/*
 * 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.phoenix.monitoring.connectionqueryservice;

import static org.apache.phoenix.monitoring.MetricType.OPEN_INTERNAL_PHOENIX_CONNECTIONS_COUNTER;
import static org.apache.phoenix.monitoring.MetricType.OPEN_PHOENIX_CONNECTIONS_COUNTER;
import static org.apache.phoenix.monitoring.MetricType.PHOENIX_CONNECTIONS_THROTTLED_COUNTER;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.conf.Configuration;
import org.apache.phoenix.monitoring.ConnectionQueryServicesMetric;
import org.apache.phoenix.monitoring.ConnectionQueryServicesMetricImpl;
import org.apache.phoenix.monitoring.MetricType;

/**
 * Class for Connection Query Service Metrics.
 */
public class ConnectionQueryServicesMetrics {
  /**
   * List Metrics tracked in Connection Query Service Metrics
   */
  public enum QueryServiceMetrics {
    CONNECTION_QUERY_SERVICE_OPEN_PHOENIX_CONNECTIONS_COUNTER(OPEN_PHOENIX_CONNECTIONS_COUNTER),
    CONNECTION_QUERY_SERVICE_OPEN_INTERNAL_PHOENIX_CONNECTIONS_COUNTER(
      OPEN_INTERNAL_PHOENIX_CONNECTIONS_COUNTER),
    CONNECTION_QUERY_SERVICE_PHOENIX_CONNECTIONS_THROTTLED_COUNTER(
      PHOENIX_CONNECTIONS_THROTTLED_COUNTER);

    private MetricType metricType;
    private ConnectionQueryServicesMetric metric;

    QueryServiceMetrics(MetricType metricType) {
      this.metricType = metricType;
    }
  }

  private final String connectionQueryServiceName;
  private Map<MetricType, ConnectionQueryServicesMetric> metricRegister;
  private ConnectionQueryServicesMetricsHistograms connectionQueryServiceMetricsHistograms;

  public ConnectionQueryServicesMetrics(final String connectionQueryServiceName,
    Configuration conf) {
    this.connectionQueryServiceName = connectionQueryServiceName;
    metricRegister = new HashMap<>();
    for (QueryServiceMetrics connectionQueryServiceMetric : QueryServiceMetrics.values()) {
      connectionQueryServiceMetric.metric =
        new ConnectionQueryServicesMetricImpl(connectionQueryServiceMetric.metricType);
      metricRegister.put(connectionQueryServiceMetric.metricType,
        connectionQueryServiceMetric.metric);
    }
    connectionQueryServiceMetricsHistograms =
      new ConnectionQueryServicesMetricsHistograms(connectionQueryServiceName, conf);
  }

  /**
   * This function is used to update the value of Metric In case of counter val will be passed as 1.
   * @param type metric type
   * @param val  update value. In case of counters, this will be 1
   */
  public void setMetricValue(MetricType type, long val) {
    if (!metricRegister.containsKey(type)) {
      return;
    }
    ConnectionQueryServicesMetric metric = metricRegister.get(type);
    metric.set(val);
  }

  /**
   * This function is used to get the value of Metric.
   * @param type metric type
   * @return val current value of metric.
   */
  public long getMetricValue(MetricType type) {
    if (!metricRegister.containsKey(type)) {
      return 0;
    }
    ConnectionQueryServicesMetric metric = metricRegister.get(type);
    return metric.getValue();
  }

  public String getConnectionQueryServiceName() {
    return connectionQueryServiceName;
  }

  /**
   * This method is called to aggregate all the Metrics across all Connection Query Service.
   * @return map of Connection Query Service name -> list of ConnectionQueryServicesMetric.
   */
  public List<ConnectionQueryServicesMetric> getAllMetrics() {
    return new ArrayList<>(metricRegister.values());
  }

  public ConnectionQueryServicesMetricsHistograms getConnectionQueryServiceHistograms() {
    return connectionQueryServiceMetricsHistograms;
  }
}
