// Author       : Brandon Hawkins
// Date         : 9-12-18
// File         : program_004_social_security
// Course       : Computer Science 309
// Instructor   : Dr. Menon
// Goal         : Read from 3 different files, create special ID's
//              from social security numbers and prime squared.
//              Print the names, gpa and special ID's to new file

#define MAX_NAME_LENGTH 20
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct presidents {
    int soc_sec;
    int prime;
    float gpa;
    char firstName[MAX_NAME_LENGTH];
    char lastName[MAX_NAME_LENGTH];
};

int main()
{
    int i;
    struct presidents final[10];
    struct presidents temp;
    FILE * fp1;
    FILE * fp2;
    FILE * fp3;
    FILE * fp4;

    //open file to read primes
    fp1 = fopen("10_primes.txt", "r");
    if (fp1 == NULL) {
        printf("\n\n Unable to open the file for reading... SORRY... Exiting the program");

        return 1; // Error indicated with a return value of 1
    }

    //read first file with primes and save them in struct array
    while(!(feof(fp1)))
    {
        for(i = 0; i < 10; i++)
        {
            fscanf(fp1, "%d", &temp.prime);
            final[i].prime = temp.prime;
        }
    }
    fclose(fp1);

    //open file to read gpa
    fp2 = fopen("gpa.txt", "r");
    if (fp2 == NULL) {
        printf("\n\n Unable to open the file for reading... SORRY... Exiting the program");

        return 1; // Error indicated with a return value of 1
    }

    //read second files with GPA and save them in struct array
    while(!(feof(fp2)))
    {
        for(i = 0; i < 10; i++)
        {
            fscanf(fp2, "%f", &temp.gpa);
            final[i].gpa = temp.gpa;
        }
    }
    fclose(fp2);

    //open file to read social security numbers
    fp3 = fopen("social_security.txt", "r");
    if (fp3 == NULL) {
        printf("\n\n Unable to open the file for reading... SORRY... Exiting the program");

        return 1; // Error indicated with a return value of 1
    }

    //read third file to save names and social security to struct array
    while(!(feof(fp3)))
    {
        for(i = 0; i < 10; i++)
        {
            fscanf(fp3, "%s %s %d", temp.firstName, temp.lastName, &temp.soc_sec);
            strcpy(final[i].firstName, temp.firstName);
            strcpy(final[i].lastName, temp.lastName);
            final[i].soc_sec = temp.soc_sec;
        }
    }
    fclose(fp3);

    fp4 = fopen("finalList.txt", "w");
    if (fp4 == NULL) {
        printf("\n\n Unable to open the file for writing... SORRY... Exiting the program");

        return 1; // Error indicated with a return value of 1
    }

    for(i = 0; i < 10; i++)
    {
        fprintf(fp4, "%d %s %s %f", (final[i].soc_sec+(final[i].prime * final[i].prime)), final[i].firstName, final[i].lastName, final[i].gpa);
    }
    fclose(fp4);

    return 0;
}