page_loop.exs

defmodule Utils do 
  @username Application.get_env(:app_name, :username)
  @password Application.get_env(:app_name, :password)
  @base_url "https://api.intrinio.com/"
  @headers %{"Authorization" => "Basic " <> Base.encode64("#{@username}:#{@password}")}

  def page_loop(current_page \\ 1, acc \\ [], ticker \\ "") do 
    %HTTPoison.Response{body: response} = 
      HTTPoison.get! @base_url <> "prices?ticker=#{ticker}" <>
      "&page_number=#{current_page}", @headers 

    data = response |> process_resp() |> Map.get("data")
    data_list = [data | acc]

    case get_total_pages(response) do 
      ^current_page -> List.flatten data_list
      _ -> page_loop(current_page + 1, data_list, ticker)
    end
  end
end