/*
 * This file is part of PowerDNS or dnsdist.
 * Copyright -- PowerDNS.COM B.V. and its contributors
 *
 * 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 "pdns/utility.hh"
#include <map>
#include <sstream>
#include <string>

#include "pdns/dns.hh"
#include "pdns/dnsbackend.hh"
#include "pdns/dnspacket.hh"
#include "pdns/pdnsexception.hh"
#include "pdns/logger.hh"
#include "pdns/arguments.hh"
#include "sodbc.hh"
#include "godbcbackend.hh"

// Connects to the database.
gODBCBackend::gODBCBackend(const std::string& mode, const std::string& suffix) :
  GSQLBackend(mode, suffix)
{
  if (g_slogStructured) {
    d_slog = g_slog->withName("godbc" + suffix);
  }

  try {
    setDB(std::unique_ptr<SSql>(new SODBC(d_slog, getArg("datasource"), getArg("username"), getArg("password"))));
  }
  catch (SSqlException& e) {
    SLOG(g_log << Logger::Error << mode << " Connection failed: " << e.txtReason() << std::endl,
         d_slog->error(Logr::Error, e.txtReason(), "Database connection failed", "mode", Logging::Loggable(mode)));
    throw PDNSException("Unable to launch " + mode + " connection: " + e.txtReason());
  }

  allocateStatements();

  SLOG(g_log << Logger::Warning << mode << " Connection successful" << std::endl,
       d_slog->info(Logr::Info, "Database connection successful", "mode", Logging::Loggable(mode)));
}

//! Constructs a gODBCBackend
class gODBCFactory : public BackendFactory
{
public:
  //! Constructor.
  gODBCFactory(const std::string& mode) :
    BackendFactory(mode), d_mode(mode)
  {
  }

  //! Declares all needed arguments.
  void declareArguments(const std::string& suffix = "") override
  {
    declare(suffix, "datasource", "Datasource (DSN) to use", "PowerDNS");
    declare(suffix, "username", "User to connect as", "powerdns");
    declare(suffix, "password", "Password to connect with", "");
    declare(suffix, "dnssec", "Enable DNSSEC processing", "no");

    string record_query = "SELECT content,ttl,prio,type,domain_id,disabled,name,auth FROM records WHERE";

    declare(suffix, "basic-query", "Basic query", record_query + " disabled=0 and type=? and name=?");
    declare(suffix, "id-query", "Basic with ID query", record_query + " disabled=0 and type=? and name=? and domain_id=?");
    declare(suffix, "any-query", "Any query", record_query + " disabled=0 and name=?");
    declare(suffix, "any-id-query", "Any with ID query", record_query + " disabled=0 and name=? and domain_id=?");

    declare(suffix, "api-id-query", "API basic with ID query", record_query + " (disabled=0 or disabled=?) and type=? and name=? and domain_id=?");
    declare(suffix, "api-any-id-query", "API any with ID query", record_query + " (disabled=0 or disabled=?) and name=? and domain_id=?");

    declare(suffix, "list-query", "AXFR query", "SELECT content,ttl,prio,type,domain_id,disabled,name,auth,CONVERT(varchar(255), ordername, 0) FROM records WHERE (disabled=0 OR disabled=?) and domain_id=? order by name, type");
    declare(suffix, "list-subzone-query", "Subzone listing", record_query + " disabled=0 and (name=? OR name like ?) and domain_id=?");

    declare(suffix, "remove-empty-non-terminals-from-zone-query", "remove all empty non-terminals from zone", "delete from records where domain_id=? and type is null");
    declare(suffix, "delete-empty-non-terminal-query", "delete empty non-terminal from zone", "delete from records where domain_id=? and name=? and type is null");

    declare(suffix, "info-zone-query", "", "select id,name,master,last_check,notified_serial,type,options,catalog,account from domains where name=?");

    declare(suffix, "info-all-secondaries-query", "", "select domains.id, domains.name, domains.type, domains.master, domains.last_check, records.content from domains LEFT JOIN records ON records.domain_id=domains.id AND records.type='SOA' AND records.name=domains.name where domains.type in ('SLAVE', 'CONSUMER')");
    declare(suffix, "autoprimary-query", "", "select account from supermasters where ip=? and nameserver=?");
    declare(suffix, "autoprimary-name-to-ips", "", "select ip,account from supermasters where nameserver=? and account=?");
    declare(suffix, "autoprimary-add", "", "insert into supermasters (ip, nameserver, account) values (?,?,?)");
    declare(suffix, "autoprimary-remove", "", "delete from supermasters where ip = ? and nameserver = ?");
    declare(suffix, "list-autoprimaries", "", "select ip,nameserver,account from supermasters");

