Only print buildable items if they can be built in addition to existing

game2_input.txt

@@ -115,6 +115,7 @@ build?
 build axe
 build club
 build fireplace
+build?
 build shack
 build sailingraft
 rollD6 1

game2_output.txt

@@ -56,6 +56,13 @@ shack
 OK
 OK
 OK
+axe
+ballon
+club
+hangglider
+sailingraft
+shack
+steamboat
 OK
 OK
 lose

src/edu/kit/informatik/model/CardGame.java

@@ -124,7 +124,7 @@ public class CardGame {
             throw new InvalidInputException("can not build item");
         } else if (item.requiresFireplace() && !items.contains(FIREPLACE)) {
             throw new InvalidInputException("need fireplace to build");
-        } else if (items.contains(item) && !item.canBeBuiltMultipleTimes()) {
+        } else if (items.contains(item) && !item.canHaveMoreThanOne()) {
             throw new InvalidInputException("already built");
         } else if (canBuild(item)) {
             // remove used resources
@@ -154,6 +154,9 @@ public class CardGame {
         if (item.requiresFireplace() && !items.contains(FIREPLACE)) {
             return false;
         }
+        if (!item.canHaveMoreThanOne() && items.contains(item)) {
+            return false;
+        }
         final Card[] resourcesNeeded = item.resourcesNeeded();
         for (final Card resource : resources) {
             for (int j = 0; j < resourcesNeeded.length; j++) {

src/edu/kit/informatik/model/Item.java

@@ -41,7 +41,7 @@ public enum Item {
         return this.equals(STEAMBOAT) || this.equals(BALLOON);
     }
 
-    public boolean canBeBuiltMultipleTimes() {
+    public boolean canHaveMoreThanOne() {
         return this.equals(AXE) || this.equals(CLUB);
     }