/*
 * 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.swift;

import org.apache.hadoop.fs.BlockLocation;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.swift.http.SwiftProtocolConstants;
import org.apache.hadoop.fs.swift.util.SwiftTestUtils;
import org.junit.Test;

import java.io.IOException;

/**
 * Test block location logic.
 * The endpoint may or may not be location-aware
 */
public class TestSwiftFileSystemBlockLocation extends SwiftFileSystemBaseTest {


  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateSingleFileBlocks() throws Throwable {
    describe("verify that a file returns 1+ blocks");
    FileStatus fileStatus = createFileAndGetStatus();
    BlockLocation[] locations =
      getFs().getFileBlockLocations(fileStatus, 0, 1);
    assertNotEqual("No block locations supplied for " + fileStatus, 0,
                   locations.length);
    for (BlockLocation location : locations) {
      assertLocationValid(location);
    }
  }

  private void assertLocationValid(BlockLocation location) throws
                                                           IOException {
    LOG.info(location);
    String[] hosts = location.getHosts();
    String[] names = location.getNames();
    assertNotEqual("No hosts supplied for " + location, 0, hosts.length);
    //for every host, there's a name.
    assertEquals("Unequal names and hosts in " + location,
                 hosts.length, names.length);
    assertEquals(SwiftProtocolConstants.BLOCK_LOCATION,
                 location.getNames()[0]);
    assertEquals(SwiftProtocolConstants.TOPOLOGY_PATH,
                 location.getTopologyPaths()[0]);
  }

  private FileStatus createFileAndGetStatus() throws IOException {
    Path path = path("/test/locatedFile");
    createFile(path);
    return fs.getFileStatus(path);
  }

  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateNullStatus() throws Throwable {
    describe("verify that a null filestatus maps to a null location array");
    BlockLocation[] locations =
      getFs().getFileBlockLocations((FileStatus) null, 0, 1);
    assertNull(locations);
  }

  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateNegativeSeek() throws Throwable {
    describe("verify that a negative offset is illegal");
    try {
      BlockLocation[] locations =
        getFs().getFileBlockLocations(createFileAndGetStatus(),
                                      -1,
                                      1);
      fail("Expected an exception, got " + locations.length + " locations");
    } catch (IllegalArgumentException e) {
      //expected
    }
  }

  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateNegativeLen() throws Throwable {
    describe("verify that a negative length is illegal");
    try {
      BlockLocation[] locations =
        getFs().getFileBlockLocations(createFileAndGetStatus(),
                                      0,
                                      -1);
      fail("Expected an exception, got " + locations.length + " locations");
    } catch (IllegalArgumentException e) {
      //expected
    }
  }


  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateOutOfRangeLen() throws Throwable {
    describe("overshooting the length is legal, as long as the" +
             " origin location is valid");

    BlockLocation[] locations =
      getFs().getFileBlockLocations(createFileAndGetStatus(),
                                    0,
                                    data.length + 100);
    assertNotNull(locations);
    assertTrue(locations.length > 0);
  }

  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateOutOfRangeSrc() throws Throwable {
    describe("Seeking out of the file length returns an empty array");

    BlockLocation[] locations =
      getFs().getFileBlockLocations(createFileAndGetStatus(),
                                    data.length + 100,
                                    1);
    assertEmptyBlockLocations(locations);
  }

  private void assertEmptyBlockLocations(BlockLocation[] locations) {
    assertNotNull(locations);
    if (locations.length!=0) {
      fail("non empty locations[] with first entry of " + locations[0]);
    }
  }

  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateDirectory() throws Throwable {
    describe("verify that locating a directory is an error");
    createFile(path("/test/filename"));
    FileStatus status = fs.getFileStatus(path("/test"));
    LOG.info("Filesystem is " + fs + "; target is " + status);
    SwiftTestUtils.assertIsDirectory(status);
    BlockLocation[] locations;
    locations = getFs().getFileBlockLocations(status,
                                              0,
                                              1);
    assertEmptyBlockLocations(locations);
  }


  @Test(timeout = SWIFT_TEST_TIMEOUT)
  public void testLocateRootDirectory() throws Throwable {
    describe("verify that locating the root directory is an error");
    FileStatus status = fs.getFileStatus(path("/"));
    SwiftTestUtils.assertIsDirectory(status);
    BlockLocation[] locations;
    locations = getFs().getFileBlockLocations(status,
                                              0,
                                              1);
    assertEmptyBlockLocations(locations);
  }


}