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

#include "RugnuxDefaults.h"

namespace {
    // Smoothing range for the per-frame scale G on rotation data (XDS DELPHI-like), in degrees.
    constexpr double SMOOTH_G_DEG = 5.0;
    // Per-observation outlier rejection for the rotation combine, in sigma.
    constexpr double REJECT_OUTLIERS_NSIGMA = 6.0;
}

void ApplyRugnuxExperimentDefaults(DiffractionExperiment &experiment) {
    // The Lp correction the integrator applies to every reflection. Without it the intensities carry an
    // azimuthal, intensity-proportional modulation (~1.3x at 2 A for a 1 A beam) that symmetry mates do
    // NOT share, because they sit at the same 2-theta but a different azimuth - which is exactly the
    // "unequal intensities forced together" signature the space-group search vetoes as pseudo-symmetry.
    experiment.PolarizationFactor(0.99);
}

void ClearStoredCrystal(DiffractionExperiment &experiment) {
    experiment.SpaceGroupNumber(std::nullopt);
    experiment.SetUnitCell(std::nullopt);
}

ScalingSettings RugnuxDefaultScalingSettings(bool rotation) {
    ScalingSettings s;

    // Refit the per-frame scale on the combined fulls. Rotation only - it is what lifts ISa there, and
    // there is no combine on the stills path.
    s.ScaleFulls(rotation);
    s.SmoothGDegrees(rotation ? SMOOTH_G_DEG : 0.0);

    // Drop edge-of-sweep fulls whose rocking curve was captured less than this. 0.7 rather than 0.5 also
    // strips the partiality-extrapolated fulls that dominate the intensity second moment on weakly
    // diffracting crystals, without which the de-novo space-group search is starved by the error-model
    // I/sigma floor and falls back to P1.
    s.MinCapturedFraction(rotation ? 0.7 : 0.0);

    // Capture-aware systematic sigma: down-weights the over-extrapolated under-captured fulls.
    s.CaptureUncertaintyCoeff(rotation ? 1.0 : 0.0);

    // A single un-rejected artifact wrecks the intensity-correlation and second-moment statistics the
    // space-group and twinning tests are built on.
    s.OutlierRejectNsigma(rotation ? REJECT_OUTLIERS_NSIGMA : 0.0);

    // Run the de-novo space-group search a second time on a merge of only the well-measured
    // observations and keep whichever found more symmetry. It cannot lose symmetry, so an imperfect cut
    // only means the second opinion contributes nothing.
    s.SearchMinZeta(rotation ? 0.85 : 0.0);

    return s;
}