class CourseSecondCategory < ApplicationRecord
  default_scope { order("course_second_categories.position ASC") }

  belongs_to :course
  belongs_to :course_module
  belongs_to :parent, class_name: "CourseSecondCategory", foreign_key: "parent_id", optional: true

  has_many :homework_commons
  has_many :children, -> { order(position: :asc ) }, class_name: "CourseSecondCategory", foreign_key: "parent_id", dependent: :destroy

  scope :first_categories,                   -> { where(parent_id: 0) }

  validates :name, length: { maximum: 60, too_long: "不能超过60个字符" }

  def category_type_str
    category_type == "graduation" && name == "毕设选题" ? "graduation_topics" : (
    category_type == "graduation" && name == "毕设任务" ? "graduation_tasks" : category_type
    )
  end

  def homework_publish_count
    homework_commons.select{|homework| homework.publish_time.present? && homework.publish_time <= Time.now}.size
  end

  def homework_unpublish_count
    homework_commons.select{|homework| homework.publish_time.nil? || homework.publish_time > Time.now}.size
  end

end