/**
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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.hadoop.ozone.om;

import org.apache.commons.lang3.RandomStringUtils;
import org.apache.hadoop.hdds.scm.storage.BlockInputStream;
import org.apache.hadoop.ozone.client.io.KeyInputStream;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import static java.nio.charset.StandardCharsets.UTF_8;
import static org.junit.Assert.assertEquals;

/**
 * This class tests KeyInputStream and KeyOutputStream.
 */
public class TestChunkStreams {

  @Rule
  public ExpectedException exception = ExpectedException.none();

  @Test
  public void testReadGroupInputStream() throws Exception {
    try (KeyInputStream groupInputStream = new KeyInputStream()) {

      String dataString = RandomStringUtils.randomAscii(500);
      byte[] buf = dataString.getBytes(UTF_8);
      int offset = 0;
      for (int i = 0; i < 5; i++) {
        int tempOffset = offset;
        BlockInputStream in =
            new BlockInputStream(null, 100, null, null, true, null) {
              private long pos = 0;
              private ByteArrayInputStream in =
                  new ByteArrayInputStream(buf, tempOffset, 100);

              @Override
              public synchronized void seek(long pos) throws IOException {
                throw new UnsupportedOperationException();
              }

              @Override
              public synchronized long getPos() {
                return pos;
              }

              @Override
              public boolean seekToNewSource(long targetPos)
                  throws IOException {
                throw new UnsupportedOperationException();
              }

              @Override
              public synchronized int read() throws IOException {
                return in.read();
              }

              @Override
              public synchronized  int read(byte[] b, int off, int len)
                  throws IOException {
                int readLen = in.read(b, off, len);
                pos += readLen;
                return readLen;
              }
            };
        offset += 100;
        groupInputStream.addStream(in);
      }

      byte[] resBuf = new byte[500];
      int len = groupInputStream.read(resBuf, 0, 500);

      assertEquals(500, len);
      assertEquals(dataString, new String(resBuf, UTF_8));
    }
  }

  @Test
  public void testErrorReadGroupInputStream() throws Exception {
    try (KeyInputStream groupInputStream = new KeyInputStream()) {

      String dataString = RandomStringUtils.randomAscii(500);
      byte[] buf = dataString.getBytes(UTF_8);
      int offset = 0;
      for (int i = 0; i < 5; i++) {
        int tempOffset = offset;
        BlockInputStream in =
            new BlockInputStream(null, 100, null, null, true, null) {
              private long pos = 0;
              private ByteArrayInputStream in =
                  new ByteArrayInputStream(buf, tempOffset, 100);

              @Override
              public synchronized void seek(long pos) throws IOException {
                throw new UnsupportedOperationException();
              }

              @Override
              public synchronized long getPos() {
                return pos;
              }

              @Override
              public synchronized boolean seekToNewSource(long targetPos)
                  throws IOException {
                throw new UnsupportedOperationException();
              }

              @Override
              public synchronized int read() throws IOException {
                return in.read();
              }

              @Override
              public synchronized int read(byte[] b, int off, int len)
                  throws IOException {
                int readLen = in.read(b, off, len);
                pos += readLen;
                return readLen;
              }
            };
        offset += 100;
        groupInputStream.addStream(in);
      }

      byte[] resBuf = new byte[600];
      // read 300 bytes first
      int len = groupInputStream.read(resBuf, 0, 340);
      assertEquals(3, groupInputStream.getCurrentStreamIndex());
      assertEquals(60, groupInputStream.getRemainingOfIndex(3));
      assertEquals(340, len);
      assertEquals(dataString.substring(0, 340),
          new String(resBuf, UTF_8).substring(0, 340));

      // read following 300 bytes, but only 200 left
      len = groupInputStream.read(resBuf, 340, 260);
      assertEquals(4, groupInputStream.getCurrentStreamIndex());
      assertEquals(0, groupInputStream.getRemainingOfIndex(4));
      assertEquals(160, len);
      assertEquals(dataString, new String(resBuf, UTF_8).substring(0, 500));

      // further read should get EOF
      len = groupInputStream.read(resBuf, 0, 1);
      // reached EOF, further read should get -1
      assertEquals(-1, len);
    }
  }
}