#include <stdio.h>
#include <stdlib.h>
void setupDummyData();
void saveToFile();
void readFile();
void printPrimesToScreen();



int primes[100];
int result[100];
int count = 0;

int main()
{


   //When answering tutorial questions, be as precise and descriptive as possible

   //TUTORIAL BLOCK 1:
   //a. What does the code accomplish if the following multiline comment is removed?

  /* printPrimesToScreen();
   setupDummyData();
   printPrimesToScreen();*/



   //TUTORIAL BLOCK 2:
   //a. Redo the multiline comment above.
   //b. What does the code accomplish if the following multiline comment is removed?
   /*
   printPrimesToScreen();
   setupDummyData();
   saveToFile();
   printPrimesToScreen();   */



   //TUTORIAL BLOCK 3:
   //a. Redo the multiline comment above.
   //b. What does the code accomplish if the following multiline comment is removed?
   //c. Where did the data in the array come from on the second printPrimesToScreen()?
   /*
   printPrimesToScreen();
   readFile();
   printPrimesToScreen();//2nd printPrimesToScreen()
   */

   //TUTORIAL BLOCK 4:
   //a. Redo the multiline comment above.
   //b. DELETE the file "primes.txt"
   //c. What does the code accomplish if the following multiline comment is removed?
   //d. What data exists in the file "primes.txt"
   /*
   printPrimesToScreen();
   readFile();
   saveToFile();
   readFile();
   printPrimesToScreen();
   */

   //DELETE primes.txt if you need to retry this tutorial.

   printf("Program quitting...\n");
   return 0;
}

//HARDCODE Data into array
void setupDummyData()
{
   count = 8;
    primes[0]= 2;
    primes[1]= 3;
    primes[2]= 5;
    primes[3]= 7;
    primes[4]= 11;
    primes[5]= 13;
    primes[6]= 17;
    primes[7]= 19;
    primes[8]= 23;
    primes[9]= 29;
}

//empty all contents into a file in overwritemode
void saveToFile()
{
   FILE* filePtr = fopen("primes.txt","w");
   if (filePtr==NULL)
      printf("Error creating savefile.....Check that file is not in use\n\n");
   else
   {
      //write the number of records in the array on the first line
      fprintf(filePtr, "%d\n",count);
      //write each prime number on a separate line in the file
      for (int i = 0 ; i<count;i++)
         fprintf(filePtr, "%d\n",primes[i]);
   }
   fclose(filePtr);//close file for use by other processes
   printf("Datafile Saved!\n\n");
}


//read all data into array
void readFile()
{
   FILE* filePtr = fopen("primes.txt","r");
   if (filePtr==NULL)
      printf("Error reading file, does it exist?\n\n");
   else
   {
      //read the number of records in the file from the first line
      fscanf(filePtr, "%d",&count);
      //write each prime number on a separate line in the file
      for (int i = 0 ; i<count;i++)
         fscanf(filePtr, "%d",&primes[i]);
   }
   fclose(filePtr);//close file for use by other processes
}



void printPrimesToScreen()
{
   printf("\n\n****Now Displaying all Primes in the array\n");
   if (count==0)
         printf("\nPrime Array Is empty...\n\n");
   else
   {
      for (int i = 0 ; i<count;i++)
         printf("index: %d , prime: %d \n",i,primes[i]);
      printf("\n");

   }

}