ash_outstanding

# SPDX-FileCopyrightText: 2025 ash_outstanding contributors <https://github.com/diffo-dev/ash_outstanding/graphs.contributors>
#
# SPDX-License-Identifier: MIT

defmodule AshOutstanding.Expressions.IsOutstanding do
  use Ash.CustomExpression,
    name: :is_outstanding,
    arguments: [
      [:term, :term]
    ]

  def expression(data_layer, [expected, actual])
      when data_layer in [
             Ash.DataLayer.Ets,
             Ash.DataLayer.Simple,
             AshNeo4j.DataLayer,
             AshCsv.DataLayer
           ] do
    {:ok, expr(fragment(&__MODULE__.is_outstanding/2, ^expected, ^actual))}
  end

  def expression(_data_layer, _args), do: :unknown

  @doc "Computes is_outstanding on two terms using Outstanding protocol"
  def is_outstanding(expected, actual) do
    Outstanding.outstanding?(expected, actual)
  end
end