package metrics

import (
	"net/http/httptest"
	"strings"
	"testing"
	"time"

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

func TestMetricsRecord(t *testing.T) {
	m := New()
	m.ObserveCheck("drift", 100*time.Millisecond)
	m.ObserveCheck("in_sync", 50*time.Millisecond)
	m.IncNotification("telegram", "ok")
	m.SetDrift(3)

	if got := testutil.ToFloat64(m.ChecksTotal.WithLabelValues("drift")); got != 1 {
		t.Fatalf("checks drift = %v", got)
	}
	if got := testutil.ToFloat64(m.DriftDomains); got != 3 {
		t.Fatalf("drift gauge = %v", got)
	}
	if got := testutil.ToFloat64(m.NotificationsTotal.WithLabelValues("telegram", "ok")); got != 1 {
		t.Fatalf("notif = %v", got)
	}
}

func TestCheckDurationUsesNetworkCallBuckets(t *testing.T) {
	m := New()
	m.ObserveCheck("in_sync", 100*time.Millisecond)
	rec := httptest.NewRecorder()
	m.Handler().ServeHTTP(rec, httptest.NewRequest("GET", "/metrics", nil))
	body := rec.Body.String()

	// DefBuckets (le="0.005", ...) is tuned for sub-10ms in-process calls;
	// dns_ar_check_duration_seconds is a network call to a DNS provider, so
	// it must use the wider explicit buckets instead.
	for _, want := range []string{`le="0.05"`, `le="1"`, `le="30"`} {
		if !strings.Contains(body, `dns_ar_check_duration_seconds_bucket{`+want) {
			t.Fatalf("expected bucket %s in exposed metrics:\n%s", want, body)
		}
	}
	if strings.Contains(body, `dns_ar_check_duration_seconds_bucket{le="0.005"`) {
		t.Fatalf("found default histogram bucket 0.005, expected custom buckets:\n%s", body)
	}
}

func TestHandlerExposesMetrics(t *testing.T) {
	m := New()
	m.ObserveCheck("in_sync", time.Millisecond)
	rec := httptest.NewRecorder()
	m.Handler().ServeHTTP(rec, httptest.NewRequest("GET", "/metrics", nil))
	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "dns_ar_checks_total") {
		t.Fatalf("metrics not exposed: %d", rec.Code)
	}
}