/**
  * @RDE_HEADER@
  * $Id$
  * $HeadURL$
  * $Author$
  */
#include "pws_vnc_viewer_dialog.h"
#include "ui_pws_vnc_viewer_dialog.h"

#include <LtsProjectionWorkstation/logger.h>

#include <QMutexLocker>
#include <QPainter>
#include <QOpenGLPaintDevice>
#include <QOpenGLFunctions>
#include <QThread>
#include <QTimer>

#include <cmath>


namespace ProjectionWorkstation
{

// Dialog

VncViewerDialog::VncViewerDialog(const QString &name, QWidget *parent)
  : LtsWidgets::LtsDialog(parent, LtsWidgets::ButtonCombination::SeamlessDialog, false)
  , m_ui(new Ui::VncViewerDialog)
  , m_handler(nullptr)
  , m_renderArea(nullptr)
  , m_mouseButtonMask(0)
  , m_mouseScrollReleaseTimer(new QTimer(this))
  , m_name(name)
  , m_isConnected(false)
  , m_logger(LtsProjectionWorkstation::getLogger(QStringLiteral("VncViewerDialog")))
{
  m_ui->setupUi(this);
  setFocusPolicy(Qt::ClickFocus);
}

VncViewerDialog::~VncViewerDialog()
{
  delete m_ui;
}

bool VncViewerDialog::init(const QHostAddress &host, quint16 port, const QSize &remoteResolution)
{
  m_handler = new VncHandler(host, port, this);
  m_renderArea = new VncRenderArea(remoteResolution, this);
  m_remoteResolution = remoteResolution;
  m_ui->gridLayout->addWidget(m_renderArea);

  connect(m_handler, &VncHandler::frameBufferUpdateReceived, m_renderArea, &VncRenderArea::frameBufferUpdateReceived);
  connect(m_handler, &VncHandler::cutTextReceived, this, &VncViewerDialog::handleServerCuttext);
  connect(m_handler, &VncHandler::beepReceived, this, &QApplication::beep);
  connect(m_handler, &VncHandler::connected, this, &VncViewerDialog::show);
  connect(m_handler, &VncHandler::disconnected, this, &VncViewerDialog::slotOnDisconnected);
  connect(m_mouseScrollReleaseTimer, &QTimer::timeout, this, &VncViewerDialog::onScrollRelease);
  setMouseTracking(true);

  m_mouseScrollReleaseTimer->setSingleShot(true);
  m_mouseScrollReleaseTimer->setInterval(5);

  m_handler->connectToHost();

  hide();

  return true;
}

void VncViewerDialog::retranslate()
{
  translate(m_ui, m_name);
}

void VncViewerDialog::handleServerCuttext(const QString &cutText)
{
  DEBUG_LOG(m_logger) << "Got cuttext: " << cutText;
}

void VncViewerDialog::slotOnDisconnected()
{
  //  closeRequest();
  //  m_renderArea->clear();
  emit disconnected();
}

void VncViewerDialog::focusInEvent(QFocusEvent *event)
{
  Q_UNUSED(event)
  grabKeyboard();
  //  setCursor(Qt::BlankCursor);
  if (m_renderArea)
  {
    QByteArray data = RfbProtocol::CTS::RfbFrameBufferUpdateRequest(false, 0, 0, m_renderArea->frameSize().width(), m_renderArea->frameSize().height());
    m_handler->writeData(data);
  }
}

void VncViewerDialog::focusOutEvent(QFocusEvent *event)
{
  Q_UNUSED(event)
  releaseKeyboard();
  //  unsetCursor();
}

void VncViewerDialog::onScrollRelease()
{
  m_mouseButtonMask &= ~(3 << 3);

  QByteArray data = RfbProtocol::CTS::RfbPointerEvent(m_mouseButtonMask, m_lastScrollPos.x(), m_lastScrollPos.y());
  m_handler->writeData(data);
}

void VncViewerDialog::onSlotConnected()
{
  m_isConnected = true;
}

void VncViewerDialog::mousePressEvent(QMouseEvent *event)
{
  event->accept();
  if (event->button() == Qt::LeftButton)
    m_mouseButtonMask |= (1 << 0);
  else if (event->button() == Qt::MidButton)
    m_mouseButtonMask |= (1 << 1);
  else if (event->button() == Qt::RightButton)
    m_mouseButtonMask |= (1 << 2);

  QPoint mapped = mapMousePosition(event->pos());

