/*
 * 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.quotas;

import static org.apache.hbase.thirdparty.com.google.common.collect.Iterables.size;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNull;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Connection;
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.quotas.SpaceQuotaSnapshot.SpaceQuotaStatus;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.Before;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;

import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos;
import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos.Quotas;
import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos.SpaceQuota;

/**
 * Test class for {@link TableQuotaSnapshotStore}.
 */
@Category(SmallTests.class)
public class TestTableQuotaViolationStore {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
    HBaseClassTestRule.forClass(TestTableQuotaViolationStore.class);

  private static final long ONE_MEGABYTE = 1024L * 1024L;

  private Connection conn;
  private QuotaObserverChore chore;
  private Map<RegionInfo, Long> regionReports;
  private TableQuotaSnapshotStore store;

  @Before
  public void setup() {
    conn = mock(Connection.class);
    chore = mock(QuotaObserverChore.class);
    regionReports = new HashMap<>();
    store = new TableQuotaSnapshotStore(conn, chore, regionReports);
  }

  @Test
  public void testFilterRegionsByTable() throws Exception {
    TableName tn1 = TableName.valueOf("foo");
    TableName tn2 = TableName.valueOf("bar");
    TableName tn3 = TableName.valueOf("ns", "foo");

    assertEquals(0, size(store.filterBySubject(tn1)));

    for (int i = 0; i < 5; i++) {
      regionReports.put(RegionInfoBuilder.newBuilder(tn1).setStartKey(Bytes.toBytes(i))
        .setEndKey(Bytes.toBytes(i + 1)).build(), 0L);
    }
    for (int i = 0; i < 3; i++) {
      regionReports.put(RegionInfoBuilder.newBuilder(tn2).setStartKey(Bytes.toBytes(i))
        .setEndKey(Bytes.toBytes(i + 1)).build(), 0L);
    }
    for (int i = 0; i < 10; i++) {
      regionReports.put(RegionInfoBuilder.newBuilder(tn3).setStartKey(Bytes.toBytes(i))
        .setEndKey(Bytes.toBytes(i + 1)).build(), 0L);
    }
    assertEquals(18, regionReports.size());
    assertEquals(5, size(store.filterBySubject(tn1)));
    assertEquals(3, size(store.filterBySubject(tn2)));
    assertEquals(10, size(store.filterBySubject(tn3)));
  }

  @Test
  public void testTargetViolationState() throws IOException {
    mockNoSnapshotSizes();
    TableName tn1 = TableName.valueOf("violation1");
    TableName tn2 = TableName.valueOf("observance1");
    TableName tn3 = TableName.valueOf("observance2");
    SpaceQuota quota = SpaceQuota.newBuilder().setSoftLimit(1024L * 1024L)
      .setViolationPolicy(ProtobufUtil.toProtoViolationPolicy(SpaceViolationPolicy.DISABLE))
      .build();

    // Create some junk data to filter. Makes sure it's so large that it would
    // immediately violate the quota.
    for (int i = 0; i < 3; i++) {
      regionReports.put(RegionInfoBuilder.newBuilder(tn2).setStartKey(Bytes.toBytes(i))
        .setEndKey(Bytes.toBytes(i + 1)).build(), 5L * ONE_MEGABYTE);
      regionReports.put(RegionInfoBuilder.newBuilder(tn3).setStartKey(Bytes.toBytes(i))
        .setEndKey(Bytes.toBytes(i + 1)).build(), 5L * ONE_MEGABYTE);
    }
    regionReports.put(RegionInfoBuilder.newBuilder(tn1).setStartKey(Bytes.toBytes(0))
      .setEndKey(Bytes.toBytes(1)).build(), 1024L * 512L);
    regionReports.put(RegionInfoBuilder.newBuilder(tn1).setStartKey(Bytes.toBytes(1))
      .setEndKey(Bytes.toBytes(2)).build(), 1024L * 256L);

    SpaceQuotaSnapshot tn1Snapshot =
      new SpaceQuotaSnapshot(SpaceQuotaStatus.notInViolation(), 1024L * 768L, 1024L * 1024L);

    // Below the quota
    assertEquals(tn1Snapshot, store.getTargetState(tn1, quota));

    regionReports.put(RegionInfoBuilder.newBuilder(tn1).setStartKey(Bytes.toBytes(2))
      .setEndKey(Bytes.toBytes(3)).build(), 1024L * 256L);
    tn1Snapshot =
      new SpaceQuotaSnapshot(SpaceQuotaStatus.notInViolation(), 1024L * 1024L, 1024L * 1024L);

    // Equal to the quota is still in observance
    assertEquals(tn1Snapshot, store.getTargetState(tn1, quota));

    regionReports.put(RegionInfoBuilder.newBuilder(tn1).setStartKey(Bytes.toBytes(3))
      .setEndKey(Bytes.toBytes(4)).build(), 1024L);
    tn1Snapshot = new SpaceQuotaSnapshot(new SpaceQuotaStatus(SpaceViolationPolicy.DISABLE),
      1024L * 1024L + 1024L, 1024L * 1024L);

    // Exceeds the quota, should be in violation
    assertEquals(tn1Snapshot, store.getTargetState(tn1, quota));
  }

  @Test
  public void testGetSpaceQuota() throws Exception {
    TableQuotaSnapshotStore mockStore = mock(TableQuotaSnapshotStore.class);
    when(mockStore.getSpaceQuota(any())).thenCallRealMethod();

    Quotas quotaWithSpace = Quotas.newBuilder().setSpace(SpaceQuota.newBuilder().setSoftLimit(1024L)
      .setViolationPolicy(QuotaProtos.SpaceViolationPolicy.DISABLE).build()).build();
    Quotas quotaWithoutSpace = Quotas.newBuilder().build();

    AtomicReference<Quotas> quotaRef = new AtomicReference<>();
    when(mockStore.getQuotaForTable(any())).then(new Answer<Quotas>() {
      @Override
      public Quotas answer(InvocationOnMock invocation) throws Throwable {
        return quotaRef.get();
      }
    });

    quotaRef.set(quotaWithSpace);
    assertEquals(quotaWithSpace.getSpace(), mockStore.getSpaceQuota(TableName.valueOf("foo")));
    quotaRef.set(quotaWithoutSpace);
    assertNull(mockStore.getSpaceQuota(TableName.valueOf("foo")));
  }

  void mockNoSnapshotSizes() throws IOException {
    Table quotaTable = mock(Table.class);
    ResultScanner scanner = mock(ResultScanner.class);
    when(conn.getTable(QuotaTableUtil.QUOTA_TABLE_NAME)).thenReturn(quotaTable);
    when(quotaTable.getScanner(any(Scan.class))).thenReturn(scanner);
    when(scanner.iterator()).thenReturn(Collections.<Result> emptyList().iterator());
  }
}
