/**
 * 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.fs.viewfs;

import java.io.IOException;
import java.net.URISyntaxException;

import javax.security.auth.login.LoginException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FileSystemTestHelper;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.BeforeAll;

/**
 * Make sure that ViewFileSystem works when the root of an FS is mounted to a
 * ViewFileSystem mount point.
 */
public class TestViewFileSystemAtHdfsRoot extends ViewFileSystemBaseTest {

  private static MiniDFSCluster cluster;
  private static final Configuration CONF = new Configuration();
  private static FileSystem fHdfs;
  
  @Override
  protected FileSystemTestHelper createFileSystemHelper() {
    return new FileSystemTestHelper("/tmp/TestViewFileSystemAtHdfsRoot");
  }
  
  @BeforeAll
  public static void clusterSetupAtBegining() throws IOException,
      LoginException, URISyntaxException {
    SupportsBlocks = true;
    CONF.setBoolean(
        DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_ALWAYS_USE_KEY, true);
    
    cluster = new MiniDFSCluster.Builder(CONF)
      .numDataNodes(2)
      .build();
    cluster.waitClusterUp();
    
    fHdfs = cluster.getFileSystem();
  }
      
  @AfterAll
  public static void clusterShutdownAtEnd() throws Exception {
    if (cluster != null) {
      cluster.shutdown();
    }
  }

  @Override
  @BeforeEach
  public void setUp() throws Exception {
    fsTarget = fHdfs;
    super.setUp();
  }

  /**
   * Override this so that we don't set the targetTestRoot to any path under the
   * root of the FS, and so that we don't try to delete the test dir, but rather
   * only its contents.
   */
  @Override
  void initializeTargetTestRoot() throws IOException {
    targetTestRoot = fHdfs.makeQualified(new Path("/"));
    for (FileStatus status : fHdfs.listStatus(targetTestRoot)) {
      fHdfs.delete(status.getPath(), true);
    }
  }

  @Override
  int getExpectedDelegationTokenCount() {
    return 1; // all point to the same fs so 1 unique token
  }

  @Override
  int getExpectedDelegationTokenCountWithCredentials() {
    return 1;
  }
}
