Setup Firebase Functions for Token Issuer

This CL enables the app to request debugging access tokens from the
remote web service using Firebase Functions. Only signed-in users can
request tokens.

Bug: 173732645
Test: Place google-services.json in app/
Test: Get credentials from valentine/#/show/1611079519238994
Test: Set envvars DRC_TEST_EMAIL and DRC_TEST_PASSWORD
Test: ./gradlew connectedAndroidTest
Test: ./gradlew createDebugCoverageReport

Change-Id: I162f95ac2a74b01995f92e63a11247a27217dddc

8 files changed, 173 insertions, 59 deletions

diff --git a/app/build.gradle b/app/build.gradle
index df2c4b7..f5c4ee1 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -52,5 +52,6 @@ dependencies {
     testImplementation 'junit:junit:4.+'
     androidTestImplementation 'androidx.test.ext:junit:1.1.2'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.3.0'
+    androidTestImplementation 'androidx.test.espresso:espresso-contrib:3.3.0'
     androidTestImplementation 'androidx.test.espresso:espresso-intents:3.3.0'
 }
diff --git a/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/UiTest.java b/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/LoginTest.java
index 2be1c7c..b90bc67 100644
--- a/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/UiTest.java
+++ b/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/LoginTest.java
@@ -37,7 +37,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 
 @RunWith(AndroidJUnit4.class)
-public class UiTest {
+public class LoginTest {
 
