/**
 * 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.hadoop.io;

import static org.mockito.Mockito.*;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocalFileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.io.SequenceFile.CompressionType;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.CompressionInputStream;
import org.apache.hadoop.io.compress.CompressionOutputStream;
import org.apache.hadoop.io.compress.Compressor;
import org.apache.hadoop.io.compress.Decompressor;
import org.apache.hadoop.test.GenericTestUtils;
import org.apache.hadoop.util.Progressable;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import org.junit.Before;
import org.junit.Test;

public class TestBloomMapFile {
  private static Configuration conf = new Configuration();
  private static final Path TEST_ROOT = new Path(GenericTestUtils.getTempPath(
      TestMapFile.class.getSimpleName()));
  private static final Path TEST_DIR = new Path(TEST_ROOT, "testfile");
  private static final Path TEST_FILE = new Path(TEST_ROOT, "testfile");

  @Before
  public void setUp() throws Exception {
    LocalFileSystem fs = FileSystem.getLocal(conf);
    if (fs.exists(TEST_ROOT) && !fs.delete(TEST_ROOT, true)) {
      fail("Can't clean up test root dir");
    }
    fs.mkdirs(TEST_ROOT);
  }
  
  @SuppressWarnings("deprecation")
  @Test
  public void testMembershipTest() throws Exception {
    // write the file
    FileSystem fs = FileSystem.getLocal(conf);
    Path qualifiedDirName = fs.makeQualified(TEST_DIR);
    conf.setInt("io.mapfile.bloom.size", 2048);
    BloomMapFile.Writer writer = null;
    BloomMapFile.Reader reader = null;
    try {
      writer = new BloomMapFile.Writer(conf, fs, qualifiedDirName.toString(),
        IntWritable.class, Text.class);
      IntWritable key = new IntWritable();
      Text value = new Text();
      for (int i = 0; i < 2000; i += 2) {
        key.set(i);
        value.set("00" + i);
        writer.append(key, value);
      }
      writer.close();

      reader = new BloomMapFile.Reader(fs, qualifiedDirName.toString(), conf);
      // check false positives rate
      int falsePos = 0;
      int falseNeg = 0;
      for (int i = 0; i < 2000; i++) {
        key.set(i);
        boolean exists = reader.probablyHasKey(key);
        if (i % 2 == 0) {
          if (!exists)
            falseNeg++;
        } else {
          if (exists)
            falsePos++;
        }
      }
      reader.close();
      fs.delete(qualifiedDirName, true);
      System.out.println("False negatives: " + falseNeg);
      assertEquals(0, falseNeg);
      System.out.println("False positives: " + falsePos);
      assertTrue(falsePos < 2);
    } finally {
      IOUtils.cleanup(null, writer, reader);
    }
  }

  @SuppressWarnings("deprecation")
  private void checkMembershipVaryingSizedKeys(List<Text> keys)
      throws Exception {
    FileSystem fs = FileSystem.getLocal(conf);
    Path qualifiedDirName = fs.makeQualified(TEST_DIR);
    BloomMapFile.Writer writer = null;
    BloomMapFile.Reader reader = null;
    try {
      writer = new BloomMapFile.Writer(conf, fs, qualifiedDirName.toString(),
        Text.class, NullWritable.class);
      for (Text key : keys) {
        writer.append(key, NullWritable.get());
      }
      writer.close();

      // will check for membership in opposite order of how keys were inserted
      reader = new BloomMapFile.Reader(fs, qualifiedDirName.toString(), conf);
      Collections.reverse(keys);
      for (Text key : keys) {
        assertTrue("False negative for existing key " + key,
          reader.probablyHasKey(key));
      }
      reader.close();
      fs.delete(qualifiedDirName, true);
    } finally {
      IOUtils.cleanup(null, writer, reader);
    }
  }

  @Test
  public void testMembershipVaryingSizedKeysTest1() throws Exception {
    ArrayList<Text> list = new ArrayList<Text>();
    list.add(new Text("A"));
    list.add(new Text("BB"));
    checkMembershipVaryingSizedKeys(list);
  }

  @Test
  public void testMembershipVaryingSizedKeysTest2() throws Exception {
    ArrayList<Text> list = new ArrayList<Text>();
    list.add(new Text("AA"));
    list.add(new Text("B"));
    checkMembershipVaryingSizedKeys(list);
  }

  /**
   * test {@code BloomMapFile.delete()} method
   */
  @Test
  public void testDeleteFile() {
    BloomMapFile.Writer writer = null;
    try {
      FileSystem fs = FileSystem.getLocal(conf);
      writer = new BloomMapFile.Writer(conf, TEST_FILE,
          MapFile.Writer.keyClass(IntWritable.class),
          MapFile.Writer.valueClass(Text.class));
      assertNotNull("testDeleteFile error !!!", writer);
      writer.close();
      BloomMapFile.delete(fs, TEST_FILE.toString());
    } catch (Exception ex) {
      fail("unexpect ex in testDeleteFile !!!");
    } finally {
      IOUtils.cleanup(null, writer);
    }
  }
  
