#!/usr/bin/env bash

set -euo pipefail

get_image_id() {
  local image_name

  image_name=$1
  ctr image list | grep "${image_name}" | awk '{ print $3 }'
}

pull_image() { 
  local image_name image_id1 image_id2

  image_name=$1

  set +e; ctr image rm "${image_name}"; set -e

  # first round
  ctr --debug image pull "${image_name}"
  image_id1="$(get_image_id ${image_name})"

  # second round to make sure the image id should not be changed
  ctr image pull "${image_name}"
  image_id2="$(get_image_id ${image_name})"

  [[ "'${image_id1}'" != "'${image_id2}'" ]] \
    && echo "image id changed after repull image" \
    && exit 1

  # last round...
  ctr image pull "${image_name}"
  image_id2="$(get_image_id ${image_name})"

  [[ "'${image_id1}'" != "'${image_id2}'" ]] \
    && echo "image id changed after repull image" \
    && exit 1

  ctr image rm --sync "${image_name}"
}

main() {
  local image_list

  image_list=(
    gcr.io/google_containers/pause:3.0
    gcr.io/google_containers/busybox:1.24
    gcr.io/google_containers/nginx-slim:0.7
    k8s.gcr.io/busybox:1.24
  )

  for image in "${image_list[@]}"; do
    pull_image "${image}"
  done

}

main