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

#pragma once

#include <cstdint>
#include <map>
#include <string>
#include <vector>

#include "../../common/JFJochMessages.h"
#include "../image_preprocessing/ImagePreprocessorBuffer.h"

class DiffractionExperiment;

// Computes per-ROI statistics over an assembled image: sum, sum of squares,
// good-pixel count, maximum and intensity-weighted centre of mass. Each pixel
// carries a 16-bit mask selecting which of up to 16 ROIs it belongs to, so a
// single pixel can contribute to none, one, or several ROIs at once. This is
// the software counterpart of the FPGA roi_calc kernel.
class ROIIntegration {
protected:
    std::vector<uint16_t> roi_map;   // per-pixel ROI bitmask, assembled (converted) geometry
    size_t width;                    // assembled image width, to recover x/y from a pixel index
    size_t npixel;
    uint16_t roi_count;
    std::vector<std::string> roi_name;  // ROI name indexed by bit position

    // Result accumulators, filled by Run() in the derived class
    std::vector<int64_t>  roi_sum;
    std::vector<uint64_t> roi_sum2;
    std::vector<uint64_t> roi_pixels;
    std::vector<int64_t>  roi_x_weighted;
    std::vector<int64_t>  roi_y_weighted;
    std::vector<int64_t>  roi_max;

    void Export(std::map<std::string, ROIMessage> &out) const;
public:
    explicit ROIIntegration(const DiffractionExperiment &experiment);
    virtual ~ROIIntegration() = default;

    [[nodiscard]] uint16_t Count() const { return roi_count; }
    [[nodiscard]] bool empty() const { return roi_count == 0; }

    virtual void Run(const ImagePreprocessorBuffer &image, std::map<std::string, ROIMessage> &out) = 0;
};