require 'active_record'

ActiveRecord::Base.establish_connection(:adapter=>"sqlite3",:database=>":memory:")

ActiveRecord::Schema.define do
  create_table :events do |table|
    table.column :title, :string, :null => false
    table.column :start_at, :datetime, :null => false
    table.column :end_at, :datetime, :null => false
  end

  create_table :registration_announcements do |table|
    table.references :event
    table.column :announcement, :string
    table.column :cutoff_at, :datetime
  end

  create_table :registrations do |table|
    table.references :registration_announcement
    table.column :contact_email, :string, :null => false
    table.column :adults, :integer, :default => 0
    table.column :children, :integer, :default => 0
  end
end

class Event < ActiveRecord::Base
  has_one :registration_announcement
end

class RegistrationAnnouncement < ActiveRecord::Base
  belongs_to :event
  has_many :registrations
end

class Registration < ActiveRecord::Base
  belongs_to :registration_announcement
end

puts 'Scenario 1'
@e1 = Event.create(:title => "Bake Sale", :start_at => '2010-12-15 12pm', :end_at => '2010-12-15 4pm')
@a1 = @e1.build_registration_announcement(:announcement => "Please bring a favorite baked dish.")
@a1.registrations.build(:contact_email => "jdoe@yahoo.com", :adults => 1)
#registration doesn't know about its unsaved registration_announcement parent
puts @a1.registrations.first.registration_announcement  #=> nil

puts 'Scenario 2'
@e2 = Event.create(:title => "Community Yard Sale", :start_at => '2010-11-16 10am', :end_at => '2010-11-16 3pm')
@a2 = @e2.create_registration_announcement(:announcement => "Fall house cleaning!")
@a2.registrations.build(:contact_email => "tara.smith@yahoo.com", :adults => 5)
#registration knows about its saved registration_announcement parent
puts @a2.registrations.first.registration_announcement #=> <#RegistrationAnnouncement:...>

puts 'Scenario 3'
@e3 = Event.create(:title => "Hoagie Sale", :start_at => '2010-11-10 1pm', :end_at => '2010-11-10 6pm')
@a3 = @e3.build_registration_announcement(:announcement => "Italian hoagies for $4.00.")
r = @a3.registrations.build(:contact_email => "ethan.allen@yahoo.com", :adults => 1)
r.registration_announcement = @e.registration_announcement
#registration knows about its unsaved registration_announcement parent but only because we explicitly assigned the parent (line immediately above)
puts @a3.registrations.first.registration_announcement #=> <#RegistrationAnnouncement:...>