/*
    * 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.commons.io;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotNull;
  
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.charset.StandardCharsets;
  import java.util.HashMap;
  import java.util.Random;
  
  import org.apache.commons.io.input.CharSequenceInputStream;
  import org.apache.commons.io.input.DemuxInputStream;
  import org.apache.commons.io.output.ByteArrayOutputStream;
  import org.apache.commons.io.output.DemuxOutputStream;
  import org.apache.commons.io.test.TestUtils;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link DemuxInputStream}.
   */
  public class DemuxInputStreamTest {
  
      private static final class ReaderThread extends Thread {
          private final DemuxInputStream demuxInputStream;
          private final InputStream inputStream;
          private final StringBuffer stringBuffer = new StringBuffer();
  
          ReaderThread(final String name, final InputStream input, final DemuxInputStream demux) {
              super(name);
              inputStream = input;
              demuxInputStream = demux;
          }
  
          public String getData() {
              return stringBuffer.toString();
          }
  
          @Override
          public void run() {
              demuxInputStream.bindStream(inputStream);
  
              try {
                  int ch = demuxInputStream.read();
                  while (-1 != ch) {
                      // System.out.println( "Reading: " + (char)ch );
                      stringBuffer.append((char) ch);
  
                      final int sleepMillis = Math.abs(RANDOM.nextInt() % 10);
                      TestUtils.sleep(sleepMillis);
                      ch = demuxInputStream.read();
                  }
              } catch (final Exception e) {
                  e.printStackTrace();
              }
          }
      }
  
      private static final class WriterThread extends Thread {
          private final byte[] byteArray;
          private final DemuxOutputStream demuxOutputStream;
          private final OutputStream outputStream;
  
          WriterThread(final String name, final String data, final OutputStream output, final DemuxOutputStream demux) {
              super(name);
              outputStream = output;
              demuxOutputStream = demux;
              byteArray = data.getBytes();
          }
  
          @Override
          public void run() {
              demuxOutputStream.bindStream(outputStream);
              for (final byte element : byteArray) {
                  try {
                      // System.out.println( "Writing: " + (char)byteArray[ i ] );
                      demuxOutputStream.write(element);
                      final int sleepMillis = Math.abs(RANDOM.nextInt() % 10);
                      TestUtils.sleep(sleepMillis);
                  } catch (final Exception e) {
                      e.printStackTrace();
                  }
              }
         }
     }
 
     private static final Random RANDOM = new Random();
     private static final String DATA1 = "Data for thread1";
 
     private static final String DATA2 = "Data for thread2";
     private static final String DATA3 = "Data for thread3";
     private static final String DATA4 = "Data for thread4";
     private static final String T1 = "Thread1";
 
     private static final String T2 = "Thread2";
     private static final String T3 = "Thread3";
     private static final String T4 = "Thread4";
 
     private final HashMap<String, ByteArrayOutputStream> outputMap = new HashMap<>();
 
     private final HashMap<String, Thread> threadMap = new HashMap<>();
 
     private void doJoin() throws InterruptedException {
         for (final String name : threadMap.keySet()) {
             final Thread thread = threadMap.get(name);
             thread.join();
         }
     }
 
     private void doStart() {
         threadMap.keySet().forEach(name -> threadMap.get(name).start());
     }
 
     private String getInput(final String threadName) {
         final ReaderThread thread = (ReaderThread) threadMap.get(threadName);
         assertNotNull(thread, "getInput()");
         return thread.getData();
     }
 
     private String getOutput(final String threadName) {
         final ByteArrayOutputStream output = outputMap.get(threadName);
         assertNotNull(output, "getOutput()");
         return output.toString(StandardCharsets.UTF_8);
     }
 
     private void startReader(final String name, final String data, final DemuxInputStream demux) {
         final InputStream input = CharSequenceInputStream.builder().setCharSequence(data).get();
         final ReaderThread thread = new ReaderThread(name, input, demux);
         threadMap.put(name, thread);
     }
 
     private void startWriter(final String name, final String data, final DemuxOutputStream demux) {
         final ByteArrayOutputStream output = new ByteArrayOutputStream();
         outputMap.put(name, output);
         final WriterThread thread = new WriterThread(name, data, output, demux);
         threadMap.put(name, thread);
     }
 
     @Test
     public void testInputStream() throws Exception {
         try (final DemuxInputStream input = new DemuxInputStream()) {
             startReader(T1, DATA1, input);
             startReader(T2, DATA2, input);
             startReader(T3, DATA3, input);
             startReader(T4, DATA4, input);
 
             doStart();
             doJoin();
 
             assertEquals(DATA1, getInput(T1), "Data1");
             assertEquals(DATA2, getInput(T2), "Data2");
             assertEquals(DATA3, getInput(T3), "Data3");
             assertEquals(DATA4, getInput(T4), "Data4");
         }
     }
 
     @Test
     public void testOutputStream() throws Exception {
         try (final DemuxOutputStream output = new DemuxOutputStream()) {
             startWriter(T1, DATA1, output);
             startWriter(T2, DATA2, output);
             startWriter(T3, DATA3, output);
             startWriter(T4, DATA4, output);
 
             doStart();
             doJoin();
 
             assertEquals(DATA1, getOutput(T1), "Data1");
             assertEquals(DATA2, getOutput(T2), "Data2");
             assertEquals(DATA3, getOutput(T3), "Data3");
             assertEquals(DATA4, getOutput(T4), "Data4");
         }
     }
 
     @Test
     public void testReadEOF() throws Exception {
         try (final DemuxInputStream input = new DemuxInputStream()) {
             assertEquals(IOUtils.EOF, input.read());
         }
     }
 }