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

#pragma once

#include <cstdint>
#include <optional>
#include <string>
#include <vector>

// A CrystFEL detector geometry file (.geom), as far as it places pixels and says what they are worth:
// the panels with their pixel ranges in the stored frame, fast/slow-scan directions and corners, the
// camera length, the pixel size, the gain and the regions to leave out. Both the current syntax and
// the older one - global keys that only take effect for the panels that follow them, bad regions
// stated in whole-frame coordinates - are read.
//
// Every length is in pixels except clen and coffset, which are in metres. A value CrystFEL takes from
// the image file instead (clen = /path, photon_energy = /path) is kept as that path, for the reader
// to resolve.
namespace crystfel {

struct Panel {
    std::string name;
    int64_t min_fs = 0, max_fs = 0, min_ss = 0, max_ss = 0;   // inclusive, in the stored frame
    double fs_x = 1, fs_y = 0, ss_x = 0, ss_y = 1;
    double corner_x = 0, corner_y = 0;
    double res = 0;                // pixels per metre
    std::string clen;              // metres, or an HDF5 path
    double coffset = 0;            // metres
    std::optional<double> adu_per_eV;
    std::optional<double> adu_per_photon;
    std::optional<double> max_adu;
    bool no_index = false;
};

// A region to leave out: either a pixel range on one panel (or, in the old syntax, on the whole
// frame), or a box in the laboratory plane, in pixels.
struct BadRegion {
    std::string panel;             // empty: fs/ss are whole-frame coordinates
    bool in_lab = false;
    double min_x = 0, max_x = 0, min_y = 0, max_y = 0;
    int64_t min_fs = 0, max_fs = 0, min_ss = 0, max_ss = 0;
};

struct Geometry {
    std::vector<Panel> panels;
    std::vector<BadRegion> bad;
    std::string data = "/data/data";
    std::string photon_energy;     // eV, or an HDF5 path
    std::string mask;              // HDF5 path, or empty
    std::string mask_file;         // file holding it, or empty for the image file itself
    uint32_t mask_good = 0, mask_bad = 0;
};

Geometry Read(const std::string &filename);

}  // namespace crystfel