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

#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>

#include <sys/poll.h>

#include <fcntl.h>

#include <unistd.h>

#include <errno.h>

#include "dns2.h"
#include "utils.h"
#include "packet.h"
#include "constants.h"
#include "glist.h"
#include "rr.h"

#include "dns2-private.h"

DNS2 *dns2_updater_new (const char *zone) {
	DNS2 *updater;
	
	updater = dns2_new ();
	
	if (updater == NULL) {
		return NULL;
	}
	
	updater->type = DNS_UPDATER;
	/* Sanitizar "zona" */
	updater->zone = dns_dup_trim_name (zone);
	
	if (updater->zone == NULL) {
		free (updater);
		
		return NULL;
	}
	
	updater->packet = dns_packet_create_request (updater->zone, RR_TYPE_SOA, RR_CLASS_IN);
	
	if (updater->packet == NULL) {
		free (updater->zone);
		free (updater);
		
		return NULL;
	}
	
	updater->packet->header.opcode = OPCODE_UPDATE;
	
	return updater;
}

int dns_updater_check_name (DNS2 *updater, const char *name) {
	int len, nlen;
	
	/* TODO: ¿Usar la zona o el question[0]->qname? */
	len = strlen (updater->zone);
	
	nlen = strlen (name);
	if (nlen < len) {
		return 0;
	}
	
	if (strcmp (name, updater->zone) == 0) {
		return 1;
	}
	
	if (strcmp (&name[nlen - len], updater->zone) != 0) {
		return 0;
	}
	
	if (name[nlen - len - 1] != '.') {
		return 0;
	}
	
	return 1;
}

void dns2_updater_add (DNS2 *updater, DNSRR *rr) {
	if (dns_updater_check_name (updater, rr->name) == 0) {
		/* Fuera de la zona */
		return;
	}
	
	if (g_list_find (updater->packet->authority, rr) == NULL) {
		updater->packet->authority = g_list_append (updater->packet->authority, rr);
	}
}

DNSRR * dns_updater_packet_get_tsig (DNSPacket *response) {
	int g;
	GList *last;
	DNSRR *rr;
	
	if (response->header.arcount == 0) {
		return NULL;
	}
	
	last = g_list_last (response->additional);
	while (last != NULL) {
		rr = (DNSRR *) last->data;
		
		if (rr->type == RR_TYPE_TSIG) {
			return rr;
		}
		
		last = last->prev;
	}
	
	return NULL;
}

int dns_updater_packet_has_valid_tsig (DNS2 *updater, DNSPacket *response) {
	DNSRR *rr, *mysig;
	DNSPacket *dup;
	
	rr = dns_updater_packet_get_tsig (response);
	
	if (rr == NULL) {
		return 0;
	}
	
	if (updater->auth_signature == NULL) {
		return 0;
	}
	
	/* Eliminar temporalmente el rr de la lista */
	response->additional = g_list_remove (response->additional, rr);
	response->header.arcount = g_list_length (response->additional);
	
	/* Recalcular la firma, */
	mysig = dns2_rr_dup (updater->auth_signature);
	
	if (mysig->type == RR_TYPE_TSIG /*||
	    mysig->tipo == RR_TYPE_SIG*/) {
	    
	    dns_rr_pack_generate_signature (mysig, response);
	}
	
	/* Comparar firmas */
	
	
	/* Re-anexar la firma original */
	response->additional = g_list_append (response->additional, rr);
	response->header.arcount = g_list_length (response->additional);
	
	return 1;
}