   private static final String TEST_EMAIL = BuildConfig.DRC_TEST_EMAIL;
   private static final String TEST_PASSWORD = BuildConfig.DRC_TEST_PASSWORD;
@@ -45,6 +45,7 @@ public class UiTest {
   private static final String SHORT_PASSWORD = "word";
   private static final String WRONG_PASSWORD = "wrong_password";
   private final FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
+
   @Rule
   public ActivityScenarioRule<LoginActivity> activityScenarioRule =
       new ActivityScenarioRule<LoginActivity>(LoginActivity.class);
diff --git a/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/TokenTest.java b/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/TokenTest.java
new file mode 100644
index 0000000..604c347
--- /dev/null
+++ b/app/src/androidTest/java/com/android/car/debuggingrestrictioncontroller/TokenTest.java
@@ -0,0 +1,87 @@
+package com.android.car.debuggingrestrictioncontroller;
+
+import static androidx.test.espresso.Espresso.onView;
+import static androidx.test.espresso.action.ViewActions.click;
+import static androidx.test.espresso.assertion.ViewAssertions.matches;
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.matcher.ViewMatchers.isEnabled;
+import static androidx.test.espresso.matcher.ViewMatchers.withId;
+import static org.junit.Assert.assertThat;
+
+import android.app.Activity;
+import androidx.test.espresso.IdlingRegistry;
+import androidx.test.espresso.contrib.ActivityResultMatchers;
+import androidx.test.espresso.idling.CountingIdlingResource;
+import androidx.test.ext.junit.rules.ActivityScenarioRule;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.android.car.debuggingrestrictioncontroller.ui.token.TokenActivity;
+import com.google.android.gms.tasks.Tasks;
+import com.google.firebase.auth.FirebaseAuth;
+import java.util.concurrent.ExecutionException;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class TokenTest {
+
+  private static final String TEST_EMAIL = BuildConfig.DRC_TEST_EMAIL;
+  private static final String TEST_PASSWORD = BuildConfig.DRC_TEST_PASSWORD;
+  private final FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
+  @Rule
+  public ActivityScenarioRule<TokenActivity> activityScenarioRule =
+      new ActivityScenarioRule<TokenActivity>(TokenActivity.class);
+  private CountingIdlingResource idlingResource;
+
+  public TokenTest() throws ExecutionException, InterruptedException {
+    Tasks.await(firebaseAuth.signInWithEmailAndPassword(TEST_EMAIL, TEST_PASSWORD));
+  }
+
+  @Before
+  public void setUp() {
+    activityScenarioRule.getScenario().onActivity(activity -> {
+      idlingResource = activity.getIdlingResource();
+    });
+    IdlingRegistry.getInstance().register(idlingResource);
+  }
+
+  @After
+  public void tearDown() {
+    IdlingRegistry.getInstance().unregister(idlingResource);
+    firebaseAuth.signOut();
+  }
+
+  @Test
+  public void initialButtonStates() {
+    onView(withId(R.id.agreement)).check(matches(isDisplayed()));
+    onView(withId(R.id.agree)).check(matches(isDisplayed()));
+    onView(withId(R.id.agree)).check(matches(isEnabled()));
+    onView(withId(R.id.disagree)).check(matches(isDisplayed()));
+  }
+
+  @Test
+  public void agree() {
+    onView(withId(R.id.agree)).check(matches(isEnabled()));
+    onView(withId(R.id.agree)).perform(click());
+    assertThat(activityScenarioRule.getScenario().getResult(),
+        ActivityResultMatchers.hasResultCode(Activity.RESULT_OK));
+  }
+
+  @Test
+  public void disagree() {
+    onView(withId(R.id.disagree)).check(matches(isEnabled()));
+    onView(withId(R.id.disagree)).perform(click());
+    assertThat(activityScenarioRule.getScenario().getResult(),
+        ActivityResultMatchers.hasResultCode(Activity.RESULT_CANCELED));
+  }
+
+  @Test
+  public void userNotSignedIn() {
+    firebaseAuth.signOut();
+    onView(withId(R.id.agree)).perform(click());
+    assertThat(activityScenarioRule.getScenario().getResult(),
+        ActivityResultMatchers.hasResultCode(Activity.RESULT_CANCELED));
+  }
+}
diff --git a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/ViewModelFactory.java b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/ViewModelFactory.java
deleted file mode 100644
index 0c3379a..0000000
--- a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/ViewModelFactory.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package com.android.car.debuggingrestrictioncontroller.ui;
-
-import androidx.annotation.NonNull;
-import androidx.lifecycle.ViewModel;
-import androidx.lifecycle.ViewModelProvider;
-import com.android.car.debuggingrestrictioncontroller.ui.login.LoginViewModel;
-import com.android.car.debuggingrestrictioncontroller.ui.token.TokenViewModel;
-
-/**
- * ViewModel provider factory to instantiate LoginViewModel. Required given LoginViewModel has a
- * non-empty constructor
- */
-public class ViewModelFactory implements ViewModelProvider.Factory {
-
-  @NonNull
-  @Override
-  @SuppressWarnings("unchecked")
-  public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
-    if (modelClass.isAssignableFrom(LoginViewModel.class)) {
-      return (T) new LoginViewModel();
-    } else if (modelClass.isAssignableFrom(TokenViewModel.class)) {
-      return (T) new TokenViewModel();
-    } else {
-      throw new IllegalArgumentException("Unknown ViewModel class");
-    }
-  }
-}
diff --git a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/login/LoginActivity.java b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/login/LoginActivity.java
index e498ce6..1dff976 100644
--- a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/login/LoginActivity.java
+++ b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/login/LoginActivity.java
@@ -12,15 +12,14 @@ import android.widget.Button;
 import android.widget.EditText;
 import android.widget.ProgressBar;
 import android.widget.TextView;
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.StringRes;
 import androidx.annotation.VisibleForTesting;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.lifecycle.Observer;
-import androidx.lifecycle.ViewModelProvider;
 import androidx.test.espresso.idling.CountingIdlingResource;
 import com.android.car.debuggingrestrictioncontroller.R;
-import com.android.car.debuggingrestrictioncontroller.ui.ViewModelFactory;
 import com.android.car.debuggingrestrictioncontroller.ui.token.TokenActivity;
 import com.google.android.material.snackbar.Snackbar;
 import com.google.firebase.auth.FirebaseAuth;
@@ -33,7 +32,7 @@ public class LoginActivity extends AppCompatActivity {
   private final FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
   @VisibleForTesting
   private final CountingIdlingResource idlingResource = new CountingIdlingResource(TAG);
-  private LoginViewModel loginViewModel;
+  private final LoginViewModel loginViewModel = new LoginViewModel();
   private Button loginButton;
   private Button nextButton;
 
@@ -46,8 +45,6 @@ public class LoginActivity extends AppCompatActivity {
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_login);
-    loginViewModel = new ViewModelProvider(this, new ViewModelFactory())
-        .get(LoginViewModel.class);
 
     final EditText usernameEditText = findViewById(R.id.username);
     final EditText passwordEditText = findViewById(R.id.password);
@@ -55,14 +52,9 @@ public class LoginActivity extends AppCompatActivity {
     nextButton = findViewById(R.id.next);
     final ProgressBar loadingProgressBar = findViewById(R.id.loading);
 
