/*
 * MapperGLCanvas.cpp
 *
 * (c) 2013 Sofian Audry -- info(@)sofianaudry(.)com
 * (c) 2013 Alexandre Quessy -- alexandre(@)quessy(.)net
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "MapperGLCanvas.h"

#include "MainWindow.h"

MapperGLCanvas::MapperGLCanvas(MainWindow* mainWindow, QWidget* parent, const QGLWidget * shareWidget, QGraphicsScene* scene)
  : QGraphicsView(parent),
    _mainWindow(mainWindow),
    _mousePressedOnVertex(false),
    _activeVertex(NO_VERTEX),
    _shapeGrabbed(false), // comment out?
    _shapeFirstGrab(false), // comment out?
    _displayControls(true),
    _stickyVertices(true),
    _zoomLevel(0)
{
  // For now clicking on the window doesn't do anything.
  setDragMode(QGraphicsView::NoDrag);

  setRenderHint(QPainter::Antialiasing, true);
  setRenderHint(QPainter::TextAntialiasing, true);

  //setFrameStyle(Sunken | StyledPanel);
  // TODO: check this
  // setOptimizationFlags(QGraphicsView::DontSavePainterState);
  //setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
  setTransformationAnchor(QGraphicsView::AnchorUnderMouse);

  resetTransform();
  // setAcceptDrops(true);

  // Render with OpenGL.
  setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers), this, shareWidget));
  setViewportUpdateMode(QGraphicsView::FullViewportUpdate);

  // TODO: do we need to delete scene (or call new QGraphicsScene(this)?)
  setScene(scene ? scene : new QGraphicsScene);

  // Black background.
  this->scene()->setBackgroundBrush(Qt::black);
}

//void MapperGLCanvas::initializeGL()
//{
//  //qDebug() << "initializeGL" << endl;
//  // Clear to black.
//  qglClearColor(Qt::black);
//  // Antialiasing options.
//  //QGLWidget::setFormat(QGLFormat(QGL::SampleBuffers));
//}
//
//void MapperGLCanvas::resizeGL(int width, int height)
//{
//  glViewport(0, 0, width, height);
//  glMatrixMode (GL_PROJECTION);
//  glLoadIdentity ();
//  glOrtho (
//    0.0f, (GLfloat) width, // left, right
//    (GLfloat) height, 0.0f, // bottom, top
//    -1.0, 1.0f);
//  glMatrixMode (GL_MODELVIEW);
//  //qDebug() << "done resizing" << endl;
//}
//
//void MapperGLCanvas::paintGL()
//{
//}
//
//void MapperGLCanvas::draw(QPainter* painter)
//{
//  //qDebug() << "draw mappergl" << endl;
//  enterDraw(painter);
//  doDraw(painter);
//  exitDraw(painter);
//  // qDebug() << "done." << endl;
//}

//void MapperGLCanvas::enterDraw(QPainter* painter)
//{
//  painter->beginNativePainting();
//
//  // Clear to black.
//  glClearColor(0.0, 0.0, 0.0, 1.0);
//
//  // Clear buffer.
//  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
//
//  painter->endNativePainting();
//
//  // Antialiasing.
//  painter->setRenderHint(QPainter::Antialiasing);
//  //painter->setBackground(Qt::black);
//  painter->setPen(Qt::NoPen);
//  painter->setBrush(Qt::NoBrush);
//}
//
//void MapperGLCanvas::exitDraw(QPainter* painter)
//{
//  Q_UNUSED(painter);
//}

