/**
 * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
 *
 * Licensed 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 com.linkedin.pinot.core.segment.store;

import com.linkedin.pinot.common.segment.ReadMode;
import com.linkedin.pinot.core.indexsegment.generator.SegmentVersion;
import com.linkedin.pinot.core.segment.index.SegmentMetadataImpl;
import com.linkedin.pinot.core.segment.memory.PinotDataBuffer;
import java.io.File;
import java.io.IOException;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.io.FileUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.testng.Assert;
import org.testng.annotations.AfterClass;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;


public class FilePerIndexDirectoryTest {
  private static final Logger LOGGER = LoggerFactory.getLogger(SingleFileIndexDirectoryTest.class);
  private static final File TEST_DIRECTORY = new File(FilePerIndexDirectoryTest.class.toString());

  private File segmentDir;
  private SegmentMetadataImpl segmentMetadata;

  static final long ONE_KB = 1024L;
  static final long ONE_MB = ONE_KB * ONE_KB;
  static final long ONE_GB = ONE_MB * ONE_KB;

  @BeforeMethod
  public void setUpTest()
      throws IOException, ConfigurationException {
    segmentDir = new File(TEST_DIRECTORY, "segmentDirectory");

    if (segmentDir.exists()) {
      FileUtils.deleteQuietly(segmentDir);
    }
    if (segmentDir.exists()) {
      throw new RuntimeException("directory exists");
    }
    segmentDir.mkdirs();
    segmentMetadata = ColumnIndexDirectoryTestHelper.writeMetadata(SegmentVersion.v1);

  }

  @AfterMethod
  public void tearDownTest()
      throws IOException {
    FileUtils.deleteQuietly(segmentDir);
    Assert.assertFalse(segmentDir.exists());
  }

  @AfterClass
  public void tearDownClass() {
    FileUtils.deleteQuietly(TEST_DIRECTORY);
  }

  @Test
  public void testEmptyDirectory()
      throws Exception {
    Assert.assertEquals(0, segmentDir.list().length, segmentDir.list().toString());
    try (FilePerIndexDirectory fpiDir = new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.heap);
        PinotDataBuffer buffer = fpiDir.newDictionaryBuffer("col1", 1024) ) {
      Assert.assertEquals(1, segmentDir.list().length, segmentDir.list().toString());

      buffer.putLong(0, 0xbadfadL);
      buffer.putInt(8, 51);
      // something at random location
      buffer.putInt(101, 55);
    }

    Assert.assertEquals(1, segmentDir.list().length);

    try (FilePerIndexDirectory colDir = new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap);
        PinotDataBuffer readBuffer = colDir.getDictionaryBufferFor("col1")) {
      Assert.assertEquals(readBuffer.getLong(0), 0xbadfadL);
      Assert.assertEquals(readBuffer.getInt(8), 51);
      Assert.assertEquals(readBuffer.getInt(101), 55);
    }
  }

  @Test
  public void testMmapLargeBuffer()
      throws Exception {
    testMultipleRW(ReadMode.mmap, 6, 3L * ONE_MB);
  }

  @Test
  public void testLargeRWDirectBuffer()
      throws Exception {
    testMultipleRW(ReadMode.heap, 6, 3L * ONE_MB);
  }

  @Test
  public void testReadModeChange()
      throws Exception {
    // first verify it all works for one mode
    testMultipleRW(ReadMode.heap, 6, 100 * ONE_MB);
    try(ColumnIndexDirectory columnDirectory = new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap)) {
      ColumnIndexDirectoryTestHelper.verifyMultipleReads(columnDirectory, "foo", 6);
    }
  }

  private void testMultipleRW(ReadMode readMode, int numIter, long size)
      throws Exception {
    try (FilePerIndexDirectory columnDirectory = new FilePerIndexDirectory(segmentDir, segmentMetadata, readMode)) {
      ColumnIndexDirectoryTestHelper.performMultipleWrites(columnDirectory, "foo", size, numIter);
    }
    // now read and validate data
    try(FilePerIndexDirectory columnDirectory = new FilePerIndexDirectory(segmentDir, segmentMetadata, readMode) ){
      ColumnIndexDirectoryTestHelper.verifyMultipleReads(columnDirectory, "foo", numIter);
    }
  }

  @Test(expectedExceptions = RuntimeException.class)
  public void testWriteExisting()
      throws Exception {
    try (FilePerIndexDirectory columnDirectory = new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap);
        PinotDataBuffer buffer = columnDirectory.newDictionaryBuffer("column1", 1024)) {
    }
    try (FilePerIndexDirectory columnDirectory =
          new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap);
        PinotDataBuffer repeatBuffer = columnDirectory.newDictionaryBuffer("column1", 1024)) {
    }
  }

  @Test (expectedExceptions = IllegalArgumentException.class)
  public void testMissingIndex()
      throws IOException {
    try (FilePerIndexDirectory fpiDirectory =
        new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap);
        PinotDataBuffer buffer = fpiDirectory.getDictionaryBufferFor("noSuchColumn")) {

    }
  }

  @Test
  public void testHasIndex()
      throws IOException {
    try (FilePerIndexDirectory fpiDirectory =
        new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap)) {
      PinotDataBuffer buffer = fpiDirectory.newDictionaryBuffer("foo", 1024);
      buffer.putInt(0, 100);
      Assert.assertTrue(fpiDirectory.hasIndexFor("foo", ColumnIndexType.DICTIONARY));
    }
  }

  @Test
  public void testRemoveIndex()
      throws IOException {
    try (FilePerIndexDirectory fpi = new FilePerIndexDirectory(segmentDir, segmentMetadata, ReadMode.mmap)) {
      try (PinotDataBuffer buffer = fpi.newForwardIndexBuffer("col1", 1024)) {}
      try (PinotDataBuffer buffer = fpi.newDictionaryBuffer("col2", 100)) {}
      Assert.assertTrue(fpi.getFileFor("col1", ColumnIndexType.FORWARD_INDEX).exists());
      Assert.assertTrue(fpi.getFileFor("col2", ColumnIndexType.DICTIONARY).exists());
      Assert.assertTrue(fpi.isIndexRemovalSupported());
      fpi.removeIndex("col1", ColumnIndexType.FORWARD_INDEX);
      Assert.assertFalse(fpi.getFileFor("col1", ColumnIndexType.FORWARD_INDEX).exists());
    }
  }


}