// Copyright (2019-2024) Paul Scherrer Institute

#include "AzimuthalIntegration.h"
#include "../common/JFJochException.h"
#include "../common/RawToConvertedGeometry.h"
#include "../common/DiffractionGeometry.h"

AzimuthalIntegration::AzimuthalIntegration(const DiffractionExperiment& experiment, const AzimuthalIntegrationMapping &mapping) :
        pixel_to_bin(experiment.GetPixelsNum(), UINT16_MAX),
        corrections(experiment.GetPixelsNum(), 1.0),
        nbins(mapping.GetBinNumber()),
        sum(mapping.GetBinNumber(), 0),
        count(mapping.GetBinNumber(), 0)
{
    auto mapping_raw = mapping.GetPixelToBinMappingRaw();
    RawToConvertedGeometry(experiment, pixel_to_bin.data(), mapping_raw.data());

    auto &bin_to_q = mapping.GetBinToQ();

    solid_angle_corr.resize(mapping.GetBinNumber());
    for (int i = 0; i < mapping.GetBinNumber(); i++)
        solid_angle_corr[i] = 1.0 / CalcAzIntSolidAngleCorr(experiment, bin_to_q[i]);
}

void AzimuthalIntegration::Process(const int16_t *data, size_t npixel) {
    if (npixel != pixel_to_bin.size())
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid,
                              "Mismatch in size of pixel-to-bin mapping and image");

    for (int i = 0; i < npixel; i++) {
        auto bin = pixel_to_bin[i];
        auto value  = data[i];
        if ((value > INT16_MIN + 4) && (value < INT16_MAX - 4) && (bin < nbins)) {
            sum[bin]   += value;
            count[bin] += 1;
        }
    }
}

void AzimuthalIntegration::GetResult(std::vector<double> &result) const {
    result.resize(nbins);

    for (int i = 0; i < nbins; i++) {
        if (count[i] > 0)
            result[i] = static_cast<double>(sum[i]) / static_cast<double>(count[i]) * solid_angle_corr[i];
        else
            result[i] = 0;
    }
}