/* Icinga 2 | (c) 2012 Icinga GmbH | GPLv2+ */

#include "perfdata/opentsdbwriter.hpp"
#include "perfdata/opentsdbwriter-ti.cpp"
#include "icinga/service.hpp"
#include "icinga/checkcommand.hpp"
#include "icinga/macroprocessor.hpp"
#include "icinga/icingaapplication.hpp"
#include "icinga/compatutility.hpp"
#include "base/tcpsocket.hpp"
#include "base/configtype.hpp"
#include "base/objectlock.hpp"
#include "base/logger.hpp"
#include "base/convert.hpp"
#include "base/utility.hpp"
#include "base/perfdatavalue.hpp"
#include "base/application.hpp"
#include "base/stream.hpp"
#include "base/networkstream.hpp"
#include "base/exception.hpp"
#include "base/statsfunction.hpp"
#include <boost/algorithm/string.hpp>
#include <boost/algorithm/string/replace.hpp>

using namespace icinga;

REGISTER_TYPE(OpenTsdbWriter);

REGISTER_STATSFUNCTION(OpenTsdbWriter, &OpenTsdbWriter::StatsFunc);

/*
 * Enable HA capabilities once the config object is loaded.
 */
void OpenTsdbWriter::OnConfigLoaded()
{
	ObjectImpl<OpenTsdbWriter>::OnConfigLoaded();

	if (!GetEnableHa()) {
		Log(LogDebug, "OpenTsdbWriter")
			<< "HA functionality disabled. Won't pause connection: " << GetName();

		SetHAMode(HARunEverywhere);
	} else {
		SetHAMode(HARunOnce);
	}
}

/**
 * Feature stats interface
 *
 * @param status Key value pairs for feature stats
 */
void OpenTsdbWriter::StatsFunc(const Dictionary::Ptr& status, const Array::Ptr&)
{
	DictionaryData nodes;

	for (const OpenTsdbWriter::Ptr& opentsdbwriter : ConfigType::GetObjectsByType<OpenTsdbWriter>()) {
		nodes.emplace_back(opentsdbwriter->GetName(), new Dictionary({
			{ "connected", opentsdbwriter->GetConnected() }
		}));
	}

	status->Set("opentsdbwriter", new Dictionary(std::move(nodes)));
}

/**
 * Resume is equivalent to Start, but with HA capabilities to resume at runtime.
 */
void OpenTsdbWriter::Resume()
{
	ObjectImpl<OpenTsdbWriter>::Resume();

	Log(LogInformation, "OpentsdbWriter")
		<< "'" << GetName() << "' resumed.";

	ReadConfigTemplate(m_ServiceConfigTemplate, m_HostConfigTemplate);

	m_ReconnectTimer = Timer::Create();
	m_ReconnectTimer->SetInterval(10);
	m_ReconnectTimer->OnTimerExpired.connect([this](const Timer * const&) { ReconnectTimerHandler(); });
	m_ReconnectTimer->Start();
	m_ReconnectTimer->Reschedule(0);

	m_HandleCheckResults = Service::OnNewCheckResult.connect([this](const Checkable::Ptr& checkable, const CheckResult::Ptr& cr, const MessageOrigin::Ptr&) {
		CheckResultHandler(checkable, cr);
	});
}

/**
 * Pause is equivalent to Stop, but with HA capabilities to resume at runtime.
 */
void OpenTsdbWriter::Pause()
{
	m_HandleCheckResults.disconnect();
	m_ReconnectTimer->Stop(true);

	Log(LogInformation, "OpentsdbWriter")
		<< "'" << GetName() << "' paused.";

	m_Stream->close();

	SetConnected(false);

	ObjectImpl<OpenTsdbWriter>::Pause();
}

/**
 * Reconnect handler called by the timer.
 * Handles TLS
 */
void OpenTsdbWriter::ReconnectTimerHandler()
{
	if (IsPaused())
		return;

	SetShouldConnect(true);

	if (GetConnected())
		return;

	double startTime = Utility::GetTime();

	Log(LogNotice, "OpenTsdbWriter")
		<< "Reconnecting to OpenTSDB TSD on host '" << GetHost() << "' port '" << GetPort() << "'.";

	/*
	 * We're using telnet as input method. Future PRs may change this into using the HTTP API.
	 * http://opentsdb.net/docs/build/html/user_guide/writing/index.html#telnet
	 */
	m_Stream = Shared<AsioTcpStream>::Make(IoEngine::Get().GetIoContext());

	try {
		icinga::Connect(m_Stream->lowest_layer(), GetHost(), GetPort());
	} catch (const std::exception& ex) {
		Log(LogWarning, "OpenTsdbWriter")
			<< "Can't connect to OpenTSDB on host '" << GetHost() << "' port '" << GetPort() << "'.";

