Added two new stats to the admin area for my reporting and awareness

app/components/admin/stats/table_component.rb

@@ -23,7 +23,20 @@ def month_header(month)
       end
 
       def cell_value(row, month)
-        number_with_delimiter(row.cells.fetch(month, 0))
+        value = row.cells.fetch(month, 0)
+        return number_with_delimiter(value) unless percentage_row?(row)
+
+        "#{number_with_delimiter(value)} (#{percentage_of_total(value, row.total)}%)"
+      end
+
+      def percentage_row?(row)
+        Admin::Stats::Monthly::RETURNING_LABELS.value?(row.label)
+      end
+
+      def percentage_of_total(value, total)
+        return 0 if total.zero?
+
+        (value.to_f / total * 100).round
       end
 
       def total_value(row)

app/services/admin/stats/monthly.rb

@@ -19,6 +19,10 @@ class Monthly
                             coach_check_ins: 'Coach check-ins',
                             student_rsvps: 'Student RSVPs',
                             coach_rsvps: 'Coach RSVPs' }.freeze
+      RETURNING_LABELS = { returning_students: 'Returning students',
+                           returning_coaches: 'Returning coaches' }.freeze
+      RETURNING_KEYS = { 'Student' => :returning_students, 'Coach' => :returning_coaches }.freeze
+      TRANSITION_LABEL = 'Students who became coaches'
       SIGN_UP_LABELS = { students: 'New students',
                          coaches: 'New coaches',
                          uncategorised: 'Uncategorised',
@@ -32,21 +36,61 @@ def call(range)
           return Result.new(months: [], rows: []) if months.empty?
 
           @month_keys = months.index_by(&:itself)
-          rows = attendance_rows(months) + sign_up_rows(months) + [workshop_row(months)]
+          rows = attendance_rows(months) + sign_up_rows(months) + [workshop_row(months), *transition_rows(months)]
           Result.new(months:, rows:)
         end
 
         private
 
         def attendance_rows(months)
           counts = blank_counts(months, ATTENDANCE_LABELS.keys)
-          grouped_attendance(months).each do |month, role, attended, attending, count|
+          tally_attendance(counts, grouped_attendance(months))
+          ATTENDANCE_LABELS.map { |key, label| row(:attendance, label, months, counts[key]) } + returning_rows(months)
+        end
+
+        def tally_attendance(counts, rows)
+          rows.each do |month, role, attended, attending, count|
             key = @month_keys[month]
             next unless key
 
             attendance_keys(role, attended, attending).each { |row_key| counts[row_key][key] += count }
           end
-          ATTENDANCE_LABELS.map { |key, label| row(:attendance, label, months, counts[key]) }
+        end
+
+        # A returning member attended at least one workshop in an earlier
+        # calendar month than the one being counted, so the same-month repeat
+        # does not count. Distinct per month and role.
+        def returning_rows(months)
+          counts = blank_counts(months, RETURNING_LABELS.keys)
+          grouped_returning(months).each do |month, role, count|
+            key = @month_keys[month]
+            next unless key
+
+            row_key = RETURNING_KEYS[role]
+            counts[row_key][key] += count if row_key
+          end
+          RETURNING_LABELS.map { |key, label| row(:attendance, label, months, counts[key]) }
+        end
+
+        def grouped_returning(months)
+          WorkshopInvitation.joins(:workshop)
+                            .where(workshops: { date_and_time: window(months) }, attended: true)
+                            .where(prior_attendance_exists)
+                            .group(month_bucket('workshops.date_and_time'), :role)
+                            .pluck(month_bucket('workshops.date_and_time'), :role,
+                                   Arel.sql('COUNT(DISTINCT workshop_invitations.member_id)'))
+        end
+
+        def prior_attendance_exists
+          Arel.sql(<<~SQL.squish)
+            EXISTS (
+              SELECT 1 FROM workshop_invitations AS prior_invitations
+              INNER JOIN workshops AS prior_workshops ON prior_workshops.id = prior_invitations.workshop_id
+              WHERE prior_invitations.member_id = workshop_invitations.member_id
+                AND prior_invitations.attended = TRUE
+                AND #{month_bucket('prior_workshops.date_and_time')} < #{month_bucket('workshops.date_and_time')}
+            )
+          SQL
         end
 
         def grouped_attendance(months)
@@ -69,6 +113,50 @@ def attendance_keys(role, attended, attending)
           end
         end
 
