class Person < ApplicationRecord
  belongs_to :birth_country, class_name: Country.name
  has_many :admissions

  def stays
    stays = []
    admissions.ordered.includes(:country).all.each_cons(2) do |a, b|
      stays.push(
        country: a.country,
        arrival: a.arrived_on,
        departure: b.arrived_on,
        duration: (b.arrived_on - a.arrived_on).to_i + 1
      )
    end

    stays
  end
end