/*
    * 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.mapreduce;
  
  import com.google.common.base.Function;
  import com.google.common.collect.ImmutableList;
  import com.google.common.collect.Multimaps;
  import edu.umd.cs.findbugs.annotations.Nullable;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Scan;
  import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
  import org.apache.hadoop.hbase.snapshot.SnapshotTestingUtils;
  import org.apache.hadoop.hbase.testclassification.LargeTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.apache.hadoop.mapreduce.Job;
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.experimental.categories.Category;
  
  import java.io.IOException;
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  
  @Category({ LargeTests.class })
  public class TestMultiTableSnapshotInputFormat extends MultiTableInputFormatTestBase {
  
    protected Path restoreDir;
  
    @BeforeClass
    public static void setUpSnapshots() throws Exception {
  
      TEST_UTIL.enableDebug(MultiTableSnapshotInputFormat.class);
      TEST_UTIL.enableDebug(MultiTableSnapshotInputFormatImpl.class);
  
      // take a snapshot of every table we have.
      for (String tableName : TABLES) {
        SnapshotTestingUtils
            .createSnapshotAndValidate(TEST_UTIL.getHBaseAdmin(), TableName.valueOf(tableName),
                ImmutableList.of(MultiTableInputFormatTestBase.INPUT_FAMILY), null,
                snapshotNameForTable(tableName), FSUtils.getRootDir(TEST_UTIL.getConfiguration()),
                TEST_UTIL.getTestFileSystem(), true);
      }
    }
  
    @Before
    public void setUp() throws Exception {
      this.restoreDir = TEST_UTIL.getRandomDir();
    }
  
    @Override
    protected void initJob(List<Scan> scans, Job job) throws IOException {
      TableMapReduceUtil
          .initMultiTableSnapshotMapperJob(getSnapshotScanMapping(scans), ScanMapper.class,
              ImmutableBytesWritable.class, ImmutableBytesWritable.class, job, true, restoreDir);
    }
  
    protected Map<String, Collection<Scan>> getSnapshotScanMapping(final List<Scan> scans) {
      return Multimaps.index(scans, new Function<Scan, String>() {
        @Nullable
        @Override
        public String apply(Scan input) {
          return snapshotNameForTable(
              Bytes.toStringBinary(input.getAttribute(Scan.SCAN_ATTRIBUTES_TABLE_NAME)));
        }
      }).asMap();
    }
  
    public static String snapshotNameForTable(String tableName) {
      return tableName + "_snapshot";
    }
  
  }