  /**
   * test {@link BloomMapFile.Reader} constructor with 
   * IOException
   */
  @Test
  public void testIOExceptionInWriterConstructor() {
    Path dirNameSpy = spy(TEST_FILE);
    BloomMapFile.Reader reader = null;
    BloomMapFile.Writer writer = null;
    try {
      writer = new BloomMapFile.Writer(conf, TEST_FILE,
          MapFile.Writer.keyClass(IntWritable.class),
          MapFile.Writer.valueClass(Text.class));
      writer.append(new IntWritable(1), new Text("123124142"));
      writer.close();

      when(dirNameSpy.getFileSystem(conf)).thenThrow(new IOException());
      reader = new BloomMapFile.Reader(dirNameSpy, conf,
          MapFile.Reader.comparator(new WritableComparator(IntWritable.class)));

      assertNull("testIOExceptionInWriterConstructor error !!!",
          reader.getBloomFilter());
    } catch (Exception ex) {
      fail("unexpect ex in testIOExceptionInWriterConstructor !!!");
    } finally {
      IOUtils.cleanup(null, writer, reader);
    }
  }

  /**
   *  test {@link BloomMapFile.Reader#get(WritableComparable, Writable)} method
   */
  @Test
  public void testGetBloomMapFile() {
    int SIZE = 10;
    BloomMapFile.Reader reader = null;
    BloomMapFile.Writer writer = null;
    try {
      writer = new BloomMapFile.Writer(conf, TEST_FILE,
          MapFile.Writer.keyClass(IntWritable.class),
          MapFile.Writer.valueClass(Text.class));

      for (int i = 0; i < SIZE; i++) {
        writer.append(new IntWritable(i), new Text());
      }
      writer.close();

      reader = new BloomMapFile.Reader(TEST_FILE, conf,
          MapFile.Reader.comparator(new WritableComparator(IntWritable.class)));

      for (int i = 0; i < SIZE; i++) {
        assertNotNull("testGetBloomMapFile error !!!",
            reader.get(new IntWritable(i), new Text()));
      }
            
      assertNull("testGetBloomMapFile error !!!",
          reader.get(new IntWritable(SIZE + 5), new Text()));
    } catch (Exception ex) {
      fail("unexpect ex in testGetBloomMapFile !!!");
    } finally {
      IOUtils.cleanup(null, writer, reader);
    }
  }

  /**
   * test {@code BloomMapFile.Writer} constructors
   */
  @SuppressWarnings("deprecation")
  @Test
  public void testBloomMapFileConstructors() {
    BloomMapFile.Writer writer = null;
    try {
      FileSystem ts = FileSystem.get(conf);
      String testFileName = TEST_FILE.toString();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, IntWritable.class, Text.class, CompressionType.BLOCK,
          defaultCodec, defaultProgress);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, IntWritable.class, Text.class, CompressionType.BLOCK,
          defaultProgress);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, IntWritable.class, Text.class, CompressionType.BLOCK);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, IntWritable.class, Text.class, CompressionType.RECORD,
          defaultCodec, defaultProgress);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, IntWritable.class, Text.class, CompressionType.RECORD,
          defaultProgress);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, IntWritable.class, Text.class, CompressionType.RECORD);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
      writer = new BloomMapFile.Writer(conf, ts,
          testFileName, WritableComparator.get(Text.class), Text.class);
      assertNotNull("testBloomMapFileConstructors error !!!", writer);
      writer.close();
    } catch (Exception ex) {
      fail("testBloomMapFileConstructors error !!!");
    } finally {
      IOUtils.cleanup(null, writer);
    }
  }

  static final Progressable defaultProgress = new Progressable() {
    @Override
    public void progress() {
    }
  };

  static final CompressionCodec defaultCodec = new CompressionCodec() {
    @Override
    public String getDefaultExtension() {
      return null;
    }

    @Override
    public Class<? extends Decompressor> getDecompressorType() {
      return null;
    }

    @Override
    public Class<? extends Compressor> getCompressorType() {
      return null;
    }

    @Override
    public CompressionOutputStream createOutputStream(OutputStream out,
        Compressor compressor) throws IOException {
      return mock(CompressionOutputStream.class);
    }

    @Override
    public CompressionOutputStream createOutputStream(OutputStream out)
        throws IOException {
      return mock(CompressionOutputStream.class);
    }

    @Override
    public CompressionInputStream createInputStream(InputStream in,
        Decompressor decompressor) throws IOException {
      return null;
    }

    @Override
    public CompressionInputStream createInputStream(InputStream in)
        throws IOException {
      return null;
    }

    @Override
    public Decompressor createDecompressor() {
      return null;
    }

    @Override
    public Compressor createCompressor() {
      return null;
    }
  };
}