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

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

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

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

    if (m_currentPlane != SketchPlane::NONE) {
        m_sketchGrid->paintGL(static_cast<SketchGrid::SketchPlane>(m_currentPlane), projection, model);
    }

    // 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());

    if (m_currentPlane != SketchPlane::NONE) {
        QPainter painter(this);
        drawAxisLabels(painter, model, projection);
        painter.end();
    }
}

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();
}

void ViewportWidget::startSketch(SketchPlane plane)
{
    m_currentPlane = plane;
    panX = 0;
    panY = 0;
    zoom = -20.0f; // Zoom out to see the grid

    switch (plane) {
        case SketchPlane::XY: // Top view
            xRot = -90 * 16;
            yRot = 0;
            break;
        case SketchPlane::XZ: // Front view
            xRot = 0;
            yRot = 0;
            break;
        case SketchPlane::YZ: // Right view
            xRot = 0;
            yRot = 90 * 16;
            break;
        case SketchPlane::NONE:
            break;
    }
    update();
}

QVector3D ViewportWidget::project(const QVector3D& worldCoord, const QMatrix4x4& modelView, const QMatrix4x4& projection, const QRect& viewport)
{
    QVector4D clipCoord = projection * modelView * QVector4D(worldCoord, 1.0);
    if (qFuzzyCompare(clipCoord.w(), 0.0f)) {
        return QVector3D(-1, -1, -1);
    }

    QVector3D ndc(clipCoord.x() / clipCoord.w(), clipCoord.y() / clipCoord.w(), clipCoord.z() / clipCoord.w());

    float winX = viewport.x() + viewport.width() * (ndc.x() + 1.0) / 2.0;
    float winY = viewport.y() + viewport.height() * (1.0 - (ndc.y() + 1.0) / 2.0); // Y is inverted

    return QVector3D(winX, winY, (ndc.z() + 1.0) / 2.0);
}

void ViewportWidget::drawAxisLabels(QPainter& painter, const QMatrix4x4& modelView, const QMatrix4x4& projection)
{
    painter.setPen(Qt::white);
    painter.setFont(QFont("Arial", 10));

    const int range = 50;
    const int step = 5;

    auto drawLabelsForAxis = [&](int axis_idx) {
        for (int i = -range; i <= range; i += step) {
            if (i == 0) continue;
            QVector3D worldCoord;
            worldCoord[axis_idx] = i;

            QVector3D screenPos = project(worldCoord, modelView, projection, rect());
            if (screenPos.z() < 1.0f) { // Not clipped
                painter.drawText(screenPos.toPoint(), QString::number(i));
            }
        }
    };

    if (m_currentPlane == SketchPlane::XY) {
        drawLabelsForAxis(0); // X
        drawLabelsForAxis(1); // Y
    } else if (m_currentPlane == SketchPlane::XZ) {
        drawLabelsForAxis(0); // X
        drawLabelsForAxis(2); // Z
    } else if (m_currentPlane == SketchPlane::YZ) {
        drawLabelsForAxis(1); // Y
        drawLabelsForAxis(2); // Z
    }
}