package testbench;

import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
import java.util.Random;

import Bench.IBenchmark;

class Dummy {
    public void m() {
    }
}

public class TestCPUDigitsOfPi implements IBenchmark {
    protected int array[];
    protected int n;
    private boolean running;

    BigDecimal a = new BigDecimal(1.0);
    BigDecimal b = new BigDecimal(1.0 / (2^(1/2)));
    BigDecimal t = new BigDecimal(1/4.0);
    BigDecimal p = new BigDecimal(1.0);




    public void initialize(Object ...params) {

        this.running = true; //set running
        Random random = new Random();
        this.n = (Integer) params[0];
        this.array = new int[n];

        for(int i = 0; i < n; i++)
            array[i] = random.nextInt(1000);

    }


    private void computePi3() {
    }

    private void computePi2() {

    }


    public static int log2(int x)
    {
        return (int)(Math.log(x) / Math.log(2));
    }


    BigDecimal pi = new BigDecimal("0");
    BigDecimal a1;
    MathContext mc = new MathContext(100);
    MathContext power = new MathContext(2);

    private BigDecimal computePi1(int n) // numar de cifre corecte in pi
    {
        double i = 0;
        System.out.println(log2(n));
        for(i = 0; i <= n; i++)//while(i <= n )//log2(n)
        {

            a1 = (a.add(b, mc));
            a1 = a1.divide(new BigDecimal(2.0), mc); //inainte avea mc aici

            b = (a.multiply(b, mc));
            b = b.sqrt(mc);

            t = t.subtract(p.multiply((a.subtract(a1).pow(2, mc)), mc));

            p = p.multiply(new BigDecimal(2.0), mc);

            //a = a1;

        }
        pi = ((a1.add(b, mc)).pow(2, mc)).divide(t.multiply(new BigDecimal(4.0), mc), mc);
        return pi;
    }

    public void run(Object[] ... param) {
    }

    @Override
    public void clean() {

    }

    @Override
    public void cancel() {
        this.running = false; //clear running
    }

    @Override
    public void run(Object... param) {
        int option = (Integer)(param[0]);
        switch(option)
        {
        case 1:
            BigDecimal pi = new BigDecimal(1.0);
            pi = computePi1((Integer)(param[1])); //al doilea argument
            System.out.println(pi);
            break;
        case 2:
            computePi2();
            break;
        case 3:
            computePi3();
            break;
        default:
            throw new IllegalArgumentException("Invalid option, press 1 - 3");
        }

    }

    @Override
    public void warmup() {
        for (int i = 0; i < 100000; i++) {
            Dummy dummy = new Dummy();
            dummy.m();
        }

    }


    @Override
    public void run() {
        // TODO Auto-generated method stub

    }
}