Merge pull request #302 from samtstern/version-1.0.0-dev

SmartLock Deletion

Author: samtstern

app/src/main/java/com/firebase/uidemo/auth/SignedInActivity.java

@@ -114,9 +114,8 @@ public void onClick(DialogInterface dialogInterface, int i) {
     }
 
     private void deleteAccount() {
-        FirebaseAuth.getInstance()
-                .getCurrentUser()
-                .delete()
+        AuthUI.getInstance()
+                .delete(this)
                 .addOnCompleteListener(new OnCompleteListener<Void>() {
                     @Override
                     public void onComplete(@NonNull Task<Void> task) {

auth/README.md

@@ -262,6 +262,32 @@ public void onClick(View v) {
 }
 ```
 
+### Deleting accounts
+
+With the integrations provided by FirebaseUI Auth, deleting a user is a multi-stage process:
+
+1. The user must be deleted from Firebase Auth.
+2. SmartLock for Passwords must be told to delete any existing Credentials for the user, so
+   that they are not automatically prompted to sign in with a saved credential in the future.
+   
+This process is encapsulated by the `AuthUI.delete()` method, which returns a `Task` representing
+the entire operation:
+
+```java
+AuthUI.getInstance()
+        .delete(this)
+        .addOnCompleteListener(new OnCompleteListener<Void>() {
+            @Override
+            public void onComplete(@NonNull Task<Void> task) {
+                if (task.isSuccessful()) {
+                    // Deletion succeeded
+                } else {
+                    // Deletion failed
+                }
+            }
+        });
+```
+
 ### Authentication flow chart
 
 The authentication flow implemented on Android is more complex than on other

auth/src/main/java/com/firebase/ui/auth/AuthUI.java

@@ -33,7 +33,9 @@
 import com.firebase.ui.auth.util.GoogleApiClientTaskHelper;
 import com.firebase.ui.auth.util.Preconditions;
 import com.firebase.ui.auth.util.ProviderHelper;
+import com.firebase.ui.auth.util.SmartlockUtil;
 import com.google.android.gms.auth.api.Auth;
+import com.google.android.gms.auth.api.credentials.Credential;
 import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
 import com.google.android.gms.common.api.GoogleApiClient;
 import com.google.android.gms.common.api.Status;
@@ -42,7 +44,9 @@
 import com.google.android.gms.tasks.Tasks;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.auth.FirebaseAuth;
+import com.google.firebase.auth.FirebaseUser;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
@@ -307,6 +311,56 @@ public Void then(@NonNull Task<GoogleApiClient> task) throws Exception {
         return Tasks.whenAll(disableCredentialsTask, googleSignOutTask);
     }
 
+    /**
+     * Delete the use from FirebaseAuth and delete any associated credentials from the Credentials
+     * API. Returns a {@code Task} that succeeds if the Firebase Auth user deletion succeeds and
+     * fails if the Firebase Auth deletion fails. Credentials deletion failures are handled
+     * silently.
+     * @param activity the calling {@link Activity}.
+     */
+    public Task<Void> delete(@NonNull Activity activity) {
+        FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
+        if (firebaseUser == null) {
+            // If the current user is null, return a failed task immediately
+            return Tasks.forException(new Exception("No currently signed in user."));
+        }
+
+        // Delete the Firebase user
+        Task<Void> deleteUserTask = firebaseUser.delete();
+
+        // Initialize SmartLock helper
+        GoogleApiClientTaskHelper gacHelper = GoogleApiClientTaskHelper.getInstance(activity);
+        gacHelper.getBuilder().addApi(Auth.CREDENTIALS_API);
+        CredentialsApiHelper credentialHelper = CredentialsApiHelper.getInstance(gacHelper);
+
+        // Get all SmartLock credentials associated with the user
+        List<Credential> credentials = SmartlockUtil.credentialsFromFirebaseUser(firebaseUser);
+
+        // For each Credential in the list, create a task to delete it.
+        List<Task<?>> credentialTasks = new ArrayList<>();
+        for (Credential credential : credentials) {
+            credentialTasks.add(credentialHelper.delete(credential));
+        }
+
+        // Create a combined task that will succeed when all credential delete operations
+        // have completed (even if they fail).
+        final Task<Void> combinedCredentialTask = Tasks.whenAll(credentialTasks);
+
+        // Chain the Firebase Auth delete task with the combined Credentials task
+        // and return.
+        return deleteUserTask.continueWithTask(new Continuation<Void, Task<Void>>() {
+            @Override
+            public Task<Void> then(@NonNull Task<Void> task) throws Exception {
+                // Call getResult() to propagate failure by throwing an exception
+                // if there was one.
+                task.getResult(Exception.class);
+
+                // Return the combined credential task
+                return combinedCredentialTask;
+            }
+        });
+    }
+
     /**
      * Starts the process of creating a sign in intent, with the mandatory application
