// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include "ImagePreprocessorCPU.h"

ImagePreprocessorCPU::ImagePreprocessorCPU(const DiffractionExperiment &experiment, const PixelMask &mask)
    : ImagePreprocessor(experiment),
      mask_1bit(npixels, false) {
    for (int i = 0; i < npixels; i++)
        mask_1bit[i] = (mask.GetMask().at(i) != 0);
}

ImageStatistics ImagePreprocessorCPU::Analyze(ImagePreprocessorBuffer &processed_image, const uint8_t *image_ptr, CompressedImageMode image_mode) {
    if (processed_image.size() != npixels)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Processed image size mismatch");

    ImageStatistics ret{};
    AnalyzeBlock(processed_image, 0, image_ptr, npixels, image_mode, ret);
    return ret;
}

void ImagePreprocessorCPU::AnalyzeBlock(ImagePreprocessorBuffer &processed_image, size_t first, const uint8_t *input,
                                        size_t n, CompressedImageMode image_mode, ImageStatistics &stats) {
    switch (image_mode) {
        case CompressedImageMode::Int8:
            return AnalyzeBlock<int8_t>(processed_image, first, input, n, INT8_MIN, INT8_MAX, stats);
        case CompressedImageMode::Int16:
            return AnalyzeBlock<int16_t>(processed_image, first, input, n, INT16_MIN, INT16_MAX, stats);
        case CompressedImageMode::Int32:
            return AnalyzeBlock<int32_t>(processed_image, first, input, n, INT32_MIN, INT32_MAX, stats);
        case CompressedImageMode::Uint8:
            return AnalyzeBlock<uint8_t>(processed_image, first, input, n, UINT8_MAX, UINT8_MAX, stats);
        case CompressedImageMode::Uint16:
            return AnalyzeBlock<uint16_t>(processed_image, first, input, n, UINT16_MAX, UINT16_MAX, stats);
        case CompressedImageMode::Uint32:
            return AnalyzeBlock<uint32_t>(processed_image, first, input, n, UINT32_MAX, UINT32_MAX, stats);
        default:
            throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "RGB/float mode not supported");
    }
}

template<class T>
void ImagePreprocessorCPU::AnalyzeBlock(ImagePreprocessorBuffer &processed_image, size_t first, const uint8_t *input,
                                        size_t n, T err_pixel_val, T sat_pixel_val, ImageStatistics &ret) {
    auto image = reinterpret_cast<const T *>(input);
    int32_t *out = processed_image.data() + first;

    if (sat_pixel_val > saturation_limit)
        sat_pixel_val = static_cast<T>(saturation_limit);

    for (size_t i = 0; i < n; i++) {
        if (mask_1bit[first + i] != 0) {
            out[i] = INT32_MIN;
            ++ret.masked_pixel_count;
        } else if (image[i] == err_pixel_val) {
            // Error/invalid marker = the pixel type's extreme value (0xFFFFFFFF for EIGER uint32).
            // Tested before saturation, since for unsigned types the marker also exceeds sat_pixel_val
            // (which is clipped above to the HDF5 saturation_value).
            out[i] = INT32_MIN;
            ++ret.error_pixel_count;
        } else if (image[i] >= sat_pixel_val) {
            out[i] = INT32_MAX;
            ++ret.saturated_pixel_count;
        } else {
            out[i] = static_cast<int32_t>(image[i]);
            if (image[i] > ret.max_value)
                ret.max_value = image[i];
            if (image[i] < ret.min_value)
                ret.min_value = image[i];
        }
    }
}