/*
 * Authors: Petr Spacek <pspacek@redhat.com>
 *
 * Copyright (C) 2012  Red Hat
 * see file 'COPYING' for use and warranty information
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; version 2 or later
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <isc/mem.h>
#include <isc/result.h>
#include <isc/util.h>
#include <isc/hash.h>

#include <dns/db.h>
#include <dns/diff.h>
#include <dns/rbt.h>
#include <dns/result.h>
#include <dns/soa.h>

#include <string.h>

void
logger(const char *format, ...)
{
	va_list args;

	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
}

#define CHECK(op)						\
	do {							\
		logger("%4u: %s = ", __LINE__, #op);		\
		result = (op);					\
		logger("%s\n", dns_result_totext(result));	\
		if (result != ISC_R_SUCCESS)			\
			goto cleanup;				\
	} while (0)

#define PRINT(op)						\
	do {							\
		logger("%4u: %s\n", __LINE__, #op);		\
		(op);						\
	} while (0)

static isc_result_t
do_one_tuple(dns_difftuple_t **tuple, dns_db_t *db, dns_dbversion_t *ver,
	     dns_diff_t *diff)
{
	dns_diff_t temp_diff;
	isc_result_t result;

	/*
	 * Create a singleton diff.
	 */
	dns_diff_init(diff->mctx, &temp_diff);
	temp_diff.resign = diff->resign;
	ISC_LIST_APPEND(temp_diff.tuples, *tuple, link);

	/*
	 * Apply it to the database.
	 */
	result = dns_diff_apply(&temp_diff, db, ver);
	ISC_LIST_UNLINK(temp_diff.tuples, *tuple, link);
	if (result != ISC_R_SUCCESS) {
		dns_difftuple_free(tuple);
		return (result);
	}

	/*
	 * Merge it into the current pending journal entry.
	 */
	dns_diff_appendminimal(diff, tuple);

	/*
	 * Do not clear temp_diff.
	 */
	return (ISC_R_SUCCESS);
}

static isc_result_t
update_one_rr(dns_db_t *db, dns_dbversion_t *ver, dns_diff_t *diff,
	      dns_diffop_t op, dns_name_t *name, dns_ttl_t ttl,
	      dns_rdata_t *rdata)
{
	dns_difftuple_t *tuple = NULL;
	isc_result_t result;
	result = dns_difftuple_create(diff->mctx, op,
				      name, ttl, rdata, &tuple);
	if (result != ISC_R_SUCCESS)
		return (result);
	return (do_one_tuple(&tuple, db, ver, diff));
}

/*
 * Create an SOA record for a newly-created zone
 */
static isc_result_t
add_soa(dns_db_t *db, dns_dbversion_t *ver) {
	isc_result_t result;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	unsigned char buf[DNS_SOA_BUFFERSIZE];
	dns_diff_t diff;

	dns_diff_init(db->mctx, &diff);

	/* Build SOA record */
	result = dns_soa_buildrdata(dns_rootname, dns_rootname, dns_rdataclass_in,
				    0, 0, 0, 0, 0, buf, &rdata);
	if (result != ISC_R_SUCCESS) {
		logger("add_soa:dns_soa_buildrdata -> %s",
		       dns_result_totext(result));
		goto failure;
	}

	result = update_one_rr(db, ver, &diff, DNS_DIFFOP_ADD,
			       dns_rootname, 0, &rdata);

failure:
	dns_diff_clear(&diff);

	return (result);
}


int
main (int argc, char ** argv) {
	isc_result_t result = ISC_R_SUCCESS;
	dns_db_t  *rbtdb = NULL;
	isc_mem_t *mctx = NULL;
	void *node = NULL;
	dns_dbversion_t *version = NULL;

	CHECK(isc_mem_create2(0, 0, &mctx, ISC_MEMFLAG_DEFAULT));
	CHECK(isc_hash_create(mctx, NULL, 256));
	CHECK(dns_db_create(mctx, "rbt", dns_rootname, dns_dbtype_zone,
			    dns_rdataclass_in, 0, NULL, &rbtdb));

	CHECK(dns_db_getoriginnode(rbtdb, &node));
	/* This still works, references == 1. */
	PRINT(dns_db_printnode(rbtdb, node, stderr));
	PRINT(dns_db_detachnode(rbtdb, &node));
	/* I think that the origin_node is invalid here. */

	CHECK(dns_db_newversion(rbtdb, &version));
	/* Following block crashes, so I commented it out. */
	/*
	{
		CHECK(dns_db_getoriginnode(rbtdb, &node));
		PRINT(dns_db_printnode(rbtdb, node, stderr));
		PRINT(dns_db_detachnode(rbtdb, &node));
	}
	*/

	/* New origin_node is created in dns_diff_apply() call. */
	CHECK(add_soa(rbtdb, version));

	/* This works again, references == 2. */
	CHECK(dns_db_getoriginnode(rbtdb, &node));
	PRINT(dns_db_printnode(rbtdb, node, stderr));

	/* Discard the new record from RBTDB. */
	PRINT(dns_db_closeversion(rbtdb, &version, ISC_FALSE));

	/* This still works, references == 1. */
	PRINT(dns_db_printnode(rbtdb, node, stderr));
	/* RDATASET_ATTR_IGNORE is set! */
	PRINT(dns_db_detachnode(rbtdb, &node));

	/* Next block crashes again - origin_node is invalid (again). */
	{
		CHECK(dns_db_getoriginnode(rbtdb, &node));
		PRINT(dns_db_printnode(rbtdb, node, stderr));
		PRINT(dns_db_detachnode(rbtdb, &node));
	}

cleanup:
	if (result != ISC_R_SUCCESS)
		logger("error: %s\n", dns_result_totext(result));

	(void) argc;
	(void) argv;

	return 0;
}