		SetConnected(false);

		return;
	}

	SetConnected(true);

	Log(LogInformation, "OpenTsdbWriter")
		<< "Finished reconnecting to OpenTSDB in " << std::setw(2) << Utility::GetTime() - startTime << " second(s).";
}

/**
 * Registered check result handler processing data.
 * Calculates tags from the config.
 *
 * @param checkable Host/service object
 * @param cr Check result
 */
void OpenTsdbWriter::CheckResultHandler(const Checkable::Ptr& checkable, const CheckResult::Ptr& cr)
{
	if (IsPaused())
		return;

	CONTEXT("Processing check result for '" << checkable->GetName() << "'");

	if (!IcingaApplication::GetInstance()->GetEnablePerfdata() || !checkable->GetEnablePerfdata())
		return;

	Service::Ptr service = dynamic_pointer_cast<Service>(checkable);
	Host::Ptr host;
	Dictionary::Ptr config_tmpl;
	Dictionary::Ptr config_tmpl_tags;
	String config_tmpl_metric;

	if (service) {
		host = service->GetHost();
		config_tmpl = m_ServiceConfigTemplate;
	}
	else {
		host = static_pointer_cast<Host>(checkable);
		config_tmpl = m_HostConfigTemplate;
	}

	// Get the tags nested dictionary in the service/host template in the config
	if (config_tmpl) {
		config_tmpl_tags = config_tmpl->Get("tags");
		config_tmpl_metric = config_tmpl->Get("metric");
	}

	String metric;
	std::map<String, String> tags;

	// Resolve macros in configuration template and build custom tag list
	if (config_tmpl_tags || !config_tmpl_metric.IsEmpty()) {

		// Configure config template macro resolver
		MacroProcessor::ResolverList resolvers;
		if (service)
			resolvers.emplace_back("service", service);
		resolvers.emplace_back("host", host);

		// Resolve macros for the service and host template config line
		if (config_tmpl_tags) {
			ObjectLock olock(config_tmpl_tags);
			
			for (const Dictionary::Pair& pair : config_tmpl_tags) {
				
				String missing_macro;
				Value value = MacroProcessor::ResolveMacros(pair.second, resolvers, cr, &missing_macro);
				
				if (!missing_macro.IsEmpty()) {
					Log(LogDebug, "OpenTsdbWriter")
						<< "Unable to resolve macro '" << missing_macro 
						<< "' for checkable '" << checkable->GetName() << "'.";
					
					continue;
				}

				if (value.IsEmpty()) {
					Log(LogDebug, "OpenTsdbWriter")
						<< "Resolved macro '" << pair.second
						<< "' for checkable '" << checkable->GetName() << "' to '', skipping.";

					continue;
				}
				
				String tagname = Convert::ToString(pair.first);
				tags[tagname] = EscapeTag(value);
				
			}
		}
		
		// Resolve macros for the metric config line
		if (!config_tmpl_metric.IsEmpty()) {
			
			String missing_macro;
			Value value = MacroProcessor::ResolveMacros(config_tmpl_metric, resolvers, cr, &missing_macro);
			
			if (!missing_macro.IsEmpty()) {
				Log(LogDebug, "OpenTsdbWriter")
					<< "Unable to resolve macro '" << missing_macro 
					<< "' for checkable '" << checkable->GetName() << "'.";
				
			}
			else {
			
				config_tmpl_metric = Convert::ToString(value);
			
			}
		}
	}

	String escaped_hostName = EscapeTag(host->GetName());
	tags["host"] = escaped_hostName;

	double ts = cr->GetExecutionEnd();

	if (service) {

		if (!config_tmpl_metric.IsEmpty()) {
			metric = config_tmpl_metric;
		} else {
			String serviceName = service->GetShortName();
			String escaped_serviceName = EscapeMetric(serviceName);
			metric = "icinga.service." + escaped_serviceName;
		}
		
		SendMetric(checkable, metric + ".state", tags, service->GetState(), ts);

	} else {
		if (!config_tmpl_metric.IsEmpty()) {
			metric = config_tmpl_metric;
		} else {
			metric = "icinga.host";
		}
		SendMetric(checkable, metric + ".state", tags, host->GetState(), ts);
	}

	SendMetric(checkable, metric + ".state_type", tags, checkable->GetStateType(), ts);
	SendMetric(checkable, metric + ".reachable", tags, checkable->IsReachable(), ts);
	SendMetric(checkable, metric + ".downtime_depth", tags, checkable->GetDowntimeDepth(), ts);
	SendMetric(checkable, metric + ".acknowledgement", tags, checkable->GetAcknowledgement(), ts);

