nug

defmodule Nug.RequestInterceptor do
  @behaviour Tesla.Middleware
  alias Nug.Recording

  def call(env, next, intercept_options) do
    handler = Keyword.fetch!(intercept_options, :handler)

    case Recording.find(env, handler) do
      {:ok, response} -> file_to_tesla(response)
      nil -> run_and_store(env, next, handler)
    end
  end

  def run_and_store(env, next, handler) do
    with {:ok, response} <- Tesla.run(env, next),
         :ok <- Nug.Recording.add(response, handler) do
      {:ok, response}
    end
  end

  def file_to_tesla(json) do
    with normalized <- normalize(json),
         struct <- struct(Tesla.Env, normalized) do
      Tesla.run(struct, [])
    end
  end

  def normalize(raw_env) do
    Map.update(raw_env, :headers, [], fn list ->
      Enum.map(list, fn [key, value] -> {key, value} end)
    end)
  end
end