// Copyright 2019-2020 CERN and copyright holders of ALICE O2.

// See https://alice-o2.web.cern.ch/copyright for details of the copyright holders.

// All rights not expressly granted are reserved.

//

// This software is distributed under the terms of the GNU General Public

// License v3 (GPL Version 3), copied verbatim in the file "COPYING".

//

// In applying this license CERN does not waive the privileges and immunities

// granted to it by virtue of its status as an Intergovernmental Organization

// or submit itself to any jurisdiction.

#include "DPLMonitoringBackend.h"

#include "Framework/DriverClient.h"

#include "Framework/ServiceRegistry.h"

#include "Framework/RuntimeError.h"

#include "Framework/VariantHelpers.h"

#include <fmt/format.h>

#include <sstream>

namespace o2::framework

{

DPLMonitoringBackend::DPLMonitoringBackend(ServiceRegistryRef registry)

: mRegistry{registry}

{

}

void DPLMonitoringBackend::addGlobalTag(std::string_view name, std::string_view value)

{

// FIXME: tags are ignored by DPL in any case...

mTagString += fmt::format("{}{}={}", mTagString.empty() ? "" : ",", name.data(), value);

}

void DPLMonitoringBackend::send(std::vector<o2::monitoring::Metric>&& metrics)

{

for (auto& m : metrics) {

send(m);

}

}

inline unsigned long convertTimestamp(const std::chrono::time_point<std::chrono::system_clock>& timestamp)

{

return std::chrono::duration_cast<std::chrono::milliseconds>(

timestamp.time_since_epoch())

.count();

}

void DPLMonitoringBackend::send(o2::monitoring::Metric const& metric)

{

std::array<char, 4096> buffer;

auto mStream = fmt::format_to(buffer.begin(), "[METRIC] {}", metric.getName());

for (auto& value : metric.getValues()) {

auto stringValue = std::visit(overloaded{

[](const std::string& value) -> std::string { return value; },

[](auto value) -> std::string { return std::to_string(value); }},

value.second);

if (metric.getValuesSize() == 1) {

mStream = fmt::format_to(mStream, ",{} {}", metric.getFirstValueType(), stringValue);

} else {

mStream = fmt::format_to(mStream, " {}={}", value.first, stringValue);

}

}

// FIXME: tags are ignored by the DPL backend in any case...

mStream = fmt::format_to(mStream, " {} {}", convertTimestamp(metric.getTimestamp()), mTagString);

bool first = mTagString.empty();

for (const auto& [key, value] : metric.getTags()) {

if (!first) {

mStream = fmt::format_to(mStream, ",");

}

first = true;

mStream = fmt::format_to(mStream, "{}={}", o2::monitoring::tags::TAG_KEY[key], o2::monitoring::tags::GetValue(value));

}

mStream = fmt::format_to(mStream, "\n");

auto size = std::distance(buffer.begin(), mStream);

if (size + 1 >= 4096) {

throw runtime_error_f("Metric too long");

}

buffer[size] = '\0';

mRegistry.get<framework::DriverClient>().tell(buffer.data(), size);

}

} // namespace o2::framework