#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define TRUE 1
#define FALSE 0

int main(void)
{
    int selection;

    printf("~~ FAST FOOD RESTARAUNT SIMULATION ~~\n\nPress 1 to initialize scenario 1. \nPress 2 to initialize scenario 2. \nPress any other key to exit the program.\n\nSelection: ");
    scanf("%d",&selection);

    switch(selection)
    {
        case 1:
            scenarioOne();
            break;
        case 2:
            scenarioTwo();
            break;
        default:
            break;
    }
return 0;
}

int scenarioOne(void)
{
    printf("SCENARIO ONE CHOSEN.\n\n");

/// USER DEFINES CUSTOMERS PER MINUTE
    double r;
    printf("Define the arrival rate of customers per minute: ");
    scanf("%lf",&r);

/// CUSTOMERS PER SECOND
    double customerArrive; // the chance a customer will arrive at any given second
    customerArrive=(r*1.0)/60;
    printf("Theoretically, there will be %f customers arriving per second.\n Press 'Enter' to continue.\n",customerArrive);

        getchar();
        getchar();

/// EACH ITERATION IS A 10-MINUTE INTERVAL
    int i;
    for (i=0; i<18; i++)
        interval(customerArrive);
}

int interval(double customerArrive)
{
        int totalCustomer=0; // total # of customers
        int totalWait=0; // total wait time
        int avgWait=0; // AVERAGE wait time

        int queue=0; // customer queue count

        int cash1empty=1; // whether or not a customer can get served by cash 1
        int cash2empty=1; // whether or not a customer can get served by cash 2

        int cash1salad,cash1burger,cash2salad,cash2burger; // different types of orders

        /// EACH ITERATION IS ONE SECOND
            int t;
            for (t=0;t<600;t++)
            {
                /// Generate random value between 0 and 1.
                double x;
                x= (double) rand() / (double) RAND_MAX;

                if (customerArrive>=x)
                {
                    // A customer arrived during this second!
                    totalCustomer++;
                    queue++;

                    if (queue > 0)
                    {

                        // if both cashiers are empty, then it is 50/50 to decide where to go
                        if ((cash1empty==TRUE)&&(cash2empty==TRUE))
                        {
                            switch((rand()%2))
                            {
                                case 0:
                                    cash1empty=FALSE;
                                    break;
                                case 1:
                                    cash2empty=FALSE;
                                    break;

                            }
                        }

                        if (cash1empty==TRUE)
                        {
                            cash1empty=FALSE;
                            //queue--;

                            switch((rand()%2))
                            {
                                case 0:
                                    cash1salad=(rand()%(66-55)+55);
                                    totalWait+=cash1salad;
                                    break;
                                case 1:
                                    cash1burger=(rand()%(131-111)+111);
                                    totalWait+=cash1burger;
                                    break;
                            }
                        }
                        else if (cash2empty=TRUE)
                        {
                            cash2empty=FALSE;
                            //queue--;

                            switch(rand()%2)
                            {
                                case 0:
                                    cash2salad=(rand()%(76-65)+65);
                                    totalWait+=cash2salad;
                                    break;
                                case 1:
                                    cash2burger=(rand()%(141-121)+121);
                                    totalWait+=cash2burger;
                                    break;
                            }
                        }
                    }
                }
            }

            /// extra code: just to check
            // Counter to determine which interval is currently running.
            static int intNum;
            intNum++;


            /// extra code: just to check
            // customer arrival rate per minute, by probability
            double R;
            R=(totalCustomer*1.0)/600;
            printf("Customers arriving per minute in interval %d: %f\n",intNum,R);


            avgWait=((totalWait*1.0)/(totalCustomer));
                if (avgWait>=0)
                {
                    printf("Average wait time per customer: %d\n",avgWait);
                }
                else
                {
                    printf("No customers arrived in this interval.\n");
                }

            /// extra code : just to check
            printf("Amount of people who got queued: %d\n\n",queue);

}


int scenarioTwo(void)
{
    printf("SCENARIO TWO CHOSEN.\n\n");
}