// SPDX-FileCopyrightText: 2025 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#pragma once

#include "HKLKey.h"
#include "Merge.h"
#include "../../common/DiffractionExperiment.h"
#include "../IntegrationOutcome.h"

#include <map>
#include <vector>


struct ScaleOnTheFlyResult {
    double G = 1.0;
    double cc = NAN;
    size_t cc_n = 0;
};

// Per-image reference scaling with the FIXED partiality model: each reflection's stored partiality is
// used as-is (it is 1 for stills and the zeta/erf rocking-curve value already set at prediction for
// rotation data). No partiality recompute, no mosaicity or wedge refinement: the fit is linear in G, a
// robust 1-D IRLS. Rotation self-scaling/merging offline uses the dedicated RotationScaleMerge path.
class ScaleOnTheFly {
    constexpr static size_t MIN_REFLECTIONS = 20;

    const ScalingSettings s;
    const HKLKeyGenerator hkl_key_generator;
    std::map<HKLKey, double> reference_data;

    bool Accept(const Reflection &r) const;
public:
    ScaleOnTheFly(const DiffractionExperiment &x, const std::vector<MergedReflection> &ref);

    void Scale(IntegrationOutcome &integration_outcome) const;
    void Scale(std::vector<IntegrationOutcome> &integration_outcome, size_t nthreads = 0) const;

    // Leave an image unscaled when its fitted scale collapsed far below the run median (see the .cpp).
    // Called by the multi-image Scale, which is where the run median exists; public so a caller that
    // scales images one at a time can apply it once it has them all.
    static void RejectCollapsedScales(std::vector<IntegrationOutcome> &integration);
};