Add first-open time to Remote Config fetch request. (#3653)

* Add first-open time to Remote Config fetch request.

* Removed dependency on jodaTime and replaced it with SimpleDateFormat, as per review comments.

* fixed error in FetchHttpClientTest

* fixed a comment nit

Author: richaurora

firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigConstants.java

@@ -48,7 +48,8 @@ public final class RemoteConfigConstants {
     RequestFieldKey.APP_VERSION,
     RequestFieldKey.PACKAGE_NAME,
     RequestFieldKey.SDK_VERSION,
-    RequestFieldKey.ANALYTICS_USER_PROPERTIES
+    RequestFieldKey.ANALYTICS_USER_PROPERTIES,
+    RequestFieldKey.FIRST_OPEN_TIME
   })
   @Retention(RetentionPolicy.SOURCE)
   public @interface RequestFieldKey {
@@ -64,6 +65,7 @@ public final class RemoteConfigConstants {
     String PACKAGE_NAME = "packageName";
     String SDK_VERSION = "sdkVersion";
     String ANALYTICS_USER_PROPERTIES = "analyticsUserProperties";
+    String FIRST_OPEN_TIME = "firstOpenTime";
   }
 
   /** Keys of fields in the Fetch response body from the Firebase Remote Config server. */

firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandler.java

@@ -79,6 +79,12 @@ public class ConfigFetchHandler {
    */
   @VisibleForTesting static final int HTTP_TOO_MANY_REQUESTS = 429;
 
+  /**
+   * First-open time key name in GA user-properties. First-open time is a predefined user-dimension
+   * automatically collected by GA.
+   */
+  @VisibleForTesting static final String FIRST_OPEN_TIME_KEY = "_fot";
+
   private final FirebaseInstallationsApi firebaseInstallations;
   private final Provider<AnalyticsConnector> analyticsConnector;
 
@@ -110,7 +116,6 @@ public ConfigFetchHandler(
     this.fetchedConfigsCache = fetchedConfigsCache;
     this.frcBackendApiClient = frcBackendApiClient;
     this.frcMetadata = frcMetadata;
-
     this.customHttpHeaders = customHttpHeaders;
   }
 
@@ -311,6 +316,7 @@ private FetchResponse fetchFromBackend(
               getUserProperties(),
               frcMetadata.getLastFetchETag(),
               customHttpHeaders,
+              getFirstOpenTime(),
               currentTime);
 
       if (response.getLastFetchETag() != null) {
@@ -492,8 +498,8 @@ private void updateLastFetchStatusAndTime(
   }
 
   /**
-   * Returns the list of user properties in Analytics. If the Analytics SDK is not available,
-   * returns an empty list.
+   * Returns the list of custom user properties in Analytics. If the Analytics SDK is not available,
+   * this method returns an empty list.
    */
   @WorkerThread
   private Map<String, String> getUserProperties() {
@@ -510,6 +516,20 @@ private Map<String, String> getUserProperties() {
     return userPropertiesMap;
   }
 
+  /**
+   * Returns first-open time from Analytics. If the Analytics SDK is not available, or if Analytics
+   * does not have first-open time for the app, this method returns null.
+   */
+  @WorkerThread
+  private Long getFirstOpenTime() {
+    AnalyticsConnector connector = this.analyticsConnector.get();
+    if (connector == null) {
+      return null;
+    }
+
+    return (Long) connector.getUserProperties(/*includeInternal=*/ true).get(FIRST_OPEN_TIME_KEY);
+  }
+
   /** Used to verify that the fetch handler is getting Analytics as expected. */
   @VisibleForTesting
   public Provider<AnalyticsConnector> getAnalyticsConnector() {

firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClient.java

@@ -21,6 +21,7 @@
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.APP_ID;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.APP_VERSION;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.COUNTRY_CODE;
+import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.FIRST_OPEN_TIME;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.INSTANCE_ID;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.INSTANCE_ID_TOKEN;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.LANGUAGE_CODE;
@@ -58,6 +59,7 @@
 import java.net.HttpURLConnection;
 import java.net.URL;
 import java.net.URLConnection;
+import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.Locale;
@@ -92,6 +94,9 @@ public class ConfigFetchHttpClient {
   private final long connectTimeoutInSeconds;
   private final long readTimeoutInSeconds;
 
