module Concernz
  module Booking
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'booking_id'

      # Booking involves Person
      belongs_to :person, :foreign_key => :person_id

      # Booking involves Session
      belongs_to :session, :foreign_key => :session_id

      # Booking is involved in Seat Allocation
      has_many :seat_allocations, :class_name => 'SeatAllocation', :foreign_key => :booking_id, :dependent => :destroy
      has_many :seats, :through => :seat_allocations

      validates :number, :presence => true
      validates :person_id, :presence => true
      validates :session_id, :presence => true
    end
  end
end

module Concernz
  module Cinema
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'cinema_id'

      # Cinema contains Row and Row contains Seat
      has_many :seats_via_row, :class_name => 'Seat', :foreign_key => :row_cinema_id, :dependent => :destroy
      has_many :row_nrs, :through => :seats_via_row

      # Cinema is involved in Session
      has_many :sessions, :class_name => 'Session', :foreign_key => :cinema_id, :dependent => :destroy
    end
  end
end

module Concernz
  module Film
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'film_id'

      # Film is involved in Session
      has_many :sessions, :class_name => 'Session', :foreign_key => :film_id, :dependent => :destroy
    end
  end
end

module Concernz
  module Person
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'person_id'

      # Person is involved in Booking
      has_many :bookings, :class_name => 'Booking', :foreign_key => :person_id, :dependent => :destroy

      validates :login_name, :presence => true
    end
  end
end

module Concernz
  module Seat
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'seat_id'

      # Seat is in Row and Row is in Cinema
      belongs_to :cinema_via_row, :class_name => 'Cinema', :foreign_key => :row_cinema_id

      # Seat is involved in Seat Allocation
      has_many :seat_allocations, :class_name => 'SeatAllocation', :foreign_key => :allocated_seat_id, :dependent => :destroy
      has_many :bookings, :through => :seat_allocations

      validates :row_cinema_id, :presence => true
      validates :row_nr, :presence => true
      validates :seat_number, :presence => true
    end
  end
end

module Concernz
  module SeatAllocation
    extend ActiveSupport::Concern
    included do
      # Seat Allocation involves Booking
      belongs_to :booking, :foreign_key => :booking_id

      # Seat Allocation involves Seat
      belongs_to :allocated_seat, :class_name => 'Seat', :foreign_key => :allocated_seat_id

      validates :booking_id, :presence => true
      validates :allocated_seat_id, :presence => true
    end
  end
end

module Concernz
  module Session
    extend ActiveSupport::Concern
    included do
      self.primary_key = 'session_id'

      # Session involves Cinema
      belongs_to :cinema, :foreign_key => :cinema_id

      # Session involves Film
      belongs_to :film, :foreign_key => :film_id

      # Session is involved in Booking
      has_many :bookings, :class_name => 'Booking', :foreign_key => :session_id, :dependent => :destroy

      validates :cinema_id, :presence => true
      validates :date_time_value, :presence => true
      validates :film_id, :presence => true
    end
  end
end