import java.io.File;

public class Planet {
    double myXPos;
    double myYPos;
    double myXVel;
    double myYVel;
    double myMass;
    String myFileName;

    double gConst;

    public Planet(double xp, double yp, double xv, double yv, double mass, String filename) {
        this.myXPos = xp;
        this.myYPos = yp;
        this.myXVel = xv;
        this.myYVel = yv;
        this.myMass = mass;
        this.myFileName = filename;

        this.gConst = 6.67 * Math.pow(10, -11);
    }

    public Planet(Planet p) {
        this.myXPos = p.myXPos;
        this.myYPos = p.myYPos;
        this.myXVel = p.myXVel;
        this.myYVel = p.myYVel;
        this.myMass = p.myMass;
        this.myFileName = p.myFileName;
    }

    public double calcDistance(Planet otherPlanet) {
        double xres = Math.pow(otherPlanet.myXPos - this.myXPos, 2);
        double yres = Math.pow(otherPlanet.myYPos - this.myYPos, 2);
        return Math.sqrt(xres + yres);
    }

    public double calcForceExertedBy(Planet otherPlanet) {
        double force = (gConst * otherPlanet.myMass * this.myMass) / Math.pow(calcDistance(otherPlanet), 2);
        return force;
    }

    public double calcForceExertedByX(Planet otherPlanet) {
        double dx = otherPlanet.myXPos - this.myXPos;
        double dy = otherPlanet.myYPos - this.myYPos;
        double radius = Math.sqrt(Math.pow(dx, 2) + Math.pow(dy, 2));
        double force = calcForceExertedBy(otherPlanet);

        return (force * dx) / radius;
    }

    public double calcForceExertedByY(Planet otherPlanet) {
        double dx = otherPlanet.myXPos - this.myXPos;
        double dy = otherPlanet.myYPos - this.myYPos;
        double radius = Math.sqrt(Math.pow(dx, 2) + Math.pow(dy, 2));
        double force = calcForceExertedBy(otherPlanet);

        return (force * dy) / radius;
    }

    public double calcNetForceExertedByX(Planet[] planets) {
        double total = 0.0;
        for (Planet planet : planets) {
            if (!this.equals(planet)) {
                total += calcForceExertedByX(planet);
            }
        }
        return total;
    }

    public double calcNetForceExertedByY(Planet[] planets) {
        double total = 0.0;
        for (Planet planet : planets) {
            if (!this.equals(planet)) {
                total += calcForceExertedByY(planet);
            }
        }
        return total;
    }

    public void update(double seconds, double xforce, double yforce) {
        double accelerationx = xforce / myMass;
        double accelerationy = yforce / myMass;

        this.myXVel = myXVel + seconds * accelerationx;
        this.myYVel = myYVel + seconds * accelerationy;
        this.myXPos = myXPos + seconds * myXVel;
        this.myYPos = myYPos + seconds * myYVel;
    }

    public void draw() {
        StdDraw.picture(myXPos, myYPos, "images/" + myFileName);
    }

}