// Copyright Istio Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,

// Copyright Istio Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,

	).ValueFrom(func() float64 {
		return time.Since(serverStart).Seconds()
	})

	versionTag   = monitoring.CreateLabel("version")
	pilotVersion = monitoring.NewGauge(
		"pilot_info",
		"Pilot version and build information.",
	)
)

func init() {
	pilotVersion.With(versionTag.Value(version.Info.String())).Record(1)
}

func addMonitor(mux *http.ServeMux) error {
	exporter, err := monitoring.RegisterPrometheusExporter(nil, nil)

		monitoring.WithUnit(monitoring.Bytes),
	)
)

func recordXDSClients(version string, delta float64) {
	xdsClientTrackerMutex.Lock()
	defer xdsClientTrackerMutex.Unlock()
	xdsClientTracker[version] += delta
	xdsClients.With(versionTag.Value(version)).Record(xdsClientTracker[version])
}

// triggerMetric is a precomputed monitoring.Metric for each trigger type. This saves on a lot of allocations