ecto_context

  @doc """
  Returns a `<%= inspect(schema) %>` changeset for tracking changes.

  Raises `ArgumentError` if `permission(:create, ...)` (new record) or
  `permission(:update, ...)` (existing record) denies the scope.

  ## Options

    * `:changeset` - changeset function to use (default: `:changeset`)

  If a `changeset_permission/2` function is exported by the calling module,
  it is consulted whenever a non-default `:changeset` is passed.  Raises
  `ArgumentError` if denied.

  """
  def change(scope, %<%= inspect(schema) %>{} = <%= singular %>, attrs \\ %{}, opts \\ []) when is_map(scope) do
    EctoContext.Validate.validate_opts!(opts, [:changeset])

    changeset_fn = Keyword.get(opts, :changeset, <%= inspect(default_changeset) %>)

    if changeset_fn != <%= inspect(default_changeset) %> and function_exported?(__MODULE__, :changeset_permission, 2) do
      unless apply(__MODULE__, :changeset_permission, [changeset_fn, scope]) do
        raise ArgumentError, "unauthorized: #{__MODULE__}.change/4 — changeset :#{changeset_fn} not permitted for this scope"
      end
    end

    changeset = apply(<%= inspect(schema) %>, changeset_fn, [<%= singular %>, attrs, scope])
    action = if is_nil(<%= singular %>.id), do: :create, else: :update

    unless permission(action, Ecto.Changeset.apply_changes(changeset), scope) do
      raise ArgumentError, "unauthorized: #{__MODULE__}.change/4 called with insufficient scope"
    end

    changeset
  end