feat(dunning): Populate dunning_campaign_completed on existing customers

db/migrate/20241126102447_set_dunning_campaign_completed_to_customers.rb

@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+class SetDunningCampaignCompletedToCustomers < ActiveRecord::Migration[7.1]
+  def change
+    reversible do |dir|
+      dir.up do
+        safety_assured do
+          # Set dunning_campaign_completed when the explicit assigned campaign is completed.
+          execute <<-SQL
+            UPDATE customers c
+            SET dunning_campaign_completed = true
+            FROM dunning_campaigns dc
+            WHERE c.applied_dunning_campaign_id = dc.id
+            AND c.dunning_campaign_completed = false
+            AND c.last_dunning_campaign_attempt >= dc.max_attempts;
+          SQL
+
+          # Set dunning_campaign_completed when the campaign inherited from organization is completed.
+          execute <<-SQL
+            UPDATE customers c
+            SET dunning_campaign_completed = true
+            FROM dunning_campaigns dc
+            WHERE c.organization_id = dc.organization_id
+            AND dc.applied_to_organization = true
+            AND c.applied_dunning_campaign_id IS NULL
+            AND c.dunning_campaign_completed = false
+            AND c.exclude_from_dunning_campaign = false
+            AND c.last_dunning_campaign_attempt >= dc.max_attempts;
+          SQL
+        end
+      end
+    end
+  end
+end