defmodule Ami.Unit do
  use Ecto.Schema

  alias Ami.{
    Course,
    Lesson,
    UnitLesson
  }

  schema "units" do
    field(:title, :string)
    field(:description, :string)
    field(:grade_value, :integer)
    field(:position, :integer)
    field(:created_at, :utc_datetime)
    field(:updated_at, :utc_datetime)

    belongs_to(:course, Course)

    # has_many(:lessons, Lesson)
    has_many(:unit_lessons, UnitLesson, on_delete: :delete_all)
    has_many(:lessons, through: [:unit_lessons, :lesson])
  end

  def completed?(unit, enrollment) do
    Enum.all?(unit.lessons, &(Lesson.completed?(&1, enrollment) == true))
  end
end