/*
 * 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.hbase;

import static org.junit.Assert.assertEquals;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellBuilderFactory;
import org.apache.hadoop.hbase.CellBuilderType;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.RegionInfoBuilder;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.client.TableState;
import org.apache.hadoop.hbase.util.Bytes;

import org.junit.Before;
import org.junit.Test;
import org.mockito.Mockito;

import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos;

public class TestFsRegionsMetaRecoverer {

  private Connection mockedConnection;
  private FileSystem mockedFileSystem;
  private Table mockedTable;
  private FsRegionsMetaRecoverer fixer;
  private String testTblDir;

  @Before
  public void setup() throws Exception {
    this.mockedConnection = Mockito.mock(Connection.class);
    this.mockedFileSystem = Mockito.mock(FileSystem.class);
    this.mockedTable = Mockito.mock(Table.class);
    Configuration config = HBaseConfiguration.create();
    Mockito.when(this.mockedConnection.getConfiguration()).thenReturn(config);
    Mockito.when(this.mockedConnection.getTable(TableName.META_TABLE_NAME)).thenReturn(mockedTable);
    this.testTblDir = config.get(HConstants.HBASE_DIR) + "/data/default/test-tbl";
    this.fixer = new FsRegionsMetaRecoverer(config, mockedConnection, mockedFileSystem);
  }

  private RegionInfo createRegionInfo(String table){
    long regionTS = System.currentTimeMillis();
    RegionInfo info = RegionInfoBuilder.newBuilder(TableName.valueOf(table))
      .setRegionId(regionTS)
      .build();
    return info;
  }

  private Cell createCellForRegionInfo(RegionInfo info){
    byte[] regionInfoValue = ProtobufUtil.prependPBMagic(ProtobufUtil.toRegionInfo(info)
      .toByteArray());
    Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY)
      .setRow(info.getRegionName())
      .setFamily(Bytes.toBytes("info"))
      .setQualifier(Bytes.toBytes("regioninfo"))
      .setType(Cell.Type.Put)
      .setValue(regionInfoValue)
      .build();
    return cell;
  }

  private Cell createCellForTableState(TableName tableName){
    Cell cell = CellBuilderFactory.create(CellBuilderType.SHALLOW_COPY)
      .setRow(tableName.getName())
      .setFamily(Bytes.toBytes("table"))
      .setQualifier(Bytes.toBytes("state"))
      .setType(Cell.Type.Put)
      .setValue(HBaseProtos.TableState.newBuilder()
        .setState(TableState.State.ENABLED.convert()).build().toByteArray())
      .build();
    return cell;
  }

  @Test
  public void testFindMissingRegionsInMETANoMissing() throws  Exception {
    ResultScanner mockedRS = Mockito.mock(ResultScanner.class);
    Mockito.when(this.mockedTable.getScanner(Mockito.any(Scan.class))).thenReturn(mockedRS);
    RegionInfo info = createRegionInfo("test-tbl");
    List<Cell> cells = new ArrayList<>();
    cells.add(createCellForRegionInfo(info));
    Result result = Result.create(cells);
    Mockito.when(mockedRS.next()).thenReturn(result,(Result)null);
    FileStatus status = new FileStatus();
    status.setPath(new Path(this.testTblDir + "/" + info.getEncodedName()));
    Mockito.when(mockedFileSystem.listStatus(new Path(this.testTblDir)))
      .thenReturn(new FileStatus[]{status});
    assertEquals("Should had returned 0 missing regions",
      0, fixer.findMissingRegionsInMETA("test-tbl").size());
  }

  @Test
  public void testFindMissingRegionsInMETAOneMissing() throws  Exception {
    ResultScanner mockedRS = Mockito.mock(ResultScanner.class);
    Mockito.when(this.mockedTable.getScanner(Mockito.any(Scan.class))).thenReturn(mockedRS);
    List<Cell> cells = new ArrayList<>();
    Result result = Result.create(cells);
    Mockito.when(mockedRS.next()).thenReturn(result,(Result)null);
    Path p = new Path(this.testTblDir+ "/182182182121");
    FileStatus status = new FileStatus(0, true, 0, 0,0, p);
    Mockito.when(mockedFileSystem.listStatus(new Path(this.testTblDir)))
      .thenReturn(new FileStatus[]{status});
    List<Path> missingRegions = fixer.findMissingRegionsInMETA("test-tbl");
    assertEquals("Should had returned 1 missing region",
      1, missingRegions.size());
    assertEquals(p,missingRegions.get(0));
  }

  @Test
  public void testPutRegionInfoFromHdfsInMeta() throws Exception {
    RegionInfo info = this.createRegionInfo("test-tbl");
    Path regionPath = new Path("/hbase/data/default/test-tbl/" + info.getEncodedName());
    FSDataInputStream fis = new FSDataInputStream(new TestInputStreamSeekable(info));
    Mockito.when(this.mockedFileSystem.open(new Path(regionPath, ".regioninfo")))
      .thenReturn(fis);
    fixer.putRegionInfoFromHdfsInMeta(regionPath);
    Mockito.verify(this.mockedConnection).getTable(TableName.META_TABLE_NAME);
    Mockito.verify(this.mockedTable).put(Mockito.any(Put.class));
  }

  @Test
  public void testReportTablesMissingRegionsOneMissing() throws  Exception {
    ResultScanner mockedRS = Mockito.mock(ResultScanner.class);
    Mockito.when(this.mockedTable.getScanner(Mockito.any(Scan.class))).thenReturn(mockedRS);
    List<Cell> cells = new ArrayList<>();
    cells.add(createCellForTableState(TableName.valueOf("test-tbl")));
    Result result = Result.create(cells);
    Mockito.when(mockedRS.next()).thenReturn(result,(Result)null);
    FileStatus status = new FileStatus();
    Path p = new Path(this.testTblDir+ "/182182182121");
    status.setPath(p);
    Mockito.when(mockedFileSystem.listStatus(new Path(this.testTblDir)))
      .thenReturn(new FileStatus[]{status});
    Mockito.when(this.mockedConnection.getTable(TableName.META_TABLE_NAME))
      .thenReturn(this.mockedTable);
    Map<TableName, List<Path>> report = fixer.reportTablesMissingRegions(null);
    assertEquals("Should had returned 1 missing region",
      1,report.size());
  }

  private static final class TestInputStreamSeekable extends FSInputStream {

    private ByteArrayInputStream in;
    private long length;

    private TestInputStreamSeekable(RegionInfo info) throws Exception {
      byte[] bytes = RegionInfo.toDelimitedByteArray(info);
      this.length = bytes.length;
      this.in = new ByteArrayInputStream(bytes);
    }

    @Override
    public void seek(long l) throws IOException {
      this.in.skip(l);
    }

    @Override
    public long getPos() throws IOException {
      return this.length - in.available();
    }

    @Override
    public boolean seekToNewSource(long l) throws IOException {
      this.in.skip(l);
      return true;
    }

    @Override
    public int read() throws IOException {
      return in.read();
    }
  }

}