[android] Implement handling of billing connection state and executing asyn request in the play store manager

android/src/com/mapswithme/maps/purchase/BillingConnection.java

@@ -0,0 +1,28 @@
+package com.mapswithme.maps.purchase;
+
+import android.support.annotation.NonNull;
+
+/**
+ * Represents a billing connection abstraction.
+ */
+public interface BillingConnection
+{
+  /**
+   * Connects to the billing manager.
+   */
+  void connect();
+
+  /**
+   * @return the connection state of the billing manager.
+   */
+  @NonNull
+  State getState();
+
+  enum State
+  {
+    DISCONNECTED,
+    CONNECTING,
+    CONNECTED,
+    CLOSED
+  }
+}

android/src/com/mapswithme/maps/purchase/BillingManager.java

@@ -4,20 +4,43 @@ import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
 /**
- * Manages a billing flow.
+ * Manages a billing flow for the specific product.
  */
-interface BillingManager
+public interface BillingManager<T>
 {
   /**
-   * Launches the billing flow. Controls whole native part of billing.
-   * @param productId id of product which is going to be bought by user.
+   * Initializes the current billing manager.
    */
-  void launchBillingFlow(@NonNull String productId);
+  void initialize();
+
+  /**
+   * Destroys the billing manager.
+   */
+  void destroy();
+
+  /**
+   * Launches the billing flow. Controls whole native part of billing.
+   */
+  void launchBillingFlow();
 
   /**
    * Obtains a purchase token if it exists.
-   * @param productId id of product which token is needed for.
    */
   @Nullable
-  String obtainTokenForProduct(@NonNull String productId);
+  String obtainPurchaseToken();
+
+  /**
+   * Queries product details. They will be delivered to the caller through callback {@link T}.
+   */
+  void queryProductDetails();
+
+  /**
+   * Adds a billing callback.
+   */
+  void addCallback(@NonNull T callback);
+
+  /**
+   * Removes the billing callback.
+   */
+  void removeCallback(@NonNull T callback);
 }

android/src/com/mapswithme/maps/purchase/Factory.java

@@ -3,6 +3,8 @@ package com.mapswithme.maps.purchase;
 import android.app.Activity;
 import android.support.annotation.NonNull;
 
+import com.android.billingclient.api.BillingClient;
+
 public enum Factory
 {
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@@ -16,9 +18,9 @@ public enum Factory
 
         @NonNull
         @Override
-        BillingManager createBillingManager(@NonNull Activity activity)
+        public BillingManager createBillingManager(@NonNull Activity activity, @NonNull String productId)
         {
-          return new PlayStoreBillingManager(activity);
+          return new PlayStoreBillingManager(activity, productId, BillingClient.SkuType.SUBS);
         }
       };
 
@@ -26,5 +28,5 @@ public enum Factory
   public abstract PurchaseValidator createPurchaseManager();
 
   @NonNull
-  abstract BillingManager createBillingManager(@NonNull Activity activity);
+  public abstract BillingManager createBillingManager(@NonNull Activity activity, @NonNull String productId);
 }

android/src/com/mapswithme/maps/purchase/PlayStoreBillingCallback.java

@@ -0,0 +1,10 @@
+package com.mapswithme.maps.purchase;
+
+import android.support.annotation.NonNull;
+
+import java.util.List;
+
+public interface PlayStoreBillingCallback
+{
+  void onPurchaseDetailsLoaded(@NonNull List<PurchaseDetails> details);
+}

android/src/com/mapswithme/maps/purchase/PlayStoreBillingConnection.java

@@ -0,0 +1,69 @@
+package com.mapswithme.maps.purchase;
+
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import com.android.billingclient.api.BillingClient;
+import com.android.billingclient.api.BillingClientStateListener;
+import com.mapswithme.util.log.Logger;
+import com.mapswithme.util.log.LoggerFactory;
+
+class PlayStoreBillingConnection implements BillingConnection,
+                                            BillingClientStateListener
+{
+  private static final Logger LOGGER = LoggerFactory.INSTANCE.getLogger(LoggerFactory.Type.MISC);
+  private static final String TAG = PlayStoreBillingConnection.class.getSimpleName();
+  @NonNull
+  private final BillingClient mBillingClient;
+  @NonNull
+  private State mState = State.DISCONNECTED;
+  @Nullable
+  private final ConnectionListener mListener;
+
+  PlayStoreBillingConnection(@NonNull BillingClient billingClient,
+                             @Nullable ConnectionListener listener)
+  {
+    mBillingClient = billingClient;
+    mListener = listener;
+  }
+
+  @Override
+  public void connect()
+  {
+    mState = State.CONNECTING;
+    mBillingClient.startConnection(this);
+  }
+
+  @NonNull
+  @Override
+  public State getState()
+  {
+    return mState;
+  }
+
+  @Override
+  public void onBillingSetupFinished(int responseCode)
+  {
+    LOGGER.i(TAG, "Setup finished. Response code: " + responseCode);
+    if (responseCode == BillingClient.BillingResponse.OK)
+    {
+      mState = State.CONNECTED;
+      if (mListener != null)
+        mListener.onConnected();
+      return;
+    }
+
+    mState = State.DISCONNECTED;
+  }
+
+  @Override
+  public void onBillingServiceDisconnected()
+  {
+    mState = State.DISCONNECTED;
+  }
+
+  interface ConnectionListener
+  {
+    void onConnected();
+  }
+}

android/src/com/mapswithme/maps/purchase/PlayStoreBillingManager.java

@@ -8,31 +8,91 @@ import com.android.billingclient.api.BillingClient;
 import com.android.billingclient.api.BillingClient.BillingResponse;
 import com.android.billingclient.api.Purchase;
 import com.android.billingclient.api.PurchasesUpdatedListener;
+import com.android.billingclient.api.SkuDetails;
+import com.android.billingclient.api.SkuDetailsParams;
 import com.mapswithme.util.log.Logger;
 import com.mapswithme.util.log.LoggerFactory;
 
