feat(edit-draft-invoice): Apply adjusted fee on subscription fee

app/services/adjusted_fees/create_service.rb

@@ -24,13 +24,13 @@ def call
         subscription: fee.subscription,
         charge: fee.charge,
         group: fee.group,
-        adjusted_units: params[:unit_amount_cents]&.blank?,
-        adjusted_amount: params[:unit_amount_cents]&.present?,
+        adjusted_units: params[:unit_amount_cents].blank?,
+        adjusted_amount: params[:unit_amount_cents].present?,
         invoice_display_name: params[:invoice_display_name],
         fee_type: fee.fee_type,
         properties: fee.properties,
-        units: params[:units],
-        unit_amount_cents: params[:unit_amount_cents],
+        units: params[:units] || 0,
+        unit_amount_cents: params[:unit_amount_cents] || 0,
       )
 
       adjusted_fee.save!

app/services/fees/subscription_service.rb

@@ -14,8 +14,29 @@ def create
       return result if already_billed?
 
       new_amount_cents = compute_amount.round
+      new_fee = initialize_fee(new_amount_cents)
+      new_fee.precise_unit_amount = new_fee.unit_amount.to_f
+
+      ActiveRecord::Base.transaction do
+        new_fee.save!
+        adjusted_fee.update!(fee: new_fee) if invoice.draft? && adjusted_fee
+      end
+
+      result.fee = new_fee
+      result
+    rescue ActiveRecord::RecordInvalid => e
+      result.record_validation_failure!(record: e.record)
+    end
+
+    private
+
+    attr_reader :invoice, :subscription, :boundaries
+
+    delegate :customer, to: :invoice
+    delegate :previous_subscription, :plan, to: :subscription
 
-      new_fee = Fee.new(
+    def initialize_fee(new_amount_cents)
+      base_fee = Fee.new(
         invoice:,
         subscription:,
         amount_cents: new_amount_cents,
@@ -29,21 +50,31 @@ def create
         taxes_amount_cents: 0,
         unit_amount_cents: new_amount_cents,
       )
-      new_fee.precise_unit_amount = new_fee.unit_amount.to_f
-      new_fee.save!
 
-      result.fee = new_fee
-      result
-    rescue ActiveRecord::RecordInvalid => e
-      result.record_validation_failure!(record: e.record)
-    end
+      return base_fee unless invoice.draft?
+      return base_fee unless adjusted_fee
 
-    private
+      units = adjusted_fee.units
+      unit_amount_cents = adjusted_fee.unit_amount_cents.round
+      amount_cents = adjusted_fee.adjusted_units? ? (units * new_amount_cents) : (units * unit_amount_cents)
 
-    attr_reader :invoice, :subscription, :boundaries
+      base_fee.amount_cents = amount_cents.round
+      base_fee.units = units
+      base_fee.unit_amount_cents = adjusted_fee.adjusted_units? ? new_amount_cents : unit_amount_cents
+      base_fee.invoice_display_name = adjusted_fee.invoice_display_name
 
-    delegate :customer, to: :invoice
-    delegate :previous_subscription, :plan, to: :subscription
+      base_fee
+    end
+
+    def adjusted_fee
+      return @adjusted_fee if defined? @adjusted_fee
+
+      @adjusted_fee = AdjustedFee
+        .where(invoice:, subscription:, fee_type: :subscription)
+        .where("properties->>'from_datetime' = ?", boundaries.from_datetime&.iso8601(3))
+        .where("properties->>'to_datetime' = ?", boundaries.to_datetime&.iso8601(3))
+        .first
+    end
 
     def already_billed?
       existing_fee = invoice.fees.subscription_kind.find_by(subscription_id: subscription.id)

