#include "OpenGLView.h"

#include "MainModelerWindow.h"
#include "ModelerCameras.h"
#include "OpenGLRenderer.h"
#include <QHoverEvent>
#include <QQuickWindow>

OpenGLView::OpenGLView(QQuickItem *parent) : QQuickItem(parent) {
    initialized = false;
    window = NULL;
    renderer = NULL;
    delayed = 10;

    setAcceptedMouseButtons(Qt::AllButtons);
    setAcceptHoverEvents(true);

    mouse_button = Qt::NoButton;

    connect(this, SIGNAL(windowChanged(QQuickWindow *)), this, SLOT(handleWindowChanged(QQuickWindow *)));
    connect(this, SIGNAL(widthChanged()), this, SLOT(handleResize()));
    connect(this, SIGNAL(heightChanged()), this, SLOT(handleResize()));
}

void OpenGLView::handleWindowChanged(QQuickWindow *win) {
    if (win) {
        window = qobject_cast<MainModelerWindow *>(win);
        if (window) {
            renderer = window->getRenderer();
            initialized = false;

            win->setClearBeforeRendering(false);

            connect(win, SIGNAL(sceneGraphInitialized()), this, SLOT(handleSceneGraphReady()));
        }
    }
}

void OpenGLView::paint() {
    if (delayed > 1) {
        return;
    }

    if (renderer->isStopped()) {
        emit stopped();
        return;
    }

    if (not initialized or not renderer) {
        renderer->initialize();
        initialized = true;
        resized = true;
    }

    if (resized) {
        renderer->resize(width(), height());
        resized = false;
    }

    renderer->prepareOpenGLState(false);
    renderer->paint(false);

    if (window) {
        window->resetOpenGLState();
    }
}

void OpenGLView::handleResize() {
    resized = true;
}

void OpenGLView::handleSceneGraphReady() {
    connect(window, SIGNAL(beforeRendering()), this, SLOT(paint()), Qt::DirectConnection);
    startTimer(50);
}

void OpenGLView::wheelEvent(QWheelEvent *event) {
    if (not acceptInputs()) {
        return;
    }

    double factor = getSpeedFactor(event);
    window->getCamera()->processZoom(0.01 * factor * to_double(event->angleDelta().y()));
}

void OpenGLView::mousePressEvent(QMouseEvent *event) {
    if (not acceptInputs()) {
        return;
    }

    mouse_button = event->button();
    mouse_pos = event->windowPos();
}

void OpenGLView::mouseReleaseEvent(QMouseEvent *) {
    if (not acceptInputs()) {
        return;
    }

    mouse_button = Qt::NoButton;
}

void OpenGLView::mouseMoveEvent(QMouseEvent *event) {
    if (not acceptInputs()) {
        return;
    }

    double factor = getSpeedFactor(event);
    QPointF diff = event->windowPos() - mouse_pos;
    if (mouse_button == Qt::LeftButton) {
        window->getCamera()->processPanning(0.002 * factor * diff.x(), 0.001 * factor * diff.y());
    } else if (mouse_button == Qt::RightButton) {
        window->getCamera()->processScroll(-0.02 * factor * diff.x(), 0.02 * factor * diff.y());
    }
    mouse_pos = event->windowPos();

    renderer->setMouseLocation(event->pos().x(), height() - event->pos().y());
}

void OpenGLView::hoverMoveEvent(QHoverEvent *event) {
    renderer->setMouseLocation(event->pos().x(), height() - event->pos().y());
}

void OpenGLView::timerEvent(QTimerEvent *) {
    if (delayed > 1) {
        delayed--;
    } else if (delayed == 1) {
        if (renderer->isDisplayed()) {
            delayed = 0;
            window->setState("Init");
        }
    }

    if (window) {
        window->update();
    }
}

bool OpenGLView::acceptInputs() const {
    return window->getState() != "Render Dialog";
}

double OpenGLView::getSpeedFactor(QInputEvent *event) {
    if (event->modifiers() & Qt::ControlModifier) {
        return 0.2;
    } else if (event->modifiers() & Qt::ShiftModifier) {
        return 3.0;
    } else {
        return 1.0;
    }
}