#!/usr/bin/env bash
# The verifier must retry a failed describe-images call. set -e used to abort
# the loop on the first ImageNotFoundException.
set -euo pipefail

root="$(cd "$(dirname "$0")/.." && pwd)"
verifier="${root}/.github/actions/verify-ecr-promote-digest/verify.sh"
failures=0

assert_eq() {
  local name="$1"
  local got="$2"
  local want="$3"
  if [ "${got}" != "${want}" ]; then
    echo "${name}: got ${got}, want ${want}" >&2
    failures=$((failures + 1))
  fi
}

run_case() {
  local name="$1"
  local expect_status="$2"
  local stub_dir
  stub_dir="$(mktemp -d)"
  cat > "${stub_dir}/aws" <<'EOF'
#!/usr/bin/env bash
set -euo pipefail
tag=""
for arg in "$@"; do
  case "${arg}" in
    imageTag=*) tag="${arg#imageTag=}" ;;
  esac
done
if [ -z "${tag}" ]; then
  echo "stub aws: missing image tag" >&2
  exit 1
fi
dir="${AWS_STUB_DIR}"
count_file="${dir}/count-${tag}"
n=0
if [ -f "${count_file}" ]; then
  n="$(cat "${count_file}")"
fi
n=$((n + 1))
printf '%s\n' "${n}" > "${count_file}"
line="$(sed -n "${n}p" "${dir}/behavior-${tag}" || true)"
if [ -z "${line}" ]; then
  line="$(tail -n 1 "${dir}/behavior-${tag}")"
fi
case "${line}" in
  ok\ *)
    printf '%s\n' "${line#ok }"
    ;;
  fail)
    echo "ImageNotFoundException: ${tag}" >&2
    exit 254
    ;;
  *)
    echo "stub aws: no behavior for ${tag} call ${n}" >&2
    exit 1
    ;;
esac
EOF
  chmod +x "${stub_dir}/aws"
  shift 2
  while [ "$#" -gt 0 ]; do
    printf '%s\n' "$2" > "${stub_dir}/behavior-$1"
    shift 2
  done
  set +e
  IMAGE_NAME=actions-runner \
    SHA=0123456789abcdef0123456789abcdef01234567 \
    PROMOTE_TAG=current \
    DIGEST_RETRY_SLEEP=0 \
    AWS_STUB_DIR="${stub_dir}" \
    PATH="${stub_dir}:${PATH}" \
    bash "${verifier}" >"${stub_dir}/out" 2>"${stub_dir}/err"
  status=$?
  set -e
  if [ "${status}" -ne "${expect_status}" ]; then
    echo "${name}: exit ${status}, want ${expect_status}" >&2
    cat "${stub_dir}/err" >&2
    failures=$((failures + 1))
  fi
  sha_calls=0
  promote_calls=0
  if [ -f "${stub_dir}/count-sha-0123456789abcdef0123456789abcdef01234567" ]; then
    sha_calls="$(cat "${stub_dir}/count-sha-0123456789abcdef0123456789abcdef01234567")"
  fi
  if [ -f "${stub_dir}/count-current" ]; then
    promote_calls="$(cat "${stub_dir}/count-current")"
  fi
  printf '%s\n' "${sha_calls}" > "${stub_dir}/sha_calls"
  printf '%s\n' "${promote_calls}" > "${stub_dir}/promote_calls"
  # shellcheck disable=SC2034
  CASE_DIR="${stub_dir}"
}

run_case "match on first read" 0 \
  "sha-0123456789abcdef0123456789abcdef01234567" "ok sha256:aaa" \
  "current" "ok sha256:aaa"
assert_eq "match on first read sha calls" "$(cat "${CASE_DIR}/sha_calls")" "1"
assert_eq "match on first read promote calls" "$(cat "${CASE_DIR}/promote_calls")" "1"
rm -rf "${CASE_DIR}"

run_case "retry when promote tag is not visible yet" 0 \
  "sha-0123456789abcdef0123456789abcdef01234567" "ok sha256:aaa" \
  "current" "$(printf 'fail\nok sha256:aaa')"
assert_eq "not visible yet sha calls" "$(cat "${CASE_DIR}/sha_calls")" "2"
assert_eq "not visible yet promote calls" "$(cat "${CASE_DIR}/promote_calls")" "2"
rm -rf "${CASE_DIR}"

run_case "give up when describe-images keeps failing" 1 \
  "sha-0123456789abcdef0123456789abcdef01234567" "fail" \
  "current" "fail"
assert_eq "keep failing sha calls" "$(cat "${CASE_DIR}/sha_calls")" "6"
assert_eq "keep failing promote calls" "$(cat "${CASE_DIR}/promote_calls")" "6"
rm -rf "${CASE_DIR}"

if [ "${failures}" -ne 0 ]; then
  echo "${failures} assertion(s) failed" >&2
  exit 1
fi
echo "verify_ecr_promote_digest: ok"