[iOS] New Feed Activity Buckets metric.

Added a new metric to distribute users into feed activity buckets to be
able to better understand how users use the feed.

(cherry picked from commit 8eb7669)

Bug: 1446085
Change-Id: I8ab00931e09b0244297400f040e0bbdb8cb79917
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4507183
Auto-Submit: Guillem Perez <guiperez@google.com>
Commit-Queue: Justin DeWitt <dewittj@chromium.org>
Reviewed-by: Adam Arcaro <adamta@google.com>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1148786}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4575801
Commit-Queue: Guillem Perez <guiperez@google.com>
Cr-Commit-Position: refs/branch-heads/5790@{#360}
Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}

ios/chrome/browser/ui/ntp/metrics/feed_metrics_constants.h

@@ -31,6 +31,9 @@ extern const int kMinutesBetweenSessions;
 // The max amount of cards in the Discover Feed.
 extern const int kMaxCardsInFeed;
 
+// The number of days for the Activity Buckets calculations.
+extern const int kRangeForActivityBucketsInDays;
+
 // Stores the time when the user visits an article on the feed.
 extern NSString* const kArticleVisitTimestampKey;
 // Stores the time elapsed on the feed when the user leaves.
@@ -47,6 +50,12 @@ extern NSString* const kLastInteractionTimeForFollowingGoodVisits;
 extern NSString* const kLastDayTimeInFeedReportedKey;
 // Stores the time spent on the feed for a day.
 extern NSString* const kTimeSpentInFeedAggregateKey;
+// Stores the last time the activity bucket was reported.
+extern NSString* const kActivityBucketLastReportedDateKey;
+// Stores the last 28 days of activity bucket reported days.
+extern NSString* const kActivityBucketLastReportedDateArrayKey;
+// Stores the latest activity bucket the user was on.
+extern NSString* const kActivityBucketKey;
 
 #pragma mark - Enums
 
@@ -208,6 +217,21 @@ enum class FeedSortType {
   kMaxValue = kSortedByLatest,
 };
 
+// TODO(crbug.com/1447234): Clean up the kError enum.
+// The values for the Feed Activity Buckets metric.
+enum class FeedActivityBucket {
+  // No activity bucket for users active 0/28 days.
+  kNoActivity = 0,
+  // Low activity bucket for users active 1-7/28 days.
+  kLowActivity = 1,
+  // Medium activity bucket for users active 8-15/28 days.
+  kMediumActivity = 2,
+  // High activity bucket for users active 16+/28 days.
+  kHighActivity = 3,
+  // Highest enumerator. Recommended by Histogram metrics best practices.
+  kMaxValue = kHighActivity,
+};
+
 #pragma mark - Histograms
 
 // Histogram name for the Time Spent in Feed.
@@ -223,6 +247,9 @@ extern const char kDiscoverFeedEngagementTypeHistogram[];
 extern const char kFollowingFeedEngagementTypeHistogram[];
 extern const char kAllFeedsEngagementTypeHistogram[];
 
+// Histogram name for the feed activity bucket metric.
+extern const char kAllFeedsActivityBucketsHistogram[];
+
 // Histogram name for a Discover feed card shown at index.
 extern const char kDiscoverFeedCardShownAtIndex[];
 

ios/chrome/browser/ui/ntp/metrics/feed_metrics_constants.mm

@@ -13,6 +13,7 @@
 const int kNonShortClickSeconds = 10;
 const int kMinutesBetweenSessions = 5;
 const int kMaxCardsInFeed = 50;
+const int kRangeForActivityBucketsInDays = 28;
 
 NSString* const kArticleVisitTimestampKey = @"ShortClickInteractionTimestamp";
 NSString* const kLongFeedVisitTimeAggregateKey =
@@ -30,6 +31,11 @@
     @"LastInteractionTimeForGoodVisitsFollowing";
 NSString* const kLastDayTimeInFeedReportedKey = @"LastDayTimeInFeedReported";
 NSString* const kTimeSpentInFeedAggregateKey = @"TimeSpentInFeedAggregate";
+NSString* const kActivityBucketLastReportedDateKey =
+    @"ActivityBucketLastReportedDate";
+NSString* const kActivityBucketLastReportedDateArrayKey =
+    @"ActivityBucketLastReportedDateArray";
+NSString* const kActivityBucketKey = @"FeedActivityBucket";
 
