const (
	// SchedulerSubsystem - subsystem name used by scheduler
	SchedulerSubsystem = "scheduler"
	// SchedulingLatencyName - scheduler latency metric name
	SchedulingLatencyName = "scheduling_latencies_summary"

	// OperationLabel - operation label name
	OperationLabel = "operation"
	// Binding - binding operation label value
	Binding = "binding"
	// SchedulingAlgorithm - scheduling algorithm operation label value
	SchedulingAlgorithm = "scheduling_algorithm"
	// E2eScheduling - e2e scheduling operation label value
	E2eScheduling = "e2e_scheduling"
)

var (
	SchedulingLatency = prometheus.NewSummaryVec(
		prometheus.SummaryOpts{
			Subsystem: SchedulerSubsystem,
			Name:      SchedulingLatencyName,
			Help:      "Scheduling latency in microseconds split by sub-parts of the scheduling operation",

			MaxAge: 5 * time.Hour,
		},
		[]string{OperationLabel},
	)
	SchedulingAlgorithmPredicateEvaluationDuration = prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "scheduling_algorithm_predicate_evaluation",
			Help:      "Scheduling algorithm predicate evaluation duration",
			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
		},
	)
	SchedulingAlgorithmPriorityEvaluationDuration = prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "scheduling_algorithm_priority_evaluation",
			Help:      "Scheduling algorithm priority evaluation duration",
			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
		},
	)
	SchedulingAlgorithmPremptionEvaluationDuration = prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "scheduling_algorithm_preemption_evaluation",
			Help:      "Scheduling algorithm preemption evaluation duration",
			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
		},
	)
	PreemptionVictims = prometheus.NewGauge(
		prometheus.GaugeOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "pod_preemption_victims",
			Help:      "Number of selected preemption victims",
		})
	PreemptionAttempts = prometheus.NewCounter(
		prometheus.CounterOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "total_preemption_attempts",
			Help:      "Total preemption attempts in the cluster till now",
		})
)