#include<stdio.h>
#include<stdlib.h>
#include<string.h>


struct Shift
{
char name[100];
char day_of_week[100];
int start_hour;
int end_hour;
};

struct Shift shift_data[100];
struct Shift temp;

int read_data(struct Shift shift_data[], int *num_shifts);
void sort_data(struct Shift shift_data[], int *num_shifts);
void print_data(struct Shift shift[], int num_shifts);






int main (void)
{

int num_shifts;


read_data(shift_data, &num_shifts);

sort_data(shift_data, &num_shifts);

print_data(shift_data, num_shifts);




return 0;
}




// Preconditions: array of structure "Shift" to store data
// Postconditions: number of shifts read in from data file
// Actions: Ask user for name of input file. Read the number
// of shifts, then read in the data for all
// of the shifts. Return the number of shifts.
int read_data(struct Shift shift_data[], int *num_shifts)
{
    int i;
    char infile_name[50];
    char shift_name[100], shift_day[100];


        printf("What is the name of your input file?\n"); //ask user for input file name
        scanf("%s", infile_name);

        FILE *input;                        //declare file pointer
        input = fopen(infile_name, "r");    //open input file

        fscanf(input, "%d", num_shifts);

            for (i=0; i<*num_shifts; i++) // read in data
            {
                fscanf(input, "%s", &shift_data[i].name);
                fscanf(input, "%s", &shift_data[i].day_of_week);
                fscanf(input, "%d", &shift_data[i].start_hour);
                fscanf(input, "%d", &shift_data[i].end_hour);
            }


fclose(input);
return num_shifts;
}




// Preconditions: array of structure "Shift"
// integer value indicating number of shifts
// Postconditions: none - this function does not return anything.
// Actions: Sort the shifts by the TA's first name.
void sort_data(struct Shift shift_data[], int *num_shifts)
{
    int i, changed;
    do
    {
        changed = 0;
        for (i=0; i < (*num_shifts) - 1; i++)
        {
            if (strcmp(shift_data[i].name, shift_data[i+1].name) > 0)
            {
                memcpy(&temp, shift_data + i, sizeof (struct Shift));
                memcpy(shift_data + i, shift_data + i + 1, sizeof (struct Shift));
                memcpy(shift_data + i + 1, &temp, sizeof (struct Shift));
                changed = 1;
           }
        }
    } while (changed != 0);
}




// Preconditions: array of structure "Shift"
// integer value indicating number of shifts
// Postconditions: none - this function does not return anything.
// Actions: Print the sorted data in the format described below.
void print_data(struct Shift shift[], int num_shifts)
{

int i;

printf("\n");
printf("TA shifts:\n\n=================================================\n\n");

    for (i=0; i<num_shifts; i++)
    {
        printf("%-5s\t", shift_data[i].name);
        printf("%-8s\t", shift_data[i].day_of_week);


            //decide whether to convert time value and place am and pm in correct locations
            if (shift_data[i].start_hour > 12)
                    {
                       shift_data[i].start_hour -= 12;
                       printf("%3d:00 pm  to  ",  shift_data[i].start_hour);
                    }
            else if (shift_data[i].start_hour < 12)
                    {
                       printf("%3d:00 am  to  ",  shift_data[i].start_hour);
                    }
            else if (shift_data[i].start_hour == 12)
                    {
                       printf("%3d:00 pm  to  ",  shift_data[i].start_hour);
                    }



            if (shift_data[i].end_hour > 12)
                    {
                       shift_data[i].end_hour -= 12;
                       printf("%3d:00 pm\n", shift_data[i].end_hour);
                    }
            else if (shift_data[i].start_hour < 12)
                    {
                       printf("%3d:00 am\n", shift_data[i].end_hour);
                    }

            else if (shift_data[i].end_hour == 12)
                    {
                       printf("%3d:00 pm\n",  shift_data[i].end_hour);
                    }
                }
printf("\n=================================================\n\n");


}