 #pragma mark - Histograms
 
@@ -49,6 +55,8 @@
     "NewTabPage.ContentSuggestions.Shown";
 const char kFollowingFeedCardShownAtIndex[] =
     "ContentSuggestions.Feed.WebFeed.Shown";
+const char kAllFeedsActivityBucketsHistogram[] =
+    "ContentSuggestions.Feed.AllFeeds.Activity";
 const char kDiscoverFeedNoticeCardFulfilled[] =
     "ContentSuggestions.Feed.NoticeCardFulfilled2";
 const char kDiscoverFeedArticlesFetchNetworkDurationSuccess[] =

ios/chrome/browser/ui/ntp/metrics/feed_metrics_recorder.mm

@@ -47,6 +47,10 @@ @interface FeedMetricsRecorder ()
 @property(nonatomic, assign) BOOL goodVisitReportedDiscover;
 @property(nonatomic, assign) BOOL goodVisitReportedFollowing;
 
+// Tracking property to avoid duplicate recordings of the Activity Buckets
+// metric.
+@property(nonatomic, assign) NSDate* activityBucketLastReportedDate;
+
 // Tracks whether user has engaged with the latest refreshed content. The term
 // "engaged" is defined by its usage in this file. For example, it may be
 // similar to `engagedSimpleReportedDiscover`.
@@ -194,6 +198,7 @@ - (void)recordNTPDidChangeVisibility:(BOOL)visible {
     // Total time spent in feed metrics.
     self.timeSpentInFeed =
         base::Seconds([defaults doubleForKey:kTimeSpentInFeedAggregateKey]);
+    [self computeActivityBuckets];
     [self recordTimeSpentInFeedIfDayIsDone];
 
     self.previousTimeInFeedForGoodVisitSession =
@@ -887,6 +892,117 @@ - (void)recordDiscoverFeedUserActionHistogram:(FeedUserActionType)actionType
   }
 }
 
+// Logs engagement daily for the Activity Buckets Calculation.
+- (void)logDailyActivity {
+  NSDate* now = [NSDate date];
+  NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
+
+  // Check if the array is initialized.
+  NSMutableArray<NSDate*>* lastReportedArray = [[defaults
+      arrayForKey:kActivityBucketLastReportedDateArrayKey] mutableCopy];
+  if (!lastReportedArray) {
+    // Initialized before (could be empty).
+    lastReportedArray = [NSMutableArray new];
+  }
+
+  // Adds a daily entry to the `lastReportedArray` array
+  // only once when the user engages.
+  if ([now timeIntervalSinceDate:[lastReportedArray lastObject]] >=
+          (24 * 60 * 60) ||
+      lastReportedArray.count == 0) {
+    [lastReportedArray addObject:now];
+    [defaults setObject:lastReportedArray
+                 forKey:kActivityBucketLastReportedDateArrayKey];
+  }
+}
+
+// Calculates the amount of dates the user has been active for the past 28 days.
+- (void)computeActivityBuckets {
+  NSDate* now = [NSDate date];
+  NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
+
+  NSDate* lastActivityBucketReported = base::mac::ObjCCast<NSDate>(
+      [defaults objectForKey:kActivityBucketLastReportedDateKey]);
+  // If the `lastActivityBucketReported` does not exist, set it to now to
+  // prevent the first day from logging a metric.
+  if (!lastActivityBucketReported) {
+    lastActivityBucketReported = now;
+    [defaults setObject:lastActivityBucketReported
+                 forKey:kActivityBucketLastReportedDateKey];
+  }
+
+  // Check if the last time the activity was reported is more than 24 hrs ago,
+  // and return for performance.
+  if ([now timeIntervalSinceDate:lastActivityBucketReported] < (24 * 60 * 60)) {
+    return;
+  }
+
+  // Retrieve activity bucket from storage.
+  FeedActivityBucket activityBucket =
+      (FeedActivityBucket)[defaults integerForKey:kActivityBucketKey];
+
+  // Calculate activity buckets.
+  // Check if the array is initialized.
+  NSMutableArray<NSDate*>* lastReportedArray = [[defaults
+      arrayForKey:kActivityBucketLastReportedDateArrayKey] mutableCopy];
+  if (!lastReportedArray) {
+    // Initialized before (could be empty).
+    lastReportedArray = [NSMutableArray new];
+  }
+
+  // Check for dates > 28 days and remove older items.
+  NSMutableIndexSet* toDelete = [[NSMutableIndexSet alloc] init];
+  for (NSUInteger i = 0; i < lastReportedArray.count; i++) {
+    if ([now timeIntervalSinceDate:[lastReportedArray objectAtIndex:i]] /
+            (24 * 60 * 60) >
+        kRangeForActivityBucketsInDays) {
+      [toDelete addIndex:i];
+    } else {
+      break;
+    }
+  }
+
+  // The count should never be < 1 for `lastReportedArray` when toDelete > 0 to
+  // prevent a crash / out of bounds errors.
+  if (toDelete.count > 0) {
+    CHECK(lastReportedArray.count >= 1);
+    [lastReportedArray removeObjectsAtIndexes:toDelete];
+  }
+  [defaults setObject:lastReportedArray
+               forKey:kActivityBucketLastReportedDateArrayKey];
+
+  // Check how many items in array.
+  NSUInteger datesActive = lastReportedArray.count;
+  switch (datesActive) {
+    case 0:
+      activityBucket = FeedActivityBucket::kNoActivity;
+      break;
+    case 1 ... 7:
+      activityBucket = FeedActivityBucket::kLowActivity;
+      break;
+    case 8 ... 15:
+      activityBucket = FeedActivityBucket::kMediumActivity;
+      break;
+    case 16 ... 28:
+      activityBucket = FeedActivityBucket::kHighActivity;
+      break;
+    default:
+      // This should never be reached, as dates should never be > 28 days.
+      CHECK(NO);
+      break;
+  }
+  [defaults setInteger:(int)activityBucket forKey:kActivityBucketKey];
+
+  // Activity Buckets Daily Run.
+  [self recordActivityBuckets:activityBucket];
+  [defaults setObject:now forKey:kActivityBucketLastReportedDateKey];
+}
+
+// Records the engagement buckets.
+- (void)recordActivityBuckets:(FeedActivityBucket)activityBucket {
+  UMA_HISTOGRAM_ENUMERATION(kAllFeedsActivityBucketsHistogram, activityBucket);
+}
+
 // Records Feed engagement.
 - (void)recordEngagement:(int)scrollDistance interacted:(BOOL)interacted {
   scrollDistance = abs(scrollDistance);
@@ -1055,6 +1171,9 @@ - (void)recordEngaged {
     NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
     [defaults setBool:YES forKey:kEngagedWithFeedKey];
 
