/* http://www.mrwadlo.com */
#include <stdio.h>
#include <conio.h>

void showpercent(int percent);
void createfilename();

int mark;

char inputfile[15];
char outputfile[15];

int main()
{
	long i;
	long filesize;
	char sym;
	int percent;

	long fib = 1;
	long last = 0;
	long temp;
	int fib_mod;

	char oper;

	FILE *fpREAD;
	FILE *fpWRITE;

	clrscr();

        printf("\n Please Select Operation: [E]ncrypt [D]ecrypt");
	do {
		oper = getch();

		if ( oper == 'e' || oper == 'E' || oper == 'd' || oper == 'D' )
		     break;
		else
			printf("\a");

	} while ( 1 );

	if ( oper == 'e' )
		oper = 'E';
	else if ( oper == 'd' )
        	oper = 'D';

	do {
		printf("\n Enter First Filename Using 8.3 limit: ");
		scanf("%12s", &inputfile);

		if ( fopen(inputfile,"rb") )
		     break;
		else
		     printf(" %s <-- No Such File, Try Again!", inputfile);

	} while ( 1 );

	createfilename();
	printf(" Outputting to: %s", outputfile);

		printf("\n  ");
		for ( i=0 ; i<38 ; i++ )
			printf("- ");

		fpREAD = fopen(inputfile,"rb");
		fpWRITE = fopen(outputfile,"wb");
        
		fseek(fpREAD, 0, SEEK_END);
		filesize = ftell(fpREAD);
		rewind(fpREAD);

		printf("\n %12s Filesize = %ld", inputfile, filesize);

		printf("\n %12s ", inputfile);
		percent = 0;

		for ( i=0 ; i < filesize ; i++ )
		{
			temp = fib;
			fib = fib + last;
			last = temp;

			fib_mod = fib % 254;

                        fib = fib % 9000000000;
                        last = last % 9000000000;

			fread(&sym, 1, 1, fpREAD);

			if ( oper == 'E' )
				sym = sym + fib_mod;
			if ( oper == 'D' )
				sym = sym - fib_mod;

			if ( sym > 253 )
				sym % 254;
			if ( sym < 0 )
				sym + 254;

			fwrite(&sym, 1, 1, fpWRITE);

			if ( 100*i/filesize > percent )
			{
				percent++;
				showpercent(percent);
			}
                
		}

		while (percent < 100 )
			showpercent(++percent);

		printf("\n Done");

		fclose(fpREAD);
		fclose(fpWRITE);

		printf("\n Press Any Key To Exit...");
		getch();

	return 0;
}
void showpercent(int percent)
{
	if( percent % 2 == 0) 
	{
        		mark++;
		

			if ( mark % 2 == 0)
			{
				printf("%c",223);
                	}
			else
			{
				printf("%c",220);
			}

		printf(" %3d%%", percent);
		printf("\b\b\b\b\b");
        }
}
void createfilename()
{
	int i;

	for ( i=0 ; i<13 ; i++ )
	{
		if ( inputfile[i] == '.' )
                        break;
		else
			outputfile[i] = 'O';
        }

	while ( i<13 && inputfile[i] != '\n')
	{
		outputfile[i] = inputfile[i];
		i++;
	}
}