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

#include "ROIIntegration.h"
#include "../../common/DiffractionExperiment.h"

#include <algorithm>
#include <cmath>

ROIIntegration::ROIIntegration(const DiffractionExperiment &experiment)
    : roi_map(experiment.ExportROIMap()),
      width(experiment.GetXPixelsNumConv()),
      npixel(roi_map.size()),
      roi_count(experiment.ROI().size()),
      roi_name(roi_count),
      roi_sum(roi_count),
      roi_sum2(roi_count),
      roi_pixels(roi_count),
      roi_x_weighted(roi_count),
      roi_y_weighted(roi_count),
      roi_max(roi_count),
      modules(experiment.GetModules()),
      panel_slots(std::max<size_t>(modules.size(), 1)),
      roi_panel_v(roi_count * panel_slots),
      roi_panel_x(roi_count * panel_slots),
      roi_panel_y(roi_count * panel_slots) {
    for (const auto &[name, id] : experiment.ROI().GetROINameMap())
        roi_name[id] = name;
}

void ROIIntegration::PlaceWeighted() {
    for (uint16_t r = 0; r < roi_count; r++) {
        if (modules.empty()) {
            roi_x_weighted[r] = roi_panel_x[r];
            roi_y_weighted[r] = roi_panel_y[r];
            continue;
        }
        // Sum over panels of v * (o + (x - x0) f + (y - y0) s).
        double x = 0, y = 0;
        for (size_t p = 0; p < modules.size(); p++) {
            const auto &m = modules[p];
            const size_t k = r * panel_slots + p;
            const auto v = static_cast<double>(roi_panel_v[k]);
            const auto u = static_cast<double>(roi_panel_x[k] - m.x0 * roi_panel_v[k]);
            const auto w = static_cast<double>(roi_panel_y[k] - m.y0 * roi_panel_v[k]);
            x += m.ox * v + m.fx * u + m.sx * w;
            y += m.oy * v + m.fy * u + m.sy * w;
        }
        roi_x_weighted[r] = std::llround(x);
        roi_y_weighted[r] = std::llround(y);
    }
}

void ROIIntegration::Export(std::map<std::string, ROIMessage> &out) const {
    for (uint16_t r = 0; r < roi_count; r++)
        out[roi_name[r]] = ROIMessage{
            .sum           = roi_sum[r],
            .sum_square    = roi_sum2[r],
            .max_count     = roi_max[r],
            .pixels        = roi_pixels[r],
            .pixels_masked = 0,
            .x_weighted    = roi_x_weighted[r],
            .y_weighted    = roi_y_weighted[r],
        };
}