#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <limits.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <stdint.h>

#include "zen.h"
#include "debug.h"

long
strtol(nptr, endptr, base)
	const char *nptr;
	char **endptr;
	register int base;
{
	register const char *s = nptr;
	register unsigned long acc;
	register int c;
	register unsigned long cutoff;
	register int neg = 0, any, cutlim;

	/*
	 * Skip white space and pick up leading +/- sign if any.
	 * If base is 0, allow 0x for hex and 0 for octal, else
	 * assume decimal; if base is already 16, allow 0x.
	 */
	do {
		c = *s++;
	} while (isspace(c));
	if (c == '-') {
		neg = 1;
		c = *s++;
	} else if (c == '+')
		c = *s++;
	if ((base == 0 || base == 16) &&
	    c == '0' && (*s == 'x' || *s == 'X')) {
		c = s[1];
		s += 2;
		base = 16;
	} else if ((base == 0 || base == 2) &&
	    c == '0' && (*s == 'b' || *s == 'B')) {
		c = s[1];
		s += 2;
		base = 2;
	}
	if (base == 0)
		base = c == '0' ? 8 : 10;

	/*
	 * Compute the cutoff value between legal numbers and illegal
	 * numbers.  That is the largest legal value, divided by the
	 * base.  An input number that is greater than this value, if
	 * followed by a legal input character, is too big.  One that
	 * is equal to this value may be valid or not; the limit
	 * between valid and invalid numbers is then based on the last
	 * digit.  For instance, if the range for longs is
	 * [-2147483648..2147483647] and the input base is 10,
	 * cutoff will be set to 214748364 and cutlim to either
	 * 7 (neg==0) or 8 (neg==1), meaning that if we have accumulated
	 * a value > 214748364, or equal but the next digit is > 7 (or 8),
	 * the number is too big, and we will return a range error.
	 *
	 * Set any if any `digits' consumed; make it negative to indicate
	 * overflow.
	 */
	cutoff = neg ? -(unsigned long)LONG_MIN : LONG_MAX;
	cutlim = cutoff % (unsigned long)base;
	cutoff /= (unsigned long)base;
	for (acc = 0, any = 0;; c = *s++) {
		if (isdigit(c))
			c -= '0';
		else if (isalpha(c))
			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
		else
			break;
		if (c >= base)
			break;
		if (any < 0 || acc > cutoff || acc == cutoff && c > cutlim)
			any = -1;
		else {
			any = 1;
			acc *= base;
			acc += c;
		}
	}
	if (any < 0) {
		acc = neg ? LONG_MIN : LONG_MAX;
//		errno = ERANGE;
	} else if (neg)
		acc = -acc;
	if (endptr != 0)
		*endptr = (char *)(any ? s - 1 : nptr);
	return (acc);
}

int main()
{

	int run=1;
	int const max_sz=1024;
	char cmd[max_sz];
	int sz;

	int fd_in=-1;
	

	W( run )
	{
		write( 1, ">", 1 );
		sz = read(  2, cmd, max_sz-1 );
		cmd[sz]=0;
		printf("%s",cmd);
		S( cmd[0] )
		{
			//>f [MODE] [fname]
			case 'f':
				{
					//check if size is more then needed
					//>"f t" is min?
					//add modes?
					I(sz<3)B;
					cmd[sz-1]=0;
					fd_in = open(&cmd[2],O_WRONLY|O_CREAT,S_IRUSR);
					PRINT("%s",&cmd[2]);
				}
				break;
			case 'a':
				{

				}
				break;
			//close >c
			case 'c':
				{
					PNL();
					I(fd_in!=-1)
					{
						close( fd_in );
						fd_in=-1;
					}
				}
				break;
			//file position >p [NUMBER]
			case 'p':
				{	
					I(fd_in==-1)B;
					off_t p=lseek(fd_in,strtol(&cmd[2],NULL,10),SEEK_SET);
					printf("Position: %d",p);
				}
				break;
			//put bytes into file at current position >e 0x00 0xaa 0x11
			case 'e':
				{
					char *iter;
					int i=0;
					uint8_t num;

					I(fd_in==-1)B;
					I(sz<6)B;

					i = 2;
					iter = &cmd[i];
					while ( i<sz )
					{
						num = (uint8_t)strtol( iter, NULL, 16 );
						write( fd_in, &num, 1 );
						i += 5;
						iter = &cmd[i];
					}

				}
				break;
			// dump hex >v [SIZE] how much bytes to see
			case 'v':
				{
					I(fd_in==-1)B;
					I(sz<3)B;
					int i;
					int dumpsz=strtol(&cmd[2],NULL,10);
					uint8_t val;
					for (i=0;i<dumpsz;i++)
					{
						read( fd_in, &val, 1);
						printf("%02x ", val);
					}
					write(1,"\n",1);
				}
				break;
			case 'h':
				{
					char s[]="Help:\n\
f [FILE] - create file with name FILE\n\
p [POSITION] - set postion in file\n\
q - exit\n\
e [0x00] ... - write value with hex fow \n\
c - close file \n";
					write(1,s,strlen(s) );
				}	
				break;
			case 'q':
				write(1,"exiting ...\n",strlen("exiting ...\n"));
				run = 0;
				break;
			default:
				{};
		}
	}

	return 0;
}