// vim:ts=4:sts=4:sw=4:noet:tw=72

package ircd

import (
	"net/http"
	"runtime"
	"time"

	"github.com/prometheus/client_golang/prometheus"
)

var (
	gaugeGoroutinesRunning  prometheus.Gauge
	gaugePacketsTransferred prometheus.Gauge
	gaugeConnectionsCurrent prometheus.Gauge
	gaugeConnectionsCount   prometheus.Gauge
	gaugeLocalQueueLen      prometheus.Gauge
	gaugeRemoteQueueLen     prometheus.Gauge
)

func monitoringRun(sv *Server) {
	gaugeGoroutinesRunning = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "ircd_goroutines_running",
		Help: "Goroutines runnning",
	})
	gaugePacketsTransferred = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "ircd_packets_transferred",
		Help: "Packets handled",
	})
	gaugeConnectionsCurrent = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "ircd_connections_current",
		Help: "Client connections",
	})
	gaugeConnectionsCount = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "ircd_connections_count",
		Help: "Client connections",
	})
	gaugeLocalQueueLen = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "ircd_local_queue_len",
		Help: "Unhandled msgs in dispatcher local queue",
	})
	gaugeRemoteQueueLen = prometheus.NewGauge(prometheus.GaugeOpts{
		Name: "ircd_remote_queue_len",
		Help: "Unhandled msgs in dispatcher remote queue",
	})
	prometheus.MustRegister(gaugeGoroutinesRunning)
	prometheus.MustRegister(gaugePacketsTransferred)
	prometheus.MustRegister(gaugeConnectionsCurrent)
	prometheus.MustRegister(gaugeConnectionsCount)
	prometheus.MustRegister(gaugeLocalQueueLen)
	prometheus.MustRegister(gaugeRemoteQueueLen)
	go monitoringUpdater(sv)
	http.Handle("/metrics", prometheus.Handler())
	laddr, _ := sv.config.GetString("net", "listen_prom")
	http.ListenAndServe(laddr, nil)
}

func monitoringUpdater(sv *Server) {
	for {
		time.Sleep(5 * time.Second)
		gaugeGoroutinesRunning.Set(float64(runtime.NumGoroutine()))
		gaugePacketsTransferred.Set(sv.packetsTransferred)
		gaugeConnectionsCurrent.Set(float64(len(sv.clients)))
		gaugeConnectionsCount.Set(sv.connectionsCount)
		gaugeLocalQueueLen.Set(float64(len(sv.localq)))
		gaugeRemoteQueueLen.Set(float64(len(sv.remoteq)))
	}
}