	SendPerfdata(checkable, metric, tags, cr, ts);

	metric = "icinga.check";

	if (service) {
		tags["type"] = "service";
		String serviceName = service->GetShortName();
		String escaped_serviceName = EscapeTag(serviceName);
		tags["service"] = escaped_serviceName;
	} else {
		tags["type"] = "host";
	}

	SendMetric(checkable, metric + ".current_attempt", tags, checkable->GetCheckAttempt(), ts);
	SendMetric(checkable, metric + ".max_check_attempts", tags, checkable->GetMaxCheckAttempts(), ts);
	SendMetric(checkable, metric + ".latency", tags, cr->CalculateLatency(), ts);
	SendMetric(checkable, metric + ".execution_time", tags, cr->CalculateExecutionTime(), ts);
}

/**
 * Parse and send performance data metrics to OpenTSDB
 *
 * @param checkable Host/service object
 * @param metric Full metric name
 * @param tags Tag key pairs
 * @param cr Check result containing performance data
 * @param ts Timestamp when the check result was received
 */
void OpenTsdbWriter::SendPerfdata(const Checkable::Ptr& checkable, const String& metric,
	const std::map<String, String>& tags, const CheckResult::Ptr& cr, double ts)
{
	Array::Ptr perfdata = cr->GetPerformanceData();

	if (!perfdata)
		return;

	CheckCommand::Ptr checkCommand = checkable->GetCheckCommand();

	ObjectLock olock(perfdata);
	for (const Value& val : perfdata) {
		PerfdataValue::Ptr pdv;

		if (val.IsObjectType<PerfdataValue>())
			pdv = val;
		else {
			try {
				pdv = PerfdataValue::Parse(val);
			} catch (const std::exception&) {
				Log(LogWarning, "OpenTsdbWriter")
					<< "Ignoring invalid perfdata for checkable '"
					<< checkable->GetName() << "' and command '"
					<< checkCommand->GetName() << "' with value: " << val;
				continue;
			}
		}
		
		String metric_name;
		std::map<String, String> tags_new = tags;

		// Do not break original functionality where perfdata labels form
		// part of the metric name
		if (!GetEnableGenericMetrics()) {
			String escaped_key = EscapeMetric(pdv->GetLabel());
			boost::algorithm::replace_all(escaped_key, "::", ".");
			metric_name = metric + "." + escaped_key;
		} else {
			String escaped_key = EscapeTag(pdv->GetLabel());
			metric_name = metric;
			tags_new["label"] = escaped_key;
		}

		SendMetric(checkable, metric_name, tags_new, pdv->GetValue(), ts);

		if (!pdv->GetCrit().IsEmpty())
			SendMetric(checkable, metric_name + "_crit", tags_new, pdv->GetCrit(), ts);
		if (!pdv->GetWarn().IsEmpty())
			SendMetric(checkable, metric_name + "_warn", tags_new, pdv->GetWarn(), ts);
		if (!pdv->GetMin().IsEmpty())
			SendMetric(checkable, metric_name + "_min", tags_new, pdv->GetMin(), ts);
		if (!pdv->GetMax().IsEmpty())
			SendMetric(checkable, metric_name + "_max", tags_new, pdv->GetMax(), ts);
	}
}

/**
 * Send given metric to OpenTSDB
 *
 * @param checkable Host/service object
 * @param metric Full metric name
 * @param tags Tag key pairs
 * @param value Floating point metric value
 * @param ts Timestamp where the metric was received from the check result
 */
void OpenTsdbWriter::SendMetric(const Checkable::Ptr& checkable, const String& metric,
	const std::map<String, String>& tags, double value, double ts)
{
	String tags_string = "";

	for (const Dictionary::Pair& tag : tags) {
		tags_string += " " + tag.first + "=" + Convert::ToString(tag.second);
	}

	std::ostringstream msgbuf;
	/*
	 * must be (http://opentsdb.net/docs/build/html/user_guide/query/timeseries.html)
	 * put <metric> <timestamp> <value> <tagk1=tagv1[ tagk2=tagv2 ...tagkN=tagvN]>
	 * "tags" must include at least one tag, we use "host=HOSTNAME"
	 */
	msgbuf << "put " << metric << " " << static_cast<long>(ts) << " " << Convert::ToString(value) << tags_string;

	Log(LogDebug, "OpenTsdbWriter")
		<< "Checkable '" << checkable->GetName() << "' adds to metric list: '" << msgbuf.str() << "'.";

	/* do not send \n to debug log */
	msgbuf << "\n";
	String put = msgbuf.str();

