#include "graphwidget.hpp"

#include "edge.hpp"
#include "node.hpp"

#include <graph/graph.hpp>
#include "floats.hpp"

#include <QtGui/QKeyEvent>
#include <QtGui/QWheelEvent>
#include <QtGui/QGraphicsScene>

#include <QtGui/QApplication>

#include <QtCore/QtGlobal>

#include <math.h>

namespace std {
  template <>
  struct hash<float2>
  {
    std::size_t operator()(const float2& f2) const {
      std::size_t h1 = std::hash<float>()(f2.x);
      std::size_t h2 = std::hash<float>()(f2.y);
      return h1 ^ (h2 << 1);
    }
  };
}


GraphWidget::GraphWidget(Graph<float2>* graph, QWidget *p)
    : QGraphicsView(p)
    , m_graph(graph)
{
    QGraphicsScene *s = new QGraphicsScene(this);
    s->setItemIndexMethod(QGraphicsScene::NoIndex);
    s->setSceneRect(-200, -200, 400, 400);
    setScene(s);

    setCacheMode(CacheBackground);
    setViewportUpdateMode(BoundingRectViewportUpdate);
    setRenderHint(QPainter::Antialiasing);
    setTransformationAnchor(AnchorUnderMouse);
    scale(qreal(0.8), qreal(0.8));
    setMinimumSize(400, 400);
    setWindowTitle(tr("Elastic Nodes"));
}

void GraphWidget::itemMoved(const QPointF oldPos, const QPointF newPos)
{
  float2 old_v = float2(oldPos.x(), oldPos.y());
  float2 new_v = float2(newPos.x(), newPos.y());
  m_graph->modifyVertex(old_v, new_v);
}

void GraphWidget::updateFromGraph()
{
//   for (const auto cit : m_graph) {
  for (Graph<float2>::iterator cit = m_graph->begin(); cit != m_graph->end(); ++cit) {
    Node *node = new Node(this);
    scene()->addItem(node);
    node->setPos(cit->x, cit->y);
  }

//     for (const auto cit : g) {
  for (Graph<float2>::iterator cit = m_graph->begin(); cit != m_graph->end(); ++cit) {
    for (const auto cit2 : m_graph->neighboursOf(*cit)) {

      float2 v = *cit;
      Node* node1 = dynamic_cast<Node*>(scene()->itemAt(v.x, v.y)); /// @bug itemAt sometimes doesn't work
      Q_CHECK_PTR(node1);

      float2 v2 = cit2;
      Node* node2 = dynamic_cast<Node*>(scene()->itemAt(v2.x, v2.y)); /// @bug itemAt sometimes doesn't work
      Q_CHECK_PTR(node2);

      scene()->addItem(new Edge(node1, node2));
    }
  }
}

void GraphWidget::keyPressEvent(QKeyEvent *e)
{
    switch (e->key()) {
    case Qt::Key_Plus:
        zoomIn();
        break;
    case Qt::Key_Minus:
        zoomOut();
        break;
    default:
        QGraphicsView::keyPressEvent(e);
    }
}

void GraphWidget::wheelEvent(QWheelEvent *e)
{
    scaleView(pow((double)2, -e->delta() / 240.0));
}

void GraphWidget::drawBackground(QPainter *painter, const QRectF &r)
{
    // Shadow
    QRectF scene_rect = this->sceneRect();
    QRectF rightShadow(scene_rect.right(), scene_rect.top() + 5, 5, scene_rect.height());
    QRectF bottomShadow(scene_rect.left() + 5, scene_rect.bottom(), scene_rect.width(), 5);
    if (rightShadow.intersects(r) || rightShadow.contains(r))
        painter->fillRect(rightShadow, Qt::darkGray);
    if (bottomShadow.intersects(r) || bottomShadow.contains(r))
        painter->fillRect(bottomShadow, Qt::darkGray);

    // Fill
    QLinearGradient gradient(scene_rect.topLeft(), scene_rect.bottomRight());
    gradient.setColorAt(0, Qt::white);
    gradient.setColorAt(1, Qt::lightGray);
    painter->fillRect(r.intersect(scene_rect), gradient);
    painter->setBrush(Qt::NoBrush);
    painter->drawRect(scene_rect);
}

void GraphWidget::scaleView(qreal scaleFactor)
{
    qreal factor = transform().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
    if (factor < 0.07 || factor > 100)
        return;

    scale(scaleFactor, scaleFactor);
}

void GraphWidget::zoomIn()
{
    scaleView(qreal(1.2));
}

void GraphWidget::zoomOut()
{
    scaleView(1 / qreal(1.2));
}

void GraphWidget::quit()
{
  QApplication::quit();
}