/*
 * 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.iotdb.db.queryengine.metric;

import org.apache.iotdb.commons.service.metric.enums.Metric;
import org.apache.iotdb.commons.service.metric.enums.Tag;
import org.apache.iotdb.db.storageengine.buffer.ChunkCache;
import org.apache.iotdb.metrics.AbstractMetricService;
import org.apache.iotdb.metrics.metricsets.IMetricSet;
import org.apache.iotdb.metrics.utils.MetricLevel;
import org.apache.iotdb.metrics.utils.MetricType;

import java.util.Objects;

public class ChunkCacheMetrics implements IMetricSet {

  private final ChunkCache chunkCache;

  public ChunkCacheMetrics(ChunkCache chunkCache) {
    this.chunkCache = chunkCache;
  }

  @Override
  public void bindTo(AbstractMetricService metricService) {
    metricService.createAutoGauge(
        Metric.CACHE_HIT_RATE.toString(),
        MetricLevel.IMPORTANT,
        chunkCache,
        ChunkCache::getHitRate,
        Tag.NAME.toString(),
        "chunk");
  }

  @Override
  public void unbindFrom(AbstractMetricService metricService) {
    metricService.remove(
        MetricType.AUTO_GAUGE, Metric.CACHE_HIT_RATE.toString(), Tag.NAME.toString(), "chunk");
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }
    ChunkCacheMetrics that = (ChunkCacheMetrics) o;
    return Objects.equals(chunkCache, that.chunkCache);
  }

  @Override
  public int hashCode() {
    return Objects.hash(chunkCache);
  }
}
