/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 * originally authored by Norbert Sendetzky
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * In addition, for the avoidance of any doubt, permission is granted to
 * link this program with OpenSSL and to (re)distribute the binaries
 * produced as the result of such linking.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#include "exceptions.hh"
#include "ldapbackend.hh"
#include <cstdlib>

void LdapBackend::getUpdatedPrimaries(vector<DomainInfo>& domains, std::unordered_set<DNSName>& catalogs, CatalogHashMap& catalogHashes)
{
  string filter;
  PowerLDAP::SearchResult::Ptr search;
  PowerLDAP::sentry_t result;
  const char* attronly[] = {
    "associatedDomain",
    NULL};

  try {
    // First get all domains on which we are primary.
    filter = strbind(":target:", "&(SOARecord=*)(PdnsDomainId=*)", getArg("filter-axfr"));
    search = d_pldap->search(getArg("basedn"), LDAP_SCOPE_SUBTREE, filter, attronly);
  }
  catch (LDAPTimeout& lt) {
    g_log << Logger::Warning << d_myname << " Unable to search LDAP directory: " << lt.what() << endl;
    throw DBException("LDAP server timeout");
  }
  catch (LDAPNoConnection& lnc) {
    g_log << Logger::Warning << d_myname << " Connection to LDAP lost, trying to reconnect" << endl;
    if (reconnect())
      this->getUpdatedPrimaries(domains, catalogs, catalogHashes);
    else
      throw PDNSException("Failed to reconnect to LDAP server");
  }
  catch (LDAPException& le) {
    g_log << Logger::Error << d_myname << " Unable to search LDAP directory: " << le.what() << endl;
    throw PDNSException("LDAP server unreachable"); // try to reconnect to another server
  }
  catch (std::exception& e) {
    throw DBException("STL exception");
  }

  while (search->getNext(result)) {
    if (!result.count("associatedDomain") || result["associatedDomain"].empty())
      continue;

    DomainInfo di;
    if (!getDomainInfo(DNSName(result["associatedDomain"][0]), di))
      continue;

    if (di.notified_serial < di.serial)
      domains.push_back(di);
  }
}

void LdapBackend::setNotified(uint32_t id, uint32_t serial)
{
  string filter;
  PowerLDAP::SearchResult::Ptr search;
  PowerLDAP::sresult_t results;
  PowerLDAP::sentry_t entry;
  const char* attronly[] = {"associatedDomain", NULL};

  try {
    // Try to find the notified domain
    filter = strbind(":target:", "PdnsDomainId=" + std::to_string(id), getArg("filter-axfr"));
    search = d_pldap->search(getArg("basedn"), LDAP_SCOPE_SUBTREE, filter, attronly);
    search->getAll(results, true);
  }
  catch (LDAPTimeout& lt) {
    g_log << Logger::Warning << d_myname << " Unable to search LDAP directory: " << lt.what() << endl;
    throw DBException("LDAP server timeout");
  }
  catch (LDAPNoConnection& lnc) {
    g_log << Logger::Warning << d_myname << " Connection to LDAP lost, trying to reconnect" << endl;
    if (reconnect())
      this->setNotified(id, serial);
    else
      throw PDNSException("Failed to reconnect to LDAP server");
  }
  catch (LDAPException& le) {
    g_log << Logger::Error << d_myname << " Unable to search LDAP directory: " << le.what() << endl;
    throw PDNSException("LDAP server unreachable"); // try to reconnect to another server
  }
  catch (std::exception& e) {
    throw DBException("STL exception");
  }

  if (results.empty())
    throw PDNSException("No results found when trying to update domain notified_serial for ID " + std::to_string(id));

  entry = results.front();
  string dn = entry["dn"][0];
  string serialStr = std::to_string(serial);
  LDAPMod* mods[2];
  LDAPMod mod;
  char* vals[2];

  mod.mod_op = LDAP_MOD_REPLACE;
  mod.mod_type = (char*)"PdnsDomainNotifiedSerial";
  vals[0] = const_cast<char*>(serialStr.c_str());
  vals[1] = NULL;
  mod.mod_values = vals;

  mods[0] = &mod;
  mods[1] = NULL;

  try {
    d_pldap->modify(dn, mods);
  }
  catch (LDAPNoConnection& lnc) {
    g_log << Logger::Warning << d_myname << " Connection to LDAP lost, trying to reconnect" << endl;
    if (reconnect())
      this->setNotified(id, serial);
    else
      throw PDNSException("Failed to reconnect to LDAP server");
  }
  catch (LDAPException& le) {
    g_log << Logger::Error << d_myname << " Unable to search LDAP directory: " << le.what() << endl;
    throw PDNSException("LDAP server unreachable"); // try to reconnect to another server
  }
  catch (std::exception& e) {
    throw DBException("STL exception");
  }
}
