/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*! \file */

/***

 *** Imports

 ***/

#include <inttypes.h>

#include <isc/result.h>

#include <isc/string.h>

#include <isc/util.h>

#include <dns/db.h>

#include <dns/dbiterator.h>

#include <dns/rdata.h>

#include <dns/rdataset.h>

#include <dns/rdatasetiter.h>

#include <dns/rriterator.h>

/***

 *** RRiterator methods

 ***/

isc_result_t

dns_rriterator_init(dns_rriterator_t *it, dns_db_t *db, dns_dbversion_t *ver,

        isc_stdtime_t now) {

  it->magic = RRITERATOR_MAGIC;

  it->db = db;

  it->dbit = NULL;

  it->ver = ver;

  it->now = now;

  it->node = NULL;

  RETERR(dns_db_createiterator(it->db, 0, &it->dbit));

  it->rdatasetit = NULL;

  dns_rdata_init(&it->rdata);

  dns_rdataset_init(&it->rdataset);

  dns_fixedname_init(&it->fixedname);

  INSIST(!dns_rdataset_isassociated(&it->rdataset));

  it->result = ISC_R_SUCCESS;

  return it->result;

}

isc_result_t

dns_rriterator_first(dns_rriterator_t *it) {

  REQUIRE(VALID_RRITERATOR(it));

  /* Reset state */

  dns_rdataset_cleanup(&it->rdataset);

  if (it->rdatasetit != NULL) {

    dns_rdatasetiter_destroy(&it->rdatasetit);

  }

  if (it->node != NULL) {

    dns_db_detachnode(&it->node);

  }

  it->result = dns_dbiterator_first(it->dbit);

  /*

   * The top node may be empty when out of zone glue exists.

   * Walk the tree to find the first node with data.

   */

  while (it->result == ISC_R_SUCCESS) {

    it->result = dns_dbiterator_current(

      it->dbit, &it->node,

      dns_fixedname_name(&it->fixedname));

    if (it->result != ISC_R_SUCCESS) {

      return it->result;

    }

    it->result = dns_db_allrdatasets(it->db, it->node, it->ver, 0,

             it->now, &it->rdatasetit);

    if (it->result != ISC_R_SUCCESS) {

      return it->result;

    }

    it->result = dns_rdatasetiter_first(it->rdatasetit);

    if (it->result != ISC_R_SUCCESS) {

      /*

       * This node is empty. Try next node.

       */

      dns_rdatasetiter_destroy(&it->rdatasetit);

      dns_db_detachnode(&it->node);

      it->result = dns_dbiterator_next(it->dbit);

      continue;

    }

    dns_rdatasetiter_current(it->rdatasetit, &it->rdataset);

    dns_rdataset_getownercase(&it->rdataset,

            dns_fixedname_name(&it->fixedname));

    it->result = dns_rdataset_first(&it->rdataset);

    return it->result;

  }

  return it->result;

}

isc_result_t

dns_rriterator_nextrrset(dns_rriterator_t *it) {

  REQUIRE(VALID_RRITERATOR(it));

  dns_rdataset_cleanup(&it->rdataset);

  it->result = dns_rdatasetiter_next(it->rdatasetit);

  /*

   * The while loop body is executed more than once

   * only when an empty dbnode needs to be skipped.

   */

  while (it->result == ISC_R_NOMORE) {

    dns_rdatasetiter_destroy(&it->rdatasetit);

    dns_db_detachnode(&it->node);

    it->result = dns_dbiterator_next(it->dbit);

    if (it->result == ISC_R_NOMORE) {

      /* We are at the end of the entire database. */

      return it->result;

    }

    if (it->result != ISC_R_SUCCESS) {

      return it->result;

    }

    it->result = dns_dbiterator_current(

      it->dbit, &it->node,

      dns_fixedname_name(&it->fixedname));

    if (it->result != ISC_R_SUCCESS) {

      return it->result;

    }

    it->result = dns_db_allrdatasets(it->db, it->node, it->ver, 0,

             it->now, &it->rdatasetit);

    if (it->result != ISC_R_SUCCESS) {

      return it->result;

    }

    it->result = dns_rdatasetiter_first(it->rdatasetit);

  }

  if (it->result != ISC_R_SUCCESS) {

    return it->result;

  }

  dns_rdatasetiter_current(it->rdatasetit, &it->rdataset);

  dns_rdataset_getownercase(&it->rdataset,

          dns_fixedname_name(&it->fixedname));

  it->result = dns_rdataset_first(&it->rdataset);

  return it->result;

}

isc_result_t

dns_rriterator_next(dns_rriterator_t *it) {

  REQUIRE(VALID_RRITERATOR(it));

  if (it->result != ISC_R_SUCCESS) {

    return it->result;

  }

  INSIST(it->dbit != NULL);

  INSIST(it->node != NULL);

  INSIST(it->rdatasetit != NULL);

  it->result = dns_rdataset_next(&it->rdataset);

  if (it->result == ISC_R_NOMORE) {

    return dns_rriterator_nextrrset(it);

  }

  return it->result;

}

void

dns_rriterator_pause(dns_rriterator_t *it) {

  REQUIRE(VALID_RRITERATOR(it));

  RUNTIME_CHECK(dns_dbiterator_pause(it->dbit) == ISC_R_SUCCESS);

}

void

dns_rriterator_destroy(dns_rriterator_t *it) {

  REQUIRE(VALID_RRITERATOR(it));

  dns_rdataset_cleanup(&it->rdataset);

  if (it->rdatasetit != NULL) {

    dns_rdatasetiter_destroy(&it->rdatasetit);

  }

  if (it->node != NULL) {

    dns_db_detachnode(&it->node);

  }

  dns_dbiterator_destroy(&it->dbit);

}

void

dns_rriterator_current(dns_rriterator_t *it, dns_name_t **name, uint32_t *ttl,

           dns_rdataset_t **rdataset, dns_rdata_t **rdata) {

  REQUIRE(name != NULL && *name == NULL);

  REQUIRE(VALID_RRITERATOR(it));

  REQUIRE(it->result == ISC_R_SUCCESS);

  REQUIRE(rdataset == NULL || *rdataset == NULL);

  REQUIRE(rdata == NULL || *rdata == NULL);

  *name = dns_fixedname_name(&it->fixedname);

  *ttl = it->rdataset.ttl;

  dns_rdata_reset(&it->rdata);

  dns_rdataset_current(&it->rdataset, &it->rdata);

  SET_IF_NOT_NULL(rdataset, &it->rdataset);

  SET_IF_NOT_NULL(rdata, &it->rdata);

}