/**
    * Copyright The Apache Software Foundation
    *
    * 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.client;
  
  import java.io.IOException;
  import java.util.Arrays;
  import static junit.framework.TestCase.assertTrue;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.CoprocessorEnvironment;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
  import org.apache.hadoop.hbase.coprocessor.ObserverContext;
  import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
  import org.apache.hadoop.hbase.testclassification.ClientTests;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({MediumTests.class, ClientTests.class})
  public class TestResultFromCoprocessor {
    private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    private static final byte[] ROW = Bytes.toBytes("normal_row");
    private static final byte[] FAMILY = Bytes.toBytes("fm");
    private static final byte[] QUAL = Bytes.toBytes("qual");
    private static final byte[] VALUE = Bytes.toBytes(100L);
    private static final byte[] FIXED_VALUE = Bytes.toBytes("fixed_value");
    private static final Cell FIXED_CELL = CellUtil.createCell(ROW, FAMILY,
            QUAL, 0, KeyValue.Type.Put.getCode(), FIXED_VALUE);
    private static final Result FIXED_RESULT = Result.create(Arrays.asList(FIXED_CELL));
    private static final TableName TABLE_NAME = TableName.valueOf("TestResultFromCoprocessor");
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      TEST_UTIL.startMiniCluster(3);
      HTableDescriptor desc = new HTableDescriptor(TABLE_NAME);
      desc.addCoprocessor(MyObserver.class.getName())
          .addFamily(new HColumnDescriptor(FAMILY));
      TEST_UTIL.getHBaseAdmin().createTable(desc);
    }
  
    @AfterClass
    public static void tearDownAfterClass() throws Exception {
      TEST_UTIL.shutdownMiniCluster();
    }
  
    @Test
    public void testAppend() throws IOException {
      try (Table t = TEST_UTIL.getConnection().getTable(TABLE_NAME)) {
        Put put = new Put(ROW);
        put.addColumn(FAMILY, QUAL, VALUE);
        t.put(put);
        assertRowAndValue(t.get(new Get(ROW)), ROW, VALUE);
        Append append = new Append(ROW);
        append.add(FAMILY, QUAL, FIXED_VALUE);
        assertRowAndValue(t.append(append), ROW, FIXED_VALUE);
        assertRowAndValue(t.get(new Get(ROW)), ROW, Bytes.add(VALUE, FIXED_VALUE));
      }
    }
  
    @Test
    public void testIncrement() throws IOException {
      try (Table t = TEST_UTIL.getConnection().getTable(TABLE_NAME)) {
        Put put = new Put(ROW);
        put.addColumn(FAMILY, QUAL, VALUE);
        t.put(put);
        assertRowAndValue(t.get(new Get(ROW)), ROW, VALUE);
        Increment inc = new Increment(ROW);
        inc.addColumn(FAMILY, QUAL, 99);
        assertRowAndValue(t.increment(inc), ROW, FIXED_VALUE);
        assertRowAndValue(t.get(new Get(ROW)), ROW, Bytes.toBytes(199L));
      }
    }
  
    private static void assertRowAndValue(Result r, byte[] row, byte[] value) {
      for (Cell c : r.rawCells()) {
       assertTrue(Bytes.equals(CellUtil.cloneRow(c), row));
       assertTrue(Bytes.equals(CellUtil.cloneValue(c), value));
     }
   }
 
   public static class MyObserver extends BaseRegionObserver {
 
     @Override
     public Result postAppend(final ObserverContext<RegionCoprocessorEnvironment> c,
       final Append append, final Result result) {
       return FIXED_RESULT;
     }
 
     @Override
     public Result postIncrement(final ObserverContext<RegionCoprocessorEnvironment> c,
       final Increment increment, final Result result) {
       return FIXED_RESULT;
     }
 
     @Override
     public void start(CoprocessorEnvironment env) throws IOException {
     }
 
     @Override
     public void stop(CoprocessorEnvironment env) throws IOException {
     }
   }
 
 }