FIX: send activity summaries based on "last seen"

instead of "last emailed" so that people getting email notifications (from a watched topic for example) also get the activity summaries.

Context - https://meta.discourse.org/t/activity-summary-not-sent-if-other-emails-are-sent/293040

Internal Ref - t//125582

app/jobs/regular/user_email.rb

@@ -120,21 +120,21 @@ module Jobs
 
       if type == "digest"
         return if user.staged
-        if user.last_emailed_at &&
-             user.last_emailed_at >
+
+        if user.last_seen_at
+          if user.last_seen_at >
                (
                  user.user_option&.digest_after_minutes ||
                    SiteSetting.default_email_digest_frequency.to_i
                ).minutes.ago
-          return
+            return
+          end
         end
       end
 
       seen_recently =
-        (
-          user.last_seen_at.present? &&
-            user.last_seen_at > SiteSetting.email_time_window_mins.minutes.ago
-        )
+        user.last_seen_at && user.last_seen_at > SiteSetting.email_time_window_mins.minutes.ago
+
       if !args[:force_respect_seen_recently] &&
            (
              always_email_regular?(user, type) || always_email_private_message?(user, type) ||

app/jobs/scheduled/enqueue_digest_emails.rb

@@ -5,13 +5,13 @@ module Jobs
     every 30.minutes
 
     def execute(args)
-      if SiteSetting.disable_digest_emails? || SiteSetting.private_email? ||
-           SiteSetting.disable_emails == "yes"
-        return
-      end
-      users = target_user_ids
+      return if SiteSetting.disable_emails == "yes"
+      return if SiteSetting.disable_digest_emails?
+      return if SiteSetting.private_email?
 
-      users.each { |user_id| ::Jobs.enqueue(:user_email, type: "digest", user_id: user_id) }
+      target_user_ids.each do |user_id|
+        ::Jobs.enqueue(:user_email, type: "digest", user_id: user_id)
+      end
     end
 
     def target_user_ids
@@ -21,14 +21,11 @@ module Jobs
           .real
           .activated
           .not_suspended
-          .where(staged: false)
+          .not_staged
           .joins(:user_option, :user_stat, :user_emails)
           .where("user_options.email_digests")
           .where("user_stats.bounce_score < ?", SiteSetting.bounce_score_threshold)
           .where("user_emails.primary")
-          .where(
-            "COALESCE(last_emailed_at, '2010-01-01') <= CURRENT_TIMESTAMP - ('1 MINUTE'::INTERVAL * user_options.digest_after_minutes)",
-          )
           .where(
             "COALESCE(user_stats.digest_attempted_at, '2010-01-01') <= CURRENT_TIMESTAMP - ('1 MINUTE'::INTERVAL * user_options.digest_after_minutes)",
           )

app/mailers/user_notifications.rb

@@ -224,7 +224,7 @@ class UserNotifications < ActionMailer::Base
     build_summary_for(user)
     @unsubscribe_key = UnsubscribeKey.create_key_for(@user, UnsubscribeKey::DIGEST_TYPE)
 
-    min_date = opts[:since] || user.last_emailed_at || user.last_seen_at || 1.month.ago
+    min_date = opts[:since] || user.last_seen_at || 1.month.ago
 
     # Fetch some topics and posts to show
     digest_opts = {

spec/jobs/user_email_spec.rb

@@ -68,6 +68,20 @@ RSpec.describe Jobs::UserEmail do
         user.user_option.update!(digest_after_minutes: 1.day.to_i / 60)
       end
 
+      it "still sends the digest email" do
+        Jobs::UserEmail.new.execute(type: :digest, user_id: user.id)
+        expect(ActionMailer::Base.deliveries).to_not be_empty
+        expect(user.user_stat.reload.digest_attempted_at).to eq_time(Time.zone.now)
+      end
+    end
+
+    context "when recently seen" do
+      before do
+        freeze_time
+        user.update!(last_seen_at: 2.hours.ago)
+        user.user_option.update!(digest_after_minutes: 1.day.to_i / 60)
+      end
+
       it "skips sending digest email" do
         Jobs::UserEmail.new.execute(type: :digest, user_id: user.id)
         expect(ActionMailer::Base.deliveries).to eq([])
@@ -269,8 +283,8 @@ RSpec.describe Jobs::UserEmail do
     it "creates an email log when the mail is sent (via Email::Sender)" do
       freeze_time
 
-      last_emailed_at = 7.days.ago
-      user.update!(last_emailed_at: last_emailed_at)
+      last_seen_at = 7.days.ago
+      user.update!(last_seen_at: last_seen_at)
       Topic.last.update(created_at: 1.minute.ago)
 
       expect do Jobs::UserEmail.new.execute(type: :digest, user_id: user.id) end.to change {
@@ -282,7 +296,7 @@ RSpec.describe Jobs::UserEmail do
       expect(email_log.user).to eq(user)
       expect(email_log.post).to eq(nil)
       # last_emailed_at should have changed
-      expect(email_log.user.last_emailed_at).to_not eq_time(last_emailed_at)
+      expect(email_log.user.last_emailed_at).to_not eq_time(last_seen_at)
     end
 
     it "creates a skipped email log when the mail is skipped" do