  QByteArray data = RfbProtocol::CTS::RfbPointerEvent(m_mouseButtonMask, mapped.x(), mapped.y());
  m_handler->writeData(data);
}

void VncViewerDialog::mouseReleaseEvent(QMouseEvent *event)
{
  event->accept();
  if (event->button() == Qt::LeftButton)
    m_mouseButtonMask &= ~(1 << 0);
  else if (event->button() == Qt::MidButton)
    m_mouseButtonMask &= ~(1 << 1);
  else if (event->button() == Qt::RightButton)
    m_mouseButtonMask &= ~(1 << 2);

  QPoint mapped = mapMousePosition(event->pos());

  QByteArray data = RfbProtocol::CTS::RfbPointerEvent(m_mouseButtonMask, mapped.x(), mapped.y());
  m_handler->writeData(data);
}

void VncViewerDialog::mouseMoveEvent(QMouseEvent *event)
{
  event->accept();
  QPoint mapped = mapMousePosition(event->pos());
  QByteArray data = RfbProtocol::CTS::RfbPointerEvent(m_mouseButtonMask, mapped.x(), mapped.y());
  m_handler->writeData(data);
}

void VncViewerDialog::keyPressEvent(QKeyEvent *event)
{
  event->accept();
  QByteArray data = RfbProtocol::CTS::RfbKeyEvent(event->nativeVirtualKey(), true);
  m_handler->writeData(data);
}

void VncViewerDialog::keyReleaseEvent(QKeyEvent *event)
{
  event->accept();
  QByteArray data = RfbProtocol::CTS::RfbKeyEvent(event->nativeVirtualKey(), false);
  m_handler->writeData(data);
}

void VncViewerDialog::wheelEvent(QWheelEvent *event)
{
  if (!m_mouseScrollReleaseTimer->isActive())
  {
    if (event->angleDelta().y() > 0)
      m_mouseButtonMask |= (1 << 3);
    else if (event->angleDelta().y() < 0)
      m_mouseButtonMask |= (1 << 4);

    QPoint mapped = mapMousePosition(event->pos());

    QByteArray data = RfbProtocol::CTS::RfbPointerEvent(m_mouseButtonMask, mapped.x(), mapped.y());
    m_handler->writeData(data);
    m_lastScrollPos = mapped;
    m_mouseScrollReleaseTimer->start();
  }
}

void VncViewerDialog::resizeEvent(QResizeEvent *event)
{
  Q_UNUSED(event)
  if (m_isConnected && m_renderArea)
  {
    emit m_renderArea->resized();
    QByteArray data = RfbProtocol::CTS::RfbFrameBufferUpdateRequest(false, 0, 0, m_renderArea->frameSize().width(), m_renderArea->frameSize().height());
    m_handler->writeData(data);
  }
}

void VncViewerDialog::showEvent(QShowEvent *event)
{
  Q_UNUSED(event)
  if (m_isConnected && m_renderArea)
  {
    QByteArray data = RfbProtocol::CTS::RfbFrameBufferUpdateRequest(false, 0, 0, m_renderArea->frameSize().width(), m_renderArea->frameSize().height());
    m_handler->writeData(data);
  }
}

static inline int mapValue(double val, double maxIn, double maxOut)
{
  val = qBound(0., val, maxIn);
  return qRound(val * (maxOut / maxIn));
}

QPoint VncViewerDialog::mapMousePosition(const QPoint &point) const
{
  QPoint clienPoint = m_renderArea->mapFromParent(point);
  int x = mapValue(clienPoint.x(), m_renderArea->scaledSize().width(),  m_renderArea->frameSize().width());
  int y = mapValue(clienPoint.y(), m_renderArea->scaledSize().height(), m_renderArea->frameSize().height());
  return QPoint(x, y);
}


// Render Area Worker
VncRenderAreaWorker::VncRenderAreaWorker()
  : m_logger(LtsProjectionWorkstation::getLogger(QStringLiteral("VncRenderArea")))
{
  qRegisterMetaType<QVector<RfbProtocol::RfbRectangle>>("QVector<RfbProtocol::RfbRectangle>");
}

void VncRenderAreaWorker::onRfbFrameBufferUpdate(const QVector<RfbProtocol::RfbRectangle> &rectangles)
{
  if (rectangles.isEmpty())
    return;

  QPainter painter(&m_renderedImage);
  // no dequeue here otherwise rectangles() is dangling
  for (const RfbProtocol::RfbRectangle &rect : rectangles)
  {
    if (rect.pixelData.isEmpty())
    {
      WARNING_LOG(m_logger) << "No valid vnc pixel data... skipping frame";
      continue;
    }
    QImage img(reinterpret_cast<const unsigned char *>(rect.pixelData.data()),
               rect.width,
               rect.height,
               QImage::Format_RGB32);
    if (img.isNull())
    {
      WARNING_LOG(m_logger) << "Could not decode image data... skipping vnc frame";
      continue;
    }
    painter.drawImage(QPoint(rect.xpos, rect.ypos), img);
  }
  painter.end();