-    updateButtonState();
-
     loginViewModel.getLoginFormState().observe(this, new Observer<LoginFormState>() {
       @Override
-      public void onChanged(@Nullable LoginFormState loginFormState) {
-        if (loginFormState == null) {
-          return;
-        }
+      public void onChanged(@NonNull LoginFormState loginFormState) {
         loginButton.setEnabled(loginFormState.isDataValid());
         if (loginFormState.getUsernameError() != null) {
           usernameEditText.setError(getString(loginFormState.getUsernameError()));
@@ -75,10 +67,7 @@ public class LoginActivity extends AppCompatActivity {
 
     loginViewModel.getLoginResult().observe(this, new Observer<LoginResult>() {
       @Override
-      public void onChanged(@Nullable LoginResult loginResult) {
-        if (loginResult == null) {
-          return;
-        }
+      public void onChanged(@NonNull LoginResult loginResult) {
         loadingProgressBar.setVisibility(View.GONE);
         if (loginResult.getError() != null) {
           showSnackBar(R.string.not_signed_in);
@@ -91,7 +80,9 @@ public class LoginActivity extends AppCompatActivity {
           loginButton.setText(R.string.button_sign_out);
           nextButton.setEnabled(true);
         }
-        idlingResource.decrement();
+        if (!idlingResource.isIdleNow()) {
+          idlingResource.decrement();
+        }
       }
     });
 
@@ -115,10 +106,10 @@ public class LoginActivity extends AppCompatActivity {
     usernameEditText.addTextChangedListener(afterTextChangedListener);
     passwordEditText.addTextChangedListener(afterTextChangedListener);
     passwordEditText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
-
       @Override
       public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
         if (actionId == EditorInfo.IME_ACTION_DONE) {
+          idlingResource.increment();
           loginViewModel.login(usernameEditText.getText().toString(),
               passwordEditText.getText().toString());
         }
diff --git a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenActivity.java b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenActivity.java
index 28e402d..37283ad 100644
--- a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenActivity.java
+++ b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenActivity.java
@@ -4,34 +4,47 @@ import android.app.Activity;
 import android.os.Bundle;
 import android.text.Html;
 import android.text.Spanned;
+import android.util.Log;
 import android.view.View;
 import android.widget.Button;
 import android.widget.ProgressBar;
 import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.lifecycle.Observer;
-import androidx.lifecycle.ViewModelProvider;
+import androidx.test.espresso.idling.CountingIdlingResource;
 import com.android.car.debuggingrestrictioncontroller.R;
-import com.android.car.debuggingrestrictioncontroller.ui.ViewModelFactory;
+import com.google.firebase.auth.FirebaseAuth;
 import java.util.HashMap;
 import java.util.Map;
 
 public class TokenActivity extends AppCompatActivity {
 
   private static final String TAG = TokenActivity.class.getSimpleName();
-  private TokenViewModel tokenViewModel;
+  private static final String API_NAME = "requestAccessToken";
+
+  private final FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
+  @VisibleForTesting
+  private final CountingIdlingResource idlingResource = new CountingIdlingResource(TAG);
+  private final TokenViewModel tokenViewModel = new TokenViewModel();
+  private Button agreeButton;
+  private Button disagreeButton;
+
+  @VisibleForTesting
+  public CountingIdlingResource getIdlingResource() {
+    return idlingResource;
+  }
 
   @Override
   public void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_token);
-    tokenViewModel = new ViewModelProvider(this, new ViewModelFactory()).get(
-        TokenViewModel.class);
 
     final TextView agreementTextView = findViewById(R.id.agreement);
-    final Button agreeButton = findViewById(R.id.agree);
-    final Button disagreeButton = findViewById(R.id.disagree);
     final ProgressBar loadingProgressBar = findViewById(R.id.token_loading);
+    agreeButton = findViewById(R.id.agree);
+    disagreeButton = findViewById(R.id.disagree);
 