      * context parameter.

auth/src/main/java/com/firebase/ui/auth/ui/account_link/SaveCredentialsActivity.java

@@ -42,6 +42,7 @@
 import com.google.firebase.auth.FacebookAuthProvider;
 import com.google.firebase.auth.FirebaseUser;
 import com.google.firebase.auth.GoogleAuthProvider;
+import com.google.firebase.auth.TwitterAuthProvider;
 
 public class SaveCredentialsActivity extends AppCompatBase
         implements GoogleApiClient.ConnectionCallbacks, ResultCallback<Status>,
@@ -117,7 +118,10 @@ public void onConnected(@Nullable Bundle bundle) {
                     translatedProvider = IdentityProviders.GOOGLE;
                 } else if (mProvider.equals(FacebookAuthProvider.PROVIDER_ID)) {
                     translatedProvider = IdentityProviders.FACEBOOK;
+                } else if (mProvider.equals(TwitterAuthProvider.PROVIDER_ID)) {
+                    translatedProvider = IdentityProviders.TWITTER;
                 }
+
                 if (translatedProvider != null) {
                     builder.setAccountType(translatedProvider);
                 }

auth/src/main/java/com/firebase/ui/auth/util/SmartlockUtil.java

@@ -2,17 +2,33 @@
 
 import android.app.Activity;
 import android.content.Intent;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.text.TextUtils;
+import android.util.Log;
 
 import com.firebase.ui.auth.ui.FlowParameters;
 import com.firebase.ui.auth.ui.account_link.SaveCredentialsActivity;
+import com.google.android.gms.auth.api.credentials.Credential;
+import com.google.android.gms.auth.api.credentials.IdentityProviders;
+import com.google.firebase.auth.EmailAuthProvider;
+import com.google.firebase.auth.FacebookAuthProvider;
 import com.google.firebase.auth.FirebaseUser;
+import com.google.firebase.auth.GoogleAuthProvider;
+import com.google.firebase.auth.TwitterAuthProvider;
+import com.google.firebase.auth.UserInfo;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
 
 /**
  * Helper class to deal with Smartlock Flows.
  */
 public class SmartlockUtil {
 
+    private static final String TAG = "SmartLockUtil";
+
     /**
      * If SmartLock is enabled and Google Play Services is available, start the save credential
      * Activity. Otherwise, finish the calling Activity with RESULT_OK.
@@ -48,6 +64,60 @@ public static void saveCredentialOrFinish(Activity activity,
         activity.startActivityForResult(saveCredentialIntent, requestCode);
     }
 
+    /**
+     * Translate a Firebase Auth provider ID (such as {@link GoogleAuthProvider#PROVIDER_ID}) to
+     * a Credentials API account type (such as {@link IdentityProviders#GOOGLE}).
+     */
+    public static String providerIdToAccountType(@NonNull String providerId) {
+        switch (providerId) {
+            case GoogleAuthProvider.PROVIDER_ID:
+                return IdentityProviders.GOOGLE;
+            case FacebookAuthProvider.PROVIDER_ID:
+                return IdentityProviders.FACEBOOK;
+            case TwitterAuthProvider.PROVIDER_ID:
+                return IdentityProviders.TWITTER;
+            case EmailAuthProvider.PROVIDER_ID:
+                // The account type for email/password creds is null
+                return null;
+        }
+
+        return null;
+    }
+
+    /**
+     * Make a list of {@link Credential} from a FirebaseUser. Useful for deleting Credentials,
+     * not for saving since we don't have access to the password.
+     */
+    public static List<Credential> credentialsFromFirebaseUser(@NonNull FirebaseUser user) {
+        if (TextUtils.isEmpty(user.getEmail())) {
+            Log.w(TAG, "Can't get credentials from user with no email: " + user);
+            return Collections.emptyList();
+        }
+
+        List<Credential> credentials = new ArrayList<>();
+        for (UserInfo userInfo : user.getProviderData()) {
+            // Get provider ID from Firebase Auth
+            String providerId = userInfo.getProviderId();
+
+            // Convert to Credentials API account type
+            String accountType = providerIdToAccountType(providerId);
+
+            // Build and add credential
+            Credential.Builder builder = new Credential.Builder(user.getEmail())
+                    .setAccountType(accountType);
+
+            // Null account type means password, we need to add a random password
+            // to make deletion succeed.
+            if (accountType == null) {
+                builder.setPassword("some_password");
+            }
+
+            credentials.add(builder.build());
+        }
+
+        return credentials;
+    }
+
     private static void finishActivity(Activity activity) {
         activity.setResult(Activity.RESULT_OK, new Intent());
         activity.finish();

common/constants.gradle

@@ -3,7 +3,7 @@ project.ext.support_library_version = '23.4.0'
 
 project.ext.submodules = ['database', 'auth']
 project.ext.group = "com.firebaseui"
-project.ext.version = '0.5.1'
+project.ext.version = '1.0.0-SNAPSHOT'
 project.ext.pomdesc = 'Firebase UI Android'
 project.ext.buildtools = '23.0.3'
 project.ext.compileSdk = 23