#ifndef OUTLINE_H
#define OUTLINE_H


//Qt
#include <QDebug>
#include <QColor>
#include <QPainter>
#include <QPainterPath>
#include <QPaintEvent>
#include <QVector>
#include <QPainterPathStroker>
#include <QPen>
#include <QWidget>
#include <QPaintEngine>
#include <qmath.h>
#include <QPixmap>


class Contour
{
public:
    Contour(double scalex,double scaley,bool bmove,double tolerance, const QString& title){
        _title = title;
        _scalex = scalex;
        _scaley = scaley;
        _move = bmove;
        _tolerance = tolerance;
    }

    Contour(QString title = "contour_0"){
        _title = title;
        _scalex = 1;
        _scaley = 1;
        _move = false;
        _tolerance = 10;
    }

    void addPoint(qreal x,qreal y){
        QPointF f(x,y);
        _points.push_back(f);
        if(polygonSelfIntersects()){
           setColor(255,0,0,50);
        }else{
           setColor(0,0,0,150);
        }
        _rectPath = QPainterPath();
        _rectPath.addPolygon(_points);
        _rectPath.setFillRule(Qt::OddEvenFill);
    }

    bool polygonSelfIntersects() {
        int n = _points.size();
        for(int i=0;i<n;++i){
            for(int j=i+1;j<n;++j){
                if(lineSegmentsIntersect(_points[j],_points[(j+1)%n],_points[i],_points[(i+1)%n])){
                    return true;
                }
            }
        }
        return false;
    }

    bool lineSegmentsIntersect(const QPointF& a, const QPointF& b, const QPointF& c, const QPointF& d) {
        QPointF ab = b-a;
        QPointF cd = d-c;
        QPointF ac = c-a;
        QPointF ad = d-a;
        QPointF ca = a-c;
        QPointF cb = b-c;

        qreal abac = ab.x()*ac.y()-ab.y()*ac.x();
        qreal abad = ab.x()*ad.y()-ab.y()*ad.x();
        qreal cdca = cd.x()*ca.y()-cd.y()*ca.x();
        qreal cdcb = cd.x()*cb.y()-cd.y()*cb.x();


        return !(abac*abad >=0 || cdca*cdcb >=0);
    }

    void setPoint(int i,qreal x,qreal y){
        QPointF f(x,y);
        _rectPath.setElementPositionAt(i,x,y);
        _points[i] = f;
        if(_move){
            if(i==0 || i==_rectPath.elementCount()-1){
                _rectPath.setElementPositionAt(0,x,y);
                _rectPath.setElementPositionAt(_rectPath.elementCount()-1,x,y);
                _points[i] = f;
                _points[_rectPath.elementCount()-1] = f;
            }
            getDotline();
        }
    }

    int pointCount(){
        return _points.count();
    }

    int elementCount(){
        return _rectPath.elementCount();
    }

    void setColor(int red,int green,int blue,int alpha=50){
        _contourColor.setRgb(red,green,blue,alpha);
    }

    QColor getColor() const{
        return _contourColor;
    }

    QString getTitle() const{
        return _title;
    }

    void setTitle(const QString& title){
        _title = title;

    }

    void saveData(){
        // TODO
    }

    void setScalex(double scalex){
        _scalex = scalex;
    }
    double getScalex() const{
        return _scalex;
    }
    double getScaley() const{
        return _scaley;
    }
    void setScaley(double scaley){
        _scaley = scaley;
    }

    bool isMove() const
    {
        return _move;
    }

    void setMove(bool move)
    {
        _move = move;
    }

    QPainterPath getRectPath() const
    {
        return _rectPath;
    }

    void addRectPath(const QPainterPath &rectPath)
    {
        _rectPath.addPath(rectPath);
    }

    QVector<QPointF> Points() const
    {
        return _points;
    }

    double getTolerance() const
    {
        return _tolerance;
    }

    void setTolerance(double value)
    {
        _tolerance = value;
    }

    void clear(){
        _rectPath = QPainterPath();
        _dotPath = QPainterPath();
        _points.clear();
    }

    void generate(){
        _points.pop_back();
        int n = _points.count();
        if(_contourColor==QColor(255,0,0,50) || polygonSelfIntersects() || n < 3){
            clear();
            return;
        }
        _points.push_back(_points[0]);
        _rectPath = QPainterPath();
        _rectPath.addPolygon(_points);
        _rectPath.closeSubpath();
        _rectPath.setFillRule(Qt::OddEvenFill);
        getDotline();

    }

    void move(QMouseEvent *event){
        qreal x = event->posF().x();
        qreal y = event->posF().y();
        qreal tx = x - last.x();
        qreal ty = y - last.y();
        _rectPath.translate(tx,ty);
        _dotPath.translate(tx,ty);
        int n = _points.count();
        for(int i=0;i<n;++i){
            qreal rx = _points[i].x();
            qreal ry = _points[i].y();
            _points[i].setX(rx+tx);
            _points[i].setY(ry+ty);
        }
        last = event->posF();
    }

    void pick(QMouseEvent* event){
        QPointF f = event->posF();
        if(!contains(f)){
            return;
        }
        setMove(true);
        last = f;
    }

    void getDotline(){
        QPainterPathStroker stroker;
        stroker.setCapStyle(Qt::RoundCap);
        stroker.setDashPattern(Qt::DashLine);
        stroker.setJoinStyle(Qt::RoundJoin);
        _dotPath = stroker.createStroke(_rectPath);
    }

    void clearDotPath(){
        _dotPath = QPainterPath();
    }

    bool contains(const QPointF& f){
        for(int i=0;i<=_tolerance;++i){
            if(_dotPath.contains(f+QPointF(i,0))||
                    _dotPath.contains(f+QPointF(-i,0))||
                    _dotPath.contains(f+QPointF(0,-i))||
                    _dotPath.contains(f+QPointF(0,i))){
                return true;
            }
        }
        return false;
    }

    int dotContains(const QPointF& f){
        qreal x = f.x();
        qreal y = f.y();
        for(int j=0;j<_points.size();++j) {
            qreal x1 = _points[j].x();
            qreal y1 = _points[j].y();
            for(int i=0;i<=_tolerance;++i){
                if(x1 <= (x+i)&&
                        x1 >= (x-i)&&
                        y1 >= (y-i)&&
                        y1 <= (y+i)){
                    return j;
                }
            }
        }
        return -1;
    }


    void paint(QPixmap& w, QPaintEvent *event=nullptr){
        QPainter painter;
        painter.begin(&w);
        painter.scale(_scalex, _scaley);
        painter.setRenderHint(QPainter::Antialiasing);
        pen.setColor(_contourColor);
        pen.setWidth(2);
        painter.setPen(pen);
        painter.setBrush(_contourColor);
        int n = _points.count();
        if(_move){
            painter.save();
            for(int i=0;i<n;++i){
                painter.setPen(Qt::NoPen);
                painter.setBrush(_contourColor);
                painter.drawEllipse(QPointF(_rectPath.elementAt(i).x,_rectPath.elementAt(i).y),5,5);
            }
            painter.restore();
            painter.drawPath(_dotPath);
        }else{
            painter.drawPath(_rectPath);
        }
        painter.end();
    }

private:
    QColor _contourColor;
    QPen pen;
    // 记录标题，比如contour_1
    QString _title;
    QVector<QPointF> _points;

    QPointF last;


    // 缩放
    double _scalex;
    double _scaley;

    // 移动
    bool _move;
    // 容差
    double _tolerance;

    // fault的路径
    QPainterPath _rectPath;

    // fault的虚线框
    QPainterPath _dotPath;

};

#endif // OUTLINE_H