#include "ViewportWidget.h"
#include "ViewCube.h"
#include <QMouseEvent>
#include <QWheelEvent>
#include <QApplication>

ViewportWidget::ViewportWidget(QWidget *parent)
    : QOpenGLWidget(parent)
{
    m_viewCube = new ViewCube();
}

ViewportWidget::~ViewportWidget()
{
    delete m_viewCube;
}

void ViewportWidget::initializeGL()
{
    initializeOpenGLFunctions();
    glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
    glEnable(GL_DEPTH_TEST);
    m_viewCube->initializeGL();
}

void ViewportWidget::paintGL()
{
    // Main scene rendering
    glViewport(0, 0, width(), height());
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    QMatrix4x4 model;
    model.translate(panX, panY, zoom);
    model.rotate(xRot / 16.0f, 1, 0, 0);
    model.rotate(yRot / 16.0f, 0, 1, 0);

    // For simplicity, we'll use a fixed-function pipeline style for drawing.
    // In a real app, this would use shaders.
    glMatrixMode(GL_PROJECTION);
    glLoadMatrixf(projection.constData());

    glMatrixMode(GL_MODELVIEW);
    glLoadMatrixf(model.constData());

    // View cube rendering
    QMatrix4x4 viewCubeModel;
    viewCubeModel.rotate(xRot / 16.0f, 1, 0, 0);
    viewCubeModel.rotate(yRot / 16.0f, 0, 1, 0);
    m_viewCube->paintGL(viewCubeModel, width(), height());

    glViewport(0, 0, width(), height());
}

void ViewportWidget::resizeGL(int w, int h)
{
    projection.setToIdentity();
    projection.perspective(45.0f, w / float(h), 0.01f, 100.0f);
}

void ViewportWidget::mousePressEvent(QMouseEvent *event)
{
    lastPos = event->pos();
}

void ViewportWidget::mouseMoveEvent(QMouseEvent *event)
{
    int dx = event->pos().x() - lastPos.x();
    int dy = event->pos().y() - lastPos.y();

    if (event->buttons() & Qt::MiddleButton) {
        if (QApplication::keyboardModifiers() & Qt::ShiftModifier) {
            // Pan
            panX += dx / 100.0f;
            panY -= dy / 100.0f;
        } else {
            // Rotate
            xRot += 8 * dy;
            yRot += 8 * dx;
        }
    }
    lastPos = event->pos();
    update();
}

void ViewportWidget::wheelEvent(QWheelEvent *event)
{
    QPoint numDegrees = event->angleDelta() / 8;
    if (!numDegrees.isNull()) {
        zoom += numDegrees.y() / 5.0f;
    }
    update();
}