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

	// OperationLabel - operation label name
	OperationLabel = "operation"

	// PredicateEvaluation - predicate evaluation operation label value
	PredicateEvaluation = "predicate_evaluation"
	// PriorityEvaluation - priority evaluation operation label value
	PriorityEvaluation = "priority_evaluation"
	// PreemptionEvaluation - preemption evaluation operation label value (occurs in case of scheduling fitError).
	PreemptionEvaluation = "preemption_evaluation"
	// Binding - binding operation label value
	Binding = "binding"
)

var (

	// PodScheduleSuccesses counts how many pods were scheduled.
	PodScheduleSuccesses = scheduleAttempts.With(prometheus.Labels{"result": "scheduled"})
	// PodScheduleFailures counts how many pods could not be scheduled.
	PodScheduleFailures = scheduleAttempts.With(prometheus.Labels{"result": "unschedulable"})
	// PodScheduleErrors counts how many pods could not be scheduled due to a scheduler error.
	PodScheduleErrors = scheduleAttempts.With(prometheus.Labels{"result": "error"})
	SchedulingLatency = prometheus.NewSummaryVec(
		prometheus.SummaryOpts{
			Subsystem: SchedulerSubsystem,
			Name:      SchedulingLatencyName,
			Help:      "Scheduling latency in seconds split by sub-parts of the scheduling operation",

			MaxAge: 5 * time.Hour,
		},
		[]string{OperationLabel},
	)
	E2eSchedulingLatency = prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "e2e_scheduling_latency_microseconds",
			Help:      "E2e scheduling latency (scheduling algorithm + binding)",
			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
		},
	)
	SchedulingAlgorithmLatency = prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "scheduling_algorithm_latency_microseconds",
			Help:      "Scheduling algorithm latency",
			Buckets:   prometheus.ExponentialBuckets(1000, 2, 15),
		},
	)
	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),
		},
	)
	BindingLatency = prometheus.NewHistogram(
		prometheus.HistogramOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "binding_latency_microseconds",
			Help:      "Binding latency",
			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",
		})

	EquivalenceCacheHits   = equivalenceCacheLookups.With(prometheus.Labels{"result": "hit"})
	EquivalenceCacheMisses = equivalenceCacheLookups.With(prometheus.Labels{"result": "miss"})

	EquivalenceCacheWrites = prometheus.NewCounterVec(
		prometheus.CounterOpts{
			Subsystem: SchedulerSubsystem,
			Name:      "equiv_cache_writes",
			Help:      "Total number of equivalence cache writes, by result",
		}, []string{"result"})
)