package metrics

import (
	"testing"

	"github.com/prometheus/client_golang/prometheus"

	controllerProvider "proxy-pool/internal/controller/provider"
	"proxy-pool/internal/domain/upstream"
)

func TestProviderCollectorRecordsOnlyFixedResultClasses(t *testing.T) {
	registry := prometheus.NewRegistry()
	collector, err := NewProviderCollector(registry)
	if err != nil {
		t.Fatalf("NewProviderCollector() error = %v", err)
	}
	collector.ObserveProviderResult(controllerProvider.Result{Class: upstream.FetchValid, ValidCount: 5, NewCount: 2})
	collector.ObserveProviderResult(controllerProvider.Result{Class: upstream.FetchDuplicateOnly, ValidCount: 3})
	collector.ObserveProviderResult(controllerProvider.Result{Class: upstream.FetchEmpty})
	collector.ObserveProviderResult(controllerProvider.Result{Class: upstream.FetchError})
	collector.ObserveProviderResult(controllerProvider.Result{Class: "invalid", ValidCount: 9, NewCount: 9})

	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "valid"}, 1)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "duplicate_only"}, 1)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "empty"}, 1)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "error"}, 1)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_valid_candidates_total", nil, 8)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_new_proxies_total", nil, 2)
}

func TestNewProviderCollectorReusesRegisteredCollectors(t *testing.T) {
	registry := prometheus.NewRegistry()
	first, err := NewProviderCollector(registry)
	if err != nil {
		t.Fatalf("first NewProviderCollector() error = %v", err)
	}
	second, err := NewProviderCollector(registry)
	if err != nil {
		t.Fatalf("second NewProviderCollector() error = %v", err)
	}
	first.ObserveProviderResult(controllerProvider.Result{Class: upstream.FetchValid, ValidCount: 1, NewCount: 1})
	second.ObserveProviderResult(controllerProvider.Result{Class: upstream.FetchValid, ValidCount: 2, NewCount: 2})
	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "valid"}, 2)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_valid_candidates_total", nil, 3)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_new_proxies_total", nil, 3)
}

func TestProviderCollectorObservesSharedStatsRecorder(t *testing.T) {
	registry := prometheus.NewRegistry()
	collector, err := NewProviderCollector(registry)
	if err != nil {
		t.Fatalf("NewProviderCollector() error = %v", err)
	}
	recorder, err := controllerProvider.NewStatsRecorder(1)
	if err != nil {
		t.Fatalf("NewStatsRecorder() error = %v", err)
	}
	recorder.AddResultObserver(collector)
	recorder.Record(controllerProvider.Result{UpstreamID: "provider-a", Class: upstream.FetchValid, ValidCount: 2, NewCount: 1})
	// The bounded Admin-status map has no room for provider-b, but metrics must
	// retain the process-wide fetch observation.
	recorder.Record(controllerProvider.Result{UpstreamID: "provider-b", Class: upstream.FetchEmpty})

	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "valid"}, 1)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_fetch_results_total", map[string]string{"class": "empty"}, 1)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_valid_candidates_total", nil, 2)
	assertMetricValue(t, registry, "proxy_pool_controller_provider_new_proxies_total", nil, 1)
}