feat(dunning): Add dunning campaign to customer, database changes

 ## Roadmap Task

👉 https://getlago.canny.io/feature-requests/p/set-up-payment-retry-logic
👉 https://getlago.canny.io/feature-requests/p/send-reminders-for-overdue-invoices

 ## Context

We want to automate dunning process so that our users don't have to look at each customer to maximize their chances of being paid retrying payments of overdue balances and sending email reminders.

We're first automating the overdue balance payment request, before looking at individual invoices.

 ## Description

The goal of this change is to create set the relationship between
customers and dunning campaigns.

A customer could have one dunning campaign applied,
or, inherit its organization default campaign (none applied)
or, be excluded from dunning at all (with a boolean flag).

Also, when deleting a dunning campaign, all customers with the campaign
assigned must be reset.

app/models/clickhouse/events_enriched.rb

@@ -10,15 +10,15 @@ class EventsEnriched < BaseRecord
 #
 # Table name: events_enriched
 #
-#  code                       :string           not null, primary key
-#  decimal_value              :decimal(26, )
-#  enriched_at                :datetime         not null
-#  precise_total_amount_cents :decimal(40, 15)
-#  properties                 :string           not null
-#  sorted_properties          :string           not null
-#  timestamp                  :datetime         not null, primary key
-#  value                      :string
-#  external_subscription_id   :string           not null, primary key
-#  organization_id            :string           not null, primary key
-#  transaction_id             :string           not null
+#  aggregation_type         :string
+#  code                     :string           not null, primary key
+#  filters                  :string           not null
+#  grouped_by               :string           not null
+#  properties               :string           not null
+#  timestamp                :datetime         not null
+#  value                    :string
+#  charge_id                :string           not null, primary key
+#  external_subscription_id :string           not null, primary key
+#  organization_id          :string           not null, primary key
+#  transaction_id           :string           not null, primary key
 #

app/models/customer.rb

@@ -28,6 +28,7 @@ class Customer < ApplicationRecord
   before_save :ensure_slug
 
   belongs_to :organization
+  belongs_to :applied_dunning_campaign, optional: true, class_name: 'DunningCampaign'
 
   has_many :subscriptions
   has_many :events
@@ -192,55 +193,61 @@ def ensure_slug
 #
 # Table name: customers
 #
-#  id                           :uuid             not null, primary key
-#  address_line1                :string
-#  address_line2                :string
-#  city                         :string
-#  country                      :string
-#  currency                     :string
-#  customer_type                :enum
-#  deleted_at                   :datetime
-#  document_locale              :string
-#  email                        :string
-#  finalize_zero_amount_invoice :integer          default("inherit"), not null
-#  firstname                    :string
-#  invoice_grace_period         :integer
-#  lastname                     :string
-#  legal_name                   :string
-#  legal_number                 :string
-#  logo_url                     :string
-#  name                         :string
-#  net_payment_term             :integer
-#  payment_provider             :string
-#  payment_provider_code        :string
-#  phone                        :string
-#  shipping_address_line1       :string
-#  shipping_address_line2       :string
-#  shipping_city                :string
-#  shipping_country             :string
-#  shipping_state               :string
-#  shipping_zipcode             :string
-#  slug                         :string
-#  state                        :string
-#  tax_identification_number    :string
-#  timezone                     :string
-#  url                          :string
-#  vat_rate                     :float
-#  zipcode                      :string
-#  created_at                   :datetime         not null
-#  updated_at                   :datetime         not null
-#  external_id                  :string           not null
-#  external_salesforce_id       :string
-#  organization_id              :uuid             not null
-#  sequential_id                :bigint
+#  id                               :uuid             not null, primary key
+#  address_line1                    :string
+#  address_line2                    :string
+#  city                             :string
+#  country                          :string
+#  currency                         :string
+#  customer_type                    :enum
+#  deleted_at                       :datetime
+#  document_locale                  :string
+#  email                            :string
+#  exclude_from_dunning_campaign    :boolean          default(FALSE), not null
+#  finalize_zero_amount_invoice     :integer          default("inherit"), not null
+#  firstname                        :string
+#  invoice_grace_period             :integer
+#  last_dunning_campaign_attempt    :integer          default(0), not null
+#  last_dunning_campaign_attempt_at :datetime
+#  lastname                         :string
+#  legal_name                       :string
+#  legal_number                     :string
+#  logo_url                         :string
+#  name                             :string
+#  net_payment_term                 :integer
+#  payment_provider                 :string
+#  payment_provider_code            :string
+#  phone                            :string
+#  shipping_address_line1           :string
+#  shipping_address_line2           :string
+#  shipping_city                    :string
+#  shipping_country                 :string
+#  shipping_state                   :string
+#  shipping_zipcode                 :string
+#  slug                             :string
+#  state                            :string
+#  tax_identification_number        :string
+#  timezone                         :string
+#  url                              :string
+#  vat_rate                         :float
+#  zipcode                          :string
+#  created_at                       :datetime         not null
+#  updated_at                       :datetime         not null
+#  applied_dunning_campaign_id      :uuid
+#  external_id                      :string           not null
+#  external_salesforce_id           :string
+#  organization_id                  :uuid             not null
+#  sequential_id                    :bigint
 #
 # Indexes
 #
+#  index_customers_on_applied_dunning_campaign_id      (applied_dunning_campaign_id)
 #  index_customers_on_deleted_at                       (deleted_at)
 #  index_customers_on_external_id_and_organization_id  (external_id,organization_id) UNIQUE WHERE (deleted_at IS NULL)
 #  index_customers_on_organization_id                  (organization_id)
 #
 # Foreign Keys
 #
+#  fk_rails_...  (applied_dunning_campaign_id => dunning_campaigns.id)
 #  fk_rails_...  (organization_id => organizations.id)
 #

app/models/dunning_campaign.rb

@@ -6,7 +6,10 @@ class DunningCampaign < ApplicationRecord
   ORDERS = %w[name code].freeze
 
   belongs_to :organization
+
   has_many :thresholds, class_name: "DunningCampaignThreshold", dependent: :destroy
+  has_many :customers, foreign_key: :applied_dunning_campaign_id, dependent: :nullify
+
   accepts_nested_attributes_for :thresholds
 
   validates :name, presence: true

db/migrate/20241016104211_add_dunning_campaign_to_customers.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class AddDunningCampaignToCustomers < ActiveRecord::Migration[7.1]
+  def change
+    safety_assured do
+      change_table :customers, bulk: true do |t|
+        t.references :applied_dunning_campaign, type: :uuid, null: true, foreign_key: {to_table: :dunning_campaigns}, index: true
+        t.boolean :exclude_from_dunning_campaign, default: false, null: false
+        t.integer :last_dunning_campaign_attempt, default: 0, null: false
+        t.timestamp :last_dunning_campaign_attempt_at
+      end
+    end
+  end
+end

spec/models/customer_spec.rb

@@ -9,6 +9,8 @@
 
   it_behaves_like 'paper_trail traceable'
 
+  it { is_expected.to belong_to(:applied_dunning_campaign).optional }
+
   it { is_expected.to have_many(:integration_customers).dependent(:destroy) }
   it { is_expected.to have_many(:payment_requests) }
 

spec/models/dunning_campaign_spec.rb

@@ -9,6 +9,7 @@
 
   it { is_expected.to belong_to(:organization) }
   it { is_expected.to have_many(:thresholds).dependent(:destroy) }
+  it { is_expected.to have_many(:customers).dependent(:nullify) }
 
   it { is_expected.to validate_presence_of(:name) }