+        # Bucketed by the month of the member's first Coaches subscription.
+        # Subscriptions are append-only (unsubscribes set discarded_at), so a
+        # Students subscription created earlier marks the transition. Chapter is
+        # ignored and a still-kept Students subscription does not disqualify.
+        def transition_rows(months)
+          counts = default_cells(months)
+          grouped_transitions(months).each do |month, count|
+            key = @month_keys[month]
+            counts[key] += count if key
+          end
+          [row(:transitions, TRANSITION_LABEL, months, counts)]
+        end
+
+        def grouped_transitions(months)
+          Subscription.from("(#{first_coach_sql}) first_coaches")
+                      .where('first_coaches.first_coach_at BETWEEN ? AND ?',
+                             window(months).begin, window(months).end)
+                      .where(prior_student_exists)
+                      .group(month_bucket('first_coaches.first_coach_at'))
+                      .pluck(month_bucket('first_coaches.first_coach_at'), Arel.sql('COUNT(*)'))
+        end
+
+        def first_coach_sql
+          <<~SQL.squish
+            SELECT s.member_id, MIN(s.created_at) AS first_coach_at
+            FROM subscriptions s
+            INNER JOIN groups g ON g.id = s.group_id
+            WHERE g.name = 'Coaches'
+            GROUP BY s.member_id
+          SQL
+        end
+
+        def prior_student_exists
+          Arel.sql(<<~SQL.squish)
+            EXISTS (
+              SELECT 1 FROM subscriptions student_subs
+              INNER JOIN groups student_groups ON student_groups.id = student_subs.group_id
+              WHERE student_subs.member_id = first_coaches.member_id
+                AND student_groups.name = 'Students'
+                AND student_subs.created_at < first_coaches.first_coach_at
+            )
+          SQL
+        end
+
         def sign_up_rows(months) # rubocop:disable Metrics/AbcSize
           counts = blank_counts(months, SIGN_UP_LABELS.keys)
           grouped_sign_ups(months).each do |month, total, students, coaches, uncategorised|

app/views/admin/stats/index.html.erb

@@ -31,9 +31,10 @@
   <% end %>
 
   <% rows_by_section = @rows.group_by(&:section) %>
-  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:attendance, []), caption: 'Attendance') %>
-  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:sign_ups, []), caption: 'New sign-ups') %>
-  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:workshops, []), caption: 'Workshops') %>
+  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:attendance, []), caption: 'Attendance per month') %>
+  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:sign_ups, []), caption: 'New sign-ups per month') %>
+  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:workshops, []), caption: 'Workshops per month') %>
+  <%= render Admin::Stats::TableComponent.new(months: @months, rows: rows_by_section.fetch(:transitions, []), caption: 'Students who became coaches') %>
 
   <%= link_to 'Download CSV',
               admin_stats_path(format: :csv,

db/schema.rb

@@ -466,10 +466,10 @@
 
   create_table "subscriptions", id: :serial, force: :cascade do |t|
     t.datetime "created_at", precision: nil
-    t.datetime "discarded_at"
     t.integer "group_id"
     t.integer "member_id"
     t.datetime "updated_at", precision: nil
+    t.datetime "discarded_at"
     t.index ["discarded_at"], name: "index_subscriptions_on_discarded_at"
     t.index ["group_id"], name: "index_subscriptions_on_group_id"
     t.index ["member_id", "group_id"], name: "index_subscriptions_on_member_id_group_id_active", unique: true, where: "(discarded_at IS NULL)"

spec/components/admin/stats/table_component_spec.rb

@@ -32,6 +32,36 @@
     expect(page).to have_css('td.text-end', text: '1,241') # totals cell
   end
 
