fix(page): prevent adding duplicate pages

common/src/main/java/net/onelitefeather/cygnus/common/map/GameMapBuilder.java

@@ -96,9 +96,10 @@ public GameMap build() {
      *
      * @param pos  the position to add
      * @param face the face of the page
+     * @return true if the page was added, false if a page at the position and face already exists
      */
-    public void addPage(Vec pos, Direction face) {
-        this.pageFaces.add(new PageResource(pos, face));
+    public boolean addPage(Vec pos, Direction face) {
+        return this.pageFaces.add(new PageResource(pos, face));
     }
 
     /**

common/src/test/java/net/onelitefeather/cygnus/common/map/GameMapTest.java

@@ -82,7 +82,7 @@ void testPageFaceHandling() {
         assertNotNull(mapBuilder);
         assertTrue(mapBuilder.getPageFaces().isEmpty());
 
-        mapBuilder.addPage(Vec.ZERO, Direction.NORTH);
+        assertTrue(mapBuilder.addPage(Vec.ZERO, Direction.NORTH));
 
         assertFalse(mapBuilder.getPageFaces().isEmpty());
 
@@ -92,6 +92,15 @@ void testPageFaceHandling() {
         assertEquals(Direction.NORTH, pageResource.face());
     }
 
+    @Test
+    void testDuplicatePageHandling() {
+        GameMapBuilder mapBuilder = new GameMapBuilder();
+        assertTrue(mapBuilder.addPage(Vec.ZERO, Direction.NORTH));
+        assertFalse(mapBuilder.addPage(Vec.ZERO, Direction.NORTH));
+        assertTrue(mapBuilder.addPage(Vec.ZERO, Direction.EAST));
+        assertEquals(2, mapBuilder.getPageFaces().size());
+    }
+
     @Test
     void testGameMapCopy() {
         Pos slenderPos = new Pos(10, 10, 10);

setup/src/main/java/net/onelitefeather/cygnus/setup/data/GameData.java

@@ -92,11 +92,15 @@ private PageableInventory createPageInventory(Player player) {
      *
      * @param pos  of the resource
      * @param face of the resource
+     * @return true if the page was added, false if a page at the position and face already exists
      */
-    public void addPage(Vec pos, Direction face) {
+    public boolean addPage(Vec pos, Direction face) {
         PageResource pageResource = new PageResource(pos, face);
-        this.gameMapBuilder.addPage(pos, face);
-        this.pageInventory.add(new PageSlot(pageResource));
+        boolean added = this.gameMapBuilder.addPage(pos, face);
+        if (added) {
+            this.pageInventory.add(new PageSlot(pageResource));
+        }
+        return added;
     }
 
     /**

setup/src/main/java/net/onelitefeather/cygnus/setup/listener/PageCreationListener.java

@@ -55,7 +55,10 @@ public void accept(PlayerBlockBreakEvent event) {
         }
 
         Vec position = event.getBlockPosition().asVec();
-        gameData.addPage(position, direction);
+        if (!gameData.addPage(position, direction)) {
+            player.sendMessage(SetupMessages.DUPLICATE_PAGE);
+            return;
+        }
 
         Component component = Component.text("Created page at: ", NamedTextColor.GRAY)
                 .append(Components.convertPoint(position).style(Style.style(NamedTextColor.GOLD)))

setup/src/main/java/net/onelitefeather/cygnus/setup/util/SetupMessages.java

@@ -34,6 +34,7 @@ public final class SetupMessages {
     public static final Component PAGE_MODE_DISABLED;
     public static final Component SURVIVOR_MODE_ENABLED;
     public static final Component SURVIVOR_MODE_DISABLED;
+    public static final Component DUPLICATE_PAGE;
 
     static {
         SPACE_SEPARATOR = Component.text("» ", NamedTextColor.GRAY);
@@ -85,6 +86,9 @@ public final class SetupMessages {
                         .append(Component.space())
                         .append(Component.text("disabled", NamedTextColor.RED))
         );
+        DUPLICATE_PAGE = Messages.withPrefix(
+                Component.text("A page with this direction already exists at this position", NamedTextColor.RED)
+        );
     }
 
     private SetupMessages() {

setup/src/test/java/net/onelitefeather/cygnus/setup/data/GameDataTest.java

@@ -44,8 +44,9 @@ void testAddAndRemovePage(Env env) {
 
         GameData gameData = new GameData(player, mapEntry);
 
-        gameData.addPage(Vec.ZERO, Direction.NORTH);
-        assertNotNull(gameData);
+        assertTrue(gameData.addPage(Vec.ZERO, Direction.NORTH));
+        assertFalse(gameData.addPage(Vec.ZERO, Direction.NORTH));
+        assertTrue(gameData.addPage(Vec.ZERO, Direction.SOUTH));
 
         env.destroyInstance(instance, true);
     }