metric

var (
	PublishResults = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "persistence_total",
		Help:      "Persistence outcomes.",
	}, []string{"result"})
	PendingMessages = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "pending_messages",
		Help:      "Admitted messages waiting for commit.",
	})
	PendingBytes = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "pending_bytes",
		Help:      "Admitted bytes waiting for commit.",
	})
	WriterHealthy = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "writer_healthy",
		Help:      "Whether the last writer flush succeeded.",
	})
	PersistenceLag = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "persistence_lag_seconds",
		Help:      "Age of the oldest message in the current flush.",
	})
	FlushTotal = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "flush_total",
		Help:      "Writer flush outcomes.",
	}, []string{"result"})
	FlushSize = prometheus.NewHistogram(prometheus.HistogramOpts{
		Namespace: "blockqueue",
		Name:      "flush_size",
		Help:      "Messages per database flush.",
		Buckets:   prometheus.ExponentialBuckets(1, 2, 11),
	})
	FlushDuration = prometheus.NewHistogram(prometheus.HistogramOpts{
		Namespace: "blockqueue",
		Name:      "flush_duration_seconds",
		Help:      "Database flush duration.",
	})
	DeliveryOperations = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "delivery_operation_total",
		Help:      "Delivery ACK/NACK/lease outcomes.",
	}, []string{"operation", "result"})
	DeliveryDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Namespace: "blockqueue",
		Name:      "delivery_operation_duration_seconds",
		Help:      "Delivery operation latency.",
	}, []string{"operation"})
	CheckpointDuration = prometheus.NewHistogram(prometheus.HistogramOpts{
		Namespace: "blockqueue",
		Name:      "checkpoint_duration_seconds",
		Help:      "SQLite checkpoint duration.",
	})
	CheckpointResults = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "checkpoint_total",
		Help:      "SQLite checkpoint outcomes.",
	}, []string{"result"})
	SchedulerOperations = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "scheduler_operation_total",
		Help:      "Scheduler outcomes.",
	}, []string{"operation", "result"})
	SchedulerHealthy = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "scheduler_healthy",
		Help:      "Whether every active scheduler can query and claim work.",
	})
	SchedulerDueLag = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "scheduler_due_lag_seconds",
		Help:      "Maximum overdue age observed by active schedulers.",
	})
	DeliveryReaperHealthy = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "delivery_reaper_healthy",
		Help:      "Whether every active lease reaper can query and update deliveries.",
	})
	DatabaseListenerHealthy = prometheus.NewGauge(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "database_listener_healthy",
		Help:      "Whether every active PostgreSQL queue has a notification listener.",
	})
	MaintenanceRows = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "maintenance_rows_total",
		Help:      "Rows processed by bounded maintenance operations.",
	}, []string{"operation"})
	MaintenancePasses = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "maintenance_pass_total",
		Help:      "Bounded maintenance pass outcomes.",
	}, []string{"operation", "result"})
	MaintenanceDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Namespace: "blockqueue",
		Name:      "maintenance_duration_seconds",
		Help:      "Duration of bounded maintenance passes.",
	}, []string{"operation"})
	WorkerJobs = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "worker_jobs_total",
		Help:      "Completed worker attempts by final disposition.",
	}, []string{"topic", "subscriber", "outcome"})
	WorkerHandlerDuration = prometheus.NewHistogramVec(prometheus.HistogramOpts{
		Namespace: "blockqueue",
		Name:      "worker_handler_duration_seconds",
		Help:      "Worker handler execution duration by return semantics.",
		Buckets:   []float64{0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30, 60, 300, 900, 3600},
	}, []string{"topic", "subscriber", "result"})
	WorkerActiveHandlers = prometheus.NewGaugeVec(prometheus.GaugeOpts{
		Namespace: "blockqueue",
		Name:      "worker_active_handlers",
		Help:      "Currently executing worker handlers.",
	}, []string{"topic", "subscriber"})
	WorkerHeartbeats = prometheus.NewCounterVec(prometheus.CounterOpts{
		Namespace: "blockqueue",
		Name:      "worker_heartbeat_total",
		Help:      "Worker lease heartbeat outcomes.",
	}, []string{"topic", "subscriber", "result"})
)