[bug] payzen amount for non 2-decimals currencies

CHANGELOG.md

@@ -6,6 +6,7 @@
 - The upgrade script will check and report the ability to access the hub API
 - Fix a bug: missing translations
 - Fix a bug: the upgrade script report an invalid version to upgrade to
+- Fix a bug: invalid amount provided to the PayZen payment gateway when using a currency with anything else than 2 decimals
 - Updated @rails/webpacker to 5.4.3
 - Updated react-refresh-webpack-plugin to 0.5.1
 - Updated react-refresh to 0.10.0

app/controllers/api/payzen_controller.rb

@@ -25,7 +25,7 @@ class API::PayzenController < API::PaymentsController
     @id = PayZen::Helper.generate_ref(params[:cart_items], params[:customer_id])
 
     client = PayZen::Charge.new
-    @result = client.create_payment(amount: amount[:amount],
+    @result = client.create_payment(amount: PayZen::Service.new.payzen_amount(amount[:amount]),
                                     order_id: @id,
                                     customer: PayZen::Helper.generate_customer(params[:customer_id], current_user.id, params[:cart_items]))
   rescue PayzenError => e

lib/pay_zen/service.rb

@@ -18,14 +18,14 @@ class PayZen::Service < Payment::Service
     token_id = order['answer']['transactions'].first['paymentMethodToken']
 
     params = {
-      amount: first_item.details['recurring'].to_i,
+      amount: payzen_amount(first_item.details['recurring'].to_i),
       effect_date: first_item.due_date.iso8601,
       payment_method_token: token_id,
       rrule: rrule(payment_schedule),
       order_id: order_id
     }
     unless first_item.details['adjustment']&.zero? && first_item.details['other_items']&.zero?
-      params[:initial_amount] = first_item.amount
+      params[:initial_amount] = payzen_amount(first_item.amount)
       params[:initial_amount_number] = 1
     end
     pz_subscription = client.create_subscription(params)
@@ -81,6 +81,14 @@ class PayZen::Service < Payment::Service
     end
   end
 
+  def payzen_amount(amount)
+    currency = Setting.get('payzen_currency')
+    return amount / 100 if zero_decimal_currencies.any? { |s| s.casecmp(currency).zero? }
+    return amount * 10 if three_decimal_currencies.any? { |s| s.casecmp(currency).zero? }
+
+    amount
+  end
+
   private
 
   def rrule(payment_schedule)
@@ -96,4 +104,13 @@ class PayZen::Service < Payment::Service
       transaction_date >= payment_schedule_item.due_date.to_date &&
       transaction_date <= payment_schedule_item.due_date.to_date + 7.days
   end
+
+  # @see https://payzen.io/en-EN/payment-file/ips/list-of-supported-currencies.html
+  def zero_decimal_currencies
+    %w[KHR JPY KRW XOF XPF]
+  end
+
+  def three_decimal_currencies
+    %w[KWD TND]
+  end
 end