import java.awt.*;
import java.awt.image.BufferedImage;

public class Triangle{
    public Point2D point1;
    public Point2D point2;
    public Point2D point3;

    private Line LineLong;
    private Line LineA;
    private Line LineB;
    // initialisation variables
    private boolean is_initialised = false;
    private Point2D min;
    private Point2D max;
    // progress variables


    public Triangle(Point2D _pA, Point2D _pB, Point2D _pC){
        point1 = _pA;
        point2 = _pB;
        point3 = _pC;
    }
    public void draw(BufferedImage img){
        if (!is_initialised){initialise();}
        int[] point1 = new int[]{0, 0};
        int[] point2 = new int[]{0, 0};
        int lastX = 0;
        int lastXLong = 0;
        char currentLine = 'A';
        LineLong.initialise();
        LineA.initialise();
        LineB.initialise();
        LineLong.draw(img);
        LineA.draw(img);
        LineB.draw(img);
        for(int x = min.x; x <= max.x; x += 1) {
            while(lastXLong == point1[0]) {
                point1 = LineLong.nextPix();
            }
            while(lastX == point2[0]) {
                if (currentLine == 'A') {
                    try{point2 = LineA.nextPix();}
                    catch (RuntimeException e){
                        currentLine = 'B';
                        point2 = LineB.nextPix();
                    }
                }
                else {
                    point2 = LineB.nextPix();
                }
            }
            lastXLong = point1[0];
            lastX = point2[0];
            if(point1[1] < point2[1]) {
                for (int y = point1[1]; y <= point2[1]; y += 1) {
                    if(x >= 0 && x < img.getWidth() && y >= 0 && y < img.getHeight()) { // check if drawing in bounds
                        img.setRGB(x, y, Color.HSBtoRGB(.5f, 1, 1));
                    }
            }} else {
                for (int y = point2[1]; y <= point1[1]; y += 1) {
                    if(x >= 0 && x < img.getWidth() && y >= 0 && y < img.getHeight()) { // check if drawing in bounds
                        img.setRGB(x, y, Color.HSBtoRGB(.5f, 1, 1));
                    }
                }}
        }
        is_initialised = false;
    }
    public void initialise(){
        if (point1 == null || point2 == null || point3 == null){
            throw new NullPointerException();
        }
        min = new Point2D(Math.min(point1.x, Math.min(point2.x, point3.x)), Math.min(point1.y, Math.min(point2.y, point3.y)));
        max = new Point2D(Math.max(point1.x, Math.max(point2.x, point3.x)), Math.max(point1.y, Math.max(point2.y, point3.y)));
        // woo horrible IFs mess.
            // if there are no vertical lines, then we need to find which points touch the edges.
        Point2D realPointA;
        Point2D realPointB;
        Point2D realPointC;
        if (point1.x == min.x) { realPointA = point1;
                if (point2.x == max.x){ realPointB = point2;
                    realPointC = point3;
                } else {
                    realPointB = point3;
                    realPointC = point2;
                }
            }
            else if (point2.x == min.x) { realPointA = point2;
                if (point1.x == max.x) { realPointB = point1;
                    realPointC = point3;
                } else { realPointB = point3;
                    realPointC = point1;
                }
            }
            else {
            realPointA = point3;
                if (point1.x == max.x) { realPointB = point1;
                    realPointC = point2;
                } else { realPointB = point2;
                    realPointC = point1;
                }
            }
        // assign points to lines
        LineLong = new Line(realPointA, realPointB);
        LineA = new Line(realPointA, realPointC);
        LineB = new Line(realPointC, realPointB);

        is_initialised = true;
    }
}