	ObjectLock olock(this);

	if (!GetConnected())
		return;

	try {
		Log(LogDebug, "OpenTsdbWriter")
			<< "Checkable '" << checkable->GetName() << "' sending message '" << put << "'.";

		boost::asio::write(*m_Stream, boost::asio::buffer(msgbuf.str()));
		m_Stream->flush();
	} catch (const std::exception& ex) {
		Log(LogCritical, "OpenTsdbWriter")
			<< "Cannot write to TCP socket on host '" << GetHost() << "' port '" << GetPort() << "'.";
	}
}

/**
 * Escape tags for OpenTSDB
 * http://opentsdb.net/docs/build/html/user_guide/query/timeseries.html#precisions-on-metrics-and-tags
 *
 * @param str Tag name
 * @return Escaped tag
 */
String OpenTsdbWriter::EscapeTag(const String& str)
{
	String result = str;

	boost::replace_all(result, " ", "_");
	boost::replace_all(result, "\\", "_");
	boost::replace_all(result, ":", "_");

	return result;
}

/**
 * Escape metric name for OpenTSDB
 * http://opentsdb.net/docs/build/html/user_guide/query/timeseries.html#precisions-on-metrics-and-tags
 *
 * @param str Metric name
 * @return Escaped metric
 */
String OpenTsdbWriter::EscapeMetric(const String& str)
{
	String result = str;

	boost::replace_all(result, " ", "_");
	boost::replace_all(result, ".", "_");
	boost::replace_all(result, "\\", "_");
	boost::replace_all(result, ":", "_");

	return result;
}

/**
* Saves the template dictionaries defined in the config file into running memory
*
* @param stemplate The dictionary to save the service configuration to
* @param htemplate The dictionary to save the host configuration to
*/
void OpenTsdbWriter::ReadConfigTemplate(const Dictionary::Ptr& stemplate, 
	const Dictionary::Ptr& htemplate)
{

	m_ServiceConfigTemplate = GetServiceTemplate();

	if (!m_ServiceConfigTemplate) {
		Log(LogDebug, "OpenTsdbWriter")
			<< "Unable to locate service template configuration.";
	} else if (m_ServiceConfigTemplate->GetLength() == 0) {
		Log(LogDebug, "OpenTsdbWriter")
			<< "The service template configuration is empty.";
	}

	m_HostConfigTemplate = GetHostTemplate();

	if (!m_HostConfigTemplate) {
		Log(LogDebug, "OpenTsdbWriter")
			<< "Unable to locate host template configuration.";
	} else if (m_HostConfigTemplate->GetLength() == 0) {
		Log(LogDebug, "OpenTsdbWriter")
			<< "The host template configuration is empty.";
	}

}


/**
* Validates the host_template configuration block in the configuration
* file and checks for syntax errors.
*
* @param lvalue The host_template dictionary
* @param utils Validation helper utilities
*/
void OpenTsdbWriter::ValidateHostTemplate(const Lazy<Dictionary::Ptr>& lvalue, const ValidationUtils& utils)
{
	ObjectImpl<OpenTsdbWriter>::ValidateHostTemplate(lvalue, utils);

	String metric = lvalue()->Get("metric");
	if (!MacroProcessor::ValidateMacroString(metric))
		BOOST_THROW_EXCEPTION(ValidationError(this, { "host_template", "metric" }, "Closing $ not found in macro format string '" + metric + "'."));

	Dictionary::Ptr tags = lvalue()->Get("tags");
	if (tags) {
		ObjectLock olock(tags);
		for (const Dictionary::Pair& pair : tags) {
			if (!MacroProcessor::ValidateMacroString(pair.second))
				BOOST_THROW_EXCEPTION(ValidationError(this, { "host_template", "tags", pair.first }, "Closing $ not found in macro format string '" + pair.second));
		}
	}
}

/**
* Validates the service_template configuration block in the 
* configuration file and checks for syntax errors.
*
* @param lvalue The service_template dictionary
* @param utils Validation helper utilities
*/
void OpenTsdbWriter::ValidateServiceTemplate(const Lazy<Dictionary::Ptr>& lvalue, const ValidationUtils& utils)
{
	ObjectImpl<OpenTsdbWriter>::ValidateServiceTemplate(lvalue, utils);

	String metric = lvalue()->Get("metric");
	if (!MacroProcessor::ValidateMacroString(metric))
		BOOST_THROW_EXCEPTION(ValidationError(this, { "service_template", "metric" }, "Closing $ not found in macro format string '" + metric + "'."));

	Dictionary::Ptr tags = lvalue()->Get("tags");
	if (tags) {
		ObjectLock olock(tags);
		for (const Dictionary::Pair& pair : tags) {
			if (!MacroProcessor::ValidateMacroString(pair.second))
				BOOST_THROW_EXCEPTION(ValidationError(this, { "service_template", "tags", pair.first }, "Closing $ not found in macro format string '" + pair.second));
		}
	}
}