defmodule Ash.Type.Map do
  @moduledoc """
  Represents a map stored in the database.

  In postgres, for example, this represents binary encoded json

  A builtin type that can be referenced via `:map`
  """
  use Ash.Type

  @impl true
  def storage_type, do: :map

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

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

  def cast_input(value, _) when is_binary(value) do
    case Jason.decode(value) do
      {:ok, value} ->
        {:ok, value}

      _ ->
        :error
    end
  end

  def cast_input(value, _) when is_map(value), do: {:ok, value}
  def cast_input(_, _), do: :error

  @impl true
  def cast_stored(nil, _), do: {:ok, nil}
  def cast_stored(value, _) when is_map(value), do: {:ok, value}
  def cast_stored(_, _), do: :error

  @impl true
  def dump_to_native(nil, _), do: {:ok, nil}
  def dump_to_native(value, _) when is_map(value), do: {:ok, value}
  def dump_to_native(_, _), do: :error
end