+  it 'shows each cell as a percentage of the row total in brackets for returning rows' do
+    returning_row = Admin::Stats::Monthly::Row.new(section: :attendance, label: 'Returning students',
+                                                   cells: { Date.new(2026, 6, 1) => 1234, Date.new(2026, 7, 1) => 7,
+                                                            Date.new(2026, 8, 1) => 0 },
+                                                   total: 1241)
+
+    render_inline(described_class.new(months:, rows: [returning_row], caption: 'Attendance'))
+
+    expect(page).to have_css('td.text-end', text: '1,234 (99%)')
+    expect(page).to have_css('td.text-end', text: '7 (1%)')
+    expect(page).to have_css('td.text-end', text: '0 (0%)')
+  end
+
+  it 'does not show percentages for other metric rows' do
+    render_inline(described_class.new(months:, rows: [row], caption: 'Attendance'))
+
+    expect(page).to have_css('td.text-end', text: '7')
+    expect(page).to have_no_css('td.text-end', text: '7 (')
+  end
+
+  it 'shows 0% when a returning row has a zero total' do
+    zero_row = Admin::Stats::Monthly::Row.new(section: :attendance, label: 'Returning coaches',
+                                              cells: { Date.new(2026, 6, 1) => 0 }, total: 0)
+
+    render_inline(described_class.new(months: [Date.new(2026, 6, 1)], rows: [zero_row], caption: 'Attendance'))
+
+    expect(page).to have_css('td.text-end', text: '0 (0%)')
+    expect(page).to have_css('td.text-end', text: '0') # totals cell
+  end
+
   it 'renders one table per metric group, with no section banner rows' do
     workshops_row = Admin::Stats::Monthly::Row.new(section: :workshops, label: 'Workshops',
                                                    cells: { Date.new(2026, 6, 1) => 2 }, total: 2)

