package org.apache.lucene.store;

/**
 * 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.
 */


import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util._TestUtil;

import org.junit.Test;

public class TestCopyBytes extends LuceneTestCase {

  private byte value(int idx) {
    return (byte) ((idx%256) * (1+(idx/256)));
  }


  @Test
  public void testCopyBytes() throws Exception {
    int num = atLeast(10);
    for(int iter=0;iter<num;iter++) {
      Directory dir = newDirectory();
      if (VERBOSE) {
        System.out.println("TEST: iter=" + iter + " dir=" + dir);
      }

      // make random file
      IndexOutput out = dir.createOutput("test");
      byte[] bytes = new byte[_TestUtil.nextInt(random, 1, 77777)];
      final int size = _TestUtil.nextInt(random, 1, 1777777);
      int upto = 0;
      int byteUpto = 0;
      while(upto < size) {
        bytes[byteUpto++] = value(upto);
        upto++;
        if (byteUpto == bytes.length) {
          out.writeBytes(bytes, 0, bytes.length);
          byteUpto = 0;
        }
      }

      out.writeBytes(bytes, 0, byteUpto);
      assertEquals(size, out.getFilePointer());
      out.close();
      assertEquals(size, dir.fileLength("test"));

      // copy from test -> test2
      final IndexInput in = dir.openInput("test");

      out = dir.createOutput("test2");

      upto = 0;
      while(upto < size) {
        if (random.nextBoolean()) {
          out.writeByte(in.readByte());
          upto++;
        } else {
          final int chunk = Math.min(_TestUtil.nextInt(random, 1, bytes.length), size-upto);
          out.copyBytes(in, chunk);
          upto += chunk;
        }
      }
      assertEquals(size, upto);
      out.close();
      in.close();

      // verify
      IndexInput in2 = dir.openInput("test2");
      upto = 0;
      while(upto < size) {
        if (random.nextBoolean()) {
          final byte v = in2.readByte();
          assertEquals(value(upto), v);
          upto++;
        } else {
          final int limit = Math.min(_TestUtil.nextInt(random, 1, bytes.length), size-upto);
          in2.readBytes(bytes, 0, limit);
          for(int byteIdx=0;byteIdx<limit;byteIdx++) {
            assertEquals(value(upto), bytes[byteIdx]);
            upto++;
          }
        }
      }
      in2.close();

      dir.deleteFile("test");
      dir.deleteFile("test2");
      
      dir.close();
    }
  }
}