Creating payments rollback function

app/models/billing_period.rb

@@ -83,10 +83,7 @@ def print_rent_payback
   def claim_expenses_for_period
     Expense.update_all(["billing_period_id = ?", id], ["created_at >= ? AND created_at <= ?", start_time, end_time])
     TalliedConsumption.update_all(["billing_period_id = ?", id], ["created_at >= ? AND created_at <= ?", start_time, end_time])
-
-    # temp hack
-    TalliedConsumption.update_all(["billing_period_id = ?", BillingPeriod.first.id], ["created_at <= ?", Time.parse('April 19, 2011 20:00')])
-
+
     raise "Need to have entered alcohol consumption for the month!" unless tallied_consumptions.count >= User.count * TalliedItem.count
     puts "#{expenses.count} expenses for current billing period"
     puts "#{tallied_consumptions.count} tallied_consumptions for current billing period"

lib/tasks/payments.rake

@@ -4,6 +4,15 @@ namespace :payments  do
     BillingPeriod.compute_new_period
   end
 
+  desc "Undo the last rake payments:compute"
+  task :rollback => :environment do
+    bp = BillingPeriod.last
+    bp.expenses.each {|e| e.update_attribute :billing_period_id, nil}
+    bp.tallied_consumptions.each {|e| e.update_attribute :billing_period_id, nil}
+    bp.payments.each {|e| e.destroy}
+    bp.destroy
+  end
+
   desc "Send emails for each unpaid payment"
   task :request => :environment do
     Payment.unpaid.each { |p| p.request }