Add option to create foodcoop transaction when creating a collection

This option can be used, if a kind of "double-entry accounting" is used
and every transaction should have a corresponding transaction.

app/controllers/finance/financial_transactions_controller.rb

@@ -84,6 +84,7 @@ class Finance::FinancialTransactionsController < ApplicationController
 
     ActiveRecord::Base.transaction do
       financial_link = FinancialLink.new if params[:create_financial_link]
+      foodcoop_amount = 0
 
       params[:financial_transactions].each do |trans|
         # ignore empty amount fields ...
@@ -96,9 +97,21 @@ class Finance::FinancialTransactionsController < ApplicationController
             amount -= ordergroup.financial_transaction_class_balance(type.financial_transaction_class)
           end
           ordergroup.add_financial_transaction!(amount, note, @current_user, type, financial_link)
+          foodcoop_amount -= amount
         end
       end
 
+      if params[:create_foodcoop_transaction]
+        ft = FinancialTransaction.new({
+          financial_transaction_type: type,
+          user: @current_user,
+          amount: foodcoop_amount,
+          note: params[:note],
+          financial_link: financial_link,
+        })
+        ft.save!
+      end
+
       financial_link.try(&:save!)
     end
 

app/views/finance/financial_transactions/new_collection.html.haml

@@ -68,6 +68,11 @@
   %p
     = link_to t('.new_ordergroup'), '#', 'data-add-transaction' => true, class: 'btn'
     = link_to t('.add_all_ordergroups'), '#', 'data-add-all-ordergroups' => true, class: 'btn'
+  - if FinancialTransaction.where(ordergroup: nil).any?
+    %p
+      %label
+        = check_box_tag :create_foodcoop_transaction, true, params[:create_foodcoop_transaction]
+        = t('.create_foodcoop_transaction')
   - if BankAccount.any?
     %p
       %label