package metrics

import "github.com/go-gost/core/metrics"

const (
	// Number of services. Labels: host.
	MetricServicesGauge metrics.MetricName = "gost_services"
	// Total service requests. Labels: host, service.
	MetricServiceRequestsCounter metrics.MetricName = "gost_service_requests_total"
	// Number of in-flight requests. Labels: host, service.
	MetricServiceRequestsInFlightGauge metrics.MetricName = "gost_service_requests_in_flight"
	// Request duration historgram. Labels: host, service.
	MetricServiceRequestsDurationObserver metrics.MetricName = "gost_service_request_duration_seconds"
	// Total service input data transfer size in bytes. Labels: host, service.
	MetricServiceTransferInputBytesCounter metrics.MetricName = "gost_service_transfer_input_bytes_total"
	// Total service output data transfer size in bytes. Labels: host, service.
	MetricServiceTransferOutputBytesCounter metrics.MetricName = "gost_service_transfer_output_bytes_total"
	// Chain node connect duration histogram. Labels: host, chain, node.
	MetricNodeConnectDurationObserver metrics.MetricName = "gost_chain_node_connect_duration_seconds"
	// Total service handler errors. Labels: host, service.
	MetricServiceHandlerErrorsCounter metrics.MetricName = "gost_service_handler_errors_total"
	// Total chain connect errors. Labels: host, chain, node.
	MetricChainErrorsCounter metrics.MetricName = "gost_chain_errors_total"
)

var (
	global metrics.Metrics = Noop()
)

func Init(m metrics.Metrics) {
	if m != nil {
		global = m
	} else {
		global = Noop()
	}
}

func IsEnabled() bool {
	return global != Noop()
}

func GetCounter(name metrics.MetricName, labels metrics.Labels) metrics.Counter {
	return global.Counter(name, labels)
}

func GetGauge(name metrics.MetricName, labels metrics.Labels) metrics.Gauge {
	return global.Gauge(name, labels)
}

func GetObserver(name metrics.MetricName, labels metrics.Labels) metrics.Observer {
	return global.Observer(name, labels)
}