defmodule Outlook.Translators.Deepl do

  def test(pid) do
    for n <- 0..100 do
      send(pid, {:progress, %{progress: n}})
      Process.sleep 50
    end
    send(pid, {:progress, %{progress: nil}})
  end

  # @options [ssl: [{:versions, [:'tlsv1.2']}], recv_timeout: 500]

  @doc """
    Upload the content to translate and return document_id and document_key as Map.
  """
  def start_translation %{auth_key: auth_key} = _credentials, content, target_lang do
    form = get_multipart_form(
      [
        {"target_lang", target_lang},
        {"file", content, {"form-data", [{:name, "file"}, {:filename, "datei.html"}]}, []}
      ]
    )

    response_raw = HTTPoison.request!(
      :post,
      "https://api-free.deepl.com/v2/document",
      form,
      get_multipart_headers(auth_key)
    )
    Jason.decode!(response_raw.body, keys: :atoms)
    |> Map.put(:auth_key, auth_key)
  end

  @doc """
    Upload the content to translate and return the estimated time until done.
  """
  def check_status credentials do
    response_raw = HTTPoison.request!(
      :post,
      "https://api-free.deepl.com/v2/document/#{credentials.document_id}",
      get_multipart_form([{"document_key", credentials.document_key}]),
      get_multipart_headers(credentials.auth_key)
    )
    response = Jason.decode!(response_raw.body, keys: :atoms)

    case response do
      %{status: "translating"} ->
        Process.sleep(String.to_integer(response.seconds_remaining) * 1000)
        check_status(credentials)
      %{status: "done"} ->
        response
      end
  end

  def get_translation credentials do

    response_raw = HTTPoison.request!(
      :post,
      "https://api-free.deepl.com/v2/document/#{credentials.document_id}/result",
      get_multipart_form([{"document_key", credentials.document_key}]),
      get_multipart_headers(credentials.auth_key)
    )
    response_raw.body
  end

  defp get_multipart_form fields do
    {:multipart, fields}
  end

  defp get_multipart_headers(auth_key) do
   [
    "Authorization": "DeepL-Auth-Key #{auth_key}",
    "Content-Type": "multipart/form-data",
    "Transfer-Encoding": "chunked",
   ]
  end
end