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


#define MAX_TIME 100000
#define MAX_STATIONS 5

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 packetsTransmitted;
    int backoff;
    timeSlot A;
};

int main()
{
    bool end = false;
    int timeArray[MAX_TIME];
    int k = 0;
    // file with numbers
    string file = "Project2_part1_rn.txt";
    ifstream inputFile;
    inputFile.open(file.c_str());
    int firstTransmissions = 0;
    int modOperand = 0;
    struct stations st[6];
    int timeSlot=0, numFromFile =0;
    const double timeInterval = 51.2; // 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
    struct timeSlot t[MAX_TIME];
    
    
    //int modOperand = pow(2,st[stationCount].collisions);

    // k * timeInterval    
    // begining at t = 0, all stations collide
    

for (int i = 0; i < MAX_TIME; i++)
{
    //cout << dashes << check << timeSlot << endl;
    for (int stationCount = 0; stationCount < MAX_STATIONS; stationCount++)
    {
        if (stationCount==0)
        {
            //cout << dashes << check << timeSlot << endl;
        }
        // station is going to transmit
        if(timeArray[timeSlot]==1 && st[stationCount].arrivalTimeSlot==timeSlot)//st[stationCount].arrivalTimeSlot==timeSlot &&  t[timeSlot].totalCollisions==0 && !t[timeSlot].collided)
        {
            t[timeSlot].transmitted=true;
                        
            st[stationCount].packetsTransmitted++;
            if (st[stationCount].packetsTransmitted==1)
            {
                firstTransmissions++;
            }
            
            // the last station transmits
            if (firstTransmissions == 5 && st[stationCount].packetsTransmitted == 1)
            {
                cout << "\n****************************************************\n" << "Part1c: \n";
                cout << "****************************************************\n";
                cout << check << timeSlot << endl;
                cout << "Station " << stationCount << " has successfully transmitted\n" << 
                "in slot number " << timeSlot << " which is " << timeInterval*timeSlot << " micro seconds\n";
                end = true;
                break;
            }
            st[stationCount].arrivalTimeSlot=st[stationCount].arrivalTimeSlot+3;
            timeArray[st[stationCount].arrivalTimeSlot]++;
            //t[st[stationCount].arrivalTimeSlot].totalCollisions++;
            st[stationCount].collisions=0;
           // cout << stationStr << stationCount << " Success! \n";
        }
        // Two or more stations have collided
        else if (st[stationCount].arrivalTimeSlot==timeSlot || timeSlot==0)
        {
            // initialize values to zero
            if (timeSlot==0)
            {
                st[stationCount].arrivalTimeSlot = 0;
                st[stationCount].backoff = 0;
                st[stationCount].collisions = 0;
                st[stationCount].packetsTransmitted = 0;
            }
            
            st[stationCount].arrivalTimeSlot++;
            st[stationCount].collisions++;
            inputFile >> numFromFile;
            modOperand = pow(2,st[stationCount].collisions);
            k = numFromFile % modOperand;
            st[stationCount].backoff = k;
            st[stationCount].arrivalTimeSlot = st[stationCount].arrivalTimeSlot+st[stationCount].backoff;
            timeArray[st[stationCount].arrivalTimeSlot]++;                        
           // cout << "\tStation " << stationCount << backing << st[stationCount].arrivalTimeSlot << collisionsStr << st[stationCount].collisions << endl;
            t[st[stationCount].arrivalTimeSlot].totalCollisions++;
        }
        else
        {
            if (timeArray[timeSlot]==0)
            {
                
               // cout << "	NO ATTEMPTS\n";
            }
        }
                    
                    
            if (end) break;
            if(stationCount==4)
            {
                //cout << dashes << endl;                        
                timeSlot++;
            }
                    
                    
    }
    if (end) break;
}       

}