/*
    * Copyright 2005 the original author or authors.
    * 
    * Licensed 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 net.sf.sensor.meter;
  
  
  /***
   * 
   * 
   * 
   * @author Age Mooy
   */
  public class MeterStatistics {
  
    // ==========================================================================
    // The nested MeterData
    // ==========================================================================
    
    /*** 
     * The nested MeterData instance that serves as the source of all statistics
     * reported by this instance.
     *  */
    private final MeterData meterData;
    
    // ==========================================================================
    // Fields
    // ==========================================================================
  
    private long currentValue = 0L;
    private long sumOfValues = 0L;
    private long averageValue = 0L;
    private long minimumValue = 0L;
    private long maximumValue = 0L;
    private long standardDeviation = 0L;
    
    private long numberOfValueChanges = 0L;
    private long sumOfSquaresOfValues = 0L;
    
    private long timeOfFirstUpdate = 0L;
    private long timeOfLastUpdate = 0L;
    
    
    // ==========================================================================
    // Construction
    // ==========================================================================
    
    /***
     * @param meterData 
     */
    public MeterStatistics(MeterData meterData) {
      this.meterData = meterData;
    }
    
    
    // ==========================================================================
    // Basic API
    // ==========================================================================
  
    /***
     * Returns the String label that uniquely identifies this instance.
     * @return the String label that uniquely identifies this instance.
     */
    public String getLabel() {
      return meterData.getLabel();
    }
  
    
    // ==========================================================================
    // Refreshing and resetting of statistics
    // ==========================================================================
    
    /***
     * Refreshes this instances and all its children.
     */
    public void refresh() {
      meterData.refreshStatistics();
    }
  
    /***
     * Callback method called from {@link MeterData#refreshStatistics(MeterStatistics)}
     * to update all statistics. Package private because it should only be called from
     * the associated {@link MeterData}.
     * 
     * @param currentValue the new value of currentValue.
     * @param numberOfValueChanges the new value of numberOfValueChanges.
     * @param sumOfValues the new value of sumOfValues.
    * @param averageValue the new value of averageValue.
    * @param standardDeviation the new value of standardDeviation.
    * @param minimumValue the new value of minimumValue.
    * @param maximumValue the new value of maximumValue.
    * @param timeOfFirstUpdate the new value of timeOfFirstUpdate.
    * @param timeOfLastUpdate the new value of timeOfLastUpdate.
    * @param sumOfSquaresOfValues the new value of sumOfSquaresOfValues.
    */
   public void refreshFromData(long currentValue, 
                               long numberOfValueChanges, 
                               long sumOfValues, 
                               long averageValue, 
                               long standardDeviation, 
                               long minimumValue, 
                               long maximumValue, 
                               long timeOfFirstUpdate, 
                               long timeOfLastUpdate, 
                               long sumOfSquaresOfValues) {
     this.currentValue = currentValue;
     this.numberOfValueChanges = numberOfValueChanges;
     this.sumOfValues = sumOfValues;
     this.averageValue = averageValue;
     this.standardDeviation = standardDeviation;
     this.minimumValue = minimumValue;
     this.maximumValue = maximumValue;
     this.timeOfFirstUpdate = timeOfFirstUpdate;
     this.timeOfLastUpdate = timeOfLastUpdate;
     this.sumOfSquaresOfValues = sumOfSquaresOfValues;
   }
   
   
   // ==========================================================================
   // Statistics API (Getters)
   // ==========================================================================
   
   /***
    * Returns the currentValue.
    * @return Returns the currentValue.
    */
   public long getCurrentValue() {
     return currentValue;
   }
   
   /***
    * Returns the numberOfValueChanges.
    * @return Returns the numberOfValueChanges.
    */
   public long getNumberOfValueChanges() {
     return numberOfValueChanges;
   }
   
   /***
    * Returns the sumOfValues.
    * @return Returns the sumOfValues.
    */
   public long getSumOfValues() {
     return sumOfValues;
   }
   
   /***
    * Returns the averageValue.
    * @return Returns the averageValue.
    */
   public long getAverageValue() {
     return averageValue;
   }
   
   /***
    * Returns the standardDeviation.
    * @return Returns the standardDeviation.
    */
   public long getStandardDeviation() {
     return standardDeviation;
   }
   
   /***
    * Returns the sumOfSquaresOfValues.
    * @return Returns the sumOfSquaresOfValues.
    */
   public long getSumOfSquaresOfValues() {
     return sumOfSquaresOfValues;
   }
   
   /***
    * Returns the minimumValue.
    * @return Returns the minimumValue.
    */
   public long getMinimumValue() {
     return minimumValue;
   }
   
   /***
    * Returns the maximumValue.
    * @return Returns the maximumValue.
    */
   public long getMaximumValue() {
     return maximumValue;
   }
   
   /***
    * Returns the timeOfFirstUpdate in millseconds since the usual 01-01-1970 00:00 UTC.
    * @return the timeOfFirstUpdate in millseconds since the usual 01-01-1970 00:00 UTC.
    */
   public long getTimeOfFirstUpdate() {
     return timeOfFirstUpdate;
   }
   
   /***
    * Returns the timeOfLastUpdate in millseconds since the usual 01-01-1970 00:00 UTC.
    * @return the timeOfLastUpdate in millseconds since the usual 01-01-1970 00:00 UTC.
    */
   public long getTimeOfLastUpdate() {
     return timeOfLastUpdate;
   }
 
   
   // ==========================================================================
   // Standard Object method overrides and simple debugging methods
   // ==========================================================================
   
   /***
    * @see java.lang.Object#toString()
    */
   public String toString() {
     return meterData.toString();
   }
   
 }