refactor(images): Move sponsor images to folder and load them dynamicly

services/templater.go

@@ -82,12 +82,11 @@ func (t *DefaultTemplater) GenerateBarcode(code string, format string, prefix st
 }
 
 func (t *DefaultTemplater) SelectSponsorImage(id int) (string, error) {
-	sponsors := []string{
-		"vrbank",
-		"odit",
-		"sparkasse",
+	sponsors, err := ListFilesInStaticSubFolder("images/sponsors")
+	if err != nil {
+		return "", err
 	}
-	return GetImage(sponsors[id%len(sponsors)]), nil
+	return GetImage("sponsors/" + strings.TrimSuffix(sponsors[id%len(sponsors)], ".base64")), nil
 }
 
 func (t *DefaultTemplater) LoadImage(name string) (string, error) {

services/templates.go

@@ -16,6 +16,22 @@ func GetTemplate(locale, templateName string) (string, error) {
 	return string(content), nil
 }
 
+func ListFilesInStaticSubFolder(folderName string) ([]string, error) {
+	files, err := os.ReadDir(fmt.Sprintf("static/%s", folderName))
+	if err != nil {
+		log.Printf("error reading files from folder %s: %v", folderName, err)
+		return nil, err
+	}
+	var images []string
+	for _, file := range files {
+		if file.IsDir() {
+			continue
+		}
+		images = append(images, file.Name())
+	}
+	return images, nil
+}
+
 func GetImage(imageName string) string {
 	content, err := os.ReadFile("static/images/" + imageName + ".base64")
 	if content == nil || err != nil {