class CharacterItem < ApplicationRecord
  belongs_to :character
  belongs_to :item
  validates :quantity, presence: true

  after_initialize do
    if self.new_record?
      self.quantity ||= 0
    end
  end

  after_save :destroy_if_zero_quantity

  scope :ordered_by_item_name, -> { includes(:item).order("items.name") }

  private
    def destroy_if_zero_quantity
      if self.quantity == 0
        destroy
      elsif self.quantity < 0
        # TODO: Can improve this (at the least, with reporting, later).
        raise ItemQuantityError
      end
    end
end