#include <iostream>
#include <iomanip>
#include <fstream>
#include <math.h>

#define MAX_ARRAY_SIZE 1000

using namespace std;

void calculations(float deltaVal, float deviationVal, string outputFileName);

int main(int argc, char const *argv[])
{
    // calculate part a
    calculations(0.125, 0.500, "P3A.txt");
    calculations(0.125, 1.500, "P3B.txt");
    calculations(0.25,  0.500, "P3C.txt");

}

void calculations(float deltaVal, float deviationVal, string outputFileName)
{
    ofstream outputFile;
    outputFile.open(outputFileName.c_str());
    // difference = sampleRTT - estimatedRTT
    // estimatedRTT = estimatedRTT + (delta * difference)
    // deviation = deviation + delta(|difference| - deviation)
    // timeOut = mu * estimatedRTT + (phi * deviation)

    float delta = 0.0, mu = 0.0, phi = 0.0; // 
    float difference[MAX_ARRAY_SIZE], estimatedRTT[MAX_ARRAY_SIZE], sampleRTT;
    float deviation[MAX_ARRAY_SIZE], timeOut = 0.0, tmpDeviation = 0.0, tmpestimateRTT = 0.0;
    // Values for Jacobson/Karels Algorithim
    delta = deltaVal;
    mu = 1.0;
    phi = 4.0;

    // do-while loop
    int i = 0;
    outputFile << "Iteration #\t\tSampleRTT\t\tEstimatedRTT\t\t  Deviation\t\tDifference\t\tTimeout\n";
    do
    {
        // initial values
        if (i == 0)
        {
            outputFile << fixed << setprecision(4);
            estimatedRTT[0] = 4.000;
            deviation[0] = deviationVal;
            outputFile << i << "\t\t\t\t - \t\t\t\t\t" << estimatedRTT[0] << "\t\t\t\t" << deviation[0] << "\t\t\t - \t\t\t - \n";
            i++;
        }
        sampleRTT = 1.0000;
        difference[i] = sampleRTT - estimatedRTT[i-1];
        // calculate estimatedRTT again
        estimatedRTT[i] = estimatedRTT[i-1] + (delta * difference[i]);
        deviation[i] = deviation[i-1] + delta*(fabs(difference[i]) - deviation[i-1]);
        timeOut = mu * estimatedRTT[i] + (phi * deviation[i]);
        // "Iteration #\t\tSampleRTT\t\tEstimatedRTT\t\tDeviation\t\tTimeout\n"
        outputFile << i << "\t\t\t\t" << setw(5) << setfill(' ') << sampleRTT << setw(10) << setfill(' ') << "\t\t" << estimatedRTT[i] << setw(8) << setfill(' ') << 
        "\t\t" << deviation[i] << setw(3) << setfill(' ') << "\t\t" << difference[i] << setw(8) << setfill(' ') << "\t" << timeOut << endl;
        i++;
    } while (timeOut > 4.0);
    outputFile.close();
}