defmodule Literature.Migrations.Postgres.V03 do
  @moduledoc """
  Add literature_redirects table
  """
  use Ecto.Migration

  def up(_opts) do
    create_if_not_exists table(:literature_redirects, primary_key: false) do
      add(:id, :binary_id, primary_key: true)
      add(:from, :string, null: false)
      add(:to, :string, null: false)
      add(:type, :integer, null: false)

      add(
        :publication_id,
        references(:literature_publications, on_delete: :nilify_all, type: :binary_id)
      )

      timestamps()
    end

    # from and to should not be equal
    create(
      constraint(:literature_redirects, :from_must_not_be_equal_to_to,
        check: "literature_redirects.from <> literature_redirects.to"
      )
    )

    create(unique_index(:literature_redirects, [:publication_id, :from, :to]))
  end

  def down(_opts) do
    drop_if_exists(constraint(:literature_redirects, :from_must_not_be_equal_to_to))
    drop_if_exists(unique_index(:literature_redirects, [:publication_id, :from, :to]))
    drop_if_exists(table(:literature_redirects))
  end
end