    declare(suffix, "insert-zone-query", "", "insert into domains (type,name,master,account,last_check,notified_serial) values(?,?,?,?,null,null)");

    declare(suffix, "insert-record-query", "", "insert into records (content,ttl,prio,type,domain_id,disabled,name,ordername,auth) values (?,?,?,?,?,?,?,convert(varbinary(255),?),?)");
    declare(suffix, "insert-empty-non-terminal-order-query", "insert empty non-terminal in zone", "insert into records (type,domain_id,disabled,name,ordername,auth,ttl,prio,content) values (null,?,0,?,convert(varbinary(255),?),?,null,null,null)");

    declare(suffix, "get-order-first-query", "DNSSEC Ordering Query, first", "select top 1 convert(varchar(255), ordername) from records where domain_id=? and disabled=0 and ordername is not null order by 1 asc");
    declare(suffix, "get-order-before-query", "DNSSEC Ordering Query, before", "select top 1 convert(varchar(255), ordername), name from records where ordername <= convert(varbinary(255),?) and domain_id=? and disabled=0 and ordername is not null order by 1 desc");
    declare(suffix, "get-order-after-query", "DNSSEC Ordering Query, after", "select convert(varchar(255), min(ordername)) from records where ordername > convert(varbinary(255),?) and domain_id=? and disabled=0 and ordername is not null");
    declare(suffix, "get-order-last-query", "DNSSEC Ordering Query, last", "select top 1 convert(varchar(255), ordername), name from records where ordername != convert(varbinary(255),'') and domain_id=? and disabled=0 and ordername is not null order by 1 desc");

    declare(suffix, "update-ordername-and-auth-query", "DNSSEC update ordername and auth for a qname query", "update records set ordername=convert(varbinary(255),?),auth=? where domain_id=? and name=? and disabled=0");
    declare(suffix, "update-ordername-and-auth-type-query", "DNSSEC update ordername and auth for a rrset query", "update records set ordername=convert(varbinary(255),?),auth=? where domain_id=? and name=? and type=? and disabled=0");
    declare(suffix, "nullify-ordername-and-update-auth-query", "DNSSEC nullify ordername and update auth for a qname query", "update records set ordername=NULL,auth=? where domain_id=? and name=? and disabled=0");
    declare(suffix, "nullify-ordername-and-update-auth-type-query", "DNSSEC nullify ordername and update auth for a rrset query", "update records set ordername=NULL,auth=? where domain_id=? and name=? and type=? and disabled=0");

    declare(suffix, "update-primary-query", "", "update domains set master=? where name=?");
    declare(suffix, "update-kind-query", "", "update domains set type=? where name=?");
    declare(suffix, "update-options-query", "", "update domains set options=? where name=?");
    declare(suffix, "update-catalog-query", "", "update domains set catalog=? where name=?");
    declare(suffix, "update-account-query", "", "update domains set account=? where name=?");
    declare(suffix, "update-serial-query", "", "update domains set notified_serial=? where id=?");
    declare(suffix, "update-lastcheck-query", "", "update domains set last_check=? where id=?");
    declare(suffix, "info-all-primary-query", "", "select domains.id, domains.name, domains.type, domains.notified_serial, domains.options, domains.catalog, records.content from records join domains on records.domain_id=domains.id and records.name=domains.name where records.type='SOA' and records.disabled=0 and domains.type in ('MASTER', 'PRODUCER') order by domains.id");
    declare(suffix, "info-producer-members-query", "", "select domains.id, domains.name, domains.type, domains.options from records join domains on records.domain_id=domains.id and records.name=domains.name where domains.type in ('MASTER', 'PRODUCER') and domains.catalog=? and records.type='SOA' and records.disabled=0");
    declare(suffix, "info-consumer-members-query", "", "select id, name, type, options, master from domains where type in ('SLAVE', 'CONSUMER') and catalog=?");
    declare(suffix, "delete-domain-query", "", "delete from domains where name=?");
    declare(suffix, "delete-zone-query", "", "delete from records where domain_id=?");
    declare(suffix, "delete-rrset-query", "", "delete from records where domain_id=? and name=? and type=?");
    declare(suffix, "delete-names-query", "", "delete from records where domain_id=? and name=?");

