// Copyright (2019-2022) Paul Scherrer Institute
// SPDX-License-Identifier: GPL-3.0-or-later

#include "DetectorGeometry.h"
#include "JFJochException.h"
#include "Definitions.h"

DetectorGeometry::DetectorGeometry(const std::vector<DetectorModuleGeometry> &in_modules)
        : modules(in_modules) {
    if (modules.empty())
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Module number must be positive");

    width = 0;
    height = 0;

    for (auto &m: modules) {
        width = std::max<int64_t>(width, m.GetMaxX()+1);
        height = std::max<int64_t>(height, m.GetMaxY()+1);
    }
}

DetectorGeometry::DetectorGeometry(int32_t nmodules, int32_t horizontal_stacking, int32_t gap_x,
                                   int32_t gap_y, bool mirror_y) {
    if (horizontal_stacking <= 0)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Horizontal stacking must be positive");
    if (nmodules <= 0)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Module number must be positive");
    if (gap_x < 0)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Gap x has to be non-negative");
    if (gap_y < 0)
        throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Gap y has to be non-negative");
    if (nmodules < horizontal_stacking)
        horizontal_stacking = nmodules;

    width = horizontal_stacking * CONVERTED_MODULE_COLS + (horizontal_stacking - 1) * gap_x;
    int64_t conv_lines = nmodules / horizontal_stacking + (nmodules % horizontal_stacking > 0 ? 1 : 0);
    height = conv_lines * CONVERTED_MODULE_LINES + (conv_lines - 1) * gap_y;

    for (int module = 0; module < nmodules; module++) {
        int64_t module_x = module % horizontal_stacking;
        int64_t module_y = module / horizontal_stacking;

        int64_t x0 = module_x * (CONVERTED_MODULE_COLS + gap_x);
        int64_t y0 = module_y * (CONVERTED_MODULE_LINES + gap_y);

        DetectorModuleGeometry::Direction fast = DetectorModuleGeometry::Direction::Xpos;
        DetectorModuleGeometry::Direction slow;
        if (mirror_y) {
            y0 = height - y0 - 1;
            slow = DetectorModuleGeometry::Direction::Yneg;
        } else
            slow = DetectorModuleGeometry::Direction::Ypos;

        modules.emplace_back(x0, y0, fast, slow);
    }
}

DetectorGeometry::operator JFJochProtoBuf::DetectorGeometry() const {
    JFJochProtoBuf::DetectorGeometry ret;
    ret.set_height_pxl(height);
    ret.set_width_pxl(width);
    for (auto &m: modules) {
        auto mpbf = ret.add_module_geometry();
        mpbf->set_pixel0(m.GetPixel0_X() + width * m.GetPixel0_Y());
        mpbf->set_fast_direction_step(GetDirectionStep(m.GetFastAxis()));
        mpbf->set_slow_direction_step(GetDirectionStep(m.GetSlowAxis()));
    }
    return ret;
}

int64_t DetectorGeometry::GetDirectionStep(DetectorModuleGeometry::Direction direction) const {
    switch (direction) {
        case DetectorModuleGeometry::Direction::Xneg:
            return -1;
        case DetectorModuleGeometry::Direction::Xpos:
            return 1;
        case DetectorModuleGeometry::Direction::Yneg:
            return -width;
        case DetectorModuleGeometry::Direction::Ypos:
            return width;
        default:
            return 0;
    }
}

int64_t DetectorGeometry::GetModulesNum() const {
    return modules.size();
}