// Package metrics defines ingest-service's Prometheus metrics. Registered
// automatically (via promauto) into the default registry on import; served
// by main.go's dedicated metrics HTTP server.
package metrics

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
)

var (
	MQTTMessagesReceived = promauto.NewCounter(prometheus.CounterOpts{
		Name: "ingest_mqtt_messages_received_total",
		Help: "Total number of telemetry messages received from MQTT.",
	})

	MQTTMessagesInvalid = promauto.NewCounter(prometheus.CounterOpts{
		Name: "ingest_mqtt_messages_invalid_total",
		Help: "Total number of telemetry messages dropped for failing validation.",
	})

	MQTTMessagesDropped = promauto.NewCounter(prometheus.CounterOpts{
		Name: "ingest_mqtt_messages_dropped_total",
		Help: "Total number of readings dropped because the worker backlog was full.",
	})

	BatchFlushes = promauto.NewCounterVec(prometheus.CounterOpts{
		Name: "ingest_batch_flush_total",
		Help: "Total number of batch flushes to ClickHouse, by outcome.",
	}, []string{"outcome"})

	BatchFlushDuration = promauto.NewHistogram(prometheus.HistogramOpts{
		Name:    "ingest_batch_flush_duration_seconds",
		Help:    "Duration of ClickHouse batch insert calls.",
		Buckets: prometheus.DefBuckets,
	})

	BatchSize = promauto.NewHistogram(prometheus.HistogramOpts{
		Name:    "ingest_batch_size",
		Help:    "Number of readings per flushed batch.",
		Buckets: []float64{1, 5, 10, 25, 50, 100, 250, 500, 1000},
	})

	RabbitMQPublishes = promauto.NewCounterVec(prometheus.CounterOpts{
		Name: "ingest_rabbitmq_publish_total",
		Help: "Total number of new-reading events published to RabbitMQ, by outcome.",
	}, []string{"outcome"})
)