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

#pragma once

#include <QPainterPath>

#include "JFJochImage.h"
#include "../../reader/JFJochReaderImage.h"
#include "../../common/ROIDefinition.h"

class ROIAzimuthal;
class DiffractionGeometry;

class JFJochDiffractionImage : public JFJochImage {
Q_OBJECT

    QColor spot_color = Qt::green;
    QColor prediction_color = Qt::darkRed;
    QColor ice_ring_color = Qt::cyan;
    QColor second_lattice_color = QColor(0xFA, 0x72, 0x68);   // coral, the viewer "finishing" accent
    // With outlining on, spot markers are drawn twice: a black pen this much wider underneath,
    // then the marker on top. The hues mean something - cyan is the colour of ice, magenta is
    // the one colour no colour map contains - so none of them moves to gain contrast. The casing
    // carries the marker where the colour map's low end is light, the bright core carries it
    // where it is dark, so one mechanism covers both without branching on the colour map. It is
    // opt-in (default off): the doubled stroke makes the markers harder to read for some users.
    // Predictions are left alone: darkRed is already legible on a light map and a black casing
    // does nothing for it on a dark one.
    static constexpr int MARKER_CASING_EXTRA_WIDTH = 4;

    float hover_resolution = NAN;
    // The "d = ... A" readout is painted in drawForeground() in viewport pixels rather than kept
    // as a scene item, so updating it dirties only its own rect. hover_text_rect_ is where it
    // currently sits, in viewport coordinates.
    QRect hover_text_rect_;
    [[nodiscard]] QString HoverResolutionLabel() const;
    // Counts are exact integers: label them from the int32 image rather than from a float copy,
    // which both avoids materialising that copy and cannot round large summed values.
    [[nodiscard]] QString PixelLabel(int x, int y) const override;

    // This is the view that has detector counts, so it is the one that offers an ROI
    [[nodiscard]] bool AllowROI() const override { return true; }

    void drawForeground(QPainter *painter, const QRectF &rect) override;
    // The readout sits at a fixed viewport position, but QGraphicsView scrolls by blitting the
    // viewport, which carries the painted text along with it - so its old and new places both have
    // to be repainted when the view pans.
    void scrollContentsBy(int dx, int dy) override;
public:
    enum class RingMode {Auto, Estimation, Manual, None, IceRings};
    Q_ENUM(RingMode)

    JFJochDiffractionImage(QWidget *parent = nullptr);
private:

    void addCustomOverlay() override;
    void LoadImageInternal();
    // Colour straight from the int32 detector image; no float copy of it is ever built
    void ColorRow(size_t y, const PixelColorMap &map, QRgb *out) const override;

    void DrawResolutionRings();
    void DrawROIs();
    void DrawAzimuthalROI(const ROIAzimuthal &az, const QColor &color, const DiffractionGeometry &geom);
    void AddROILabel(const std::string &name, const QColor &color, float px, float py);

    // Interactive editing of the selected (named) ROI: move box/circle for now.
    bool roiEditPress(const QPointF &scenePos) override;
    void roiEditMove(const QPointF &scenePos) override;
    void roiEditRelease() override;
    void roiScratchDrawn() override;
    void keyPressEvent(QKeyEvent *event) override;   // Delete removes the selected ROI
    [[nodiscard]] ROIDefinition BuildEditedROIDefinition() const;   // current ROIs with the edit applied
    [[nodiscard]] ResizeHandle hitTestBoxHandle(const QRectF &r, const QPointF &p, qreal tol) const;
    // Grab points for an azimuthal ROI: inner/outer arc (resize Q/d) and the two phi
    // edges (rotate). The phi handles are only meaningful for a sector (HasPhi()).
    void azimuthalHandles(const ROIAzimuthal &az, const DiffractionGeometry &geom,
                          QPointF &inner, QPointF &outer, QPointF &phimin, QPointF &phimax) const;

