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

#include "ImagePreprocessorBuffer.h"

ImagePreprocessorBuffer::ImagePreprocessorBuffer(size_t npixels, bool host_mirror)
    : npixels(npixels), buffer(host_mirror ? npixels : 0) {}

ImagePreprocessorBuffer::ImagePreprocessorBuffer(size_t npixels)
    : ImagePreprocessorBuffer(npixels, true) {}

void ImagePreprocessorBuffer::Gather(const std::vector<uint32_t> &npixel, std::vector<int32_t> &values) const {
    values.resize(npixel.size());
    for (size_t i = 0; i < npixel.size(); i++)
        values[i] = buffer[npixel[i]];
}

int32_t *ImagePreprocessorBuffer::getGPUBuffer() {
    return nullptr;
}

const int32_t *ImagePreprocessorBuffer::getGPUBuffer() const {
    return nullptr;
}

const int32_t *ImagePreprocessorBuffer::GatherTiles(const std::vector<int32_t> &x, const std::vector<int32_t> &y,
                                                    int width, int half) {
    const int side = 2 * half + 1;
    const int height = static_cast<int>(npixels / width);
    tiles.resize(x.size() * side * side);
    int32_t *out = tiles.data();
    for (size_t i = 0; i < x.size(); i++)
        for (int py = y[i] - half; py <= y[i] + half; py++)
            for (int px = x[i] - half; px <= x[i] + half; px++)
                *out++ = (px < 0 || py < 0 || px >= width || py >= height)
                         ? INT32_MIN : buffer[static_cast<size_t>(py) * width + px];
    return tiles.data();
}

const int32_t *ImagePreprocessorBuffer::HostImage() {
    return buffer.data();
}