublisher(new BBPublisher());
        assertThrows(NPE, () -> publisher.subscribe(null));
    }

    //  Flow.Publisher<ByteBuffer>

    @Test(dataProvider = "uris")
    void testByteBufferPublisherUnknownLength(String uri) {
        String[] body = new String[] { "You know ", "it's summer ", "in Ireland ",
                "when the ", "rain gets ", "warmer." };
        try (HttpClient client = newHttpClient(uri)) {
            HttpRequest request = newRequestBuilder(uri)
                    .POST(fromPublisher(new BBPublisher(body))).build();

            HttpResponse<String> response = client.sendAsync(request, ofString(UTF_8)).join();
            String text = response.body();
            System.out.println(text);
            assertEquals(response.statusCode(), 200);
            assertEquals(response.version(), version(uri));
            assertEquals(text, Arrays.stream(body).collect(joining()));
        }
    }

    @Test(dataProvider = "uris")
    void testByteBufferPublisherFixedLength(String uri) {
        String[] body = new String[] { "You know ", "it's summer ", "in Ireland ",
                "when the ", "rain gets ", "warmer." };
        int cl = Arrays.stream(body).mapToInt(String::length).sum();
        try (HttpClient client = newHttpClient(uri)) {
            HttpRequest request = newRequestBuilder(uri)
                    .POST(fromPublisher(new BBPublisher(body), cl)).build();

            HttpResponse<String> response = client.sendAsync(request, ofString(UTF_8)).join();
            String text = response.body();
            System.out.println(text);
            assertEquals(response.statusCode(), 200);
            assertEquals(response.version(), version(uri));
            assertEquals(text, Arrays.stream(body).collect(joining()));
        }
    }

    // Flow.Publisher<MappedByteBuffer>

    @Test(dataProvider = "uris")
    void testMappedByteBufferPublisherUnknownLength(String uri) {
        String[] body = new String[] { "God invented ", "whiskey to ", "keep the ",
                "Irish from ", "ruling the ", "world." };
        try (HttpClient client = newHttpClient(uri)) {
            HttpRequest request = newRequestBuilder(uri)
                    .POST(fromPublisher(new MBBPublisher(body))).build();

            HttpResponse<String> response = client.sendAsync(request, ofString(UTF_8)).join();
            String text = response.body();
            System.out.println(text);
            assertEquals(response.statusCode(), 200);
            assertEquals(response.version(), version(uri));
            assertEquals(text, Arrays.stream(body).collect(joining()));
        }
    }

    @Test(dataProvider = "uris")
    void testMappedByteBufferPublisherFixedLength(String uri) {
        String[] body = new String[] { "God invented ", "whiskey to ", "keep the ",
                "Irish from ", "ruling the ", "world." };
        int cl = Arrays.stream(body).mapToInt(String::length).sum();
        try (HttpClient client = newHttpClient(uri)) {
            HttpRequest request = newRequestBuilder(uri)
                    .POST(fromPublisher(new MBBPublisher(body), cl)).build();

            HttpResponse<String> response = client.sendAsync(request, ofString(UTF_8)).join();
            String text = response.body();
            System.out.println(text);
            assertEquals(response.statusCode(), 200);
            assertEquals(response.version(), version(uri));
            assertEquals(text, Arrays.stream(body).collect(joining()));
        }
    }

    // The following two tests depend on Exception detail messages, which is
    // not ideal, but necessary to discern correct behavior. They should be
    // updated if the exception message is updated.

    @Test(dataProvider = "uris")
    void testPublishTooFew(String uri) throws InterruptedException {
        String[] body = new String[] { "You know ", "it's summer ", "in Ireland ",
                "when the ", "rain gets ", "warmer." };
        int cl = Arrays.stream(body).mapToInt(String::length).sum() + 1; // length + 1
        try (HttpClient client = newHttpClient(uri)) {
            HttpRequest request = newRequestBuilder(uri)
                    .POST(fromPublisher(new BBPublisher(body), cl)).build();

            try {
                HttpResponse<String> response = client.send(request, ofString(UTF_8));
                fail("Unexpected response: " + response);
            } catch (IOException expected) {
                assertMessage(expected, "Too few bytes returned");
            }
        }
    }

    @Test(dataProvider = "uris")
    void testPublishTooMany(String uri) throws InterruptedException {
        String[] body = new String[] { "You know ", "it's summer ", "in Ireland ",
                "when the ", "rain gets ", "warmer." };
        int cl = Arrays.stream(body).mapToInt(String::length).sum() - 1; // length - 1
        try (HttpClient client = newHttpClient(uri)) {
            HttpRequest request = newRequestBuilder(uri)
                    .POST(fromPublisher(new BBPublisher(body), cl)).build();

            try {
                HttpResponse<String> response = client.send(request, ofString(UTF_8));
                fail("Unexpected response: " + response);
            } catch (IOException expected) {
                assertMessage(expected, "Too many bytes in request body");
            }
        }
    }

    private void assertMessage(Throwable t, String contains) {
        Throwable cause = t;
        do {
            if (cause.getMessage().contains(contains)) break;
        } while ((cause = cause.getCause()) != null);
        if (cause == null) {
            String error = "Exception message:[" + t + "] doesn't contain [" + contains + "]";
            throw new AssertionError(error, t);
        }
    }

    static class BBPublisher extends AbstractPublisher
        implements Flow.Publisher<ByteBuffer>
    {
        BBPublisher(String... bodyParts) { super(bodyParts); }

