/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.flink.runtime.io.network.partition;

import org.apache.flink.configuration.Configuration;
import org.apache.flink.configuration.MemorySize;
import org.apache.flink.configuration.NettyShuffleEnvironmentOptions;
import org.apache.flink.configuration.SecurityOptions;
import org.apache.flink.configuration.TaskManagerOptions;
import org.apache.flink.runtime.execution.Environment;
import org.apache.flink.runtime.io.network.api.reader.RecordReader;
import org.apache.flink.runtime.io.network.api.writer.RecordWriter;
import org.apache.flink.runtime.io.network.api.writer.RecordWriterBuilder;
import org.apache.flink.runtime.jobgraph.DistributionPattern;
import org.apache.flink.runtime.jobgraph.JobGraph;
import org.apache.flink.runtime.jobgraph.JobGraphTestUtils;
import org.apache.flink.runtime.jobgraph.JobVertex;
import org.apache.flink.runtime.jobgraph.tasks.AbstractInvokable;
import org.apache.flink.runtime.jobmanager.scheduler.SlotSharingGroup;
import org.apache.flink.runtime.minicluster.MiniCluster;
import org.apache.flink.runtime.minicluster.MiniClusterConfiguration;
import org.apache.flink.runtime.net.SSLUtilsTest;
import org.apache.flink.testutils.serialization.types.ByteArrayType;
import org.apache.flink.util.TestLogger;

import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelPromise;

import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

import java.util.Arrays;
import java.util.List;

import static org.hamcrest.Matchers.is;
import static org.junit.Assert.assertThat;

/**
 * Tests the bug reported in FLINK-131O0.
 *
 * <p>The implementation of {@link
 * org.apache.flink.runtime.io.network.partition.BoundedData.Reader#nextBuffer()} for {@link
 * BoundedBlockingSubpartitionType#FILE} assumes that there is always an available buffer, otherwise
 * an IOException is thrown and it always assumes that pool of two buffers is enough (before using
 * the 3rd buffer, first one was expected to be recycled already). But in the case of pending flush
 * operation (when the socket channel is not writable while netty thread is calling {@link
 * ChannelHandlerContext#writeAndFlush(Object, ChannelPromise)}), the first fetched buffer from
 * {@link org.apache.flink.runtime.io.network.partition.FileChannelBoundedData} has not been
 * recycled while fetching the second buffer to trigger next read ahead, which breaks the above
 * assumption.
 */
@RunWith(Parameterized.class)
public class FileBufferReaderITCase extends TestLogger {

    private static final int parallelism = 8;

    private static final int numRecords = 100_000;

    private static final int bufferSize = 4096;

    private static final int headerSize = 8;

    private static final int recordSize = bufferSize - headerSize;

    private static final byte[] dataSource = new byte[recordSize];

    @Parameterized.Parameters(name = "SSL Enabled = {0}")
    public static List<Boolean> paras() {
        return Arrays.asList(true, false);
    }

    @Parameterized.Parameter public boolean sslEnabled;

    @BeforeClass
    public static void setup() {
        for (int i = 0; i < dataSource.length; i++) {
            dataSource[i] = 0;
        }
    }

    @Test
    public void testSequentialReading() throws Exception {
        // setup
        final Configuration configuration;
        if (sslEnabled) {
            configuration = SSLUtilsTest.createInternalSslConfigWithKeyAndTrustStores("JDK");
        } else {
            configuration = new Configuration();
        }

        // Increases the handshake timeout to avoid connection reset/close issues
        // if the netty server thread could not response in time, like when it is
        // busy reading the files.
        configuration.setInteger(SecurityOptions.SSL_INTERNAL_HANDSHAKE_TIMEOUT, 100000);
        configuration.setString(
                NettyShuffleEnvironmentOptions.NETWORK_BLOCKING_SHUFFLE_TYPE, "file");
        configuration.set(TaskManagerOptions.TOTAL_FLINK_MEMORY, MemorySize.parse("1g"));
        configuration.set(
                TaskManagerOptions.MEMORY_SEGMENT_SIZE, MemorySize.parse(bufferSize + "b"));

        final MiniClusterConfiguration miniClusterConfiguration =
                new MiniClusterConfiguration.Builder()
                        .withRandomPorts()
                        .setConfiguration(configuration)
                        .setNumTaskManagers(parallelism)
                        .setNumSlotsPerTaskManager(1)
                        .build();

        try (final MiniCluster miniCluster = new MiniCluster(miniClusterConfiguration)) {
            miniCluster.start();

            final JobGraph jobGraph = createJobGraph();

            // the job needs to complete without throwing an exception
            miniCluster.executeJobBlocking(jobGraph);
        }
    }

    private static JobGraph createJobGraph() {
        final SlotSharingGroup group1 = new SlotSharingGroup();
        final SlotSharingGroup group2 = new SlotSharingGroup();

        final JobVertex source = new JobVertex("source");
        source.setInvokableClass(TestSourceInvokable.class);
        source.setParallelism(parallelism);
        source.setSlotSharingGroup(group1);

        final JobVertex sink = new JobVertex("sink");
        sink.setInvokableClass(TestSinkInvokable.class);
        sink.setParallelism(parallelism);
        sink.setSlotSharingGroup(group2);

        sink.connectNewDataSetAsInput(
                source, DistributionPattern.ALL_TO_ALL, ResultPartitionType.BLOCKING);

        return JobGraphTestUtils.batchJobGraph(source, sink);
    }

    /**
     * Basic source {@link AbstractInvokable} which sends the elements to the {@link
     * TestSinkInvokable}.
     */
    public static final class TestSourceInvokable extends AbstractInvokable {

        /**
         * Create an Invokable task and set its environment.
         *
         * @param environment The environment assigned to this invokable.
         */
        public TestSourceInvokable(Environment environment) {
            super(environment);
        }

        @Override
        public void invoke() throws Exception {
            final RecordWriter<ByteArrayType> writer =
                    new RecordWriterBuilder<ByteArrayType>().build(getEnvironment().getWriter(0));

            final ByteArrayType bytes = new ByteArrayType(dataSource);
            int counter = 0;
            while (counter++ < numRecords) {
                writer.emit(bytes);
                writer.flushAll();
            }
        }
    }

    /**
     * Basic sink {@link AbstractInvokable} which verifies the sent elements from the {@link
     * TestSourceInvokable}.
     */
    public static final class TestSinkInvokable extends AbstractInvokable {

        private int numReceived = 0;

        /**
         * Create an Invokable task and set its environment.
         *
         * @param environment The environment assigned to this invokable.
         */
        public TestSinkInvokable(Environment environment) {
            super(environment);
        }

        @Override
        public void invoke() throws Exception {
            final RecordReader<ByteArrayType> reader =
                    new RecordReader<>(
                            getEnvironment().getInputGate(0),
                            ByteArrayType.class,
                            getEnvironment().getTaskManagerInfo().getTmpDirectories());

            while (reader.hasNext()) {
                reader.next();
                numReceived++;
            }

            assertThat(numReceived, is(numRecords));
        }
    }
}