//Shape* MapperGLCanvas::getCurrentShape()
//{
//  return getShapeFromMappingId(getMainWindow()->getCurrentMappingId());
//}
//
//void MapperGLCanvas::mousePressEvent(QMouseEvent* event)
//{
//  int i;
//  int dist;
//  int minDistance;
//
//  bool mousePressedOnSomething = false;
//
//  _mousePressedPosition = event->pos();
//
//  // Note: we compare with the square value for fastest computation of the distance
//  minDistance = MM::VERTEX_SELECT_RADIUS * MM::VERTEX_SELECT_RADIUS;
//
//  // Drag the closest vertex
//  if (event->buttons() & Qt::LeftButton)
//  {
//    Shape* shape = getCurrentShape();
//    if (shape)
//    {
//      // find the ID of the nearest vertex: (from the selected shape)
//      for (i = 0; i < shape->nVertices(); i++)
//      {
//        dist = distSq(_mousePressedPosition, shape->getVertex(i)); // squared distance
//        if (dist < minDistance)
//        {
//          _activeVertex = i;
//          minDistance = dist;
//          _mousePressedOnVertex = true;
//          mousePressedOnSomething = true;
//        }
//      }
//    }
//  }
//
//  if (mousePressedOnSomething)
//    return;
//
//  // Select a shape with a click.
//  if (event->buttons() & Qt::LeftButton)
//  {
//    Shape* orig = getCurrentShape();
//    MappingManager manager = getMainWindow()->getMappingManager();
//    QVector<Mapping::ptr> mappings = manager.getVisibleMappings();
//    for (QVector<Mapping::ptr>::const_iterator it = mappings.end() - 1; it >= mappings.begin(); --it)
//    {
//      Shape *shape = getShapeFromMappingId((*it)->getId());
//      // Mouse pressed on a shape.
//      if (shape && shape->includesPoint(_mousePressedPosition))
//      {
//        mousePressedOnSomething = true;
//        // Deselect vertices.
//        deselectVertices();
//        // Change mapping.
//        if (shape != orig)
//        {
//          getMainWindow()->setCurrentMapping((*it)->getId());
//        }
//        break;
//      }
//    }
//
//    // Grab the shape.
//    if (orig && orig->includesPoint(_mousePressedPosition))
//    {
//      _shapeGrabbed = true;
//      _shapeFirstGrab = true;
//    }
//  }
//
//  if (mousePressedOnSomething)
//    return;
//
//  // Deactivate.
//  deselectAll();
//}
//
//void MapperGLCanvas::mouseReleaseEvent(QMouseEvent* event)
//{
//  Q_UNUSED(event);
////  // Click on vertex ==> select the vertex.
////  if ((event->buttons() & Qt::LeftButton) && _mousePressedOnVertex)
////  {
////  }
//  _mousePressedOnVertex = false;
//  _shapeGrabbed = false;
//}
//
//void MapperGLCanvas::mouseMoveEvent(QMouseEvent* event)
//{
//  if (_mousePressedOnVertex)
//  {
//    // std::cout << "Move event " << std::endl;
//    Shape* shape = getCurrentShape();
//    if (shape && _activeVertex != NO_VERTEX)
//    {
//      QPointF p = shape->getVertex(_activeVertex);
//      // Set point to mouse coordinates.
//      p.setX(event->x());
//      p.setY(event->y());
//
//      // Stick to vertices.
//      if (stickyVertices())
//        glueVertex(shape, &p);
//      shape->setVertex(_activeVertex, p);
//
//      update();
//      emit shapeChanged(getCurrentShape());
//    }
//  }
//  else if (_shapeGrabbed)
//  {
//    // std::cout << "Move event " << std::endl;
//    Shape* shape = getCurrentShape();
//    static QPointF prevMousePosition(0,0); // point that keeps track of last position of the mouse
//    if (shape)
//    {
//      if (!_shapeFirstGrab)
//      {
//        shape->translate(event->x() - prevMousePosition.x(), event->y() - prevMousePosition.y());
//        update();
//        emit shapeChanged(getCurrentShape());
//      }
//      else
//        _shapeFirstGrab = false;
//    }
//    // Update previous mouse position.
//    prevMousePosition.setX( event->x() );
//    prevMousePosition.setY( event->y() );
//  }
//}
//
//void MapperGLCanvas::keyPressEvent(QKeyEvent* event)
//{
//  // Checks if the key has been handled by this function or needs to be deferred to superclass.
//  bool handledKey = false;
//
//  // Active vertex selected.
//  if (hasActiveVertex())
//  {
//    Shape* shape = getCurrentShape();
//    QPointF p = shape->getVertex(_activeVertex);
//    handledKey = true;
//    switch (event->key()) {
//    // TODO: key tab should switch to next vertex: not working because somehow caught at a higher level
//    // to switch between frames of the layout
////    case Qt::Key_Tab:
////      if (shape)
////        _activeVertex = (_activeVertex + 1) % shape->nVertices();
////        p = shape->getVertex(_activeVertex); // reset to new vertex
////        qDebug() << "New active vertex : " << _activeVertex << endl;
////      break;
//    // Handle pixel-wise adjustments of vertex.
//    case Qt::Key_Up:
//      p.ry()--;
//      break;
//    case Qt::Key_Down:
//      p.ry()++;
//      break;
//    case Qt::Key_Right:
//      p.rx()++;
//      break;
//    case Qt::Key_Left:
//      p.rx()--;
//      break;
//    default:
//      handledKey = false;
//      break;
//    }
//    // TODO: this will always be called even if no arrow key has been pressed (small performance issue).
//    shape->setVertex(_activeVertex, p);
//    update();
//    emit shapeChanged(getCurrentShape());
//  }
//
//  // Defer unhandled keys to parent.
//  if (!handledKey)
//  {
//    QWidget::keyPressEvent(event);
//  }
//
////  std::cout << "Key pressed" << std::endl;
////  int xMove = 0;
////  int yMove = 0;
////  switch (event->key()) {
////  case Qt::Key_Tab:
////    if (event->modifiers() & Qt::ControlModifier)
////      switchImage( (Common::getCurrentSourceId() + 1) % Common::nImages());
////    else
////    {
////      Quad& quad = getQuad();
////      _active_vertex = (_active_vertex + 1 ) % 4;
////    }
////    break;
////  case Qt::Key_Up:
////    yMove = -1;
////    break;
////  case Qt::Key_Down:
////    yMove = +1;
////    break;
////  case Qt::Key_Left:
////    xMove = -1;
////    break;
////  case Qt::Key_Right:
////    xMove = +1;
////    break;
////  default:
////    std::cerr << "Unhandled key" << std::endl;
////    QWidget::keyPressEvent(event);
////    break;
////  }
////
////  Quad& quad = getQuad();
////  Point *p = quad.getVertex(_active_vertex);
////  p->x += xMove;
////  p->y += yMove;
////  quad.setVertex(_active_vertex, p);
////
////  update();
////
////  emit quadChanged();
//}
//
//void MapperGLCanvas::paintEvent(QPaintEvent* /* event */)
//{
//  makeCurrent();
//
//  QPainter painter(this);
//  painter.setRenderHint(QPainter::Antialiasing);
//
//  draw(&painter);
//
//  painter.end();
//}

