package yawning.mew;

import org.apache.commons.math.distribution.NormalDistributionImpl;

import ec.util.MersenneTwisterFast;

public class TestCDF {
    private static double ATTACKS = 3.0;
    private static double PCRIT = 0.6;
    private static int ITERATIONS = 1000000;
    private static double STEP = 0.01;

    public static void main(String args[]) {
        try {
            MersenneTwisterFast random = new MersenneTwisterFast();

            for (double nrAttacks = ATTACKS; nrAttacks <= ATTACKS + 1; nrAttacks += STEP) {
//              System.out.println("Attacks: " + nrAttacks);

                // Gaussian CDF
                double meanCP = nrAttacks + nrAttacks * PCRIT;
                double sdCP = Math.sqrt(nrAttacks * PCRIT * (1 - PCRIT));
                double p5cp = 1 - new NormalDistributionImpl(meanCP, sdCP).cumulativeProbability(4.5);
//              System.out.println("p(5 cp) using normal distribution modeling: " + p5cp);

                // Monte carlo
                int lower = (int)nrAttacks;
                int upperIterations = (int)((nrAttacks - lower) * ITERATIONS);
                int hit5cps = 0;
                for (int i = 0; i < ITERATIONS - upperIterations; i++) {
                    int cp = lower;
                    for (int j = 0; j < lower; j++) if (random.nextBoolean(PCRIT)) cp ++;
                    if (cp >= 5) hit5cps++;
                }
                for (int i = 0; i < upperIterations; i++) {
                    int cp = lower + 1;
                    for (int j = 0; j < lower + 1; j++) if (random.nextBoolean(PCRIT)) cp ++;
                    if (cp >= 5) hit5cps++;
                }
//              System.out.println("p(5 cp) using monte carlo modeling: " + (double)hit5cps/ITERATIONS);
//              System.out.println();

                // Linear approximation
                double deltaPdeltaA = 0;
                double meanCPlow = Math.floor(nrAttacks) + Math.floor(nrAttacks) * PCRIT;
                double sdCPlow = Math.sqrt(Math.floor(nrAttacks) * PCRIT * (1 - PCRIT));
                double p5cplow = 1 - new NormalDistributionImpl(meanCPlow, sdCPlow).cumulativeProbability(4.5);
                double meanCPhigh = Math.ceil(nrAttacks) + Math.ceil(nrAttacks) * PCRIT;
                double sdCPhigh = Math.ceil(Math.floor(nrAttacks) * PCRIT * (1 - PCRIT));
                double p5cphigh = 1 - new NormalDistributionImpl(meanCPhigh, sdCPhigh).cumulativeProbability(4.5);
                deltaPdeltaA = p5cphigh - p5cplow;
                double p5cplol = p5cplow + deltaPdeltaA * (nrAttacks - Math.floor(nrAttacks));

                System.out.println(nrAttacks + "," + p5cp + "," + ((double)hit5cps/ITERATIONS) + "," + p5cplol);
            }

        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}