#include <iostream>
#include <math.h>
#include <stdio.h>
#include <random>
#include <fstream>
#include <stdbool.h>


#define MAX_COLLISIONS 100000
#define MAX_STATIONS 6

using namespace std;
struct timeSlot { 
    int timeOfTransmission; // time slot
    int totalCollisions;
    // stations A;
    bool collided, transmitted;
};

struct stations {
    int arrivalTimeSlot; // time slot
    int collisions;
    int backoff;
    timeSlot A;
};

// function that generates the
// range of backoff slots
//int rangeOfBackoff(int k);

std::random_device                  rand_dev;
    std::mt19937                        generator(rand_dev());
    //std::uniform_int_distribution<int>  distr(0, k);
int main()
{
    bool didNotCollide, end;
    int collisionArray[MAX_COLLISIONS];
    int timeArray[MAX_COLLISIONS];
    int transmissions =0;
    int k = 0;
    // file with numbers
    string file = "Project2_part1_rn.txt";
    ifstream inputFile;
    inputFile.open(file.c_str());
    bool transmitted;
    
    int timeIndex = 0;
    int modOperand;
    struct stations st[6];
    int timeSlot=0, numFromFile;
    const int timeInterval = 512; // time interval in micro seconds

    // strings for precise code
    string check="Checking time slot: ";
    string collisionsStr = "  collisions: ";
    string backing = ": backing off to slot ";
    string dashes = "--------------------------------------------------\n";
    string stationStr = "\tStation ";
    // define variables
    int n, totalCollisions,i;
    struct timeSlot t[MAX_COLLISIONS];
    
    
    //int modOperand = pow(2,st[i].collisions);

    // k * timeInterval    
    // begining at t = 0, all stations collide
    
    while (timeSlot < MAX_COLLISIONS)
    {
        if (timeSlot==0)
        {
            
            cout << dashes << check << timeSlot << endl;
            // add total collisions to station time
            for (int i = 0; i < MAX_STATIONS; i++)
            {
                t[i].totalCollisions++;
                t[i].timeOfTransmission = i;
                st[i].arrivalTimeSlot=0; // Arrival Time slot
                //k= pow(2,st[i].collisions);
                st[i].collisions = 1;
                k=1;
                uniform_int_distribution<int>  distr(0, k);
                int o = distr(generator);
                st[i].backoff = o;
                if (o==0)
                {
                    
                    st[i].arrivalTimeSlot=1;
                    t[i].timeOfTransmission=1;
                    timeArray[1]++;
                }
                else
                {
                    //t[2].totalCollisions++;
                    timeArray[2]++;
                    st[i].arrivalTimeSlot = 2;
                }
                cout << "\tStation " << i << backing << st[i].arrivalTimeSlot << collisionsStr << st[i].collisions << endl;
                t[st[i].arrivalTimeSlot].totalCollisions++;
            }

            cout << dashes << endl;
            timeSlot++;

        }
        else
        {
            for (int i = 0; i < MAX_COLLISIONS; i++)
            {
                //cout << dashes << check << timeSlot << endl;
                for (int stationCount = 0; stationCount < MAX_STATIONS; stationCount++)
                {
                    t[stationCount].transmitted=true;
                    if (stationCount==0)
                    {
                        cout << dashes << check << timeSlot << endl;
                    }
                    transmitted==false;
                     if(timeArray[timeSlot]==1 && t[timeSlot].totalCollisions<=2  && st[stationCount].arrivalTimeSlot==timeSlot)//st[stationCount].arrivalTimeSlot==timeSlot &&  t[timeSlot].totalCollisions==0 && !t[timeSlot].collided)
                    {
                        t[timeSlot].transmitted=true;
                        cout << stationStr << stationCount << " Success! ";
                        
                        
                        transmissions++;
                        if (transmissions>1 && transmissions != 6)
                        {
                            cout << "\t\t<=== Project1b Solution\n";
                        }
                        else if (transmissions==6)
                        {
                            cout << "\t\t<=== Project1b Solution\n" << dashes << endl;
                            end = true;
                            break;
                        }
                        else
                        {
                            cout << "\t\t<=== Project1a Solution\n";
                        }
                        
                        
                        transmitted=true;
                        
                    }
                    else if (st[stationCount].arrivalTimeSlot==timeSlot && timeArray[timeSlot]>1)
                    {
                        // if (t[timeSlot].totalCollisions==1 && timeArray[timeSlot]==1 && t[timeSlot].totalCollisions==0)
                        // {
                        //     //  t[timeSlot].transmitted=true;
                        //     cout << stationStr << stationCount << " Success! " << endl;
                        //     cout << "End of program\n";
                        //     end = true;
                        // }
                        if (end) break;

                        st[stationCount].arrivalTimeSlot++;
                        st[stationCount].collisions++;
                        inputFile >> numFromFile;
                        //array[arrayIndex] = numFromFile;
                        //arrayIndex++;
                        modOperand = pow(2,st[stationCount].collisions);
                        modOperand--;
                        k = numFromFile % modOperand;
                        //uniform_int_distribution<int>  distr(0, k);
                       // int o = distr(generator);
                        st[stationCount].backoff = k;
                        st[stationCount].arrivalTimeSlot = st[stationCount].arrivalTimeSlot+st[stationCount].backoff;
                        timeArray[st[stationCount].arrivalTimeSlot]++;
                        if (timeArray[st[stationCount].arrivalTimeSlot]<=1)
                        {
                                t[st[stationCount].arrivalTimeSlot].collided=false;

                        }
                        else 
                                t[st[stationCount].arrivalTimeSlot].collided=false;
                        
                        cout << "\tStation " << stationCount << backing << st[stationCount].arrivalTimeSlot << collisionsStr << st[stationCount].collisions << endl;
                        t[st[stationCount].arrivalTimeSlot].totalCollisions++;
                    }
                    else if (t[timeSlot].totalCollisions==1 && t[timeSlot].transmitted && st[stationCount].arrivalTimeSlot==timeSlot)
                    {
                        //t[timeSlot].transmitted=true;
                        cout << stationStr << stationCount << " Success! " << endl << dashes << endl;
                        cout << "End of program\n";
                        end = true;
                    }
                    else //if (st[stationCount].arrivalTimeSlot != timeSlot && t[timeSlot].totalCollisions<1 && !t[timeSlot].transmitted)
                    {
                        if (timeArray[timeSlot]==0)
                        {
                            if(stationCount==5)
                             cout << "	NO ATTEMPTS\n";
                        }
                    }
                    
                    
                    if (end) break;
                    
                    
                    
                    
                    
                    if(stationCount==5)
                    {
                        cout << dashes << endl;                        
                        timeSlot++;
                    }
                    
                    
                }
                    if (end) break;

                    /* if (t[timeSlot].totalCollisions<2 && t[timeSlot].)
                    // {
                         cout << dashes << check << timeSlot << endl << stationStr << stationCount << " Success! " << endl 
                            << dashes;
                       } */ 
                   // if(transmitted==true) cout << dashes << endl;
                    
            }
            if (end) break;
        }

    }       
}