defmodule ItsfoundRekognition.ProcessImage do
  @moduledoc """
    This module processes an AWS Rekognition request for the labels / descriptions of what is in an image
    you need to pass it an
    #
    # ItsfoundRecognition.ProcessImage.recognise_label("1d826fd7-38b1-4349-bdc9-f2990f590a11", "png", &ImageRecognition.LoggerImageResponseParser.parse/1)
    #
    # ItsfoundRecognition.ProcessImage.recognise_label("1d826fd7-38b1-4349-bdc9-f2990f590a11", "png", &ImageRecognition.ImageLabelParser.parse/1)
    #
    # ItsfoundRecognition.ProcessImage.recognise_label("1d826fd7-38b1-4349-bdc9-f2990f590a11", "png", &ImageRecognition.ImageLabelParser.parse_top/1)
  """
  alias ExAws.Rekognition.S3Object
  alias ItsfoundRekognition.LoggerImageResponseParser

  def recognise_label(
        image_uuid,
        ending,
        process_func \\ &LoggerImageResponseParser.parse/1
      ) do
    case ending do
      "jpg" ->
        process_image(image_uuid, process_func, "original.jpg")

      "jpeg" ->
        process_image(image_uuid, process_func, "original.jpeg")

      "png" ->
        process_image(image_uuid, process_func, "original.png")

      _ ->
        %{
          error: "invalid file ending"
        }
    end
  end

  defp process_image(image_uuid, process_func, image_name) do
    bucket = ItsfoundRekognition.Utils.aws_bucket()

    object_id =
      "#{ItsfoundRekognition.Utils.aws_bucket_divider()}/items/#{image_uuid}/#{image_name}"

    process_image_from_s3(%S3Object{bucket: bucket, name: object_id, version: nil}, process_func)
  end

  defp process_image_from_s3(
         %S3Object{
           bucket: _bucket,
           name: _name,
           version: _version
         } = image,
         process_func
       ) do
    case process_detect_labels(image) do
      {:ok, response} ->
        process_func.(response)

      {:error, errors} ->
        process_func.(errors)
    end
  end

  defp process_detect_labels(image) do
    opts = ItsfoundRekognition.Utils.aws_config_options()

    image
    |> ExAws.Rekognition.detect_labels()
    |> ExAws.request(opts)
  end
end