class Building < ActiveRecord::Base
  belongs_to :tribe
  belongs_to :blueprint
  has_one :location, :as => :locateable

  validates_presence_of :tribe_id
  validates_presence_of :blueprint_id

  validate :must_own_location
  validate :must_have_prerequisite_buildings
#  validate :must_have_technology TODO: implement this
#  validate :must_have_materials TODO: implement this


  def prerequisites_met?
    check_prerequisite_buildings
  end


  private
  def must_own_location
    errors.add_to_base "Must own build location" unless (location.island.tribe == tribe)
  end


## Building prerequisites
  def must_have_prerequisite_buildings
    unless prerequisite_buildings.nil?
      prerequisite_buildings.each do |prerequisite|
        errors.add_to_base "Missing Required Building #{prerequisite.name}" unless tribe.buildings.find_by_blueprint_id(prerequisite)
      end
    end
  end

  def check_prerequisite_buildings
    unless prerequisite_buildings.nil?
      prerequisite_buildings.each do |prerequisite|
        # TODO: implement me
        return nil
      end
    end
  end

  def prerequisite_buildings
    prerequisites ||= load_prerequisite_buildings
  end

  def load_prerequisite_buildings
    prerequisites = nil
    unless blueprint.requirements.nil? then
      prerequisites = Array.new
      blueprint.requirements.each do |requirement|
        prerequisites << requirement.prerequisite
      end
      return prerequisites
    end
  end
end