Refactor: Avoid network requests when health check is disabled

This change ensures that when a site's health check is disabled, the checker returns cached metadata without making any network requests, as per issue #1446. A new helper function `getExistingSiteSnapshot` is introduced to retrieve this cached information. A new test case `TestCheckSiteSkipsNetworkWhenDisabled` is added to verify this behavior.

Co-authored-by: jacky-943572677 <jacky-943572677@qq.com>

internal/sitecheck/checker.go

@@ -293,24 +293,25 @@ func (sc *SiteChecker) CheckSite(ctx context.Context, siteURL string) (*SiteInfo
 	// Try enhanced health check first if config exists
 	config, err := LoadSiteConfig(siteURL)
 
-	// If health check is disabled, return a SiteInfo without status
+	// If health check is disabled, return cached metadata without issuing any network requests (#1446)
 	if err == nil && config != nil && !config.HealthCheckEnabled {
-		protocol := "http"
-		if config.HealthCheckConfig != nil && config.HealthCheckConfig.Protocol != "" {
-			protocol = config.HealthCheckConfig.Protocol
-		}
-
 		siteInfo := &SiteInfo{
 			SiteConfig: *config,
 			Name:       extractDomainName(siteURL),
 			Title:      config.DisplayURL,
 		}
 
-		// Try to get favicon if enabled and not a gRPC check
-		if sc.options.CheckFavicon && !isGRPCProtocol(protocol) {
-			faviconURL, faviconData := sc.tryGetFavicon(ctx, siteURL)
-			siteInfo.FaviconURL = faviconURL
-			siteInfo.FaviconData = faviconData
+		if existing := sc.getExistingSiteSnapshot(siteURL); existing != nil {
+			siteInfo.FaviconURL = existing.FaviconURL
+			siteInfo.FaviconData = existing.FaviconData
+			siteInfo.Status = existing.Status
+			siteInfo.StatusCode = existing.StatusCode
+			siteInfo.ResponseTime = existing.ResponseTime
+			siteInfo.LastChecked = existing.LastChecked
+			siteInfo.Error = existing.Error
+			if siteInfo.Title == "" {
+				siteInfo.Title = existing.Title
+			}
 		}
 
 		return siteInfo, nil
@@ -522,6 +523,20 @@ func (sc *SiteChecker) GetSitesList() []*SiteInfo {
 	return result
 }
 
+// getExistingSiteSnapshot returns a copy of the last known site info, if present.
+func (sc *SiteChecker) getExistingSiteSnapshot(siteURL string) *SiteInfo {
+	sc.mu.RLock()
+	defer sc.mu.RUnlock()
+
+	existing, ok := sc.sites[siteURL]
+	if !ok || existing == nil {
+		return nil
+	}
+
+	clone := *existing
+	return &clone
+}
+
 // extractDomainName extracts domain name from URL
 func extractDomainName(siteURL string) string {
 	parsed, err := url.Parse(siteURL)

internal/sitecheck/checker_test.go

@@ -0,0 +1,48 @@
+package sitecheck
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/0xJacky/Nginx-UI/model"
+)
+
+type roundTripFunc func(*http.Request) (*http.Response, error)
+
+func (f roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return f(req)
+}
+
+func TestCheckSiteSkipsNetworkWhenDisabled(t *testing.T) {
+	t.Cleanup(InvalidateSiteConfigCache)
+
+	options := DefaultCheckOptions()
+	checker := NewSiteChecker(options)
+
+	// Any HTTP request made by the checker should fail this test.
+	checker.client = &http.Client{
+		Transport: roundTripFunc(func(req *http.Request) (*http.Response, error) {
+			t.Fatalf("unexpected HTTP request to %s while health check is disabled", req.URL.String())
+			return nil, nil
+		}),
+	}
+
+	const siteURL = "https://example.com"
+	config := &model.SiteConfig{
+		Model:              model.Model{ID: 1},
+		Host:               "example.com:443",
+		Scheme:             "https",
+		DisplayURL:         siteURL,
+		HealthCheckEnabled: false,
+		HealthCheckConfig: &model.HealthCheckConfig{
+			Protocol: "https",
+		},
+	}
+
+	setCachedSiteConfig(config.Host, config)
+
+	if _, err := checker.CheckSite(context.Background(), siteURL); err != nil {
+		t.Fatalf("CheckSite returned error: %v", err)
+	}
+}