/*
 * 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
 *
 *   https://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.accumulo.test;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import java.util.Map;

import org.apache.accumulo.core.client.Accumulo;
import org.apache.accumulo.core.client.AccumuloClient;
import org.apache.accumulo.core.client.BatchWriter;
import org.apache.accumulo.core.client.BatchWriterConfig;
import org.apache.accumulo.core.client.IteratorSetting;
import org.apache.accumulo.core.client.Scanner;
import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Mutation;
import org.apache.accumulo.core.data.PartialKey;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.LongCombiner;
import org.apache.accumulo.core.iterators.user.SummingCombiner;
import org.apache.accumulo.core.security.Authorizations;
import org.apache.accumulo.harness.AccumuloClusterHarness;
import org.apache.hadoop.io.Text;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.collect.Iterators;

/**
 * Test writing to another table from inside an iterator.
 *
 * @see BatchWriterIterator
 */
public class BatchWriterInTabletServerIT extends AccumuloClusterHarness {
  private static final Logger log = LoggerFactory.getLogger(BatchWriterInTabletServerIT.class);

  @Override
  public boolean canRunTest(ClusterType type) {
    return type == ClusterType.MINI;
  }

  /**
   * This test should succeed.
   */
  @Test
  public void testNormalWrite() throws Exception {
    String[] uniqueNames = getUniqueNames(2);
    String t1 = uniqueNames[0];
    String t2 = uniqueNames[1];
    try (AccumuloClient c = Accumulo.newClient().from(getClientProps()).build()) {
      int numEntriesToWritePerEntry = 50;
      IteratorSetting itset = BatchWriterIterator.iteratorSetting(6, 0, 15, 1000,
          numEntriesToWritePerEntry, t2, c, getAdminToken(), false, false);
      test(t1, t2, c, itset, numEntriesToWritePerEntry);
    }
  }

  /**
   * Fixed by ACCUMULO-4229.
   * <p>
   * This tests a situation that a client which shares a LocatorCache with the tablet server may
   * fall into. Before the problem was fixed, adding a split after the Locator cache falls out of
   * sync caused the BatchWriter to continuously attempt to write to an old, closed tablet. It would
   * do so for 15 seconds until a timeout on the BatchWriter.
   */
  @Test
  public void testClearLocatorAndSplitWrite() throws Exception {
    String[] uniqueNames = getUniqueNames(2);
    String t1 = uniqueNames[0];
    String t2 = uniqueNames[1];
    try (AccumuloClient c = Accumulo.newClient().from(getClientProps()).build()) {
      int numEntriesToWritePerEntry = 50;
      IteratorSetting itset = BatchWriterIterator.iteratorSetting(6, 0, 15, 1000,
          numEntriesToWritePerEntry, t2, c, getAdminToken(), true, true);
      test(t1, t2, c, itset, numEntriesToWritePerEntry);
    }
  }

  private void test(String t1, String t2, AccumuloClient c, IteratorSetting itset,
      int numEntriesToWritePerEntry) throws Exception {
    // Write an entry to t1
    c.tableOperations().create(t1);
    Key k = new Key(new Text("row"), new Text("cf"), new Text("cq"));
    Value v = new Value("1");
    BatchWriterConfig config = new BatchWriterConfig();
    config.setMaxMemory(0);
    try (BatchWriter writer = c.createBatchWriter(t1, config)) {
      Mutation m = new Mutation(k.getRow());
      m.put(k.getColumnFamily(), k.getColumnQualifier(), v);
      writer.addMutation(m);
    }

    // Create t2 with a combiner to count entries written to it
    c.tableOperations().create(t2);
    IteratorSetting summer = new IteratorSetting(2, "summer", SummingCombiner.class);
    LongCombiner.setEncodingType(summer, LongCombiner.Type.STRING);
    LongCombiner.setCombineAllColumns(summer, true);
    c.tableOperations().attachIterator(t2, summer);

    Map.Entry<Key,Value> actual;
    try (Scanner scanner = c.createScanner(t1, Authorizations.EMPTY)) {
      // Scan t1 with an iterator that writes to table t2
      scanner.addScanIterator(itset);
      actual = Iterators.getOnlyElement(scanner.iterator());
      assertTrue(actual.getKey().equals(k, PartialKey.ROW_COLFAM_COLQUAL));
      assertEquals(BatchWriterIterator.SUCCESS_VALUE, actual.getValue());
    }

    try (Scanner scanner = c.createScanner(t2, Authorizations.EMPTY)) {
      // ensure entries correctly wrote to table t2
      actual = Iterators.getOnlyElement(scanner.iterator());
      log.debug("t2 entry is {} -> {}", actual.getKey().toStringNoTime(), actual.getValue());
      assertTrue(actual.getKey().equals(k, PartialKey.ROW_COLFAM_COLQUAL));
      assertEquals(numEntriesToWritePerEntry, Integer.parseInt(actual.getValue().toString()));
    }

    c.tableOperations().delete(t1);
    c.tableOperations().delete(t2);
  }
}
