/**
 * 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.hdfs.server.namenode;

import static org.apache.hadoop.hdfs.server.common.Util.fileAsURI;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;

import java.io.File;
import java.io.IOException;

import org.apache.hadoop.HadoopIllegalArgumentException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Options.Rename;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.fs.permission.PermissionStatus;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.MiniDFSCluster;
import org.apache.hadoop.hdfs.protocol.FSLimitException.MaxDirectoryItemsExceededException;
import org.apache.hadoop.hdfs.protocol.FSLimitException.PathComponentTooLongException;
import org.apache.hadoop.hdfs.protocol.HdfsConstants;
import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NamenodeRole;
import org.apache.hadoop.test.GenericTestUtils;
import org.junit.Before;
import org.junit.Test;

public class TestFsLimits {
  static Configuration conf;
  static FSNamesystem fs;
  static boolean fsIsReady;
  
  static final PermissionStatus perms
    = new PermissionStatus("admin", "admin", FsPermission.getDefault());

  static private FSNamesystem getMockNamesystem() throws IOException {
    FSImage fsImage = mock(FSImage.class);
    FSEditLog editLog = mock(FSEditLog.class);
    doReturn(editLog).when(fsImage).getEditLog();
    FSNamesystem fsn = new FSNamesystem(conf, fsImage);
    fsn.setImageLoaded(fsIsReady);
    return fsn;
  }

  @Before
  public void setUp() throws IOException {
    conf = new Configuration();
    conf.set(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY,
             fileAsURI(new File(MiniDFSCluster.getBaseDirectory(),
                                "namenode")).toString());
    NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
    fs = null;
    fsIsReady = true;
  }

  @Test
  public void testNoLimits() throws Exception {
    mkdirs("/1", null);
    mkdirs("/22", null);
    mkdirs("/333", null);
    mkdirs("/4444", null);
    mkdirs("/55555", null);
    mkdirs("/1/" + HdfsConstants.DOT_SNAPSHOT_DIR,
        HadoopIllegalArgumentException.class);
  }

  @Test
  public void testMaxComponentLength() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_COMPONENT_LENGTH_KEY, 2);
    
    mkdirs("/1", null);
    mkdirs("/22", null);
    mkdirs("/333", PathComponentTooLongException.class);
    mkdirs("/4444", PathComponentTooLongException.class);
  }

  @Test
  public void testMaxComponentLengthRename() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_COMPONENT_LENGTH_KEY, 2);

    mkdirs("/5", null);
    rename("/5", "/555", PathComponentTooLongException.class);
    rename("/5", "/55", null);

    mkdirs("/6", null);
    deprecatedRename("/6", "/666", PathComponentTooLongException.class);
    deprecatedRename("/6", "/66", null);
  }

  @Test
  public void testMaxDirItems() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_DIRECTORY_ITEMS_KEY, 2);
    
    mkdirs("/1", null);
    mkdirs("/22", null);
    mkdirs("/333", MaxDirectoryItemsExceededException.class);
    mkdirs("/4444", MaxDirectoryItemsExceededException.class);
  }

  @Test
  public void testMaxDirItemsRename() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_DIRECTORY_ITEMS_KEY, 2);
    
    mkdirs("/1", null);
    mkdirs("/2", null);

    mkdirs("/2/A", null);
    rename("/2/A", "/A", MaxDirectoryItemsExceededException.class);
    rename("/2/A", "/1/A", null);

    mkdirs("/2/B", null);
    deprecatedRename("/2/B", "/B", MaxDirectoryItemsExceededException.class);
    deprecatedRename("/2/B", "/1/B", null);

    rename("/1", "/3", null);
    deprecatedRename("/2", "/4", null);
  }

  @Test
  public void testMaxDirItemsLimits() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_DIRECTORY_ITEMS_KEY, 0);
    try {
      mkdirs("1", null);
    } catch (IllegalArgumentException e) {
      GenericTestUtils.assertExceptionContains("Cannot set dfs", e);
    }
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_DIRECTORY_ITEMS_KEY, 64*100*1024);
    try {
      mkdirs("1", null);
    } catch (IllegalArgumentException e) {
      GenericTestUtils.assertExceptionContains("Cannot set dfs", e);
    }
  }