+  /** ISO-8601 UTC timestamp format. */
+  private static final String ISO_DATE_PATTERN = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'";
+
   /** Creates a client for {@link #fetch}ing data from the Firebase Remote Config server. */
   public ConfigFetchHttpClient(
       Context context,
@@ -163,6 +168,7 @@ HttpURLConnection createHttpURLConnection() throws FirebaseRemoteConfigException
    *     server uses this ETag to determine if there has been a change in the response body since
    *     the last fetch.
    * @param customHeaders custom HTTP headers that will be sent to the FRC server.
+   * @param firstOpenTime first time the app was opened. This value comes from Google Analytics.
    * @param currentTime the current time on the device that is performing the fetch.
    */
   // TODO(issues/263): Set custom headers in ConfigFetchHttpClient's constructor.
@@ -174,6 +180,7 @@ FetchResponse fetch(
       Map<String, String> analyticsUserProperties,
       String lastFetchETag,
       Map<String, String> customHeaders,
+      Long firstOpenTime,
       Date currentTime)
       throws FirebaseRemoteConfigException {
     setUpUrlConnection(urlConnection, lastFetchETag, installationAuthToken, customHeaders);
@@ -182,7 +189,8 @@ FetchResponse fetch(
     JSONObject fetchResponse;
     try {
       byte[] requestBody =
-          createFetchRequestBody(installationId, installationAuthToken, analyticsUserProperties)
+          createFetchRequestBody(
+                  installationId, installationAuthToken, analyticsUserProperties, firstOpenTime)
               .toString()
               .getBytes("utf-8");
       setFetchRequestBody(urlConnection, requestBody);
@@ -292,7 +300,8 @@ private String getFingerprintHashForPackage() {
   private JSONObject createFetchRequestBody(
       String installationId,
       String installationAuthToken,
-      Map<String, String> analyticsUserProperties)
+      Map<String, String> analyticsUserProperties,
+      Long firstOpenTime)
       throws FirebaseRemoteConfigClientException {
     Map<String, Object> requestBodyMap = new HashMap<>();
 
@@ -315,7 +324,7 @@ private JSONObject createFetchRequestBody(
             : locale.toString();
     requestBodyMap.put(LANGUAGE_CODE, languageCode);
 
-    requestBodyMap.put(PLATFORM_VERSION, Integer.toString(android.os.Build.VERSION.SDK_INT));
+    requestBodyMap.put(PLATFORM_VERSION, Integer.toString(Build.VERSION.SDK_INT));
 
     requestBodyMap.put(TIME_ZONE, TimeZone.getDefault().getID());
 
@@ -336,9 +345,19 @@ private JSONObject createFetchRequestBody(
 
     requestBodyMap.put(ANALYTICS_USER_PROPERTIES, new JSONObject(analyticsUserProperties));
 
+    if (firstOpenTime != null) {
+      requestBodyMap.put(FIRST_OPEN_TIME, convertToISOString(firstOpenTime));
+    }
+
     return new JSONObject(requestBodyMap);
   }
 
+  private String convertToISOString(long millisFromEpoch) {
+    SimpleDateFormat isoDateFormat = new SimpleDateFormat(ISO_DATE_PATTERN);
+    isoDateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
+    return isoDateFormat.format(millisFromEpoch);
+  }
+
   private void setFetchRequestBody(HttpURLConnection urlConnection, byte[] requestBody)
       throws IOException {
     urlConnection.setFixedLengthStreamingMode(requestBody.length);

firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandlerTest.java

@@ -26,6 +26,7 @@
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.ResponseFieldKey.STATE;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.BACKOFF_TIME_DURATIONS_IN_MINUTES;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS;
+import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.FIRST_OPEN_TIME_KEY;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.HTTP_TOO_MANY_REQUESTS;
 import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LAST_FETCH_TIME_NO_FETCH_YET;
 import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.NO_BACKOFF_TIME;
@@ -42,6 +43,7 @@
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.doThrow;
@@ -195,6 +197,7 @@ public void fetch_firstFetch_includesInstallationAuthToken() throws Exception {
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any());
   }
 
@@ -394,7 +397,7 @@ public void fetch_gettingFetchCacheFails_doesNotThrowException() throws Exceptio
 
   @Test
   public void fetch_fetchBackendCallFails_taskThrowsException() throws Exception {
-    when(mockBackendFetchApiClient.fetch(any(), any(), any(), any(), any(), any(), any()))
+    when(mockBackendFetchApiClient.fetch(any(), any(), any(), any(), any(), any(), any(), any()))
         .thenThrow(
             new FirebaseRemoteConfigClientException("Fetch failed due to an unexpected error."));
 
