package metrics

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

func TestMetricsHandlerExportsOnlyAggregateGatewayState(t *testing.T) {
	ObserveSubmit(true, 20*time.Millisecond)
	ObserveInboundStage("api_roundtrip", true, 30*time.Millisecond)
	ObserveSubmitStage("rate_limit_wait", true, 15*time.Millisecond)
	request := httptest.NewRequest(http.MethodGet, "/metrics", nil)
	response := httptest.NewRecorder()
	Handler(func(context.Context) Snapshot {
		return Snapshot{UpstreamDesired: 2, UpstreamConnected: 1, DownstreamConnected: 3, SubmitWorkerUp: true, SubmitWorkerConcurrency: 64, SubmitWorkerInFlight: 7, InboundSubmitConcurrency: 96, InboundSubmitInFlight: 9, QueueAvailable: true, QueuePending: 4, QueueLag: 5, QueueOldestAgeSeconds: 12}
	}).ServeHTTP(response, request)

	body := response.Body.String()
	if response.Code != http.StatusOK || !strings.Contains(body, "cmpp_gateway_submit_queue_pending 4") || !strings.Contains(body, "cmpp_gateway_upstream_connections{state=\"connected\"} 1") {
		t.Fatalf("unexpected metrics response: code=%d body=%s", response.Code, body)
	}
	for _, expected := range []string{
		`cmpp_gateway_inbound_stage_duration_seconds_count{stage="api_roundtrip",result="success"} 1`,
		`cmpp_gateway_submit_stage_duration_seconds_count{stage="rate_limit_wait",result="success"} 1`,
		`cmpp_gateway_submit_worker_slots{state="configured"} 64`,
		`cmpp_gateway_submit_worker_slots{state="in_flight"} 7`,
		`cmpp_gateway_inbound_submit_slots{state="configured"} 96`,
		`cmpp_gateway_inbound_submit_slots{state="in_flight"} 9`,
	} {
		if !strings.Contains(body, expected) {
			t.Fatalf("metrics response is missing %q: %s", expected, body)
		}
	}
	for _, forbidden := range []string{"phone_number", "message_id", "channel_id"} {
		if strings.Contains(body, forbidden) {
			t.Fatalf("metrics expose forbidden label %q", forbidden)
		}
	}
}