Genshin/GAKUEngine

module Gaku
  class GradingMethodConnector < ActiveRecord::Base
    belongs_to :grading_method, required: false
    belongs_to :gradable, polymorphic: true, required: false

    validates :grading_method_id, :gradable_id, :gradable_type, presence: true

    validates(
      :gradable_type,
      inclusion: {
        in: %w[Gaku::Exam Gaku::Course Gaku::ExamSession],
        message: '%value is not a valid'
      }
    )

    validates :grading_method_id, uniqueness: { scope: %i[gradable_type gradable_id] }

    default_scope { order('position ASC') }

    before_create :proper_position
    after_destroy :refresh_positions

    private

    def proper_position
      self.position = gradable.grading_method_connectors.count if gradable
    end

    def refresh_positions
      gradable.grading_method_connectors.each_with_index do |id, index|
        gradable.grading_method_connectors.where(id: id).update_all(position: index)
      end
    end
  end
end