/*
 * 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.regionserver;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;

import java.util.HashMap;
import java.util.Map;
import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
import org.apache.hadoop.hbase.testclassification.MetricsTests;
import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.junit.jupiter.api.Tag;
import org.junit.jupiter.api.Test;

@Tag(MetricsTests.TAG)
@Tag(SmallTests.TAG)
public class TestMetricsRegionSourceImpl {

  @SuppressWarnings("SelfComparison")
  @Test
  public void testCompareToHashCodeEquals() {
    MetricsRegionServerSourceFactory fact =
      CompatibilitySingletonFactory.getInstance(MetricsRegionServerSourceFactory.class);

    MetricsRegionSource one = fact.createRegion(new RegionWrapperStub("TEST"));
    MetricsRegionSource oneClone = fact.createRegion(new RegionWrapperStub("TEST"));
    MetricsRegionSource two = fact.createRegion(new RegionWrapperStub("TWO"));

    assertEquals(0, one.compareTo(oneClone));
    assertEquals(one.hashCode(), oneClone.hashCode());
    assertNotEquals(one, two);

    assertNotEquals(0, one.compareTo(two));
    assertNotEquals(0, two.compareTo(one));
    assertNotEquals(one.compareTo(two), two.compareTo(one));
    assertEquals(0, two.compareTo(two));
  }

  @Test
  public void testNoGetRegionServerMetricsSourceImpl() {
    // This should throw an exception because MetricsRegionSourceImpl should only
    // be created by a factory.
    assertThrows(RuntimeException.class, () -> {
      CompatibilitySingletonFactory.getInstance(MetricsRegionSource.class);
    });
  }

  static class RegionWrapperStub implements MetricsRegionWrapper {

    private String regionName;

    RegionWrapperStub(String regionName) {
      this.regionName = regionName;
    }

    @Override
    public String getTableName() {
      return null;
    }

    @Override
    public String getNamespace() {
      return null;
    }

    @Override
    public String getRegionName() {
      return this.regionName;
    }

    @Override
    public long getNumStores() {
      return 0;
    }

    @Override
    public long getNumStoreFiles() {
      return 0;
    }

    @Override
    public long getStoreRefCount() {
      return 0;
    }

    @Override
    public long getMaxCompactedStoreFileRefCount() {
      return 0;
    }

    @Override
    public long getMemStoreSize() {
      return 0;
    }

    @Override
    public long getMemStoreHeapSize() {
      return 0;
    }

    @Override
    public long getMemStoreOffHeapSize() {
      return 0;
    }

    @Override
    public long getStoreFileSize() {
      return 0;
    }

    @Override
    public long getReadRequestCount() {
      return 0;
    }

    @Override
    public long getFilteredReadRequestCount() {
      return 0;
    }

    @Override
    public long getMaxStoreFileAge() {
      return 0;
    }

    @Override
    public long getMinStoreFileAge() {
      return 0;
    }

    @Override
    public long getAvgStoreFileAge() {
      return 0;
    }

    @Override
    public long getNumReferenceFiles() {
      return 0;
    }

    @Override
    public long getWriteRequestCount() {
      return 0;
    }

    @Override
    public long getNumFilesCompacted() {
      return 0;
    }

    @Override
    public long getNumBytesCompacted() {
      return 0;
    }

    @Override
    public long getLastMajorCompactionAge() {
      return 0;
    }

    @Override
    public long getNumCompactionsCompleted() {
      return 0;
    }

    @Override
    public long getNumCompactionsFailed() {
      return 0;
    }

    @Override
    public int getRegionHashCode() {
      return regionName.hashCode();
    }

    /**
     * Always return 0 for testing
     */
    @Override
    public int getReplicaId() {
      return 0;
    }

    @Override
    public long getNumCompactionsQueued() {
      return 0;
    }

    @Override
    public long getNumFlushesQueued() {
      return 0;
    }

    @Override
    public long getMaxCompactionQueueSize() {
      return 0;
    }

    @Override
    public long getMaxFlushQueueSize() {
      return 0;
    }

    @Override
    public long getTotalRequestCount() {
      return 0;
    }

    @Override
    public Map<String, Long> getMemstoreOnlyRowReadsCount() {
      Map<String, Long> map = new HashMap<String, Long>();
      map.put("info", 0L);
      return map;
    }

    @Override
    public Map<String, Long> getMixedRowReadsCount() {
      Map<String, Long> map = new HashMap<String, Long>();
      map.put("info", 0L);
      return map;
    }
  }
}
