defmodule Ash.Type.Float do
  @constraints [
    max: [
      type: {:custom, __MODULE__, :decimal, []},
      doc: "Enforces a maximum on the value"
    ],
    min: [
      type: {:custom, __MODULE__, :decimal, []},
      doc: "Enforces a minimum on the value"
    ]
  ]
  @moduledoc """
  Represents a float (floating point number)

  A builtin type that be referenced via `:float`

  ### Constraints

  #{Spark.OptionsHelpers.docs(@constraints)}
  """

  use Ash.Type

  @impl true
  def storage_type, do: :float

  @impl true
  def generator(constraints) do
    StreamData.float(Keyword.take(constraints, [:min, :max]))
  end

  @impl true
  def apply_constraints(nil, _), do: :ok

  def apply_constraints(value, constraints) do
    errors =
      Enum.reduce(constraints, [], fn
        {:max, max}, errors ->
          if value > max do
            [[message: "must be less than or equal to %{max}", max: max] | errors]
          else
            errors
          end

        {:min, min}, errors ->
          if value < min do
            [[message: "must be more than or equal to %{min}", min: min] | errors]
          else
            errors
          end
      end)

    case errors do
      [] -> :ok
      errors -> {:error, errors}
    end
  end

  @impl true
  def cast_input(value, _) do
    Ecto.Type.cast(:float, value)
  end

  @impl true
  def cast_stored(nil, _), do: {:ok, nil}

  def cast_stored(value, _) do
    Ecto.Type.load(:float, value)
  end

  @impl true

  def dump_to_native(nil, _), do: {:ok, nil}

  def dump_to_native(value, _) do
    Ecto.Type.dump(:float, value)
  end
end