package metrics

import "github.com/prometheus/client_golang/prometheus"

const stateSubsystem = "state"

// HealthStatus of the gate application.
type HealthStatus int32

const (
	HealthStatusUndefined    HealthStatus = 0
	HealthStatusStarting     HealthStatus = 1
	HealthStatusReady        HealthStatus = 2
	HealthStatusShuttingDown HealthStatus = 3
)

type stateMetrics struct {
	healthCheck prometheus.Gauge
}

func newStateMetrics() *stateMetrics {
	return &stateMetrics{
		healthCheck: prometheus.NewGauge(prometheus.GaugeOpts{
			Namespace: namespace,
			Subsystem: stateSubsystem,
			Name:      "health",
			Help:      "Current S3 gateway state",
		}),
	}
}

func (m stateMetrics) register() {
	prometheus.MustRegister(m.healthCheck)
}

func (m stateMetrics) unregister() {
	prometheus.Unregister(m.healthCheck)
}

func (m stateMetrics) SetHealth(s HealthStatus) {
	m.healthCheck.Set(float64(s))
}