#include <dht.c>
#include <error.h>
#define S0(x) (x ? x : "")

int main (int argc, char ** argv) {
	if (argc < 3)
		error_at_line(1, 0, __FILE__, __LINE__, "%s <bin|add|subtract|divide|midpoint|closer> <a> [b] [t]", S0(argv[0]));
	if (argv[1][0] == 'b' || argv[1][0] == 'B') {
		unsigned char a[strlen(argv[2])/2+1];
		a[strlen(argv[2])/2] = '\0';
		hex2bin(a, argv[2], strlen(argv[2])/2);
		if (strlen(argv[2]) != 40 || (argv[2] && strlen(argv[2]) != 40)) {
			printf("%s\n", a);
			return 0;
		}
		return 0;
	}
	if (strlen(argv[2]) != 40)
		error_at_line(3, 0, __FILE__, __LINE__, "strlen(a) != 40 && !bin");
	if (argv[1][0] == 'd' || argv[1][0] == 'D') {
		unsigned char a[20];
		hex2bin(a, argv[2], 20);
		divide(a);
		char out[41];
		out[40] = '\0';
		bin2hex(out, a, 20);
		printf("%s\n", out);
		return 0;
	}
	if (!argv[3])
		error_at_line(2, 0, __FILE__, __LINE__, "!b && !bin && !divide");
	if (strlen(argv[3]) != 40)
		error_at_line(3, 0, __FILE__, __LINE__, "strlen(b) != 40 && !bin && !divide");
	unsigned char a[20];
	unsigned char b[20];
	hex2bin(a, argv[2], 20);
	hex2bin(b, argv[3], 20);
	char out[41];
	out[40] = '\0';
	unsigned char r[20];
	if (argv[1][0] == 'c' || argv[1][0] == 'C') {
		if (!argv[4] || strlen(argv[4]) != 40)
			error_at_line(4, 0, __FILE__, __LINE__, "(!t || strlen(t) != 40) && closer");
		unsigned char t[20];
		hex2bin(t, argv[4], 20);
		return closer(a, b, t);
	}
	if (argv[1][0] == 'a' || argv[1][0] == 'A') {
		memcpy(r, a, 20);
		add(r, b);
	} else if (argv[1][0] == 's' || argv[1][0] == 'S') {
		memcpy(r, a, 20);
		subtract(r, b);
	} else {
		midpoint(r, a, b);
	}
	bin2hex(out, r, 20);
	printf("%s\n", out);
}