        @Override
        public void subscribe(Flow.Subscriber<? super ByteBuffer> subscriber) {
            this.subscriber = subscriber;
            subscriber.onSubscribe(new InternalSubscription());
        }
    }

    static class MBBPublisher extends AbstractPublisher
        implements Flow.Publisher<MappedByteBuffer>
    {
        MBBPublisher(String... bodyParts) { super(bodyParts); }

        @Override
        public void subscribe(Flow.Subscriber<? super MappedByteBuffer> subscriber) {
            this.subscriber = subscriber;
            subscriber.onSubscribe(new InternalSubscription());
        }
    }

    static abstract class AbstractPublisher {
        private final String[] bodyParts;
        protected volatile Flow.Subscriber subscriber;

        AbstractPublisher(String... bodyParts) {
            this.bodyParts = bodyParts;
        }

        class InternalSubscription implements Flow.Subscription {

            private final AtomicLong demand = new AtomicLong();
            private final AtomicBoolean cancelled = new AtomicBoolean();
            private volatile int position;

            private static final int IDLE    =  1;
            private static final int PUSHING =  2;
            private static final int AGAIN   =  4;
            private final AtomicInteger state = new AtomicInteger(IDLE);

            @Override
            public void request(long n) {
                if (n <= 0L) {
                    subscriber.onError(new IllegalArgumentException(
                            "non-positive subscription request"));
                    return;
                }
                if (cancelled.get()) {
                    return;
                }

                while (true) {
                    long prev = demand.get(), d;
                    if ((d = prev + n) < prev) // saturate
                        d = Long.MAX_VALUE;
                    if (demand.compareAndSet(prev, d))
                        break;
                }

                while (true) {
                    int s = state.get();
                    if (s == IDLE) {
                        if (state.compareAndSet(IDLE, PUSHING)) {
                            while (true) {
                                push();
                                if (state.compareAndSet(PUSHING, IDLE))
                                    return;
                                else if (state.compareAndSet(AGAIN, PUSHING))
                                    continue;
                            }
                        }
                    } else if (s == PUSHING) {
                        if (state.compareAndSet(PUSHING, AGAIN))
                            return;
                    } else if (s == AGAIN){
                        // do nothing, the pusher will already rerun
                        return;
                    } else {
                        throw new AssertionError("Unknown state:" + s);
                    }
                }
            }

            private void push() {
                long prev;
                while ((prev = demand.get()) > 0) {
                    if (!demand.compareAndSet(prev, prev -1))
                        continue;

                    int index = position;
                    if (index < bodyParts.length) {
                        position++;
                        subscriber.onNext(ByteBuffer.wrap(bodyParts[index].getBytes(UTF_8)));
                    }
                }

                if (position == bodyParts.length && !cancelled.get()) {
                    cancelled.set(true);
                    subscriber.onComplete();
                }
            }

            @Override
            public void cancel() {
                if (cancelled.compareAndExchange(false, true))
                    return;  // already cancelled
            }
        }
    }

    @BeforeTest
    public void setup() throws Exception {
        sslContext = new SimpleSSLContext().get();
        if (sslContext == null)
            throw new AssertionError("Unexpected null sslContext");

        httpTestServer = HttpTestServer.create(Version.HTTP_1_1);
        httpTestServer.addHandler(new HttpEchoHandler(), "/http1/echo");
        httpURI = "http://" + httpTestServer.serverAuthority() + "/http1/echo";

        httpsTestServer = HttpTestServer.create(Version.HTTP_1_1, sslContext);
        httpsTestServer.addHandler(new HttpEchoHandler(), "/https1/echo");
        httpsURI = "https://" + httpsTestServer.serverAuthority() + "/https1/echo";

        http2TestServer = HttpTestServer.create(Version.HTTP_2);
        http2TestServer.addHandler(new HttpEchoHandler(), "/http2/echo");
        http2URI = "http://" + http2TestServer.serverAuthority() + "/http2/echo";

        https2TestServer = HttpTestServer.create(Version.HTTP_2, sslContext);
        https2TestServer.addHandler(new HttpEchoHandler(), "/https2/echo");
        https2URI = "https://" + https2TestServer.serverAuthority() + "/https2/echo";

        httpTestServer.start();
        httpsTestServer.start();
        http2TestServer.start();
        https2TestServer.start();
    }

    @AfterTest
    public void teardown() throws Exception {
        httpTestServer.stop();
        httpsTestServer.stop();
        http2TestServer.stop();
        https2TestServer.stop();
    }

    static class HttpEchoHandler implements HttpTestHandler {
        @Override
        public void handle(HttpTestExchange t) throws IOException {
            try (InputStream is = t.getRequestBody();
                 OutputStream os = t.getResponseBody()) {
                byte[] bytes = is.readAllBytes();
                t.sendResponseHeaders(200, bytes.length);
                os.write(bytes);
            }
        }
    }
}