defimpl Phoenix.HTML.FormData, for: Map do
  alias Phoenix.HTML.Form

  def to_form(map, opts) do
    {name, opts} = Keyword.pop(opts, :as)
    {errors, opts} = Keyword.pop(opts, :errors)

    %Form{
      source: map,
      impl: __MODULE__,
      id: name,
      name: name,
      params: map,
      data: %{},
      errors: errors,
      options: opts
    }
  end

  def to_form(_data, _form, _field, _opts) do
    raise "Unimplemented"
  end

  def input_value(_data, %Form{data: data, params: params}, field) do
    key =
      case field do
        field when is_atom(field) -> Atom.to_string(field)
        field -> field
      end

    case Map.fetch(params, key) do
      {:ok, value} ->
        value

      :error ->
        Map.get(data, key)
    end
  end

  def input_validations(_data, _form, _field) do
    raise "Unimplemented"
  end

  def input_type(_data, _form, _field) do
    raise "Unimplemented"
  end
end