Add comments to the class

app/src/main/java/net/pokeranalytics/android/util/billing/AppGuard.kt

@@ -5,12 +5,32 @@ import android.content.Context
 import com.android.billingclient.api.*
 import net.pokeranalytics.android.ui.activity.IAPProducts
 
+/**
+ * the AppGuard object is in charge of contacting the Billing services to retrieve products,
+ * initiating purchases and verifying transactions
+ */
 object AppGuard : PurchasesUpdatedListener {
 
+	/**
+	 * The Billing Client making requests with Google Billing services
+	 */
 	lateinit private var billingClient: BillingClient
 
+	/**
+	 * Whether the billing client is available
+	 */
 	private var billingClientAvailable: Boolean = false
 
+	/**
+	 * Returns whether the user has the pro subscription
+	 */
+	var isProUser: Boolean = false
+		private set
+
+	/**
+	 * Initialization of AppGuard
+	 * Connects to billing services and restores purchases
+	 */
 	fun load(context: Context) {
 
 		billingClient = BillingClient.newBuilder(context).setListener(this).build()
@@ -26,6 +46,7 @@ object AppGuard : PurchasesUpdatedListener {
 
 				}
 			}
+
 			override fun onBillingServiceDisconnected() {
 				billingClientAvailable = false
 
@@ -36,16 +57,22 @@ object AppGuard : PurchasesUpdatedListener {
 
 	}
 
+	/**
+	 * Restore purchases
+	 */
 	fun restorePurchases() {
 		// Automatically checks for purchases (when switching devices for example)
-		val purchasesResult=
+		val purchasesResult =
 			billingClient.queryPurchases(BillingClient.SkuType.SUBS)
 		purchasesResult.purchasesList.forEach {
 			this.handlePurchase(it)
 		}
 	}
 
-	fun requestProducts(listener: SkuDetailsResponseListener) : Boolean {
+	/**
+	 * Requests the product descriptions
+	 */
+	fun requestProducts(listener: SkuDetailsResponseListener): Boolean {
 
 		if (this.billingClientAvailable) {
 
@@ -60,6 +87,9 @@ object AppGuard : PurchasesUpdatedListener {
 		return false
 	}
 
+	/**
+	 * Initiates purchase with the product [skuDetails]
+	 */
 	fun initiatePurchase(activity: Activity, skuDetails: SkuDetails) {
 
 		val flowParams = BillingFlowParams.newBuilder()
@@ -71,6 +101,9 @@ object AppGuard : PurchasesUpdatedListener {
 
 	// PurchasesUpdatedListener
 
+	/**
+	 * Purchase callback
+	 */
 	override fun onPurchasesUpdated(responseCode: Int, purchases: MutableList<Purchase>?) {
 
 		if (responseCode == BillingClient.BillingResponse.OK && purchases != null) {
@@ -85,6 +118,9 @@ object AppGuard : PurchasesUpdatedListener {
 
 	}
 
+	/**
+	 * Method called when a purchase has been made
+	 */
 	private fun handlePurchase(purchase: Purchase) {
 
 		val token = purchase.purchaseToken
@@ -93,9 +129,10 @@ object AppGuard : PurchasesUpdatedListener {
 		if (this.verifyPurchase(purchase)) {
 			when (purchase.sku) {
 				IAPProducts.PRO.identifier -> {
-
+					this.isProUser = true
+				}
+				else -> {
 				}
-				else -> {}
 			}
 		} else {
 			// invalid purchase
@@ -103,7 +140,10 @@ object AppGuard : PurchasesUpdatedListener {
 
 	}
 
-	private fun verifyPurchase(purchase: Purchase) : Boolean {
+	/**
+	 * Verifies the validity of a purchase
+	 */
+	private fun verifyPurchase(purchase: Purchase): Boolean {
 		return true
 	}