Add InAppPurchasesUtil.

source/funkin/InitState.hx

@@ -93,6 +93,16 @@ class InitState extends FlxState
     // Setup Haptic feedback
     funkin.haptic.Haptic.initialize();
 
+    #if FEATURE_ADMOB_ADS
+    // Setup Admob
+    funkin.mobile.util.AdMobUtil.init();
+    #end
+
+    #if android
+    // Setup In-App purchases
+    funkin.mobile.util.InAppPurchasesUtil.init();
+    #end
+
     // This ain't a pixel art game! (most of the time)
     FlxSprite.defaultAntialiasing = true;
 

source/funkin/mobile/util/AdMobUtil.hx

@@ -81,9 +81,10 @@ class AdMobUtil
 
   /**
    * Initializes the AdMob SDK and sets up event listeners for interstitial and rewarded ads.
+   *
    * The listeners display ads automatically when they are loaded.
    */
-  public static inline function init():Void
+  public static function init():Void
   {
     Admob.onStatus.add(function(event:String, message:String):Void {
       switch (event)

source/funkin/mobile/util/InAppPurchasesUtil.hx

@@ -0,0 +1,85 @@
+package funkin.mobile.util;
+
+#if android
+import iap.IAP;
+
+/**
+ * Utility class for managing in-app purchases in a mobile application.
+ * This class provides functions to initialize the in-app purchase system,
+ * handle purchase events, and manage the purchase flow for different types
+ * of in-app products, including consumables and non-consumables.
+ */
+class InAppPurchasesUtil
+{
+  /**
+   * The public key used for verifying in-app purchases, this key is used to ensure the integrity and authenticity of the purchase data.
+   */
+  static final PUBLIC_KEY:String = "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAvkjukXVNVifxcwvCdntLoVPlMo4H0y232w+7FJCyDLIE39Sif6peAZzRJx5qppCwKhEy0BPp8DNcPCo+KeuYjOroXgPGdwZ6Zr8Cwlrs+xKba2Yt0qr98VhF4PjjJMaDbrLCxtsXEtcpKfItu+Z7m6+4+R5HLP3lvUvK5JynvQ79mct0amKM5WLtnGGDF/cUHaj3prw745SmOpXawTjb43AAIvwWTvEPnFYsoIXodU+4KAm5QIS4FM55HpwXPs8McJFQouo8LaSzYu8SYwRsHBOZpAGgszDIK40gIUmKTe3Ca2Vd77Ib+YP1+EgHJywfuYfC5NAzQRatEX0uDLZ8fwIDAQAB";
+
+  /**
+   * A static final array containing the product IDs for fetching product details.
+   */
+  static final FETCH_PRODUCT_DETAILS_IDS:Array<String> = ['test_product_0'];
+
+  /**
+   * A static variable that holds an array of currently loaded product details for in-app purchases.
+   */
+  public static var currentLoadedProductDetails:Array<iap.android.IAPProductDetails> = [];
+
+  /**
+   * Initializes the in-app purchases utility.
+   */
+  public static function init():Void
+  {
+    IAP.onSetup.add(function(success:Bool):Void {
+      if (success) IAP.queryProductDetails(FETCH_PRODUCT_DETAILS_IDS);
+
+      trace(success ? 'IAP Successfully initialized!' : 'IAP Initialization Failure!');
+    });
+
+    IAP.onDebugLog.add(function(message:String):Void {
+      trace(message);
+    });
+
+    #if android
+    IAP.onQueryProductDetails.add(function(products:Array<iap.android.IAPProductDetails>):Void {
+      if (products != null && products.length > 0)
+      {
+        currentLoadedProductDetails = products;
+
+        for (product in currentLoadedProductDetails)
+        {
+          trace("Product Details found: " + product.title);
+        }
+      }
+      else
+      {
+        trace("No products found.");
+      }
+    });
+    #end
+
+    IAP.init(PUBLIC_KEY);
+  }
+
+  /**
+   * Initiates the purchase process for the specified item.
+   *
+   * @param id The identifier of the item to be purchased.
+   */
+  public static function purchase(id:String):Void
+  {
+    for (product in currentLoadedProductDetails)
+    {
+      if (product.productId == id)
+      {
+        IAP.purchase(product);
+
+        return;
+      }
+    }
+
+    trace("Didn\'t Found Product Details for ID: " + id);
+  }
+}
+#end