    QString selected_roi_;
    enum class RoiEdit { None, MoveBox, ResizeBox, MoveCircle, ResizeCircle,
                         AzimInner, AzimOuter, RotatePhiMin, RotatePhiMax };
    RoiEdit roi_edit_ = RoiEdit::None;
    ResizeHandle box_handle_ = ResizeHandle::None;
    QString edit_name_;
    QRectF edit_box_;
    QPointF edit_center_;
    double edit_radius_ = 0;
    float edit_d_min_ = 0, edit_d_max_ = 0, edit_phi_min_ = 0, edit_phi_max_ = 0;   // azimuthal edit state
    bool edit_has_phi_ = false;
    QPointF move_last_;
    bool live_pending_ = false;   // a live edit is being recomputed; throttles emissions

    void DrawSpots();
    void DrawPredictions();
    void DrawBeamCenter();
    void DrawTopPixels();
    void DrawSaturation();
    void DrawResolutionText();
    void DrawCross(float x, float y, float size, float width, float z = 1);

    void UpdateForeground();
    // The foreground the current image suggests: the top of the valid range in HDR mode, the
    // auto-contrast value otherwise. Empty when there is no image to take it from.
    [[nodiscard]] std::optional<float> AutoForegroundValue() const;
    void ResetBackground();
    bool one_shot_auto_ = false;   // `A` applied the auto value; pressing it again makes Auto permanent
    void leaveEvent(QEvent *event) override;

    std::shared_ptr<const JFJochReaderImage> image;

    int32_t show_highest_pixels = 0;

    QVector<float> res_ring = {};

    // Constant-d contours traced for res_ring, kept across overlay rebuilds; see DrawResolutionRings
    QVector<float> ring_cache_key_ = {};
    QVector<std::pair<float, QPainterPath>> ring_cache_ = {};

    RingMode ring_mode = RingMode::Estimation;

    bool show_spots = false;
    bool show_predictions = false;

    bool show_roi_labels = false;
    bool show_roi_fill = false;

    bool highlight_ice_rings = true;

    bool hide_unindexed_spots = false;
    bool hide_ice_ring_spots = false;

    bool outline_spots = false;   // black casing under spot markers, see MARKER_CASING_EXTRA_WIDTH

    void mouseHover(const QPointF &scenePos, Qt::KeyboardModifiers modifiers) override;

    // The magnifier follows the cursor only while Shift is held, and meanwhile a frame here
    // shows the area it covers. magnifier_frame_ is empty while the frame is hidden.
    QSizeF magnifier_field_;
    QRectF magnifier_frame_;
    void SetMagnifierFrame(const QRectF &r);

signals:
    void magnifierMoved(QPointF scenePos);
    void roiGeometryEdited(ROIDefinition rois);
    void roiSelected(QString name);   // user picked an ROI by clicking it on the image
public slots:
    void setSelectedROI(QString name);
    void loadImage(std::shared_ptr<const JFJochReaderImage> image);
    void setAutoForeground(bool input);
    // Apply the auto-contrast value once, leaving Auto as it was; pressing it a second time on the
    // same image switches Auto on for good (which keeps recomputing it on every subsequent image).
    void oneShotAutoForeground();
    void setResolutionRing(QVector<float> v);
    void setResolutionRingMode(RingMode mode);

    void showSpots(bool input);
    void showPredictions(bool input);

    void showROILabels(bool input);
    void showROIFill(bool input);

    void setSpotColor(QColor input);
    void setPredictionColor(QColor input);

    void showHighestPixels(int32_t v);
    void showSaturation(bool input);
    void showBeamStop(bool input);

    void highlightIceRings(bool input);
    void hideUnindexedSpots(bool input);
    void hideIceRingSpots(bool input);
    void outlineSpots(bool input);
    void setHDRMode(bool input);
    void setMagnifierField(QSizeF size);
    void hideMagnifierFrame();
};