@@ -628,21 +631,45 @@ public void fetch_serverReturnsUnexpectedCode_throwsServerException() throws Exc
   }
 
   @Test
-  public void fetch_hasAnalyticsSdk_sendsUserProperties() throws Exception {
+  public void fetch_hasAnalyticsSdk_sendsUserPropertiesAndFirstOpenTime() throws Exception {
     // Provide the mock Analytics SDK.
     AnalyticsConnector mockAnalyticsConnector = mock(AnalyticsConnector.class);
     fetchHandler = getNewFetchHandler(mockAnalyticsConnector);
+    long firstOpenTime = 1636146000000L;
 
-    Map<String, String> userProperties =
+    Map<String, String> customUserProperties =
         ImmutableMap.of("up_key1", "up_val1", "up_key2", "up_val2");
+    Map<String, Object> allUserProperties =
+        ImmutableMap.of(
+            "up_key1", "up_val1", "up_key2", "up_val2", FIRST_OPEN_TIME_KEY, firstOpenTime);
     when(mockAnalyticsConnector.getUserProperties(/*includeInternal=*/ false))
+        .thenReturn(ImmutableMap.copyOf(customUserProperties));
+    when(mockAnalyticsConnector.getUserProperties(/*includeInternal=*/ true))
+        .thenReturn(ImmutableMap.copyOf(allUserProperties));
+
+    fetchCallToHttpClientUpdatesClockAndReturnsConfig(firstFetchedContainer);
+
+    assertWithMessage("Fetch() failed!").that(fetchHandler.fetch().isSuccessful()).isTrue();
+
+    verifyBackendIsCalled(customUserProperties, firstOpenTime);
+  }
+
+  @Test
+  public void fetch_hasAnalyticsSdk_sendsUserPropertiesNoFirstOpenTime() throws Exception {
+    // Provide the mock Analytics SDK.
+    AnalyticsConnector mockAnalyticsConnector = mock(AnalyticsConnector.class);
+    fetchHandler = getNewFetchHandler(mockAnalyticsConnector);
+
+    Map<String, String> userProperties =
+        ImmutableMap.of("up_key1", "up_val1", "up_key2", "up_val2");
+    when(mockAnalyticsConnector.getUserProperties(anyBoolean()))
         .thenReturn(ImmutableMap.copyOf(userProperties));
 
     fetchCallToHttpClientUpdatesClockAndReturnsConfig(firstFetchedContainer);
 
     assertWithMessage("Fetch() failed!").that(fetchHandler.fetch().isSuccessful()).isTrue();
 
-    verifyBackendIsCalled(userProperties);
+    verifyBackendIsCalled(userProperties, null);
   }
 
   @Test
@@ -751,6 +778,7 @@ private void setBackendResponseConfigsTo(ConfigContainer container) throws Excep
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any());
   }
 
@@ -762,6 +790,7 @@ private void setBackendResponseToNoChange(Date date) throws Exception {
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any()))
         .thenReturn(FetchResponse.forBackendHasNoUpdates(date));
   }
@@ -776,6 +805,7 @@ private void fetchCallToBackendThrowsException(int httpErrorCode) throws Excepti
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any());
   }
 
@@ -855,10 +885,12 @@ private void verifyBackendIsCalled() throws Exception {
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any());
   }
 
-  private void verifyBackendIsCalled(Map<String, String> userProperties) throws Exception {
+  private void verifyBackendIsCalled(Map<String, String> userProperties, Long firstOpenTime)
+      throws Exception {
     verify(mockBackendFetchApiClient)
         .fetch(
             any(HttpURLConnection.class),
@@ -867,6 +899,7 @@ private void verifyBackendIsCalled(Map<String, String> userProperties) throws Ex
             /* analyticsUserProperties= */ eq(userProperties),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ eq(firstOpenTime),
             /* currentTime= */ any());
   }
 
@@ -879,6 +912,7 @@ private void verifyBackendIsNeverCalled() throws Exception {
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any());
   }
 
@@ -891,6 +925,7 @@ private void verifyETags(@Nullable String requestETag, String responseETag) thro
             /* analyticsUserProperties= */ any(),
             /* lastFetchETag= */ eq(requestETag),
             /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
             /* currentTime= */ any());
     assertThat(metadataClient.getLastFetchETag()).isEqualTo(responseETag);
   }