spec/services/admin/stats/monthly_spec.rb

@@ -86,6 +86,136 @@ def total_for(section, label)
     end
   end
 
+  describe 'returning member rows' do
+    it 'counts a member attending in a later month as a returning student' do
+      member = Fabricate(:member)
+      may = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 5, 6, 18, 30))
+      june = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 10, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: may, member:, role: 'Student')
+      Fabricate(:attended_workshop_invitation, workshop: june, member:, role: 'Student')
+
+      expect(cell(:attendance, 'Returning students', [2026, 5])).to eq(0)
+      expect(cell(:attendance, 'Returning students', [2026, 6])).to eq(1)
+    end
+
+    it 'counts returning coaches on the coach row' do
+      member = Fabricate(:member)
+      may = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 5, 6, 18, 30))
+      june = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 10, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: may, member:, role: 'Coach')
+      Fabricate(:attended_workshop_invitation, workshop: june, member:, role: 'Coach')
+
+      expect(cell(:attendance, 'Returning coaches', [2026, 6])).to eq(1)
+      expect(cell(:attendance, 'Returning students', [2026, 6])).to eq(0)
+    end
+
+    it 'counts prior attendance before the selected range as returning (any prior ever)' do
+      member = Fabricate(:member)
+      april = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 4, 8, 18, 30))
+      may = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 5, 6, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: april, member:, role: 'Student')
+      Fabricate(:attended_workshop_invitation, workshop: may, member:, role: 'Student')
+
+      expect(cell(:attendance, 'Returning students', [2026, 5])).to eq(1)
+    end
+
+    it 'does not count attendance in the same month as returning' do
+      member = Fabricate(:member)
+      first = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 3, 18, 30))
+      second = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 17, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: first, member:, role: 'Student')
+      Fabricate(:attended_workshop_invitation, workshop: second, member:, role: 'Student')
+
+      expect(cell(:attendance, 'Returning students', [2026, 6])).to eq(0)
+    end
+
+    it 'counts a member once per month even with multiple attendances' do
+      member = Fabricate(:member)
+      may = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 5, 6, 18, 30))
+      june_one = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 3, 18, 30))
+      june_two = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 17, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: may, member:, role: 'Student')
+      Fabricate(:attended_workshop_invitation, workshop: june_one, member:, role: 'Student')
+      Fabricate(:attended_workshop_invitation, workshop: june_two, member:, role: 'Student')
+
+      expect(cell(:attendance, 'Returning students', [2026, 6])).to eq(1)
+    end
+
+    it 'treats prior attendance in another role as returning' do
+      member = Fabricate(:member)
+      may = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 5, 6, 18, 30))
+      june = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 10, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: may, member:, role: 'Coach')
+      Fabricate(:attended_workshop_invitation, workshop: june, member:, role: 'Student')
+
+      expect(cell(:attendance, 'Returning students', [2026, 6])).to eq(1)
+    end
+
+    it 'leaves the check-in rows counting attendances' do
+      member = Fabricate(:member)
+      may = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 5, 6, 18, 30))
+      june = Fabricate(:workshop_no_sponsor, date_and_time: Time.zone.local(2026, 6, 10, 18, 30))
+      Fabricate(:attended_workshop_invitation, workshop: may, member:, role: 'Student')
+      Fabricate(:attended_workshop_invitation, workshop: june, member:, role: 'Student')
+
+      expect(cell(:attendance, 'Student check-ins', [2026, 6])).to eq(1)
+      expect(total_for(:attendance, 'Student check-ins')).to eq(2)
+    end
+  end
+
+  describe 'student to coach rows' do
+    let(:students_group) { Fabricate(:group, name: 'Students') }
+    let(:coaches_group) { Fabricate(:group, name: 'Coaches') }
+
+    def subscribe(member, group, at)
+      Fabricate(:subscription, member:, group:, created_at: at)
+    end
+
+    it 'counts a member in the month of their first coaching subscription' do
+      member = Fabricate(:member)
+      subscribe(member, students_group, Time.zone.local(2026, 5, 10))
+      subscribe(member, coaches_group, Time.zone.local(2026, 6, 10))
+
+      expect(cell(:transitions, 'Students who became coaches', [2026, 5])).to eq(0)
+      expect(cell(:transitions, 'Students who became coaches', [2026, 6])).to eq(1)
+      expect(total_for(:transitions, 'Students who became coaches')).to eq(1)
+    end
+
+    it 'counts members who kept their student subscription (across chapters)' do
+      member = Fabricate(:member)
+      subscribe(member, students_group, Time.zone.local(2026, 5, 10))
+      subscribe(member, coaches_group, Time.zone.local(2026, 6, 10))
+
+      expect(students_group.chapter_id).not_to eq(coaches_group.chapter_id)
+      expect(cell(:transitions, 'Students who became coaches', [2026, 6])).to eq(1)
+    end
+
+    it 'only counts the first coaching subscription' do
+      member = Fabricate(:member)
+      subscribe(member, students_group, Time.zone.local(2026, 4, 10))
+      subscribe(member, coaches_group, Time.zone.local(2026, 6, 10))
+      subscribe(member, Fabricate(:group, name: 'Coaches'), Time.zone.local(2026, 7, 10))
+
+      expect(cell(:transitions, 'Students who became coaches', [2026, 6])).to eq(1)
+      expect(cell(:transitions, 'Students who became coaches', [2026, 7])).to eq(0)
+    end
+
+    it 'does not count coaches who never had a student subscription' do
+      member = Fabricate(:member)
+      subscribe(member, coaches_group, Time.zone.local(2026, 6, 10))
+
+      expect(cell(:transitions, 'Students who became coaches', [2026, 6])).to eq(0)
+    end
+
+    it 'does not count a coaching subscription created before the student one' do
+      member = Fabricate(:member)
+      subscribe(member, coaches_group, Time.zone.local(2026, 5, 10))
+      subscribe(member, students_group, Time.zone.local(2026, 6, 10))
+
+      expect(total_for(:transitions, 'Students who became coaches')).to eq(0)
+    end
+  end
+
   describe 'sign-up rows (R4, D8)' do
     it 'Covers AE3. assigns a members-only-coaches group member to the coaches row' do
       member = Fabricate(:member, created_at: Time.zone.local(2026, 6, 10, 14, 0))