/******************************************************************************
 * Icinga 2                                                                   *
 * Copyright (C) 2012-2014 Icinga Development Team (http://www.icinga.org)    *
 *                                                                            *
 * 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; either version 2             *
 * of the License, or (at your option) any later version.                     *
 *                                                                            *
 * 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 St, Fifth Floor, Boston, MA 02110-1301, USA.             *
 ******************************************************************************/

#include "perfdata/gelfwriter.hpp"
#include "icinga/service.hpp"
#include "icinga/notification.hpp"
#include "icinga/macroprocessor.hpp"
#include "icinga/compatutility.hpp"
#include "icinga/perfdatavalue.hpp"
#include "base/tcpsocket.hpp"
#include "base/dynamictype.hpp"
#include "base/objectlock.hpp"
#include "base/logger.hpp"
#include "base/utility.hpp"
#include "base/stream.hpp"
#include "base/networkstream.hpp"
#include "base/json.hpp"

using namespace icinga;

REGISTER_TYPE(GelfWriter);

void GelfWriter::Start(void)
{
	DynamicObject::Start();

  m_ReconnectTimer = make_shared<Timer>();
  m_ReconnectTimer->SetInterval(10);
  m_ReconnectTimer->OnTimerExpired.connect(boost::bind(&GelfWriter::ReconnectTimerHandler, this));
  m_ReconnectTimer->Start();
  m_ReconnectTimer->Reschedule(0);

  // Send check results
	Service::OnNewCheckResult.connect(boost::bind(&GelfWriter::CheckResultHandler, this, _1, _2));
  // Send notifications
  Service::OnNotificationSentToUser.connect(boost::bind(&GelfWriter::NotificationToUserHandler, this, _1, _2, _3, _4, _5, _6, _7, _8));
  // Send state change
  Service::OnStateChange.connect(boost::bind(&GelfWriter::StateChangeHandler, this, _1, _2, _3));
}

void GelfWriter::ReconnectTimerHandler(void)
{
  if (m_Stream)
    return;

  TcpSocket::Ptr socket = make_shared<TcpSocket>();

  Log(LogNotice, "GelfWriter")
      << "Reconnecting to GELF endpoint '" << GetHost() << "' port '" << GetPort() << "'.";

  try {
    socket->Connect(GetHost(), GetPort());
  } catch (std::exception&) {
    Log(LogCritical, "GelfWriter")
        << "Can't connect to GELF endpoint '" << GetHost() << "' port '" << GetPort() << "'.";
    return;
  }

  m_Stream = make_shared<NetworkStream>(socket);
}

void GelfWriter::CheckResultHandler(const Checkable::Ptr& checkable, const CheckResult::Ptr& cr)
{
	CONTEXT("GELF Processing check result for '" + checkable->GetName() + "'");

  Dictionary::Ptr fields = make_shared<Dictionary>();
  Service::Ptr service   = dynamic_pointer_cast<Service>(checkable);
  Host::Ptr host;

  if (service) {
    host = service->GetHost();
    fields->Set("_service_name", service->GetShortName());
    fields->Set("_service_state", Service::StateToString(service->GetState()));
  } else {
    host = static_pointer_cast<Host>(checkable);
  }
  fields->Set("_hostname", host->GetName());
  fields->Set("short_message", cr->GetOutput());
  fields->Set("_type", "CHECK RESULT");

  SendLogMessage(ComposeGelfMessage(fields, "icinga"));
}

void GelfWriter::NotificationToUserHandler(const Notification::Ptr& notification, const Checkable::Ptr& checkable,
    const User::Ptr& user, NotificationType notification_type, CheckResult::Ptr const& cr,
    const String& author, const String& comment_text, const String& command_name)
{
  CONTEXT("GELF Processing notification to all users '" + checkable->GetName() + "'");
  
  Host::Ptr host;
  Service::Ptr service;
  tie(host, service) = GetHostService(checkable);

  String notification_type_str = Notification::NotificationTypeToString(notification_type);

  String author_comment = "";
  if (notification_type == NotificationCustom || notification_type == NotificationAcknowledgement) {
    author_comment = author + ";" + comment_text;
  }

  String output;
  if (cr)
    output = CompatUtility::GetCheckResultOutput(cr);

  Dictionary::Ptr fields = make_shared<Dictionary>();
  if (service) {
    host = service->GetHost();
    fields->Set("_type", "SERVICE NOTIFICATION");
    fields->Set("_service", service->GetShortName());
    fields->Set("short_message", output);
  } else {
    host = static_pointer_cast<Host>(checkable);
    fields->Set("_type", "HOST NOTIFICATION");
    fields->Set("short_message", "(" << (host->IsReachable() ? Host::StateToString(host->GetState()) : "UNREACHABLE") << ")");
  }
  fields->Set("_hostname", host->GetName());
  fields->Set("_command", command_name);
  fields->Set("_state", notification_type_str);
  fields->Set("_comment", author_comment);

  SendLogMessage(ComposeGelfMessage(fields, "icinga"));
}

void GelfWriter::StateChangeHandler(const Checkable::Ptr& checkable, const CheckResult::Ptr& cr, StateType type)
{
  CONTEXT("GELF Processing state change '" + checkable->GetName() + "'");

  Host::Ptr host;
  Service::Ptr service;
  tie(host, service) = GetHostService(checkable);

  Dictionary::Ptr fields = make_shared<Dictionary>();
  fields->Set("_state", service ? static_cast<int>(service->GetState()) : static_cast<int>(host->GetState()));
  fields->Set("_type", "STATE CHANGE");
  fields->Set("_current_check_attempt", checkable->GetCheckAttempt());
  fields->Set("_max_check_attempts", checkable->GetMaxCheckAttempts());

  if (service) {
    fields->Set("_last_state", service->GetLastState());
    fields->Set("_last_hard_state", service->GetLastHardState());
  } else {
    fields->Set("_last_state", host->GetLastState());
    fields->Set("_last_hard_state", host->GetLastHardState());
  }

  if (cr) {
    fields->Set("short_message", CompatUtility::GetCheckResultOutput(cr));
    fields->Set("full_message", CompatUtility::GetCheckResultLongOutput(cr));
    fields->Set("_check_source", cr->GetCheckSource());
  }

  SendLogMessage(ComposeGelfMessage(fields, "icinga"));
}

String GelfWriter::ComposeGelfMessage(const Dictionary::Ptr& fields, const String& source)
{
  fields->Set("version", "1.1");
  fields->Set("host", source);
  fields->Set("timestamp", Utility::GetTime());

  return JsonEncode(fields);
}

void GelfWriter::SendLogMessage(const String& gelf)
{
  std::ostringstream msgbuf;
  msgbuf << gelf;
  msgbuf << '\0';

  String log = msgbuf.str();

  ObjectLock olock(this);

  if (!m_Stream)
    return;

  try {
    m_Stream->Write(log.CStr(), log.GetLength());
  } catch (const std::exception& ex) {
    Log(LogCritical, "GelfWriter")
        << "Cannot write to TCP socket on host '" << GetHost() << "' port '" << GetPort() << "'.";

    m_Stream.reset();
  }
}