  QImage img = m_renderedImage.scaled(m_scaledSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
  if (img.size() != m_scaledSizeAspectRatio)
  {
    m_scaledSizeAspectRatio = img.size();
    emit newScaleSizeAspectRatio(m_scaledSizeAspectRatio);
  }

  {
    QMutexLocker l(&m_mutex);
    std::swap(img, m_scaledImage);
  }

  emit newImageAvailable();
}

void VncRenderAreaWorker::setImageSize(QSize s)
{
  QMutexLocker l(&m_mutex);
  m_renderedImage = QImage(s, QImage::Format_RGB32);
}

void VncRenderAreaWorker::setScaledSize(QSize s)
{
  if (m_scaledSize == s)
    return;

  QMutexLocker l(&m_mutex);
  m_scaledSize = s;
  if (!m_renderedImage.isNull())
  {
    m_scaledImage = m_renderedImage.scaled(m_scaledSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);
    m_scaledSizeAspectRatio = m_scaledImage.size();
    emit newScaleSizeAspectRatio(m_scaledSizeAspectRatio);
  }
}

QImage VncRenderAreaWorker::renderedImage() const
{
  QMutexLocker l(&m_mutex);
  return m_scaledImage;
}


//Render Area

VncRenderArea::VncRenderArea(const QSize remoteResolution, QWidget *parent)
  : QOpenGLWidget(parent)
  , m_imageRenderThread(new QThread(this))
  , m_renderAreaWorker(new VncRenderAreaWorker)
  , m_frameSize(remoteResolution)
  , m_fbo(nullptr)
  , m_logger(LtsProjectionWorkstation::getLogger(QStringLiteral("VncRenderArea")))
{
  setAttribute(Qt::WA_TransparentForMouseEvents);

  connect(this, &VncRenderArea::frameBufferUpdateReceived,
          m_renderAreaWorker, &VncRenderAreaWorker::onRfbFrameBufferUpdate);
  connect(m_renderAreaWorker, &VncRenderAreaWorker::newImageAvailable,
          this, &VncRenderArea::prepareRender);
  connect(m_renderAreaWorker, &VncRenderAreaWorker::newScaleSizeAspectRatio,
          this, [this](QSize s) { m_scaledSizeAspectRatio = s; });
  m_renderAreaWorker->setImageSize(remoteResolution);
  m_renderAreaWorker->moveToThread(m_imageRenderThread);
  m_imageRenderThread->start();
}

VncRenderArea::~VncRenderArea()
{
  delete m_fbo;

  m_imageRenderThread->quit();
  m_imageRenderThread->wait(2000);
  delete m_imageRenderThread;
  delete m_renderAreaWorker;
}

void VncRenderArea::clear()
{
  if (context())
  {
    glClearColor(1, 1, 1, 0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    update();
  }
}

void VncRenderArea::initializeGL()
{
  initializeOpenGLFunctions();
  m_blitter.create();
}

void VncRenderArea::paintGL()
{
  if (context() && m_fbo)
  {
    m_blitter.bind();
    const QRect targetRect(QPoint(0, 0), m_fbo->size());
    const QMatrix4x4 target = QOpenGLTextureBlitter::targetTransform(targetRect, targetRect); // no scaling here, is not anti-aliased
    m_blitter.blit(m_fbo->texture(), target, QOpenGLTextureBlitter::OriginBottomLeft);
    m_blitter.release();
  }
}

void VncRenderArea::maybeResized()
{
  rebuildFbo(size());
  m_renderAreaWorker->setScaledSize(size());
}

void VncRenderArea::prepareRender()
{
  if (context())
  {
    if (!m_fbo || m_fbo->size() != size())
      maybeResized();
    m_fbo->bind();
    QOpenGLPaintDevice device(size());
    QPainter painter(&device);
    painter.drawImage(QPoint(0, 0), m_renderAreaWorker->renderedImage());
    painter.end();
    m_fbo->release();

    update();
  }
}

void VncRenderArea::rebuildFbo(QSize newSize)
{
  delete m_fbo;
  QOpenGLFramebufferObjectFormat format;
  format.setAttachment(QOpenGLFramebufferObject::CombinedDepthStencil);
  m_fbo = new QOpenGLFramebufferObject(newSize, format);
}

} // ProjectionWorkstation