Documents: Add Bio-KSt. to footer

Elwig/Helpers/Validator.cs

@@ -628,5 +628,55 @@ namespace Elwig.Helpers {
 
             return new(true, null);
         }
+
+        public static ValidationResult CheckOrganicAuthorityCode(TextBox input, bool required) {
+            string text = "";
+            int pos = input.CaretIndex;
+            for (int i = 0, v = 0; i < input.Text.Length; i++) {
+                char ch = char.ToUpper(input.Text[i]);
+                if (v < 2 && char.IsAsciiLetter(ch)) {
+                    v++;
+                    text += ch;
+                } else if ((v == 2 || v == 6) && ch == '-') {
+                    v++;
+                    text += ch;
+                } else if (v >= 2 && char.IsLetterOrDigit(ch)) {
+                    if (text.StartsWith("AT")) {
+                        if (v == 3 && ch == 'B' || v == 4 && ch == 'I' || v == 5 && ch == 'O') {
+                            v++;
+                            text += ch;
+                        } else if (v > 6 && char.IsAsciiDigit(ch)) {
+                            v++;
+                            text += ch;
+                        }
+                    } else {
+                        v++;
+                        text += ch;
+                    }
+                }
+
+                if (i == input.CaretIndex - 1) {
+                    pos = text.Length;
+                } else if (text.StartsWith("AT") && v >= 10) {
+                    break;
+                }
+            }
+
+            input.Text = text;
+            input.CaretIndex = pos;
+
+            if (text.Length == 0)
+                return required ? new(false, "Bio-Kontrollstellen-Code ist nicht optional") : new(true, null);
+
+            if (text.StartsWith("AT")) {
+                if (text.Length != 10) {
+                    return new(false, "Bio-Kontrollstellen-Code ist ungültig");
+                }
+            } else {
+                return new(false, "Not implemented yet");
+            }
+
+            return new(true, null);
+        }
     }
 }