Add API v1 financial_transactions POST endpoint

In a first step we allow members to create financial transactions
for their own ordergroup.

app/controllers/api/v1/user/financial_transactions_controller.rb

@@ -3,6 +3,8 @@ class Api::V1::User::FinancialTransactionsController < Api::V1::BaseController
 
   before_action ->{ doorkeeper_authorize! 'finance:user' }
   before_action :require_ordergroup
+  before_action :require_minimum_balance, only: [:create]
+  before_action -> { require_config_enabled :use_self_service }, only: [:create]
 
   def index
     render_collection search_scope
@@ -12,10 +14,20 @@ class Api::V1::User::FinancialTransactionsController < Api::V1::BaseController
     render json: scope.find(params.require(:id))
   end
 
+  def create
+    transaction_type = FinancialTransactionType.find(create_params[:financial_transaction_type_id])
+    ft = current_ordergroup.add_financial_transaction!(create_params[:amount], create_params[:note], current_user, transaction_type)
+    render json: ft
+  end
+
   private
 
   def scope
     current_ordergroup.financial_transactions.includes(:user, :financial_transaction_type)
   end
 
+  def create_params
+    params.require(:financial_transaction).permit(:amount, :financial_transaction_type_id, :note)
+  end
+
 end

app/models/ordergroup.rb

@@ -90,6 +90,7 @@ class Ordergroup < Group
       if t.amount < 0 && self.account_balance < 0 && self.account_balance - t.amount >= 0
         Resque.enqueue(UserNotifier, FoodsoftConfig.scope, 'negative_balance', self.id, t.id)
       end
+      t
     end
   end