Update heartbeat to have the most recent useragent for a given day (#4694)

* update heartbeat to have the most recent useragent for a given day

* update comment

* update comment

* add comment

---------

Co-authored-by: Rodrigo Lazo <[email protected]>

Author: VinayGuthal

firebase-common/src/main/java/com/google/firebase/heartbeatinfo/HeartBeatInfoStorage.java

@@ -111,6 +111,15 @@ private synchronized String getStoredUserAgentString(String dateString) {
     return null;
   }
 
+  private synchronized void updateStoredUserAgent(String userAgent, String dateString) {
+    removeStoredDate(dateString);
+    Set<String> userAgentDateSet =
+        new HashSet<String>(
+            firebaseSharedPreferences.getStringSet(userAgent, new HashSet<String>()));
+    userAgentDateSet.add(dateString);
+    firebaseSharedPreferences.edit().putStringSet(userAgent, userAgentDateSet).commit();
+  }
+
   private synchronized void removeStoredDate(String dateString) {
     // Find stored heartbeat and clear it.
     String userAgentString = getStoredUserAgentString(dateString);
@@ -148,7 +157,18 @@ synchronized void storeHeartBeat(long millis, String userAgentString) {
     String dateString = getFormattedDate(millis);
     String lastDateString = firebaseSharedPreferences.getString(LAST_STORED_DATE, "");
     if (lastDateString.equals(dateString)) {
-      return;
+      String storedUserAgentString = getStoredUserAgentString(dateString);
+      if (storedUserAgentString == null) {
+        // Heartbeat already sent for today.
+        return;
+      }
+      if (storedUserAgentString.equals(userAgentString)) {
+        // UserAgent not updated.
+        return;
+      } else {
+        updateStoredUserAgent(userAgentString, dateString);
+        return;
+      }
     }
     long heartBeatCount = firebaseSharedPreferences.getLong(HEART_BEAT_COUNT_TAG, 0);
     if (heartBeatCount + 1 == HEART_BEAT_COUNT_LIMIT) {

firebase-common/src/test/java/com/google/firebase/heartbeatinfo/HeartBeatInfoStorageTest.java

@@ -75,6 +75,28 @@ public void storeOneHeartbeat_storesProperly() {
     assertThat(results.size()).isEqualTo(0);
   }
 
+  @Config(sdk = 29)
+  @Test
+  public void storeOneHeartbeat_updatesProperly() {
+    assertThat(heartBeatInfoStorage.getHeartBeatCount()).isEqualTo(0);
+    heartBeatInfoStorage.storeHeartBeat(0, "test-agent");
+    assertThat(heartBeatInfoStorage.getHeartBeatCount()).isEqualTo(1);
+    heartBeatInfoStorage.storeHeartBeat(10, "test-agent-1");
+    ArrayList<HeartBeatResult> results =
+        (ArrayList<HeartBeatResult>) heartBeatInfoStorage.getAllHeartBeats();
+    assertThat(results.size()).isEqualTo(1);
+    assertThat(results.get(0).getUserAgent()).isEqualTo("test-agent-1");
+    assertThat(results.get(0).getUsedDates())
+        .isEqualTo(new ArrayList<String>(Collections.singleton("1970-01-01")));
+    heartBeatInfoStorage.deleteAllHeartBeats();
+    heartBeatInfoStorage.storeHeartBeat(100, "test-agent-2");
+    heartBeatInfoStorage.storeHeartBeat(1000, "test-agent-1");
+    // Since the heartbeat is already sent for today no new heartbeats should be sent.
+    assertThat(heartBeatInfoStorage.getHeartBeatCount()).isEqualTo(0);
+    results = (ArrayList<HeartBeatResult>) heartBeatInfoStorage.getAllHeartBeats();
+    assertThat(results.size()).isEqualTo(0);
+  }
+
   @Config(sdk = 29)
   @Test
   public void storeTwoHeartbeat_storesProperly() {