/*
 * 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.hbase.util;

import static org.apache.hadoop.hbase.util.RecoverLeaseFSUtils.LEASE_RECOVERABLE_CLASS_NAME;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import java.io.IOException;
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.hbase.HBaseCommonTestingUtil;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.testclassification.MiscTests;
import org.apache.hadoop.hdfs.DistributedFileSystem;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;

/**
 * Test our recoverLease loop against mocked up filesystem.
 */
@Tag(MiscTests.TAG)
@Tag(MediumTests.TAG)
public class TestRecoverLeaseFSUtils {

  private static final HBaseCommonTestingUtil HTU = new HBaseCommonTestingUtil();

  private static Path FILE;

  @BeforeAll
  public static void setUp() {
    Configuration conf = HTU.getConfiguration();
    conf.setInt("hbase.lease.recovery.first.pause", 10);
    conf.setInt("hbase.lease.recovery.pause", 10);
    FILE = new Path(HTU.getDataTestDir(), "file.txt");
  }

  /**
   * Test recover lease eventually succeeding.
   */
  @Test
  public void testRecoverLease() throws IOException {
    long startTime = EnvironmentEdgeManager.currentTime();
    HTU.getConfiguration().setInt("hbase.lease.recovery.dfs.timeout", 1000);
    CancelableProgressable reporter = mock(CancelableProgressable.class);
    when(reporter.progress()).thenReturn(true);
    DistributedFileSystem dfs = mock(DistributedFileSystem.class);
    // Fail four times and pass on the fifth.
    when(dfs.recoverLease(FILE)).thenReturn(false).thenReturn(false).thenReturn(false)
      .thenReturn(false).thenReturn(true);
    RecoverLeaseFSUtils.recoverFileLease(dfs, FILE, HTU.getConfiguration(), reporter);
    verify(dfs, times(5)).recoverLease(FILE);
    // Make sure we waited at least hbase.lease.recovery.dfs.timeout * 3 (the first two
    // invocations will happen pretty fast... the we fall into the longer wait loop).
    assertTrue((EnvironmentEdgeManager.currentTime() - startTime)
        > (3 * HTU.getConfiguration().getInt("hbase.lease.recovery.dfs.timeout", 61000)));
  }

  private interface FakeLeaseRecoverable {

    boolean recoverLease(Path p) throws IOException;
  }

  private static abstract class RecoverableFileSystem extends FileSystem
    implements FakeLeaseRecoverable {
    @Override
    public boolean recoverLease(Path p) throws IOException {
      return true;
    }
  }

  /**
   * Test that we can use reflection to access LeaseRecoverable methods.
   */
  @Test
  public void testLeaseRecoverable() throws IOException {
    try {
      // set LeaseRecoverable to FakeLeaseRecoverable for testing
      RecoverLeaseFSUtils.initializeRecoverLeaseMethod(FakeLeaseRecoverable.class.getName());
      RecoverableFileSystem mockFS = mock(RecoverableFileSystem.class);
      when(mockFS.recoverLease(FILE)).thenReturn(true);
      RecoverLeaseFSUtils.recoverFileLease(mockFS, FILE, HTU.getConfiguration());
      verify(mockFS, times(1)).recoverLease(FILE);

      assertTrue(RecoverLeaseFSUtils.isLeaseRecoverable(mock(RecoverableFileSystem.class)));
    } finally {
      RecoverLeaseFSUtils.initializeRecoverLeaseMethod(LEASE_RECOVERABLE_CLASS_NAME);
    }
  }

  /**
   * Test that isFileClosed makes us recover lease faster.
   */
  @Test
  public void testIsFileClosed() throws IOException {
    // Make this time long so it is plain we broke out because of the isFileClosed invocation.
    HTU.getConfiguration().setInt("hbase.lease.recovery.dfs.timeout", 100000);
    CancelableProgressable reporter = mock(CancelableProgressable.class);
    when(reporter.progress()).thenReturn(true);
    IsFileClosedDistributedFileSystem dfs = mock(IsFileClosedDistributedFileSystem.class);
    // Now make it so we fail the first two times -- the two fast invocations, then we fall into
    // the long loop during which we will call isFileClosed.... the next invocation should
    // therefore return true if we are to break the loop.
    when(dfs.recoverLease(FILE)).thenReturn(false).thenReturn(false).thenReturn(true);
    when(dfs.isFileClosed(FILE)).thenReturn(true);
    RecoverLeaseFSUtils.recoverFileLease(dfs, FILE, HTU.getConfiguration(), reporter);
    verify(dfs, times(2)).recoverLease(FILE);
    verify(dfs, times(1)).isFileClosed(FILE);
  }

  @Test
  public void testIsLeaseRecoverable() {
    assertTrue(RecoverLeaseFSUtils.isLeaseRecoverable(new DistributedFileSystem()));
    assertFalse(RecoverLeaseFSUtils.isLeaseRecoverable(new LocalFileSystem()));
  }

  /**
   * Version of DFS that has HDFS-4525 in it.
   */
  private static class IsFileClosedDistributedFileSystem extends DistributedFileSystem {
    /**
     * Close status of a file. Copied over from HDFS-4525
     * @return true if file is already closed
     **/
    @Override
    public boolean isFileClosed(Path f) throws IOException {
      return false;
    }
  }
}