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#include <QPainter>

#include "edge.h"
#include "node.h"

#include <math.h>

static const double Pi = 3.14159265358979323846264338327950288419717;
static double TwoPi = 2.0 * Pi;

/**
 A graphical edge represents a link between two nodes
 @param sourceNode source node
 @param destNode destination node
 @param comm reference to the CommModel
 @param mw the main window
 @param highlight true when the edge should be highlighted
 */
Edge::Edge(Node *sourceNode, Node *destNode, CommModel *comm, MainWindow *mw, bool highlight)
    : arrowSize(10)
{
    if(destNode == NULL || sourceNode == NULL)
        return;
    setAcceptedMouseButtons(0);

    highlighted = highlight;

    source = sourceNode;
    dest = destNode;
    myComm = comm;
    myMW = mw;
    //Here's the problem!
    source->addEdge(this);
    dest->addEdge(this);
    adjust();
}

/**
 Determines if two points are two close (less than 100 pixels apart)
 @return true if too close
 */
bool Edge::tooShort()
{
    QLineF line(source->pos(), dest->pos());
    if (line.length() < 100)
    {
        return true;
    }

    return false;
}

/**
 Returns the source node of this edge
 @return source node
 */
Node *Edge::sourceNode() const
{
    return source;
}

/**
 Returns the destination node of this edge
 @return destination node
 */
Node *Edge::destNode() const
{
    return dest;
}

/**
 Adjusts the length of the line used to represent the edge
 */
void Edge::adjust()
{
    if (!source || !dest)
        return;

    QLineF line(mapFromItem(source, 0, 0), mapFromItem(dest, 0, 0));
    qreal length = line.length();

    prepareGeometryChange();

    if (length > qreal(20.)) {
        QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length);
        sourcePoint = line.p1() + edgeOffset;
        destPoint = line.p2() - edgeOffset;
    } else {
        sourcePoint = destPoint = line.p1();
    }
}

/**
 Calculates the bounding rectangle box for this edge
 @return bouding rectangle
 */
QRectF Edge::boundingRect() const
{
    if (!source || !dest)
        return QRectF();

    qreal penWidth = 1;
    qreal extra = (penWidth + arrowSize) / 2.0;

    return QRectF(sourcePoint, QSizeF(destPoint.x() - sourcePoint.x(),
                                      destPoint.y() - sourcePoint.y()))
        .normalized()
        .adjusted(-extra, -extra, extra, extra);
}

/**
 Uses a painter to draw this line
 @param painter the painter used
 */
void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
{
    if (!source || !dest)
        return;

    QLineF line(sourcePoint, destPoint);
    if (qFuzzyCompare(line.length(), qreal(0.)))
        return;
    
    // Draw the line itself
    if (!highlighted) {
        painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));

        int inTime = myComm->get_inactive_time(source->getNodePointer(), dest->getNodePointer());
        if (inTime > myMW->getInactiveThreshold())
        {
            painter->setOpacity(0);
        }
        else
        {
            painter->setOpacity(1 - inTime/MAX_TIME);
        }
        painter->drawLine(line);
    }
    else {
        painter->setPen(QPen(Qt::blue, 10, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
        painter->setOpacity(0.5);
        painter->drawLine(line);
    }

    
    // Draw the arrows
    if (!highlighted) {
        double angle = ::acos(line.dx() / line.length());
        if (line.dy() >= 0)
            angle = TwoPi - angle;

        /*QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize,
                                                      cos(angle + Pi / 3) * arrowSize);
        QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize,
                                                      cos(angle + Pi - Pi / 3) * arrowSize);*/
        QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize,
                                                  cos(angle - Pi / 3) * arrowSize);
        QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize,
                                                  cos(angle - Pi + Pi / 3) * arrowSize);

        painter->setBrush(Qt::black);
        //painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
        painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);
    }

    /*painter->drawText( QPointF((line.x1()+line.x2())/2, (line.y1()+line.y2())/2),
                      //QString("Dongs"));
                       (QString("Weight: %0").arg(myComm->get_weight(source->getNodePointer(), dest->getNodePointer()))));*/
}