/*
Copyright 2020 The Kubernetes 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,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
/*
// Copyright 2021 Antrea 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,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

Modifies:
- Place metrics in Antrea's namespace
*/

package cidrset

import (
	"sync"

	"k8s.io/component-base/metrics"
	"k8s.io/component-base/metrics/legacyregistry"
)

const (
	metricNamespaceAntrea = "antrea"
	nodeIpamSubsystem     = "node_ipam_controller"
)

var (
	cidrSetAllocations = metrics.NewCounterVec(
		&metrics.CounterOpts{
			Namespace:      metricNamespaceAntrea,
			Subsystem:      nodeIpamSubsystem,
			Name:           "cidrset_cidrs_allocations_total",
			Help:           "Counter measuring total number of CIDR allocations.",
			StabilityLevel: metrics.ALPHA,
		},
		[]string{"clusterCIDR"},
	)
	cidrSetReleases = metrics.NewCounterVec(
		&metrics.CounterOpts{
			Namespace:      metricNamespaceAntrea,
			Subsystem:      nodeIpamSubsystem,
			Name:           "cidrset_cidrs_releases_total",
			Help:           "Counter measuring total number of CIDR releases.",
			StabilityLevel: metrics.ALPHA,
		},
		[]string{"clusterCIDR"},
	)
	cidrSetUsage = metrics.NewGaugeVec(
		&metrics.GaugeOpts{
			Namespace:      metricNamespaceAntrea,
			Subsystem:      nodeIpamSubsystem,
			Name:           "cidrset_usage_cidrs",
			Help:           "Gauge measuring percentage of allocated CIDRs.",
			StabilityLevel: metrics.ALPHA,
		},
		[]string{"clusterCIDR"},
	)
	cidrSetAllocationTriesPerRequest = metrics.NewHistogramVec(
		&metrics.HistogramOpts{
			Namespace:      metricNamespaceAntrea,
			Subsystem:      nodeIpamSubsystem,
			Name:           "cidrset_allocation_tries_per_request",
			Help:           "Number of endpoints added on each Service sync",
			StabilityLevel: metrics.ALPHA,
			Buckets:        metrics.ExponentialBuckets(1, 5, 5),
		},
		[]string{"clusterCIDR"},
	)
)

var registerMetrics sync.Once

// registerCidrsetMetrics the metrics that are to be monitored.
func registerCidrsetMetrics() {
	registerMetrics.Do(func() {
		legacyregistry.MustRegister(cidrSetAllocations)
		legacyregistry.MustRegister(cidrSetReleases)
		legacyregistry.MustRegister(cidrSetUsage)
		legacyregistry.MustRegister(cidrSetAllocationTriesPerRequest)
	})
}
