class MigrateBankReferenceId < ActiveRecord::Migration[5.2]
  def change
    HomeworkBank.all.each do |bank|
      if bank.homework_common
        bank.homework_common.update_column("homework_bank_id", bank.id) if bank.homework_common.homework_bank_id.nil?
      end
    end

    GtopicBank.all.each do |bank|
      if bank.graduation_topic
        bank.graduation_topic.update_column("gtopic_bank_id", bank.id) if bank.graduation_topic.gtopic_bank_id.nil?
      end
    end

    GtaskBank.all.each do |bank|
      if bank.graduation_task
        bank.graduation_task.update_column("gtask_bank_id", bank.id) if bank.graduation_task.gtask_bank_id.nil?
      end
    end

    ExerciseBank.all.each do |bank|
      if bank.container_type == 'Exercise'
        exercise = Exercise.find_by(id: bank.container_id)
        exercise.update_column("exercise_bank_id", bank.id) if exercise && exercise.exercise_bank_id.nil?
      elsif bank.container_type == 'Poll'
        poll = Poll.find_by(id: bank.container_id)
        poll.update_column("exercise_bank_id", bank.id) if poll && poll.exercise_bank_id.nil?
      end
    end
  end
end