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

#include "JFJochImage.h"

#include <QScrollBar>
#include <QWheelEvent>

JFJochImage::JFJochImage(QWidget *parent) : QGraphicsView(parent) {
    setDragMode(QGraphicsView::NoDrag); // Disable default drag mode
    setTransformationAnchor(QGraphicsView::AnchorUnderMouse); // Zoom anchors
    setRenderHint(QPainter::Antialiasing); // Enable smooth rendering
    setRenderHint(QPainter::SmoothPixmapTransform);

    setFocusPolicy(Qt::ClickFocus);
    // Connect the horizontal scrollbar's valueChanged signal
    connect(horizontalScrollBar(), &QScrollBar::valueChanged, this, &JFJochImage::onScroll);

    // Connect the vertical scrollbar's valueChanged signal
    connect(verticalScrollBar(), &QScrollBar::valueChanged, this, &JFJochImage::onScroll);
}

void JFJochImage::onScroll(int value) {
    updateOverlay();
}

void JFJochImage::changeBackground(float val) {
    background = val;
    Redraw();
}

void JFJochImage::changeForeground(float val) {
    foreground = val;
    Redraw();
}

void JFJochImage::setColorMap(int color_map) {
    try {
        color_scale.Select(static_cast<ColorScaleEnum>(color_map));
        Redraw();
    } catch (...) {
    }
}

void JFJochImage::setFeatureColor(QColor input) {
    feature_color = input;
    Redraw();
}

void JFJochImage::wheelEvent(QWheelEvent *event) {
    if (!scene()) return;

    const double zoomFactor = 1.15; // Zoom factor

    // Get the position of the mouse in scene coordinates
    QPointF targetScenePos = mapToScene(event->position().toPoint());

    if (event->modifiers() == Qt::ShiftModifier) {
        float new_foreground = foreground + event->angleDelta().y() / 120.0f;
        if (new_foreground < 1)
            new_foreground = 1.0;
        foreground = new_foreground;
        emit foregroundChanged(foreground);
        Redraw();
    } else {
        // Perform zooming
        if (event->angleDelta().y() > 0) {
            if (scale_factor * zoomFactor < 500.0) {
                scale_factor *= zoomFactor;
                scale(zoomFactor, zoomFactor);
            }
        } else {
            if (scale_factor > 0.2) {
                scale_factor *= 1.0 / zoomFactor;
                scale(1.0 / zoomFactor, 1.0 / zoomFactor);
            }
        }

        // Adjust the view's center to keep the zoom focused on the mouse position
        QPointF updatedViewportCenter = mapToScene(viewport()->rect().center());
        QPointF delta = targetScenePos - updatedViewportCenter;
        translate(delta.x(), delta.y()); // Shift the view

        updateOverlay();
    }
}