     Spanned agreementString = Html
         .fromHtml(getString(R.string.agreement_text), Html.FROM_HTML_MODE_LEGACY);
@@ -39,17 +52,20 @@ public class TokenActivity extends AppCompatActivity {
 
     tokenViewModel.getTokenResult().observe(this, new Observer<TokenResult>() {
       @Override
-      public void onChanged(TokenResult result) {
-        if (result == null) {
-          return;
-        }
+      public void onChanged(@NonNull TokenResult result) {
         loadingProgressBar.setVisibility(View.GONE);
+        if (!idlingResource.isIdleNow()) {
+          idlingResource.decrement();
+        }
         if (result.getError() != null) {
           setResult(Activity.RESULT_CANCELED);
           finish();
         }
         if (result.getSuccess() != null) {
           setResult(Activity.RESULT_OK);
+          Log.d(TAG, "Message: " + result.getSuccess().getMessage());
+          HashMap<String, Boolean> approvedRestrictions = result.getSuccess()
+              .getApprovedRestrictions();
           finish();
         }
       }
@@ -58,9 +74,10 @@ public class TokenActivity extends AppCompatActivity {
     agreeButton.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View v) {
+        idlingResource.increment();
         Map<String, Object> query = new HashMap<>();
         loadingProgressBar.setVisibility(View.VISIBLE);
-        tokenViewModel.requestAccessToken("", "", query);
+        tokenViewModel.requestAccessToken("", API_NAME, query);
       }
     });
 
@@ -72,4 +89,20 @@ public class TokenActivity extends AppCompatActivity {
       }
     });
   }
+
+  @Override
+  protected void onResume() {
+    updateButtonState();
+    super.onResume();
+  }
+
+  private void updateButtonState() {
+    if (firebaseAuth.getCurrentUser() == null) {
+      agreeButton.setEnabled(false);
+      setResult(Activity.RESULT_CANCELED);
+      finish();
+    } else {
+      agreeButton.setEnabled(true);
+    }
+  }
 }
diff --git a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenViewModel.java b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenViewModel.java
index 3af4194..4ef716a 100644
--- a/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenViewModel.java
+++ b/app/src/main/java/com/android/car/debuggingrestrictioncontroller/ui/token/TokenViewModel.java
@@ -1,15 +1,24 @@
 package com.android.car.debuggingrestrictioncontroller.ui.token;
 
+import android.util.Base64;
+import android.util.Log;
 import androidx.annotation.NonNull;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
+import com.google.firebase.functions.FirebaseFunctions;
+import java.security.SecureRandom;
 import java.util.HashMap;
 import java.util.Map;
 
 public class TokenViewModel extends ViewModel {
 
   private static final String TAG = TokenViewModel.class.getSimpleName();
+  private static final String FIELD_NONCE = "nonce";
+  private static final String FIELD_TOKEN = "token";
+
+  private static final SecureRandom SECURE_RANDOM = new SecureRandom();
+  private final FirebaseFunctions firebaseFunctions = FirebaseFunctions.getInstance();
   private final MutableLiveData<TokenResult> tokenResult = new MutableLiveData<>();
 
   LiveData<TokenResult> getTokenResult() {
@@ -18,6 +27,25 @@ public class TokenViewModel extends ViewModel {
 
   public void requestAccessToken(@NonNull String hostName, @NonNull String apiName,
       @NonNull Map<String, Object> query) {
-    tokenResult.postValue(new TokenResult(new TokenView("OK", new HashMap<>())));
+    byte[] nonceBytes = new byte[16];
+    SECURE_RANDOM.nextBytes(nonceBytes);
+    final String nonce = Base64.encodeToString(nonceBytes, Base64.DEFAULT);
+    query.put(FIELD_NONCE, nonce);
+
+    firebaseFunctions
+        .getHttpsCallable(apiName)
+        .call(query)
+        .continueWith(task -> {
+          Map<String, Object> result = (Map<String, Object>) task.getResult().getData();
+          return (String) result.get(FIELD_TOKEN);
+        })
+        .addOnCompleteListener(task -> {
+          if (task.isSuccessful()) {
+            Log.d(TAG, "Token: " + task.getResult());
+            tokenResult.postValue(new TokenResult(new TokenView("OK", new HashMap<>())));
+          } else {
+            tokenResult.postValue(new TokenResult(task.getException().getMessage()));
+          }
+        });
   }
 }
diff --git a/app/src/main/res/layout/activity_token.xml b/app/src/main/res/layout/activity_token.xml
index f3c6676..95b14d9 100644
--- a/app/src/main/res/layout/activity_token.xml
+++ b/app/src/main/res/layout/activity_token.xml
@@ -24,7 +24,7 @@
         android:layout_marginStart="48dp"
         android:layout_marginEnd="48dp"
         android:layout_gravity="start"
-        android:enabled="true"
+        android:enabled="false"
         android:text="@string/button_agree"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toStartOf="@+id/disagree"