void MapperGLCanvas::updateCanvas()
{
  update();
  scene()->update();
}

void MapperGLCanvas::enableDisplayControls(bool display)
{
  _displayControls = display;
  updateCanvas();
}

void MapperGLCanvas::enableStickyVertices(bool value)
{
  _stickyVertices = value;
}

/* Stick vertex p of Shape orig to another Shape's vertex, if the 2 vertices are
 * close enough. The distance per coordinate is currently set in dist_stick
 * variable. Perhaps the sticky-sensitivity should be configurable through GUI */
void MapperGLCanvas::glueVertex(MShape *orig, QPointF *p)
{
  MappingManager manager = getMainWindow()->getMappingManager();
  for (int i = 0; i < manager.nMappings(); i++)
  {
    MShape *shape = getShapeFromMappingId(manager.getMapping(i)->getId());
    if (shape && shape != orig)
    {
      for (int vertex = 0; vertex < shape->nVertices(); vertex++)
      {
        const QPointF& v = shape->getVertex(vertex);
        if (distIsInside(v, *p, MM::VERTEX_STICK_RADIUS))
        {
          p->setX(v.x());
          p->setY(v.y());
        }
      }
    }
  }
}

void MapperGLCanvas::deselectVertices()
{
  _activeVertex = NO_VERTEX;
  _mousePressedOnVertex = false;
}

void MapperGLCanvas::deselectAll()
{
  deselectVertices();
  _shapeGrabbed = false;
  _shapeFirstGrab = false;
}

void MapperGLCanvas::wheelEvent(QWheelEvent *event)
{
  int deltaLevel = event->delta() / 120;
  qreal zoomFactor = qPow(MM::ZOOM_FACTOR, _zoomLevel);
  if (deltaLevel > 0)
  {
    // First check if we're already at max.
    while (deltaLevel && zoomFactor < MM::ZOOM_MAX) {
      _zoomLevel++;
      deltaLevel--;
      zoomFactor = qPow(MM::ZOOM_FACTOR, _zoomLevel);
    }
    zoomFactor = qMin(zoomFactor, MM::ZOOM_MAX);
  }
  else
  {
    // First check if we're already at min.
    while (deltaLevel && zoomFactor > MM::ZOOM_MIN) {
      _zoomLevel--;
      deltaLevel++;
      zoomFactor = qPow(MM::ZOOM_FACTOR, _zoomLevel);
    }
    zoomFactor = qMax(zoomFactor, MM::ZOOM_MIN);
  }

  QGraphicsView* view = scene()->views().first();
  view->resetMatrix();
  view->scale(zoomFactor, zoomFactor);
  view->update();
  event->accept();
}