class Lecture < ApplicationRecord
  belongs_to :course
  has_one :recording, dependent: :nullify

  has_many :tracked_time_entries, dependent: :destroy, as: :subject

  enum :kind, [
    :lecture,
    :problems_class,
  ], default: :lecture

  def prepared?
    tracked_time_entries.where(kind: [:preparation]).any?
  end

  def attended?
    tracked_time_entries.where(kind: [:concurrent, :catchup]).any?
  end

  def reviewed?
    tracked_time_entries.where(kind: [:review]).any?
  end

  def total_preparation_time
    tracked_time_entries.preparation.sum(&:duration).seconds
  end

  def total_overall_time
    tracked_time_entries.sum(&:duration).seconds
  end

  def total_attendance_time
    tracked_time_entries.where(kind: [:concurrent, :catchup]).sum(&:duration).seconds
  end

  def total_review_time
    tracked_time_entries.review.sum(&:duration).seconds
  end

  def week_number
    ((start_time.beginning_of_week - course.semester_start_date.to_time) / 1.week).floor + 1
  end

  def live_video_url
    nil
  end
end