defmodule NLdoc.Spec.Template do
  @moduledoc """
  This module is a template for creating new NLdoc spec resource schemas.

  To create a new resource schema:

  1. Copy this file to a new file in the same directory, renaming it to the name of the new resource in snake_case.
  2. Replace all occurrences of `Template` in that file with the name of the new resource.
  3. Add the fields for this resource to the `typed_embedded_schema`.
  4. Update the `changeset` function to cast and validate the new fields.
  5. Add the new resource type to the `NLdoc.Spec.Type` enum.
  6. Add the `t` type to the `NLdoc.Spec.object` type.
  7. Remove this section of the moduledoc up to and including `---`.
  8. Now you can use the new resource in other schemas, e.g. add it to the possible children of `NLdoc.Spec.Document`.

  ---

  This module defines the Ecto schema for the NLdoc spec Template object.
  """
  use NLdoc.Spec.Schema, type: "https://spec.nldoc.nl/Resource/Template"

  typed_embedded_schema null: false do
    field :type, :string, default: @resource_type

    field(:descriptors, {:array, PolymorphicEmbed},
      types: map(NLdoc.Spec.descriptors()),
      type_field_name: :type,
      on_replace: :delete,
      default: [],
      array?: true
    ) :: [NLdoc.Spec.descriptor()]
  end

  def changeset(object, attrs) do
    object
    |> cast(attrs, [:type], @cast_opts)
    |> cast_polymorphic_embed(:descriptors, @cast_opts)
    |> validate_required([:type])
    |> validate_inclusion(:type, [@resource_type])
  end
end