    declare(suffix, "add-domain-key-query", "", "insert into cryptokeys (domain_id, flags, active, published, content) select id, ?, ?, ?, ? from domains where name=?");
    declare(suffix, "get-last-inserted-key-id-query", "", "select ident_current('cryptokeys')");
    declare(suffix, "list-domain-keys-query", "", "select cryptokeys.id, flags, active, published, content from domains, cryptokeys where cryptokeys.domain_id=domains.id and name=?");
    declare(suffix, "get-all-domain-metadata-query", "", "select kind,content from domains, domainmetadata where domainmetadata.domain_id=domains.id and name=?");
    declare(suffix, "get-domain-metadata-query", "", "select content from domains, domainmetadata where domainmetadata.domain_id=domains.id and name=? and domainmetadata.kind=?");
    declare(suffix, "clear-domain-metadata-query", "", "delete from domainmetadata where domain_id=(select id from domains where name=?) and domainmetadata.kind=?");
    declare(suffix, "clear-domain-all-metadata-query", "", "delete from domainmetadata where domain_id=(select id from domains where name=?)");
    declare(suffix, "set-domain-metadata-query", "", "insert into domainmetadata (domain_id, kind, content) select id, ?, ? from domains where name=?");
    declare(suffix, "activate-domain-key-query", "", "update cryptokeys set active=1 where domain_id=(select id from domains where name=?) and  cryptokeys.id=?");
    declare(suffix, "deactivate-domain-key-query", "", "update cryptokeys set active=0 where domain_id=(select id from domains where name=?) and  cryptokeys.id=?");
    declare(suffix, "publish-domain-key-query", "", "update cryptokeys set published=1 where domain_id=(select id from domains where name=?) and  cryptokeys.id=?");
    declare(suffix, "unpublish-domain-key-query", "", "update cryptokeys set published=0 where domain_id=(select id from domains where name=?) and  cryptokeys.id=?");
    declare(suffix, "remove-domain-key-query", "", "delete from cryptokeys where domain_id=(select id from domains where name=?) and cryptokeys.id=?");
    declare(suffix, "clear-domain-all-keys-query", "", "delete from cryptokeys where domain_id=(select id from domains where name=?)");
    declare(suffix, "get-tsig-key-query", "", "select algorithm, secret from tsigkeys where name=?");
    // FIXME: set-tsig-key-query only works if no existing key is present right
    // now. According to the internet, we need to construct a pretty hefty
    // "merge" query: https://msdn.microsoft.com/en-us/library/bb510625.aspx
    declare(suffix, "set-tsig-key-query", "", "insert into tsigkeys (name,algorithm,secret) values(?,?,?)");
    declare(suffix, "delete-tsig-key-query", "", "delete from tsigkeys where name=?");
    declare(suffix, "get-tsig-keys-query", "", "select name,algorithm, secret from tsigkeys");

    declare(suffix, "get-all-domains-query", "Retrieve all domains", "select domains.id, domains.name, records.content, domains.type, domains.master, domains.notified_serial, domains.last_check, domains.account, domains.catalog from domains LEFT JOIN records ON records.domain_id=domains.id AND records.type='SOA' AND records.name=domains.name WHERE records.disabled=0 OR records.disabled=?");

    declare(suffix, "list-comments-query", "", "SELECT domain_id,name,type,modified_at,account,comment FROM comments WHERE domain_id=?");
    declare(suffix, "insert-comment-query", "", "INSERT INTO comments (domain_id, name, type, modified_at, account, comment) VALUES (?, ?, ?, ?, ?, ?)");
    declare(suffix, "delete-comment-rrset-query", "", "DELETE FROM comments WHERE domain_id=? AND name=? AND type=?");
    declare(suffix, "delete-comments-query", "", "DELETE FROM comments WHERE domain_id=?");
    declare(suffix, "search-records-query", "", record_query + " name LIKE ? OR content LIKE ? LIMIT ?");
    declare(suffix, "search-comments-query", "", "SELECT domain_id,name,type,modified_at,account,comment FROM comments WHERE name LIKE ? OR comment LIKE ? LIMIT ?");
  }

  //! Constructs a new gODBCBackend object.
  DNSBackend* make(const string& suffix = "") override
  {
    return new gODBCBackend(d_mode, suffix);
  }

private:
  const string d_mode;
};

//! Magic class that is activated when the dynamic library is loaded
class gODBCLoader
{
public:
  //! This reports us to the main UeberBackend class
  gODBCLoader()
  {
    BackendMakers().report(std::make_unique<gODBCFactory>("godbc"));
    // If this module is not loaded dynamically at runtime, this code runs
    // as part of a global constructor, before the structured logger has a
    // chance to be set up, so fallback to simple logging.
    g_log << Logger::Warning << "This is module godbcbackend reporting" << std::endl;
  }
};

//! Reports the backendloader to the UeberBackend.
static gODBCLoader godbcloader;