+    // Log engagement for Activity Buckets.
+    [self logDailyActivity];
+
     UMA_HISTOGRAM_ENUMERATION(kAllFeedsEngagementTypeHistogram,
                               FeedEngagementType::kFeedEngaged);
   }

tools/metrics/histograms/enums.xml

@@ -42897,6 +42897,21 @@ Called by update_permissions_policy_enum.py.-->
   <int value="5" label="kDbCleanOutdatedDataError"/>
 </enum>
 
+<enum name="FeedActivityBucket">
+  <int value="0" label="No Activity">
+    The user has no activity in the last 28 days.
+  </int>
+  <int value="1" label="Low Activity">
+    The user has 1-7 days of activity in the last 28 days.
+  </int>
+  <int value="2" label="Medium Activity">
+    The user has 8-15 days of activity in the last 28 days.
+  </int>
+  <int value="3" label="High Activity">
+    The user has 16+ days of activity in the last 28 days.
+  </int>
+</enum>
+
 <enum name="FeedAutoplayEvent">
   <obsolete>
     Removed as of 05/2021. Replaced by FeedVideoPlayEvent.

tools/metrics/histograms/metadata/content/histograms.xml

@@ -1994,6 +1994,24 @@ chromium-metrics-reviews@google.com.
   </summary>
 </histogram>
 
+<histogram name="ContentSuggestions.{FeedType}.Activity"
+    enum="FeedActivityBucket" expires_after="2023-11-24">
+  <owner>guiperez@google.com</owner>
+  <owner>feed@chromium.org</owner>
+  <summary>
+    Tracks user activity buckets with {FeedType}. Each bucket composed of the
+    user's activity level. Logs the for the first time 1 day after the metric is
+    active (only on first time use), then logs an activity bucket after at least
+    24hrs from the last log have elapsed. When the &quot;Engaged&quot; metric is
+    triggered we log one more day of activity during the past 28 days.
+  </summary>
+  <token key="FeedType">
+    <variant name="Feed" summary="the For-You feed"/>
+    <variant name="Feed.AllFeeds" summary="All Feeds combined"/>
+    <variant name="Feed.WebFeed" summary="the Following/Web Feed"/>
+  </token>
+</histogram>
+
 <histogram name="ContentSuggestions.{FeedType}.CardIndexOnSwitch" units="index"
     expires_after="2023-04-21">
   <owner>adamta@google.com</owner>