metrics

var (
	DNSQueriesTotal = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "dns",
		Name:      "queries_total",
		Help:      "Total DNS queries handled.",
	}, []string{"handler"})

	DNSQueryErrorsTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "dns",
		Name:      "query_errors_total",
		Help:      "Total DNS query errors (upstream failures).",
	})

	DNSQueryDurationSeconds = promauto.NewHistogram(prometheus.HistogramOpts{
		Namespace: namespace,
		Subsystem: "dns",
		Name:      "query_duration_seconds",
		Help:      "DNS query duration in seconds.",
		Buckets:   []float64{0.001, 0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 10},
	})
)

var (
	NodeInfo = promauto.NewGaugeVec(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "node",
		Name:      "info",
		Help:      "Static node information.",
	}, []string{"version", "peer_id", "go_version", "os", "arch"})

	NodeUptimeSeconds = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "node",
		Name:      "uptime_seconds",
		Help:      "Node uptime in seconds.",
	})

	NodeStartTimestamp = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "node",
		Name:      "start_timestamp",
		Help:      "Unix timestamp of node start.",
	})
)

var (
	P2PBootstrapPeersTotal = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "bootstrap_peers_total",
		Help:      "Total number of configured bootstrap peers.",
	})

	P2PBootstrapPeersConnected = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "bootstrap_peers_connected",
		Help:      "Number of connected bootstrap peers.",
	})

	P2PDHTRoutingTableSize = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "dht_routing_table_size",
		Help:      "DHT routing table size.",
	})

	P2POpenConnections = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "open_connections",
		Help:      "Number of open connections.",
	})

	P2POpenStreams = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "open_streams",
		Help:      "Number of open streams.",
	})

	P2PConnectedPeers = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "connected_peers",
		Help:      "Total number of connected peers (all, not just known).",
	})

	P2PPeerLatencySeconds = promauto.NewGaugeVec(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "p2p",
		Name:      "peer_latency_seconds",
		Help:      "Last measured latency to known peers in seconds.",
	}, []string{"peer_id"})
)

var (
	PeersKnownTotal = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "known_total",
		Help:      "Total number of known peers.",
	})

	PeersConnected = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "connected",
		Help:      "Number of currently connected known peers.",
	})

	PeersConfirmedTotal = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "confirmed_total",
		Help:      "Number of confirmed (mutual) peers.",
	})

	PeersBlockedTotal = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "blocked_total",
		Help:      "Number of blocked peers.",
	})

	PeersAuthRequestsIngoing = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "auth_requests_ingoing",
		Help:      "Number of pending ingoing auth requests.",
	})

	PeersAuthRequestsOutgoing = promauto.NewGauge(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "auth_requests_outgoing",
		Help:      "Number of pending outgoing auth requests.",
	})

	PeersAuthRequestsSentTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "auth_requests_sent_total",
		Help:      "Total number of auth requests sent.",
	})

	PeersAuthRequestsReceivedTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "auth_requests_received_total",
		Help:      "Total number of auth requests received.",
	})

	PeersStatusRequestsSentTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "status_requests_sent_total",
		Help:      "Total number of status requests sent.",
	})

	PeersStatusRequestsReceivedTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "status_requests_received_total",
		Help:      "Total number of status requests received.",
	})

	PeersConnectionEventsTotal = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "peers",
		Name:      "connection_events_total",
		Help:      "Total peer connection events.",
	}, []string{"event"})
)

var (
	SOCKS5ConnectionsTotal = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "socks5",
		Name:      "connections_total",
		Help:      "Total SOCKS5 connections.",
	}, []string{"direction"})

	SOCKS5ActiveConnections = promauto.NewGaugeVec(prometheus.GaugeOpts{
		Namespace: namespace,
		Subsystem: "socks5",
		Name:      "active_connections",
		Help:      "Current active SOCKS5 connections.",
	}, []string{"direction"})

	// TODO: add?
	SOCKS5BytesTransferredTotal = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "socks5",
		Name:      "bytes_transferred_total",
		Help:      "Total bytes transferred via SOCKS5.",
	}, []string{"direction"})

	SOCKS5ErrorsTotal = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "socks5",
		Name:      "errors_total",
		Help:      "Total SOCKS5 errors.",
	}, []string{"direction", "reason"})

	SOCKS5ConnectionDurationSeconds = promauto.NewHistogramVec(prometheus.HistogramOpts{
		Namespace: namespace,
		Subsystem: "socks5",
		Name:      "connection_duration_seconds",
		Help:      "SOCKS5 connection duration in seconds.",
		Buckets:   append(slices.Clone(prometheus.DefBuckets), 20, 40, 80, 160, 320, 640, 1280),
	}, []string{"direction"})
)

var (
	VPNPacketsSentTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "packets_sent_total",
		Help:      "Total VPN packets written to tunnel streams.",
	})

	VPNPacketsReceivedTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "packets_received_total",
		Help:      "Total VPN packets received from tunnel streams.",
	})

	VPNBytesSentTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "bytes_sent_total",
		Help:      "Total VPN bytes sent via tunnel streams.",
	})

	VPNBytesReceivedTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "bytes_received_total",
		Help:      "Total VPN bytes received from tunnel streams.",
	})

	VPNPacketsDroppedTotal = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "packets_dropped_total",
		Help:      "Total VPN packets dropped.",
	}, []string{"reason"})

	VPNTunReadErrorsTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "tun_read_errors_total",
		Help:      "Total TUN device read errors.",
	})

	VPNTunWriteErrorsTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "tun_write_errors_total",
		Help:      "Total TUN device write errors.",
	})

	VPNStreamOpenErrorsTotal = promauto.NewCounter(prometheus.CounterOpts{
		Namespace: namespace,
		Subsystem: "vpn",
		Name:      "stream_open_errors_total",
		Help:      "Total errors opening tunnel streams.",
	})
)