package dnstt

import (
	"strings"
	"testing"
	"time"

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

func TestExporterCollectsAggregateDNSTTMetrics(t *testing.T) {
	now := time.Unix(1000, 0)
	c := NewCollector([]string{"tunnel.example.com"}, WithNow(func() time.Time { return now }))
	c.RecordQuery("tunnel.example.com", "client-a", 100)
	c.RecordQuery("tunnel.example.com", "client-b", 300)
	c.RecordResponse("tunnel.example.com", 250)

	expected := `
# HELP dnstt_active_clients Number of DNSTT client sessions observed within the active timeout window.
# TYPE dnstt_active_clients gauge
dnstt_active_clients{domain="tunnel.example.com"} 2
# HELP dnstt_bytes_in_total Total bytes observed in DNSTT DNS queries.
# TYPE dnstt_bytes_in_total counter
dnstt_bytes_in_total{domain="tunnel.example.com"} 400
# HELP dnstt_bytes_out_total Total bytes observed in DNSTT DNS responses.
# TYPE dnstt_bytes_out_total counter
dnstt_bytes_out_total{domain="tunnel.example.com"} 250
# HELP dnstt_peak_clients Maximum concurrent active DNSTT client sessions observed.
# TYPE dnstt_peak_clients gauge
dnstt_peak_clients{domain="tunnel.example.com"} 2
# HELP dnstt_queries_total Total DNSTT DNS queries observed.
# TYPE dnstt_queries_total counter
dnstt_queries_total{domain="tunnel.example.com"} 2
# HELP dnstt_sessions_total Total unique DNSTT client sessions observed.
# TYPE dnstt_sessions_total counter
dnstt_sessions_total{domain="tunnel.example.com"} 2
`

	if err := testutil.CollectAndCompare(NewExporter(c), strings.NewReader(expected)); err != nil {
		t.Fatal(err)
	}
}