/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  package org.apache.hc.client5.http.impl.classic;
  
  import java.util.concurrent.atomic.AtomicLong;
  
  /**
   * Collection of different counters used to gather metrics for {@link FutureRequestExecutionService}.
   */
  public final class FutureRequestExecutionMetrics {
  
      private final AtomicLong activeConnections = new AtomicLong();
      private final AtomicLong scheduledConnections = new AtomicLong();
      private final DurationCounter successfulConnections = new DurationCounter();
      private final DurationCounter failedConnections = new DurationCounter();
      private final DurationCounter requests = new DurationCounter();
      private final DurationCounter tasks = new DurationCounter();
  
      FutureRequestExecutionMetrics() {
      }
  
      AtomicLong getActiveConnections() {
          return activeConnections;
      }
  
      AtomicLong getScheduledConnections() {
          return scheduledConnections;
      }
  
      DurationCounter getSuccessfulConnections() {
          return successfulConnections;
      }
  
      DurationCounter getFailedConnections() {
          return failedConnections;
      }
  
      DurationCounter getRequests() {
          return requests;
      }
  
      DurationCounter getTasks() {
          return tasks;
      }
  
      public long getActiveConnectionCount() {
          return activeConnections.get();
      }
  
      public long getScheduledConnectionCount() {
          return scheduledConnections.get();
      }
  
      public long getSuccessfulConnectionCount() {
          return successfulConnections.count();
      }
  
      public long getSuccessfulConnectionAverageDuration() {
          return successfulConnections.averageDuration();
      }
  
      public long getFailedConnectionCount() {
          return failedConnections.count();
      }
  
      public long getFailedConnectionAverageDuration() {
          return failedConnections.averageDuration();
      }
  
      public long getRequestCount() {
          return requests.count();
      }
  
      public long getRequestAverageDuration() {
          return requests.averageDuration();
     }
 
     public long getTaskCount() {
         return tasks.count();
     }
 
     public long getTaskAverageDuration() {
         return tasks.averageDuration();
     }
 
     @Override
     public String toString() {
         final StringBuilder builder = new StringBuilder();
         builder.append("[activeConnections=").append(activeConnections)
                 .append(", scheduledConnections=").append(scheduledConnections)
                 .append(", successfulConnections=").append(successfulConnections)
                 .append(", failedConnections=").append(failedConnections)
                 .append(", requests=").append(requests)
                 .append(", tasks=").append(tasks)
                 .append("]");
         return builder.toString();
     }
 
     /**
      * A counter that can measure duration and number of events.
      */
     static class DurationCounter {
 
         private final AtomicLong count = new AtomicLong(0);
         private final AtomicLong cumulativeDuration = new AtomicLong(0);
 
         public void increment(final long startTime) {
             count.incrementAndGet();
             cumulativeDuration.addAndGet(System.currentTimeMillis() - startTime);
         }
 
         public long count() {
             return count.get();
         }
 
         public long averageDuration() {
             final long counter = count.get();
             return counter > 0 ? cumulativeDuration.get() / counter : 0;
         }
 
         @Override
         public String toString() {
             final StringBuilder builder = new StringBuilder();
             builder.append("[count=").append(count())
                     .append(", averageDuration=").append(averageDuration())
                     .append("]");
             return builder.toString();
         }
 
     }
 
 }