/*

 * Copyright (c) 2018, 2019, 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.

 */

import java.io.BufferedReader;

import java.io.ByteArrayInputStream;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.StringReader;

import java.io.UncheckedIOException;

import java.net.http.HttpResponse.BodySubscriber;

import java.net.http.HttpResponse.BodySubscribers;

import java.nio.ByteBuffer;

import java.nio.charset.MalformedInputException;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import java.util.concurrent.CopyOnWriteArrayList;

import java.util.concurrent.ExecutionException;

import java.util.concurrent.Flow;

import java.util.concurrent.SubmissionPublisher;

import java.util.function.Supplier;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import org.testng.annotations.Test;

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

import static java.nio.charset.StandardCharsets.UTF_16;

import static org.testng.Assert.assertEquals;

/*

 * @test

 * @summary tests for BodySubscribers returned by fromLineSubscriber.

 *       In particular tests that surrogate characters are handled

 *       correctly.

 * @modules java.net.http java.logging

 * @run testng/othervm LineSubscribersAndSurrogatesTest

 */

public class LineSubscribersAndSurrogatesTest {

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

    private static final List<String> lines(String text, String eol) {

        if (eol == null) {

            return new BufferedReader(new StringReader(text)).lines().collect(Collectors.toList());

        } else {

            String replaced = text.replace(eol, "|");

            int i=0;

            while(replaced.endsWith("||")) {

                replaced = replaced.substring(0,replaced.length()-1);

                i++;

            }

            List<String> res = List.of(replaced.split("\\|"));

            if (i > 0) {

                res = new ArrayList<>(res);

                for (int j=0; j<i; j++) res.add("");

            }

            return res;

        }

    }

    @Test

    public void testIncomplete() throws Exception {

        // Uses U+10400 which is encoded as the surrogate pair U+D801 U+DC00

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les\n\n fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres\ud801\udc00";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<String> bodySubscriber = BodySubscribers.fromLineSubscriber(

                subscriber, Supplier::get, UTF_8, null);

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] sbytes = text.getBytes(UTF_8);

        byte[] bytes = Arrays.copyOfRange(sbytes,0, sbytes.length - 1);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i=0; i<bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        try {

            String resp = bodySubscriber.getBody().toCompletableFuture().get();

            System.out.println("***** Got: " + resp);

            ByteArrayInputStream bais = new ByteArrayInputStream(bytes);

            BufferedReader reader = new BufferedReader(new InputStreamReader(bais, UTF_8));

            String resp2 = reader.lines().collect(Collectors.joining(""));

            assertEquals(resp, resp2);

            assertEquals(subscriber.list, List.of("Bient\u00f4t",

                    " nous plongerons",

                    " dans",

                    " les",

                    "",

                    " fr\u00f4\ud801\udc00des",

                    " t\u00e9n\u00e8bres\ufffd"));

        } catch (ExecutionException x) {

            Throwable cause = x.getCause();

            if (cause instanceof MalformedInputException) {

                throw new RuntimeException("Unexpected MalformedInputException thrown", cause);

            }

            throw x;

        }

    }

    @Test

    public void testStringWithFinisherLF() throws Exception {

        // Uses U+10400 which is encoded as the surrogate pair U+D801 U+DC00

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les\n\n fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres\r";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<String> bodySubscriber = BodySubscribers.fromLineSubscriber(

                subscriber, Supplier::get, UTF_8, "\n");

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] bytes = text.getBytes(UTF_8);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i=0; i<bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        String resp = bodySubscriber.getBody().toCompletableFuture().get();

        System.out.println("***** Got: " + resp);

        List<String> expected = List.of("Bient\u00f4t\r",

                " nous plongerons\r",

                " dans\r les",

                "",

                " fr\u00f4\ud801\udc00des\r",

                " t\u00e9n\u00e8bres\r");

        assertEquals(subscriber.list, expected);

        assertEquals(resp, Stream.of(text.split("\n")).collect(Collectors.joining("")));

        assertEquals(resp, expected.stream().collect(Collectors.joining("")));

        assertEquals(subscriber.list, lines(text, "\n"));

    }

    @Test

    public void testStringWithFinisherCR() throws Exception {

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres\r\r";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<String> bodySubscriber = BodySubscribers.fromLineSubscriber(

                subscriber, Supplier::get, UTF_8, "\r");

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] bytes = text.getBytes(UTF_8);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i=0; i<bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        String resp = bodySubscriber.getBody().toCompletableFuture().get();

        System.out.println("***** Got: " + resp);

        assertEquals(resp, text.replace("\r", ""));

        assertEquals(subscriber.list, List.of("Bient\u00f4t",

                "\n nous plongerons",

                "\n dans",

                " les fr\u00f4\ud801\udc00des",

                "\n t\u00e9n\u00e8bres",

                ""));

        assertEquals(subscriber.list, lines(text, "\r"));

    }

    @Test

    public void testStringWithFinisherCRLF() throws Exception {

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<String> bodySubscriber = BodySubscribers.fromLineSubscriber(

                subscriber, Supplier::get, UTF_8, "\r\n");

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] bytes = text.getBytes(UTF_8);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i=0; i<bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        String resp = bodySubscriber.getBody().toCompletableFuture().get();

        System.out.println("***** Got: " + resp);

        assertEquals(resp, text.replace("\r\n",""));

        assertEquals(subscriber.list, List.of("Bient\u00f4t",

                " nous plongerons",

                " dans\r les fr\u00f4\ud801\udc00des",

                " t\u00e9n\u00e8bres"));

        assertEquals(subscriber.list, lines(text, "\r\n"));

