sub2api-cn-relay-manager/internal/metrics/metrics_test.go

package metrics

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

func TestHTTPRequestsTotal(t *testing.T) {
	RecordHTTPRequest("GET", "/test", 200, 100*time.Millisecond)

	// Verify the counter was incremented
	// Note: We can't easily read the counter value directly, but we can verify
	// the handler returns the metric
	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Errorf("Expected status 200, got %d", rr.Code)
	}

	body := rr.Body.String()
	if !strings.Contains(body, "http_requests_total") {
		t.Error("Expected metrics endpoint to contain http_requests_total")
	}
}

func TestRecordRouteDecision(t *testing.T) {
	RecordRouteDecision("test-group", "success")
	RecordRouteDecision("test-group", "success")
	RecordRouteDecision("test-group", "failed")

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Errorf("Expected status 200, got %d", rr.Code)
	}

	body := rr.Body.String()
	if !strings.Contains(body, "route_decisions_total") {
		t.Error("Expected metrics endpoint to contain route_decisions_total")
	}
}

func TestRecordRouteFailover(t *testing.T) {
	RecordRouteFailover()

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	body := rr.Body.String()
	if !strings.Contains(body, "route_failovers_total") {
		t.Error("Expected metrics endpoint to contain route_failovers_total")
	}
}

func TestSetActiveHosts(t *testing.T) {
	SetActiveHosts(10)

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	body := rr.Body.String()
	if !strings.Contains(body, "active_hosts") {
		t.Error("Expected metrics endpoint to contain active_hosts")
	}
}

func TestSetActiveProviders(t *testing.T) {
	SetActiveProviders(5)

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	body := rr.Body.String()
	if !strings.Contains(body, "active_providers") {
		t.Error("Expected metrics endpoint to contain active_providers")
	}
}

func TestRecordDBOperation(t *testing.T) {
	RecordDBOperation("insert", "hosts")
	RecordDBOperation("select", "hosts")

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	body := rr.Body.String()
	if !strings.Contains(body, "db_operations_total") {
		t.Error("Expected metrics endpoint to contain db_operations_total")
	}
}

func TestRecordLogFlushError(t *testing.T) {
	RecordLogFlushError()
	RecordLogFlushError()

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	body := rr.Body.String()
	if !strings.Contains(body, "log_flush_errors_total") {
		t.Error("Expected metrics endpoint to contain log_flush_errors_total")
	}
}

func TestRecordLogDroppedEvent(t *testing.T) {
	RecordLogDroppedEvent()

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	body := rr.Body.String()
	if !strings.Contains(body, "log_dropped_events_total") {
		t.Error("Expected metrics endpoint to contain log_dropped_events_total")
	}
}

func TestMiddleware(t *testing.T) {
	handler := Middleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusCreated)
		w.Write([]byte("OK"))
	}))

	req := httptest.NewRequest("POST", "/api/test", nil)
	rr := httptest.NewRecorder()

	handler.ServeHTTP(rr, req)

	if rr.Code != http.StatusCreated {
		t.Errorf("Expected status 201, got %d", rr.Code)
	}

	if rr.Body.String() != "OK" {
		t.Errorf("Expected body 'OK', got '%s'", rr.Body.String())
	}
}

func TestResponseWriter(t *testing.T) {
	base := httptest.NewRecorder()
	rw := &responseWriter{ResponseWriter: base, statusCode: 200}

	rw.WriteHeader(http.StatusTeapot)

	if rw.statusCode != http.StatusTeapot {
		t.Errorf("Expected status code %d, got %d", http.StatusTeapot, rw.statusCode)
	}
}

func TestStartServer(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	// Start metrics server on a random port
	server := StartServer(ctx, "127.0.0.1:0")

	// Give server time to start
	time.Sleep(100 * time.Millisecond)

	// Verify server is running by making a request
	addr := server.Addr
	if addr == "" {
		t.Fatal("Server address not available")
	}

	// Server should shut down gracefully when context is cancelled
	cancel()

	// Give server time to shut down
	time.Sleep(100 * time.Millisecond)
}

func TestHandlerContent(t *testing.T) {
	// Set some metrics values
	SetActiveHosts(42)
	SetActiveProviders(7)

	req := httptest.NewRequest("GET", "/metrics", nil)
	rr := httptest.NewRecorder()

	Handler().ServeHTTP(rr, req)

	if rr.Code != http.StatusOK {
		t.Errorf("Expected status 200, got %d", rr.Code)
	}

	contentType := rr.Header().Get("Content-Type")
	if !strings.Contains(contentType, "text/plain") && !strings.Contains(contentType, "application/openmetrics") {
		t.Errorf("Expected text/plain or openmetrics content type, got %s", contentType)
	}

	body := rr.Body.String()

	// Check for expected metrics
	expectedMetrics := []string{
		"# HELP",
		"# TYPE",
		"active_hosts",
		"active_providers",
	}

	for _, metric := range expectedMetrics {
		if !strings.Contains(body, metric) {
			t.Errorf("Expected metrics to contain '%s'", metric)
		}
	}
}