qgsdatetimestatisticalsummary.h

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/***************************************************************************
  qgsdatetimestatisticalsummary.h
  -------------------------------
  Date                 : May 2016
  Copyright            : (C) 2016 by Nyall Dawson
  Email                : nyall dot dawson at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSDATETIMESTATISTICALSUMMARY_H
#define QGSDATETIMESTATISTICALSUMMARY_H

#include "qgis_core.h"
#include "qgis.h"
#include "qgsinterval.h"
#include <QSet>
#include <QDateTime>
#include <QVariantList>

/***************************************************************************
 * This class is considered CRITICAL and any change MUST be accompanied with
 * full unit tests in test_qgsdatetimestatisticalsummary.py.
 * See details in QEP #17
 ****************************************************************************/

class CORE_EXPORT QgsDateTimeStatisticalSummary
{
  public:

    enum Statistic
    {
      Count = 1,  
      CountDistinct = 2,  
      CountMissing = 4,  
      Min = 8, 
      Max = 16, 
      Range = 32, 
      All = Count | CountDistinct | CountMissing | Min | Max | Range, 
    };
    Q_DECLARE_FLAGS( Statistics, Statistic )

    
    QgsDateTimeStatisticalSummary( QgsDateTimeStatisticalSummary::Statistics stats = All );

    Statistics statistics() const { return mStatistics; }

    void setStatistics( Statistics stats ) { mStatistics = stats; }

    void reset();

    void calculate( const QVariantList &values );

    void addValue( const QVariant &value );

    void finalize();

    QVariant statistic( QgsDateTimeStatisticalSummary::Statistic stat ) const;

    int count() const { return mCount; }

    int countDistinct() const { return mValues.count(); }

    QSet< QDateTime > distinctValues() const { return mValues; }

    int countMissing() const { return mCountMissing; }

    QDateTime min() const { return mMin; }

    QDateTime max() const { return mMax; }

    QgsInterval range() const { return mMax - mMin; }

    static QString displayName( QgsDateTimeStatisticalSummary::Statistic statistic );

  private:

    Statistics mStatistics;

    int mCount;
    QSet< QDateTime > mValues;
    int mCountMissing;
    QDateTime mMin;
    QDateTime mMax;
    bool mIsTimes;

    void testDateTime( const QDateTime &dateTime );
};

Q_DECLARE_OPERATORS_FOR_FLAGS( QgsDateTimeStatisticalSummary::Statistics )

#endif // QGSDATETIMESTATISTICALSUMMARY_H