spec/scenarios/invoices/adjusted_subscription_fees_spec.rb

@@ -0,0 +1,137 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe 'Adjusted Subscription Fees Scenario', :scenarios, type: :request, transaction: false do
+  let(:organization) { create(:organization, webhook_url: nil, email_settings: '') }
+
+  let(:customer) { create(:customer, organization:, invoice_grace_period: 5) }
+  let(:subscription_at) { DateTime.new(2023, 7, 19, 12, 12) }
+  let(:unit_amount_cents) { nil }
+
+  let(:adjusted_fee_params) do
+    {
+      invoice_display_name: 'test-name-25',
+      unit_amount_cents:,
+      units: 3,
+    }
+  end
+
+  let(:monthly_plan) do
+    create(
+      :plan,
+      organization:,
+      interval: 'monthly',
+      amount_cents: 12_900,
+      pay_in_advance: false,
+    )
+  end
+
+  around { |test| lago_premium!(&test) }
+
+  context 'with adjusted units' do
+    it 'creates invoices correctly' do
+      # NOTE: Jul 19th: create the subscription
+      travel_to(subscription_at) do
+        create_subscription(
+          {
+            external_customer_id: customer.external_id,
+            external_id: customer.external_id,
+            plan_code: monthly_plan.code,
+            billing_time: 'anniversary',
+            subscription_at: subscription_at.iso8601,
+          },
+        )
+      end
+
+      # NOTE: August 19th: Bill subscription
+      travel_to(DateTime.new(2023, 8, 19, 12, 12)) do
+        Subscriptions::BillingService.call
+        perform_all_enqueued_jobs
+
+        invoice = customer.invoices.order(created_at: :desc).first
+        fee = invoice.fees.first
+
+        expect(invoice.status).to eq('draft')
+        expect(invoice.total_amount_cents).to eq(12_900)
+
+        AdjustedFees::CreateService.call(organization:, fee:, params: adjusted_fee_params)
+        perform_all_enqueued_jobs
+
+        expect(invoice.reload.status).to eq('draft')
+        expect(invoice.reload.total_amount_cents).to eq(38_700)
+      end
+
+      # NOTE: August 20th: Refresh and finalize invoice
+      travel_to(DateTime.new(2023, 8, 20, 12, 12)) do
+        invoice = customer.invoices.order(created_at: :desc).first
+
+        Invoices::RefreshDraftJob.perform_later(invoice)
+        perform_all_enqueued_jobs
+
+        expect(invoice.reload.status).to eq('draft')
+        expect(invoice.reload.total_amount_cents).to eq(38_700)
+
+        Invoices::FinalizeJob.perform_later(invoice)
+        perform_all_enqueued_jobs
+
+        expect(invoice.reload.status).to eq('finalized')
+        expect(invoice.reload.total_amount_cents).to eq(38_700)
+      end
+    end
+  end
+
+  context 'with adjusted amount' do
+    let(:unit_amount_cents) { 15_000 }
+
+    it 'creates invoices correctly' do
+      # NOTE: Jul 19th: create the subscription
+      travel_to(subscription_at) do
+        create_subscription(
+          {
+            external_customer_id: customer.external_id,
+            external_id: customer.external_id,
+            plan_code: monthly_plan.code,
+            billing_time: 'anniversary',
+            subscription_at: subscription_at.iso8601,
+          },
+        )
+      end
+
+      # NOTE: August 19th: Bill subscription
+      travel_to(DateTime.new(2023, 8, 19, 12, 12)) do
+        Subscriptions::BillingService.call
+        perform_all_enqueued_jobs
+
+        invoice = customer.invoices.order(created_at: :desc).first
+        fee = invoice.fees.first
+
+        expect(invoice.status).to eq('draft')
+        expect(invoice.total_amount_cents).to eq(12_900)
+
+        AdjustedFees::CreateService.call(organization:, fee:, params: adjusted_fee_params)
+        perform_all_enqueued_jobs
+
+        expect(invoice.reload.status).to eq('draft')
+        expect(invoice.reload.total_amount_cents).to eq(45_000)
+      end
+
+      # NOTE: August 20th: Refresh and finalize invoice
+      travel_to(DateTime.new(2023, 8, 20, 12, 12)) do
+        invoice = customer.invoices.order(created_at: :desc).first
+
+        Invoices::RefreshDraftJob.perform_later(invoice)
+        perform_all_enqueued_jobs
+
+        expect(invoice.reload.status).to eq('draft')
+        expect(invoice.reload.total_amount_cents).to eq(45_000)
+
+        Invoices::FinalizeJob.perform_later(invoice)
+        perform_all_enqueued_jobs
+
+        expect(invoice.reload.status).to eq('finalized')
+        expect(invoice.reload.total_amount_cents).to eq(45_000)
+      end
+    end
+  end
+end

spec/services/fees/subscription_service_spec.rb

@@ -97,6 +97,100 @@
         end
       end
     end
+
+    context 'when there is adjusted fee' do
+      let(:adjusted_fee) do
+        create(
+          :adjusted_fee,
+          invoice:,
+          subscription:,
+          properties:,
+          adjusted_units: true,
+          adjusted_amount: false,
+          units: 3,
+        )
+      end
+      let(:properties) do
+        {
+          from_datetime: boundaries[:from_datetime],
+          to_datetime: boundaries[:to_datetime],
+        }
+      end
+
+      before do
+        adjusted_fee
+        invoice.draft!
+      end
+
+      context 'with adjusted units' do
+        it 'creates a fee' do
+          result = fees_subscription_service.create
+
+          expect(result.fee).to have_attributes(
+            id: String,
+            invoice_id: invoice.id,
+            amount_cents: 300,
+            amount_currency: 'EUR',
+            units: 3,
+            events_count: nil,
+            payment_status: 'pending',
+            unit_amount_cents: 100,
+            precise_unit_amount: 1,
+          )
+        end
+      end
+
+      context 'with adjusted amount' do
+        let(:adjusted_fee) do
+          create(
+            :adjusted_fee,
+            invoice:,
+            subscription:,
+            properties:,
+            adjusted_units: false,
+            adjusted_amount: true,
+            units: 3,
+            unit_amount_cents: 200,
+          )
+        end
+
+        it 'creates a fee' do
+          result = fees_subscription_service.create
+
+          expect(result.fee).to have_attributes(
+            id: String,
+            invoice_id: invoice.id,
+            amount_cents: 600,
+            amount_currency: 'EUR',
+            units: 3,
+            events_count: nil,
+            payment_status: 'pending',
+            unit_amount_cents: 200,
+            precise_unit_amount: 2,
+          )
+        end
+      end
+
+      context 'with invoice NOT in draft status' do
+        before { invoice.finalized! }
+
+        it 'creates a fee without using adjusted fee attributes' do
+          result = fees_subscription_service.create
+
+          expect(result.fee).to have_attributes(
+            id: String,
+            invoice_id: invoice.id,
+            amount_cents: 100,
+            amount_currency: 'EUR',
+            units: 1,
+            events_count: nil,
+            payment_status: 'pending',
+            unit_amount_cents: 100,
+            precise_unit_amount: 1,
+          )
+        end
+      end
+    end
   end
 
   context 'when subscription has never been billed' do