class EcYear < ApplicationRecord
  belongs_to :ec_major_school

  # 课堂配置
  has_many :ec_courses, dependent: :destroy
  has_many :ec_course_targets, through: :ec_courses
  has_one :ec_training_objective, dependent: :destroy
  has_many :ec_training_subitems, through: :ec_training_objective
  has_many :ec_graduation_requirements, dependent: :destroy
  has_many :ec_graduation_subitems, through: :ec_graduation_requirements
  has_many :ec_year_students, dependent: :destroy

  has_many :ec_course_users, dependent: :destroy
  has_many :managers, through: :ec_course_users, source: :user

  def prev_year
    self.class.find_by(year: year.to_i - 1)
  end
end