feat(ProgressiveBilling): Update PDF template (#2465)

## Context

AI companies want their users to pay before the end of a period if usage
skyrockets. The problem being that self-serve companies can overuse
their API without paying, triggering lots of costs on their side.

## Description

This PR updates the PDF templates to render:
- Progressive billing invoices
- Credits for previous progressive billing invoices

app/models/credit.rb

@@ -16,6 +16,7 @@ class Credit < ApplicationRecord
 
   scope :coupon_kind, -> { where.not(applied_coupon_id: nil) }
   scope :credit_note_kind, -> { where.not(credit_note_id: nil) }
+  scope :progressive_billing_invoice_kind, -> { where.not(progressive_billing_invoice_id: nil) }
 
   def item_id
     return coupon&.id if applied_coupon_id

app/views/templates/invoices/v4.slim

@@ -455,6 +455,8 @@ html
           == SlimHelper.render('templates/invoices/v4/_credit', self)
         - elsif subscriptions.count == 1
           == SlimHelper.render('templates/invoices/v4/_subscription_details', self)
+        - elsif progressive_billing?
+          == SlimHelper.render('templates/invoices/v4/_progressive_billing_details', self)
         - else
           == SlimHelper.render('templates/invoices/v4/_subscriptions_summary', self)
 

app/views/templates/invoices/v4/_progressive_billing_details.slim

@@ -0,0 +1,96 @@
+- subscription = subscriptions.first
+- invoice_subscription = invoice_subscription(subscription.id)
+
+/ Subscription fee section
+.invoice-resume.overflow-auto
+  table.invoice-resume-table width="100%"
+    tr.first_child
+      td.body-2 = I18n.t('invoice.fees_from_to_date', from_date: I18n.l(invoice_subscription.charges_from_datetime_in_customer_timezone&.to_date, format: :default), to_date: I18n.l(invoice_subscription.charges_to_datetime_in_customer_timezone&.to_date, format: :default))
+      td.body-2 = I18n.t('invoice.units')
+      td.body-2 = I18n.t('invoice.unit_price')
+      td.body-2 = I18n.t('invoice.tax_rate')
+      td.body-2 = I18n.t('invoice.amount')
+
+/ Charge fees section for subscription invoice
+- if subscription_fees(subscription.id).charge_kind.any?
+  / Charges payed in arrears OR charges and plan payed in advance
+  - if subscription.plan.charges.any?
+    .invoice-resume.overflow-auto
+      table.invoice-resume-table width="100%"
+
+        / Loop over all top level fees
+        - subscription_fees(subscription.id).charge_kind.positive_units.where(true_up_parent_fee: nil).joins(charge: :billable_metric).sort_by { |f| f.invoice_sorting_clause }.group_by(&:charge_id).each do |_charge_id, fees|
+          - fee = fees.first
+          - next if fee.charge.pay_in_advance?
+
+          / Fees for filters
+          - if fees.all? { |f| f.charge_filter_id? } && fees.sum(&:units) > 0
+            - fees.select { |f| f.units.positive? }.each do |fee|
+              - if fee.amount_details.blank?
+                == SlimHelper.render('templates/invoices/v4/_default_fee_with_filters', fee)
+              - else
+                == SlimHelper.render('templates/invoices/v4/_fee_with_filters', fee)
+
+            / True up fees attached to the fee
+            - fees.select { |f| f.true_up_fee.present? }.each do |fee|
+              == SlimHelper.render('templates/invoices/v4/_true_up_fee', fee)
+
+          / Fees without filters
+          - else
+            - fees.sort_by { |f| f.invoice_sorting_clause }.each do |fee|
+              == SlimHelper.render('templates/invoices/v4/_fees_without_filters', fee)
+
+/ Total section
+.invoice-resume.overflow-auto
+  table.total-table width="100%"
+    - if progressive_billing_credit_amount_cents.positive?
+      - credits.progressive_billing_invoice_kind.order(created_at: :asc) do |credit|
+        tr
+          td.body-2
+          / TODO(ProgressiveBilling): apply the right label
+          td.body-2 #{credit.item_name}
+          td.body-2 = '-' + MoneyHelper.format(credit.amount)
+
+    - if coupons_amount_cents.positive?
+      - credits.coupon_kind.order(created_at: :asc).each do |credit|
+        tr
+          td.body-2
+          td.body-2 #{credit.invoice_coupon_display_name}
+          td.body-2 = '-' +  MoneyHelper.format(credit.amount)
+    tr
+      td.body-2
+      td.body-2 = I18n.t('invoice.sub_total_without_tax')
+      td.body-2 = MoneyHelper.format(sub_total_excluding_taxes_amount)
+    - if applied_taxes.present?
+      - applied_taxes.order(tax_rate: :desc).each do |applied_tax|
+        tr
+          td.body-2
+          - if applied_tax.applied_on_whole_invoice?
+            td.body-2 = I18n.t('invoice.tax_name_only.' + applied_tax.tax_code)
+          - else
+            td.body-2 = I18n.t('invoice.tax_name', name: applied_tax.tax_name, rate: applied_tax.tax_rate, amount: MoneyHelper.format(applied_tax.fees_amount))
+            td.body-2 = MoneyHelper.format(applied_tax.amount)
+    - else
+      tr
+        td.body-2
+        td.body-2 = I18n.t('invoice.tax_name_with_details', name: 'Tax', rate: 0)
+        td.body-2 = MoneyHelper.format(0.to_money(currency))
+    tr
+      td.body-2
+      td.body-2 = I18n.t('invoice.sub_total_with_tax')
+      td.body-2 = MoneyHelper.format(sub_total_including_taxes_amount)
+    - if credits.credit_note_kind.any?
+      tr
+        td.body-2
+        td.body-2 = I18n.t('invoice.credit_notes')
+        td.body-2 = '-' +  MoneyHelper.format(credit_notes_amount)
+    - if subscription? && wallet_transactions.exists?
+      tr
+        td.body-2
+        td.body-2 = I18n.t('invoice.prepaid_credits')
+        td.body-2 = '-' + MoneyHelper.format(prepaid_credit_amount)
+    tr
+      td.body-2
+      td.body-1 = I18n.t('invoice.total_due')
+      td.body-1
+        = MoneyHelper.format(total_amount)

