Code.require_file("tpl.exs")

defmodule TplJson do
  # --- JSON Transpiler ---
  # transforms sexps into lists
  # braces into objects
  # tokens and strings into strings
  def to_json(ast) do
    ast
    |> Enum.map(&to_json_item/1)
    |> IO.inspect(label: "AST for JSON")
    # if the top level is a single elem, we output that directly
    |> case do
      [[single]] -> single
      [single] -> single
      multiple -> multiple
    end
    |> Jason.encode!(pretty: true)
  end

  defp to_json_item(%{t: :sexp, list: list}) do
    list |> Enum.map(&to_json_item/1)
  end

  defp to_json_item(%{t: :brace, list: list}) do
    list
    |> Enum.map(fn
      %{t: :sexp, list: [key_item | value_list]} ->
        key = to_json_item(key_item)

        value =
          case value_list do
            [ex] -> to_json_item(ex)
            _ -> value_list |> Enum.map(&to_json_item/1)
          end

        {key, value}
    end)
    |> Enum.into(%{})
  end

  defp to_json_item(%{t: :token, str: str}), do: str

  defp to_json_item(%{t: :string, chunks: chunks, values: values}) do
    # For simplicity, concatenate chunks and ignore interpolations
    Enum.join(chunks)
  end
end

json_output =
  """
  {
    asd  "something else "
    nested {
      a ( b c asd asd asd)
      d e f
      inner {
        x y z
      }
  }
  """
  |> Tpl.to_ast()
  |> TplJson.to_json()

IO.puts("\n--- Generated JSON Output ---")
IO.puts(json_output)