//# Copyright (C) 2000,2001
//# Associated Universities, Inc. Washington DC, USA.
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//# under the terms of the GNU Library General Public License as published by
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#ifndef SCIMATH_CHAUVENETCRITERIONSTATISTICS_TCC
#define SCIMATH_CHAUVENETCRITERIONSTATISTICS_TCC

#include <casacore/scimath/StatsFramework/ChauvenetCriterionStatistics.h>

#include <casacore/scimath/StatsFramework/StatisticsIncrementer.h>
#include <casacore/scimath/StatsFramework/StatisticsUtilities.h>
#include <casacore/scimath/StatsFramework/ZScoreCalculator.h>

namespace casacore {

CASA_STATD
ChauvenetCriterionStatistics<CASA_STATP>::ChauvenetCriterionStatistics(
    Double zscore, Int maxIterations
)
  : ConstrainedRangeStatistics<CASA_STATP>(
        std::shared_ptr<ConstrainedRangeQuantileComputer<CASA_STATP>>(
            new ConstrainedRangeQuantileComputer<CASA_STATP>(
                &this->_getDataset()
            )
        )
    ),
    _zscore(zscore), _maxIterations(maxIterations) {}

CASA_STATD
ChauvenetCriterionStatistics<CASA_STATP>::ChauvenetCriterionStatistics(
    const ChauvenetCriterionStatistics<CASA_STATP>& other
) : ConstrainedRangeStatistics<CASA_STATP>(other), _zscore(other._zscore),
    _maxIterations(other._maxIterations), _rangeIsSet(other._rangeIsSet),
    _niter(other._niter) {}

CASA_STATD
ChauvenetCriterionStatistics<CASA_STATP>::~ChauvenetCriterionStatistics() {}

CASA_STATD
ChauvenetCriterionStatistics<CASA_STATP>&
ChauvenetCriterionStatistics<CASA_STATP>::operator=(
    const ChauvenetCriterionStatistics<CASA_STATP>& other
) {
    if (this == &other) {
        return *this;
    }
    ConstrainedRangeStatistics<CASA_STATP>::operator=(other);
    _zscore = other._zscore;
    _maxIterations = other._maxIterations;
    _rangeIsSet = other._rangeIsSet;
    _niter = other._niter;
    return *this;
}

CASA_STATD
StatisticsAlgorithm<CASA_STATP>*
ChauvenetCriterionStatistics<CASA_STATP>::clone() const {
    return new ChauvenetCriterionStatistics<CASA_STATP>(*this);
}

CASA_STATD
void ChauvenetCriterionStatistics<CASA_STATP>::reset() {
    ConstrainedRangeStatistics<CASA_STATP>::reset();
    _rangeIsSet = False;
    _niter = 0;
}

CASA_STATD
void ChauvenetCriterionStatistics<CASA_STATP>::setCalculateAsAdded(Bool c) {
    ThrowIf(
        c,
        "ChauvenetCriterionStatistics does not support calculating "
        "statistics incrementally as data sets are added"
    );
}

CASA_STATD
void ChauvenetCriterionStatistics<CASA_STATP>::_setRange() {
    if (_rangeIsSet) {
        return;
    }
    uInt maxI = _maxIterations >= 0 ? _maxIterations : 1000;
    uInt64 prevNpts = 0;
    StatsData<AccumType> sd;
    while (_niter <= maxI) {
        if (_niter == 0) {
            ClassicalStatistics<CASA_STATP> cs(*this);
            sd = cs.getStatistics();
        }
        else {
            sd = this->getStatistics();
            if ((uInt64)sd.npts == prevNpts) {
                break;
            }
        }
        Double zScore = _zscore >= 0
            ? _zscore : ZScoreCalculator::getMaxZScore((uInt64)sd.npts);
        auto range = std::make_shared<std::pair<AccumType, AccumType>>(
            sd.mean - zScore*sd.stddev, sd.mean + zScore*sd.stddev
        );
        ConstrainedRangeStatistics<CASA_STATP>::_setRange(range);
        // _rangeIsSet is set here to prevent infinite
        // recursion on next loop iteration
        _rangeIsSet = True;
        prevNpts = (uInt64)sd.npts;
        ++_niter;
    }
    --_niter;
}

}

#endif
