class SchoolCategory < ApplicationRecord

  belongs_to :school
  belongs_to :category

  validates_associated :school
  validates_associated :category

  scope :for, -> (school, category) { where(school: school).where(category: category) }
  scope :for_parent_category, -> (school, category=nil) { where(school: school).joins(:category).merge(Category.for_parent(category)) }

  def answer_index_average
    answer_index_total.to_f / response_count.to_f
  end

  def aggregated_responses
    attempt_data = Attempt.
      for_category(category).
      for_school(school).
      select('count(attempts.id) as attempt_count').
      select('count(attempts.answer_index) as response_count').
      select('sum(case when questions.reverse then 5 - attempts.answer_index else attempts.answer_index end) as answer_index_total')[0]

    return {
      attempt_count: attempt_data.attempt_count || 0,
      response_count: attempt_data.response_count || 0,
      answer_index_total: attempt_data.answer_index_total || 0
    }
  end

  def chained_aggregated_responses
    _aggregated_responses = aggregated_responses

    child_school_categories = category.child_categories.collect do |cc|
      SchoolCategory.for(school, cc)
    end.flatten

    return {
      attempt_count:
        _aggregated_responses[:attempt_count] +
        child_school_categories.inject(0) { |total, csc| total + csc.attempt_count },
      response_count:
        _aggregated_responses[:response_count] +
        child_school_categories.inject(0) { |total, csc| total + csc.response_count },
      answer_index_total:
        _aggregated_responses[:answer_index_total] +
        child_school_categories.inject(0) { |total, csc| total + csc.answer_index_total }
    }
  end

  def sync_aggregated_responses
    return if ENV['BULK_PROCESS']
    update_attributes(chained_aggregated_responses)
    if category.parent_category.present?
      parent_school_category = SchoolCategory.for(school, category.parent_category).first
      if parent_school_category.nil?
        parent_school_category = SchoolCategory.create(school: school, category: category.parent_category)
      end
      parent_school_category.sync_aggregated_responses
    end
  end
end