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

#define HEADERSIZE  18

#define W_LSB       12
#define W_MSB       13
#define H_LSB       14
#define H_MSB       15

//#define HASHSIZE 262147
#define N        300000

int hash(int key), primecalc(int m, int n);

int main(int argc, char** argv, int startnum)
{

    int m, n;
    FILE *fp;
    unsigned char header[HEADERSIZE];

    FILE *greyscalefp;
    unsigned char greyscaleheader[HEADERSIZE];

    //system("cls");

    printf("Opening Input Image '%s' ... ", argv[1]);fflush(stdout);
    fp = fopen(argv[1],"rb");
    if(!fp)
    {
        printf("\n\nARGH! File couldn't be opened.\n");fflush(stdout);
    }
    printf("Done.");fflush(stdout);


    printf("\n\nReading %d Byte Header ... ", HEADERSIZE);fflush(stdout);
    fread(header, HEADERSIZE, 1, fp);
    printf("Done.");fflush(stdout);

    printf("\n\nHeader Contents: ");fflush(stdout);
    for(int i=1;i<HEADERSIZE;i++)
    {
      printf("|%d|", header[i]);fflush(stdout);
    }

    m = (header[W_MSB]*256) + header[W_LSB];
    n = (header[H_MSB]*256) + header[H_LSB];

    printf("\n\nDimensions Extracted: Width=%d, Height=%d.", m, n);
    //return (m, n);
    fflush(stdout);

    //Run Primecalc with those numbers
    primecalc(m, n);

    unsigned char Rt, Gt, Bt;
    unsigned char I[m][n];

    printf("\n\nReading RGB Data & Calculating Greyscale ... ");fflush(stdout);
    for(int i=0;i<m;i++)
      for(int j=0;j<n;j++)
      {
        fscanf(fp, "%c", &Rt);
        fscanf(fp, "%c", &Gt);
        fscanf(fp, "%c", &Bt);

        I[i][j] = (Rt+Gt+Bt)/3;
      }
    fclose(fp);
    printf("Done.");fflush(stdout);

    printf("\n\nOpening Output File '%s' ... ", argv[2]);fflush(stdout);
    fp = fopen(argv[2],"wb");
    printf("Done.");fflush(stdout);

    printf("\n\nWriting %d Byte Header ... ", HEADERSIZE);fflush(stdout);
    fwrite(header, 1, HEADERSIZE, fp);
    printf("Done.");fflush(stdout);

    printf("\n\nWriting Converted RGB Data ... ");fflush(stdout);
    for(int i=0;i<m;i++)
      for(int j=0;j<n;j++)
      {
        fprintf(fp, "%c", I[i][j]);
        fprintf(fp, "%c", I[i][j]);
        fprintf(fp, "%c", I[i][j]);
      }
    printf("Done.\n");fflush(stdout);
    fclose(fp);

    //---------------------Open Grescale Image---------------------//



    //system("cls");

    printf("Opening Input Greyscal Image '%s' ... ", argv[2]);fflush(stdout);
    greyscalefp = fopen(argv[2],"rb");
    if(!greyscalefp)
    {
        printf("\n\nARGH! File couldn't be opened.\n");fflush(stdout);
    }
    printf("Done.");fflush(stdout);





    //---------------------Hash Table Stuff---------------------//
    printf("\n\nPutting data in Hash Table ... ");fflush(stdout);
    int T[startnum];

    for (int i=0; i<N && !feof(fp); i++)
	{
		int v;
		fscanf(fp, "%c", &I);

		/*
		for(int j=0;j<n;j++)
      {
        fscanf(fp, "%c", &Rt);
        fscanf(fp, "%c", &Gt);
        fscanf(fp, "%c", &Bt);

        I[i][j] = (Rt+Gt+Bt)/3;
      }*/



		int k = hash(v);
		while (true)
		{
			if (k >= startnum)
			{
				printf("\n Value failed to be inserted");fflush(stdout);
				break;
			}

			if (T[k] == '\0')
			{
				T[k] = v;
				break;
			}

			k++;
		}

		fflush(stdout);
	}
	printf("Done.");fflush(stdout);
	//---------------------End Hash Table Stuff---------------------//



    fclose(fp);
}

int hash(int key, int startnum)
{
	return key % startnum;
}

int primecalc(int m, int n)
{
   int startnum = 0, calcnum = 0, counter = 0;
   bool is_prime = false;

   startnum= (m*n);//512*512;

   while (counter < 1)
   {
      is_prime = true;

      // all numbers are divided by 1 so start from 2
      for (calcnum = 2; calcnum <= startnum/2; calcnum++)
      {

         if (startnum % calcnum == 0)
         {
            is_prime = false;
         }

      }

      // only when the "for" cycle is done we know for sure if "i" is prime
      if (is_prime)
      {
         printf("%d\n", startnum);
         counter++;
         return(startnum);
      }

      startnum++;
   }
   system("pause");
}