  @Test
  public void testMaxComponentsAndMaxDirItems() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_COMPONENT_LENGTH_KEY, 3);
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_DIRECTORY_ITEMS_KEY, 2);
    
    mkdirs("/1", null);
    mkdirs("/22", null);
    mkdirs("/333", MaxDirectoryItemsExceededException.class);
    mkdirs("/4444", PathComponentTooLongException.class);
  }

  @Test
  public void testDuringEditLogs() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_COMPONENT_LENGTH_KEY, 3);
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_DIRECTORY_ITEMS_KEY, 2);
    fsIsReady = false;
    
    mkdirs("/1", null);
    mkdirs("/22", null);
    mkdirs("/333", null);
    mkdirs("/4444", null);
    mkdirs("/1/" + HdfsConstants.DOT_SNAPSHOT_DIR,
        HadoopIllegalArgumentException.class);
  }

  @Test
  /**
   * This test verifies that error string contains the
   * right parent directory name if the operation fails with
   * PathComponentTooLongException
   */
  public void testParentDirectoryNameIsCorrect() throws Exception {
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_MAX_COMPONENT_LENGTH_KEY, 20);
    mkdirs("/user", null);
    mkdirs("/user/testHome", null);
    mkdirs("/user/testHome/FileNameLength", null);

    mkdirCheckParentDirectory(
      "/user/testHome/FileNameLength/really_big_name_0003_fail",
      "/user/testHome/FileNameLength", PathComponentTooLongException.class);

    renameCheckParentDirectory("/user/testHome/FileNameLength",
      "/user/testHome/really_big_name_0003_fail", "/user/testHome/",
      PathComponentTooLongException.class);

  }


  /**
   * Verifies that Parent Directory is correct after a failed call to mkdir
   * @param name Directory Name
   * @param ParentDirName Expected Parent Directory
   * @param expected Exception that is expected
   * @throws Exception
   */
  private void mkdirCheckParentDirectory(String name, String ParentDirName,
                                         Class<?> expected)
    throws Exception {
    verify(mkdirs(name, expected), ParentDirName);
  }

  /**
   *
   /**
   * Verifies that Parent Directory is correct after a failed call to mkdir
   * @param name Directory Name
   * @param dst Destination Name
   * @param ParentDirName Expected Parent Directory
   * @param expected Exception that is expected
   * @throws Exception
   */
  private void renameCheckParentDirectory(String name, String dst,
                                          String ParentDirName,
                                          Class<?> expected)
    throws Exception {
    verify(rename(name, dst, expected), ParentDirName);
  }

  /**
   * verifies the ParentDirectory Name is present in the message given.
   * @param message - Expection Message
   * @param ParentDirName - Parent Directory Name to look for.
   */
  private void verify(String message, String ParentDirName) {
    boolean found = false;
    if (message != null) {
      String[] tokens = message.split("\\s+");
      for (String token : tokens) {
        if (token != null && token.equals(ParentDirName)) {
          found = true;
          break;
        }
      }
    }
    assertTrue(found);
  }

  private String mkdirs(String name, Class<?> expected)
  throws Exception {
    lazyInitFSDirectory();
    Class<?> generated = null;
    String errorString = null;
    try {
      fs.mkdirs(name, perms, false);
    } catch (Throwable e) {
      generated = e.getClass();
      e.printStackTrace();
      errorString = e.getMessage();
    }
    assertEquals(expected, generated);
    return errorString;
  }

  private String rename(String src, String dst, Class<?> expected)
      throws Exception {
    lazyInitFSDirectory();
    Class<?> generated = null;
    String errorString = null;
    try {
      fs.renameTo(src, dst, false, new Rename[] { });
    } catch (Throwable e) {
      generated = e.getClass();
      errorString = e.getMessage();
    }
    assertEquals(expected, generated);
    return errorString;
  }

  @SuppressWarnings("deprecation")
  private void deprecatedRename(String src, String dst, Class<?> expected)
      throws Exception {
    lazyInitFSDirectory();
    Class<?> generated = null;
    try {
      fs.renameTo(src, dst, false);
    } catch (Throwable e) {
      generated = e.getClass();
    }
    assertEquals(expected, generated);
  }

  private static void lazyInitFSDirectory() throws IOException {
    // have to create after the caller has had a chance to set conf values
    if (fs == null) {
      fs = getMockNamesystem();
    }
  }
}