#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <error.h>
#include <errno.h>

#include "config.h"
#include "lib.h"

void bits2ip4(bits b, mask_t m, char *s, int size) {
	// convert bits to in4_addr
	struct in4_addr ip;
	for (int i = 0; i < 4; ++i) {
		ip.s4_addr[i] = 0;
		for (int j = 0; j < 8; ++j) {
			ip.s4_addr[i] <<= 1;
			int p = i*8 + j;
			ip.s4_addr[i] |= (p >= m) ? 0 : b[p];
		}
	}
	// get test representation of ip
	char s_ip[INET_ADDRSTRLEN];
	if (!inet_ntop(AF_INET, &ip, s_ip, INET_ADDRSTRLEN)) error(1, errno, "bits2ip4");
	// print ip with mask to buffer
	int res = snprintf(s, size, "%s/%d", s_ip, m);
	// if printing to buffer has failed
	if (res < 0 || res >= size) error(1, errno, "bits2ip4");
}

void bits2ip6(bits b, mask_t m, char *s, int size) {
	// convert bits to in6_addr
	struct in6_addr ip;
	for (int i = 0; i < 16; ++i) {
		ip.s6_addr[i] = 0;
		for (int j = 0; j < 8; ++j) {
			ip.s6_addr[i] <<= 1;
			int p = i*8 + j;
			ip.s6_addr[i] |= (p >= m) ? 0 : b[p];
		}
	}
	// get test representation of ip
	char s_ip[INET6_ADDRSTRLEN];
	if (!inet_ntop(AF_INET6, &ip, s_ip, INET6_ADDRSTRLEN)) error(1, errno, "bits2ip6");
	// print ip with mask to buffer
	int res = snprintf(s, size, "%s/%d", s_ip, m);
	// if printing to buffer has failed
	if (res < 0 || res >= size) error(1, errno, "bits2ip6");
}

void ip42bits(char *s, bits b, mask_t *m) {
	// split ip and mask
	char *p = strchr(s, '/');
	if (p) {
		*p = 0;
		++p;
		unsigned long l = strtol(p, &p, 10);
		if (*p || l > IP4LEN) error(1, errno, "ip42bits: bad mask");
		*m = l;
	} else {
		*m = IP4LEN;
	}
	// convert ip to binary
	struct in4_addr ip;
	if (!inet_pton(AF_INET, s, &ip)) error(1, errno, "ip42bits");
	// convert binary ip to bits
	for (int i = 0; i < 4; ++i) {
		for (int j = 0; j < 8; ++j) {
			int p = i*8 + 8-1-j;
			b[p] = (p > *m) ? 0 : (ip.s4_addr[i] & 1);
			ip.s4_addr[i] >>= 1;
		}
	}
}

void ip62bits(char *s, bits b, mask_t *m) {
	// split ip and mask
	char *p = strchr(s, '/');
	if (p) {
		*p = 0;
		++p;
		unsigned long l = strtol(p, &p, 10);
		if (*p || l > IP6LEN) error(1, errno, "ip62bits: bad mask");
		*m = l;
	} else {
		*m = IP6LEN;
	}
	// convert ip to binary
	struct in6_addr ip;
	if (!inet_pton(AF_INET6, s, &ip)) error(1, errno, "ip62bits");
	// convert binary ip to bits
	for (int i = 0; i < 16; ++i) {
		for (int j = 0; j < 8; ++j) {
			int p = i*8 + 8-1-j;
			b[p] = (p > *m) ? 0 : (ip.s6_addr[i] & 1);
			ip.s6_addr[i] >>= 1;
		}
	}
}