// SPDX-FileCopyrightText: 2024 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include <cstring>

#include "JFConversionFloatingPoint.h"

JFConversionFloatingPoint::JFConversionFloatingPoint()
: gain_g0(RAW_MODULE_SIZE), gain_g1(RAW_MODULE_SIZE), gain_g2(RAW_MODULE_SIZE),
pedestal_g0(RAW_MODULE_SIZE), pedestal_g1(RAW_MODULE_SIZE), pedestal_g2(RAW_MODULE_SIZE) {}

JFConversionFloatingPoint::JFConversionFloatingPoint(const DiffractionExperiment &experiment) : JFConversionFloatingPoint() {
    threshold = experiment.GetPixelValueLowThreshold();
    summation = experiment.GetSummation();
    pixel_signed = experiment.IsPixelSigned();
    fixed_g1 = experiment.IsFixedGainG1();

    if (experiment.GetByteDepthImage() == 2) {
        if (pixel_signed) {
            err_pixel = INT16_MIN;
            overload_pixel = INT16_MAX;
            overload_value = overload_pixel;
        } else {
            err_pixel = UINT16_MAX;
            overload_pixel = UINT16_MAX;
            overload_value = overload_pixel;
        }
    } else if (experiment.GetByteDepthImage() == 4) {
        if (pixel_signed) {
            err_pixel = INT32_MIN;
            overload_pixel = INT32_MAX;
            overload_value = INT24_MAX;
        } else {
            err_pixel = UINT32_MAX;
            overload_pixel = UINT32_MAX;
            overload_value = INT24_MAX;
        }
    } else if (experiment.GetByteDepthImage() == 1) {
        if (pixel_signed) {
            err_pixel = INT8_MIN;
            overload_pixel = INT8_MAX;
            overload_value = overload_pixel;
        } else {
            err_pixel = UINT8_MAX;
            overload_pixel = UINT8_MAX;
            overload_value = overload_pixel;
        }
    }
}

inline double one_over_gain_energy(double gain_factor, double energy) {
    double tmp = gain_factor * energy;
    if (!std::isfinite(tmp) || (tmp == 0.0))
        return 0.0;
    else
        return static_cast<float>(1.0 / (gain_factor * energy));
}

void JFConversionFloatingPoint::Setup(const JFModuleGainCalibration &gain_calibration,
                                 const JFModulePedestal &in_pedestal_g0,
                                 const JFModulePedestal &in_pedestal_g1,
                                 const JFModulePedestal &in_pedestal_g2,
                                 double energy, bool using_gain_hg0) {
    memcpy(pedestal_g0.data(), in_pedestal_g0.GetPedestal(), RAW_MODULE_SIZE * sizeof(uint16_t));
    memcpy(pedestal_g1.data(), in_pedestal_g1.GetPedestal(), RAW_MODULE_SIZE * sizeof(uint16_t));
    memcpy(pedestal_g2.data(), in_pedestal_g2.GetPedestal(), RAW_MODULE_SIZE * sizeof(uint16_t));

    auto &gain_arr = gain_calibration.GetGainCalibration();
    for (int i = 0; i < RAW_MODULE_SIZE; i++) {
        if (using_gain_hg0)
            gain_g0[i] = one_over_gain_energy(gain_arr[i + 3 * RAW_MODULE_SIZE], energy);
        else
            gain_g0[i] = one_over_gain_energy(gain_arr[i], energy);
        if (fixed_g1)
            gain_g1[i] = one_over_gain_energy(gain_arr[i + RAW_MODULE_SIZE], energy)
                         * -1.0 * JFModuleGainCalibration::fixed_g1_gain_coeff;
        else
            gain_g1[i] = one_over_gain_energy(gain_arr[i + RAW_MODULE_SIZE], energy);
        gain_g2[i] = one_over_gain_energy(gain_arr[i + 2 * RAW_MODULE_SIZE], energy);
    }
}

void JFConversionFloatingPoint::ConvertFP(double *dest, const uint16_t *source) {
    for (size_t i = 0; i < RAW_MODULE_SIZE; i++) {
        uint16_t gainbits = source[i] & 0xc000;
        uint16_t adc = source[i] & 0x3fff;
        int16_t pedestal_subtracted_adu;

        double expected = err_pixel;
        bool special_val = false;

        switch (gainbits) {
            case 0:
                pedestal_subtracted_adu = adc - pedestal_g0[i];
                expected = static_cast<double>(pedestal_subtracted_adu) * gain_g0[i];
                if (fixed_g1
                    || (gain_g0[i] == 0.0)
                    || (adc == 0x0000)
                    || (adc == 0x3fff))
                    expected = err_pixel, special_val = true;
                break;
            case 0x4000:
                pedestal_subtracted_adu = adc - pedestal_g1[i];
                expected = static_cast<double>(pedestal_subtracted_adu) * gain_g1[i];
                if (adc == 0x000) expected = err_pixel, special_val = true;
                if (fixed_g1 && (adc == 0x3fff)) expected = overload_pixel, special_val = true;
                if (gain_g1[i] == 0.0)
                    expected = err_pixel, special_val = true;
                break;
            case 0xc000:
                pedestal_subtracted_adu = adc - pedestal_g2[i];
                expected = static_cast<double>(pedestal_subtracted_adu) * gain_g2[i];
                if (fixed_g1 || (gain_g2[i] == 0.0) || (adc == 0x3fff))
                    expected = err_pixel, special_val = true;
                else if (adc == 0x0000)
                    expected = overload_pixel, special_val = true;
                break;
            default:
                expected = err_pixel, special_val = true;;
                break;
        }

        if (threshold && (std::lround(expected) < threshold) && !special_val)
            expected = 0;

        if ((summation > 1) && !special_val)
            expected *= summation;

        if ((expected >= overload_value) && !special_val)
            expected = overload_pixel;

        if ((!pixel_signed) && (expected < 0))
            dest[i] = 0;
        else
            dest[i] = expected;
    }
}