Prevent Overbidding on Auctions

src/main/java/noppes/npcs/client/gui/player/GuiAuctionBidding.java

@@ -126,7 +126,7 @@ public class GuiAuctionBidding extends GuiAuctionInterface implements ISubGuiLis
     private void openBidSubGui() {
         if (listing == null) return;
         long minBid = listing.getMinimumBid(AuctionClientConfig.getMinBidIncrement());
-        setSubGui(new SubGuiAuctionBid(listing.id, minBid, playerBalance));
+        setSubGui(new SubGuiAuctionBid(listing.id, minBid, listing.buyoutPrice, playerBalance));
     }
 
     private void openBuyNowSubGui() {

src/main/java/noppes/npcs/client/gui/player/SubGuiAuctionBid.java

@@ -23,14 +23,16 @@ public class SubGuiAuctionBid extends SubGuiInterface implements ITextfieldListe
 
     private final String listingId;
     private final long minimumBid;
+    private final long buyoutPrice;
     private final long playerBalance;
     private long bidAmount;
     private boolean successful = false;
     private String errorMessage = null;
 
-    public SubGuiAuctionBid(String listingId, long minimumBid, long playerBalance) {
+    public SubGuiAuctionBid(String listingId, long minimumBid, long buyoutPrice, long playerBalance) {
         this.listingId = listingId;
         this.minimumBid = minimumBid;
+        this.buyoutPrice = buyoutPrice;
         this.playerBalance = playerBalance;
         this.bidAmount = minimumBid;
 
@@ -129,6 +131,12 @@ public class SubGuiAuctionBid extends SubGuiInterface implements ITextfieldListe
             return;
         }
 
+        if (buyoutPrice > 0 && bidAmount >= buyoutPrice) {
+            errorMessage = StatCollector.translateToLocal("auction.error.bidExceedsBuyout");
+            updateErrorLabel();
+            return;
+        }
+
         // Send bid packet
         AuctionActionPacket.placeBid(listingId, bidAmount);
         successful = true;

src/main/java/noppes/npcs/controllers/AuctionController.java

@@ -585,6 +585,11 @@ public class AuctionController implements IAuctionHandler {
                 return "Bid must be at least " + minBid + " " + ConfigMarket.CurrencyName + ".";
             }
 
+            // Prevent bidding at or above buyout price
+            if (listing.hasBuyout() && bidAmount >= listing.buyoutPrice) {
+                return "Your bid meets or exceeds the buyout price. Use Buy Now instead.";
+            }
+
             // Check currency
             PlayerData playerData = PlayerData.get(player);
             if (playerData == null) {