Make document footer more dynamic

Elwig/Helpers/Utils.cs

@@ -195,5 +195,44 @@ namespace Elwig.Helpers {
             var d = new ManualWeighingDialog();
             return d.ShowDialog() == true ? (d.Weight, d.Reason) : null;
         }
+
+        public static Footer GenerateFooter(string lineBreak, string seperator) {
+            return new Footer(lineBreak, seperator);
+        }
+
+        public class Footer {
+            private string Text = "";
+            private readonly string LineBreak;
+            private readonly string Seperator;
+            private bool FirstLine = true;
+            private bool FirstItemInLine = true;
+
+            public Footer(string lineBreak, string seperator) {
+                LineBreak = lineBreak;
+                Seperator = seperator;
+            }
+
+            public Footer Item(string? text) {
+                if (text == null) return this;
+                Text += FirstItemInLine ? (FirstLine ? "" : LineBreak) : Seperator;
+                Text += text;
+                FirstLine = false;
+                FirstItemInLine = false;
+                return this;
+            }
+
+            public Footer Item(string name, string? text) {
+                return text == null ? this : Item($"{name}: {text}");
+            }
+
+            public Footer NextLine() {
+                FirstItemInLine = true;
+                return this;
+            }
+
+            public override string ToString() {
+                return Text;
+            }
+        }
     }
 }