package metrics

import (
	"io"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
)

func TestMetricsHandlerExposesText(t *testing.T) {
	t.Parallel()
	m := New()
	m.Connections.WithLabelValues("ws").Set(3)
	m.Connections.WithLabelValues("tcp").Set(2)
	m.EndpointsTotal.Set(10)
	m.DeliveriesPending.Set(4)
	m.MessagesScheduled.Set(1)
	m.DispatchToPushSeconds.Observe(0.05)
	m.AckSeconds.Observe(0.02)
	m.WriteQueueLength.Set(7)
	m.WriteCommitSeconds.Observe(0.001)
	m.PasswordHashQueue.Set(2)
	m.ErrorsTotal.WithLabelValues("busy").Inc()

	req := httptest.NewRequest(http.MethodGet, "/metrics", nil)
	rec := httptest.NewRecorder()
	m.Handler().ServeHTTP(rec, req)
	resp := rec.Result()
	defer func() { _ = resp.Body.Close() }()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("status=%d", resp.StatusCode)
	}
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		t.Fatal(err)
	}
	text := string(body)
	for _, want := range []string{
		"nixmsg_connections",
		`transport="ws"`,
		`transport="tcp"`,
		"nixmsg_endpoints",
		"nixmsg_deliveries_pending",
		"nixmsg_messages_scheduled",
		"nixmsg_dispatch_to_push_duration_seconds",
		"nixmsg_ack_duration_seconds",
		"nixmsg_write_queue_length",
		"nixmsg_write_batch_commit_duration_seconds",
		"nixmsg_password_hash_queue_length",
		"nixmsg_errors_total",
		`code="busy"`,
	} {
		if !strings.Contains(text, want) {
			t.Fatalf("metrics text missing %q\n%s", want, text)
		}
	}
}