import java.io.IOException;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Michał Dyrcz
 */
@WebServlet(urlPatterns = {"/Ellipsoid"})
public class Ellipsoid extends HttpServlet {

    private static final long serialVersionUID = 1L;
    private List<Defekt> defekty = new ArrayList<>();
    private double a;
    private double b;
    private double c;
    private double v;
    private double g;
    private double o;
    private Random random = new Random();

    /**
     * Pusty konstruktor
     */
    public Ellipsoid() {
    }

    /**
     * Klasa reprezentująca defekt
     */
    private class Defekt {

        private double x;
        private double y;
        private double z;
        private double r;

        public Defekt(double x, double y, double z, double r) {
            this.x = x;
            this.y = y;
            this.z = z;
            this.r = r;
        }

        /**
         * Metoda sprawdzająca czy punkt jest w defekcie
         *
         * @param x
         * @param y
         * @param z
         * @return
         */
        public boolean czyPunktDefektu(double x, double y, double z) {
            return (x - this.x) * (x - this.x)
                    + (y - this.y) * (y - this.y)
                    + (z - this.z) * (z - this.z) <= r * r;
        }
    }

    /**
     *
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.defekty.add(
                new Defekt(
                        Double.parseDouble(request.getParameter("x")),
                        Double.parseDouble(request.getParameter("y")),
                        Double.parseDouble(request.getParameter("z")),
                        Double.parseDouble(request.getParameter("r"))));
    }

    /**
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        this.a = Double.parseDouble(request.getParameter("a"));
        this.b = Double.parseDouble(request.getParameter("b"));
        this.c = Double.parseDouble(request.getParameter("c"));
        this.v = Double.parseDouble(request.getParameter("v"));
        this.g = Double.parseDouble(request.getParameter("g"));

        double masa = obliczMase(15000000);
        PrintWriter out = response.getWriter();
        out.print(masa);
    }

    private double obliczMase(int n) {
        double x;
        double y;
        double z;
        long trafienieDefektu = 0;
        long trafienieElipsoide = 0;
        for (int i = 0; i < n; i++) {
            x = losowanieZakresem(-a, a);
            y = losowanieZakresem(-b, b);
            z = losowanieZakresem(-c, c);
            if (czyPunktElipsoidy(x, y, z)) {
                trafienieElipsoide++;
                if (czyJestDefekt(x, y, z)) {
                    trafienieDefektu++;
                }
            }

        }

        double P = (2.0 * a) * (2.0 * b) * (2.0 * c);//objetosc prostopadloscianu
        this.o = P * (double) trafienieElipsoide / (double) n;//objetosc elipsoidy
        double iloscUderzen = (double) trafienieDefektu / (double) trafienieElipsoide;
        double objetoscDefektu = this.o * iloscUderzen;   //objetosc defektow
        double wynik = objetoscDefektu * g + (1.0 - iloscUderzen) * this.o * v;//masa
        return wynik;
    }

    private double losowanieZakresem(double a, double b) {
        return a + (b - a) * random.nextDouble();
    }

    /**
     * Method checks whether given point is inside the ellipsoid
     *
     * @param x
     * @param y
     * @param z
     * @return
     */
    private boolean czyPunktElipsoidy(double x, double y, double z) {
        return (x * x) / (a * a)
                + (y * y) / (b * b)
                + (z * z) / (c * c) <= 1.0;
    }

    /**
     * Method checks whether given point is inside of one of the decfects
     *
     * @param x
     * @param y
     * @param z
     * @return
     */
    private boolean czyJestDefekt(double x, double y, double z) {
        for (Defekt defekt : defekty) {
            if (defekt.czyPunktDefektu(x, y, z)) {
                return true;
            }
        }
        return false;
    }
}