defmodule LiveBookWeb.ErrorHelpers do
  @moduledoc """
  Conveniences for translating and building error messages.
  """

  use Phoenix.HTML

  @doc """
  Generates tag for inlined form input errors.
  """
  def error_tag(form, field) do
    Enum.map(Keyword.get_values(form.errors, field), fn error ->
      content_tag(:span, translate_error(error),
        class: "invalid-feedback",
        phx_feedback_for: input_id(form, field)
      )
    end)
  end

  @doc """
  Translates an error message.
  """
  def translate_error({msg, opts}) do
    # Because the error messages we show in our forms and APIs
    # are defined inside Ecto, we need to translate them dynamically.
    Enum.reduce(opts, msg, fn {key, value}, acc ->
      String.replace(acc, "%{#{key}}", to_string(value))
    end)
  end
end