app/views/templates/invoices/v4/_subscription_details.slim

@@ -1,4 +1,4 @@
-- if subscription? || progressive_billing?
+- if subscription?
   - subscriptions.each do |subscription|
     - invoice_subscription = invoice_subscription(subscription.id)
     - subscription_fee = invoice_subscription.subscription_fee
@@ -52,16 +52,6 @@
                 - fees.sort_by { |f| f.invoice_sorting_clause }.each do |fee|
                   == SlimHelper.render('templates/invoices/v4/_fees_without_filters', fee)
 
-        / Progressive billing fees
-        - if progressive_billing?
-          - fees.sort_by { |f| f.invoice_sorting_clause }.each do |fee|
-            tr
-              td.body-1 = fee.invoice_name
-              td.body-2 = fee.units
-              td.body-2 = MoneyHelper.format(fee.amount)
-              td.body-2 == TaxHelper.applied_taxes(fee)
-              td.body-2 = MoneyHelper.format(fee.amount)
-
     / Charge fees section for subscription invoice
     - if subscription? && subscription_fees(subscription.id).charge_kind.any?
       / Charges payed in arrears OR charges and plan payed in advance
@@ -146,6 +136,14 @@
       table.total-table width="100%"
         - if subscriptions.count == 1
           - unless credit?
+            - if progressive_billing_credit_amount_cents.positive?
+              - credits.progressive_billing_invoice_kind.order(created_at: :asc) do |credit|
+                tr
+                  td.body-2
+                  / TODO(ProgressiveBilling): apply the right label
+                  td.body-2 #{credit.item_name}
+                  td.body-2 = '-' + MoneyHelper.format(credit.amount)
+
             - if coupons_amount_cents.positive?
               - credits.coupon_kind.order(created_at: :asc).each do |credit|
                 tr

app/views/templates/invoices/v4/_subscriptions_summary.slim

@@ -14,6 +14,14 @@ table.invoice-resume-table width="100%"
 
 table.total-table width="100%"
   - unless credit?
+    - if progressive_billing_credit_amount_cents.positive?
+      - credits.progressive_billing_invoice_kind.order(created_at: :asc) do |credit|
+        tr
+          td.body-2
+          / TODO(ProgressiveBilling): apply the right label
+          td.body-2 #{credit.item_name}
+          td.body-2 = '-' + MoneyHelper.format(credit.amount)
+
     - if coupons_amount_cents.positive?
       - credits.coupon_kind.order(created_at: :asc).each do |credit|
         tr

spec/services/invoices/progressive_billing_service_spec.rb

@@ -10,7 +10,7 @@
   let(:organization) { plan.organization }
 
   let(:customer) { create(:customer, organization:) }
-  let(:subscription) { create(:subscription, plan:, customer:) }
+  let(:subscription) { create(:subscription, plan:, customer:, started_at: timestamp - 1.week) }
   let(:lifetime_usage) { create(:lifetime_usage, subscription:, organization:) }
 
   let(:timestamp) { Time.zone.parse('2024-08-22 10:00:00') }