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

#pragma once

#include <string>
#include <vector>

#include "Coord.h"

enum class TransformationType { Rotation, Translation };

// One axis of a NeXus NXtransformations chain, held the way NXmx needs it written and nothing more.
//
// Deliberately without any cleverness: the values are either a single number, meaning an axis that
// does not move, or one number per image. Nothing here derives a position from a start and an
// increment, because the point of the structure is to be able to carry positions that were MEASURED
// rather than inferred - a custom scan, a stage that did not go exactly where it was asked. A
// million images cost 4 MB per axis at this precision, which is not a reason to be clever.
//
// A chain is a std::vector<DetectorTransformation> ordered base first, sample last - the order
// things are mounted in, which is also the order NXmx composes them in. depends_on names the axis
// this one is mounted on, and is empty for the base.
class DetectorTransformation {
    std::string name;
    TransformationType type = TransformationType::Rotation;
    std::string units = "deg";
    Coord vector = {0, 0, 1};
    Coord offset = {0, 0, 0};
    std::string depends_on;             // empty = mounted on the base ("." in NXmx)
    std::string equipment;
    std::string equipment_component;
    std::vector<float> values;          // one entry = constant, otherwise one per image

public:
    DetectorTransformation() = default;
    DetectorTransformation(std::string name, TransformationType type, const Coord &vector);

    DetectorTransformation& Name(const std::string &input);
    DetectorTransformation& Type(TransformationType input);
    DetectorTransformation& Units(const std::string &input);
    DetectorTransformation& Vector(const Coord &input);
    DetectorTransformation& Offset(const Coord &input);
    DetectorTransformation& DependsOn(const std::string &input);
    DetectorTransformation& Equipment(const std::string &input);
    DetectorTransformation& EquipmentComponent(const std::string &input);
    DetectorTransformation& Values(const std::vector<float> &input);
    DetectorTransformation& Value(float input);          // an axis that does not move

    [[nodiscard]] const std::string& GetName() const;
    [[nodiscard]] TransformationType GetType() const;
    [[nodiscard]] const std::string& GetUnits() const;
    [[nodiscard]] Coord GetVector() const;
    [[nodiscard]] Coord GetOffset() const;
    [[nodiscard]] const std::string& GetDependsOn() const;
    [[nodiscard]] const std::string& GetEquipment() const;
    [[nodiscard]] const std::string& GetEquipmentComponent() const;
    [[nodiscard]] const std::vector<float>& GetValues() const;

    [[nodiscard]] bool IsRotation() const;
    // True when the axis holds one value for the whole run rather than one per image.
    [[nodiscard]] bool IsConstant() const;
};