    }

    @Test

    public void testStringWithFinisherBR() throws Exception {

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les\r\r fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<String> bodySubscriber = BodySubscribers.fromLineSubscriber(

                subscriber, Supplier::get, UTF_8, null);

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] bytes = text.getBytes(UTF_8);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i=0; i<bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        String resp = bodySubscriber.getBody().toCompletableFuture().get();

        System.out.println("***** Got: " + resp);

        List<String> expected = List.of("Bient\u00f4t",

                " nous plongerons",

                " dans",

                " les",

                "",

                " fr\u00f4\ud801\udc00des",

                " t\u00e9n\u00e8bres");

        assertEquals(subscriber.list, expected);

        assertEquals(resp, expected.stream().collect(Collectors.joining("")));

        assertEquals(subscriber.list, lines(text, null));

    }

    @Test

    public void testStringWithFinisherBR_UTF_16() throws Exception {

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les\r\r fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres\r\r";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<String> bodySubscriber = BodySubscribers.fromLineSubscriber(

                subscriber, Supplier::get, UTF_16, null);

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] bytes = text.getBytes(UTF_16);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i=0; i<bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        String resp = bodySubscriber.getBody().toCompletableFuture().get();

        System.out.println("***** Got: " + resp);

        List<String> expected = List.of("Bient\u00f4t",

                " nous plongerons",

                " dans",

                " les",

                "",

                " fr\u00f4\ud801\udc00des",

                " t\u00e9n\u00e8bres",

                "");

        assertEquals(resp, expected.stream().collect(Collectors.joining("")));

        assertEquals(subscriber.list, expected);

        assertEquals(subscriber.list, lines(text, null));

    }

    void testStringWithoutFinisherBR() throws Exception {

        String text = "Bient\u00f4t\r\n nous plongerons\r\n dans\r" +

                " les\r\r fr\u00f4\ud801\udc00des\r\n t\u00e9n\u00e8bres";

        ObjectSubscriber subscriber = new ObjectSubscriber();

        BodySubscriber<Void> bodySubscriber = BodySubscribers.fromLineSubscriber(subscriber);

        SubmissionPublisher<List<ByteBuffer>> publisher = new SubmissionPublisher<>();

        byte[] bytes = text.getBytes(UTF_8);

        publisher.subscribe(bodySubscriber);

        System.out.println("Publishing " + bytes.length + " bytes");

        for (int i = 0; i < bytes.length; i++) {

            // ensure that surrogates are split over several buffers.

            publisher.submit(List.of(ByteBuffer.wrap(bytes, i, 1)));

        }

        publisher.close();

        Void resp = bodySubscriber.getBody().toCompletableFuture().get();

        System.out.println("***** Got: " + resp);

        List<String> expected = List.of("Bient\u00f4t",

                " nous plongerons",

                " dans",

                " les",

                "",

                " fr\u00f4\ud801\udc00des",

                " t\u00e9n\u00e8bres");

        assertEquals(subscriber.text, expected.stream().collect(Collectors.joining("")));

        assertEquals(subscriber.list, expected);

        assertEquals(subscriber.list, lines(text, null));

    }

    /** An abstract Subscriber that converts all received data into a String. */

    static abstract class AbstractSubscriber implements Supplier<String> {

        protected final List<Object> list = new CopyOnWriteArrayList<>();

        protected volatile Flow.Subscription subscription;

        protected final StringBuilder baos = new StringBuilder();

        protected volatile String text;

        protected volatile RuntimeException error;

        public void onSubscribe(Flow.Subscription subscription) {

            this.subscription = subscription;

            subscription.request(Long.MAX_VALUE);

        }

        public void onError(Throwable throwable) {

            System.out.println(this + " onError: " + throwable);

            error = new RuntimeException(throwable);

        }

        public void onComplete() {

            System.out.println(this + " onComplete");

            text = baos.toString();

        }

        @Override public String get() {

            if (error != null) throw error;

            return text;

        }

        public final List<?> list() {

            return list;

        }

    }

    static class StringSubscriber extends AbstractSubscriber

            implements Flow.Subscriber<String>, Supplier<String>

    {

        @Override public void onNext(String item) {

            System.out.println(this + " onNext: \""

                    + item.replace("\n","\\n")

                          .replace("\r", "\\r")

                    + "\"");

            baos.append(item);

            list.add(item);

        }

    }

    static class CharSequenceSubscriber extends AbstractSubscriber

            implements Flow.Subscriber<CharSequence>, Supplier<String>

    {

        @Override public void onNext(CharSequence item) {

            System.out.println(this + " onNext: \""

                    + item.toString().replace("\n","\\n")

                    .replace("\r", "\\r")

                    + "\"");

            baos.append(item);

            list.add(item);

        }

    }

    static class ObjectSubscriber extends AbstractSubscriber

            implements Flow.Subscriber<Object>, Supplier<String>

    {

        @Override public void onNext(Object item) {

            System.out.println(this + " onNext: \""

                    + item.toString().replace("\n","\\n")

                    .replace("\r", "\\r")

                    + "\"");

            baos.append(item);

            list.add(item);

        }

    }

    static void uncheckedWrite(ByteArrayOutputStream baos, byte[] ba) {

        try {

            baos.write(ba);

        } catch (IOException e) {

            throw new UncheckedIOException(e);

        }

    }

}