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
-public class PlayStoreBillingManager implements BillingManager, PurchasesUpdatedListener
+public class PlayStoreBillingManager implements BillingManager<PlayStoreBillingCallback>,
+                                                PurchasesUpdatedListener,
+                                                PlayStoreBillingConnection.ConnectionListener
 {
   private final static Logger LOGGER = LoggerFactory.INSTANCE.getLogger(LoggerFactory.Type.MISC);
   private final static String TAG = PlayStoreBillingManager.class.getSimpleName();
   @NonNull
   private final Activity mActivity;
+  @Nullable
+  private BillingClient mBillingClient;
+  @Nullable
+  private PlayStoreBillingCallback mCallback;
   @NonNull
-  private final BillingClient mBillingClient;
-
-  PlayStoreBillingManager(@NonNull Activity activity)
+  private final String mProductId;
+  @NonNull
+  @BillingClient.SkuType
+  private final String mProductType;
+  @SuppressWarnings({ "NullableProblems" })
+  @NonNull
+  private BillingConnection mConnection;
+  @NonNull
+  private final List<Runnable> mPendingRequests = new ArrayList<>();
+  
+  PlayStoreBillingManager(@NonNull Activity activity, @NonNull String productId,
+                          @NonNull @BillingClient.SkuType String productType)
   {
     mActivity = activity;
-    mBillingClient = BillingClient.newBuilder(mActivity).setListener(this).build();
+    mProductId = productId;
+    mProductType = productType;
   }
 
   @Override
-  public void launchBillingFlow(@NonNull String productId)
+  public void initialize()
+  {
+    LOGGER.i(TAG, "Creating play store billing client...");
+    mBillingClient = BillingClient.newBuilder(mActivity).setListener(this).build();
+    mConnection = new PlayStoreBillingConnection(mBillingClient, this);
+    mConnection.connect();
+  }
+
+  @Override
+  public void destroy()
+  {
+    // Coming soon.
+  }
+
+  @Override
+  public void queryProductDetails()
+  {
+    executeServiceRequest(new QueryProductDetailsRequest());
+  }
+
+  private void executeServiceRequest(@NonNull Runnable task)
+  {
+    switch (mConnection.getState())
+    {
+      case CONNECTING:
+        mPendingRequests.add(task);
+        break;
+      case CONNECTED:
+        task.run();
+        break;
+      case DISCONNECTED:
+        mConnection.connect();
+        break;
+      case CLOSED:
+        throw new IllegalStateException("Billing service connection already closed, " +
+                                        "please initialize it again.");
+    }
+  }
+
+  @Override
+  public void launchBillingFlow()
   {
     @BillingResponse
-    int result = mBillingClient.isFeatureSupported(BillingClient.FeatureType.SUBSCRIPTIONS);
+    int result = getClientOrThrow().isFeatureSupported(BillingClient.FeatureType.SUBSCRIPTIONS);
     if (result == BillingResponse.FEATURE_NOT_SUPPORTED)
     {
       LOGGER.w(TAG, "Subscription is not supported by this device!");
@@ -44,14 +104,63 @@ public class PlayStoreBillingManager implements BillingManager, PurchasesUpdated
 
   @Nullable
   @Override
-  public String obtainTokenForProduct(@NonNull String productId)
+  public String obtainPurchaseToken()
   {
     return null;
   }
 
+  @Override
+  public void addCallback(@NonNull PlayStoreBillingCallback callback)
+  {
+    mCallback = callback;
+  }
+
+  @Override
+  public void removeCallback(@NonNull PlayStoreBillingCallback callback)
+  {
+    mCallback = null;
+  }
+
   @Override
   public void onPurchasesUpdated(int responseCode, @Nullable List<Purchase> purchases)
   {
     // Coming soon.
   }
+
+  @NonNull
+  private BillingClient getClientOrThrow()
+  {
+    if (mBillingClient == null)
+      throw new IllegalStateException("Manager must be initialized! Call 'initialize' method first.");
+
+    return mBillingClient;
+  }
+
+  @Override
+  public void onConnected()
+  {
+    for(@NonNull Runnable request: mPendingRequests)
+      request.run();
+
+    mPendingRequests.clear();
+  }
+
+  private class QueryProductDetailsRequest implements Runnable
+  {
+    @Override
+    public void run()
+    {
+      SkuDetailsParams.Builder builder = SkuDetailsParams.newBuilder();
+      builder.setSkusList(Collections.singletonList(mProductId))
+             .setType(mProductType);
+      getClientOrThrow().querySkuDetailsAsync(builder.build(), this::onSkuDetailsResponseInternal);
+    }
+
+    private void onSkuDetailsResponseInternal(@BillingResponse int responseCode,
+                                              @Nullable List<SkuDetails> skuDetails)
+    {
+      LOGGER.i(TAG, "Product details response, code: " + responseCode + ", " +
+                    "details: " + skuDetails);
+    }
+  }
 }

android/src/com/mapswithme/maps/purchase/PurchaseDetails.java

@@ -0,0 +1,5 @@
+package com.mapswithme.maps.purchase;
+
+public class PurchaseDetails
+{
+}