#!/bin/bash

# parameters and default values
ARCH="i686"
DATE=$(date +%Y.%m.%d)
ISO="archlinux32-${DATE}-${ARCH}.iso"
OUTPUT_DIR="${HOME}/archisos"
#Andreas Baumann (sign) <mail@andreasbaumann.cc>
#SIGN_KEY='16194A82231E9EF823562181C8E8F5A0AF9BA7E7'
# Archlinux 32 Release Key <release@archlinux32.org>
SIGN_KEY='33CA3597B0D161AAE4173F65C17F1214114574A4'

usage() {
  >&2 echo ""
  >&2 echo "check-iso: checks sanity of ISOs built for Archlinux32 and returns data about the ISO"
  >&2 echo ""
  >&2 echo "possible options:"
  >&2 echo "  -h|--help:          show this help and exit"
  >&2 echo "  --iso               name of ISO to be checked, default is '${ISO}'."  
  >&2 echo "  --output-dir        where to write the isos, default is '${OUTPUT_DIR}."
  >&2 echo "  --check             check sanity of the image, returns an exit code only."
  >&2 echo "  --expected-sign-key expected PGP key the ISO has to be signed with, default '${SIGN_KEY}'."
  >&2 echo "  --md5sum            get md5 of the ISO."
  >&2 echo "  --sha512sum         get sha512sum of the ISO."
  >&2 echo "  --sign-key          get GPG signing key of the ISO."  
  >&2 echo "  --size              get size of the ISO."
  >&2 echo "  --kernel-version    get version of the kernel on the ISO."  
  >&2 echo "  --no-cleanup        do not clean up tmpdir after run, for debugging."
  [ -z "$1" ] && exit 1 || exit "$1"
}

# fail on first error
set -e

# cleanup hook
tmp_dir="$(mktemp -d)"
cleanup() {
  if mountpoint -q "${tmp_dir}"; then
    sudo umount "${tmp_dir}"
  fi
  rm -rf --one-file-system "${tmp_dir}"
}
trap cleanup EXIT

eval set -- "$(
  getopt -o h \
  --long help \
  --long iso: \
  --long output-dir: \
  --long check \
  --long expected-sign-key: \
  --long md5sum \
  --long sha512sum \
  --long sign-key \
  --long size \
  --long kernel-version \
  -n "$(basename "$0")" -- "$@" || \
  echo usage
)"

iso="$ISO"
output_dir="${OUTPUT_DIR}"
check=0
expected_sign_key="${SIGN_KEY}"
md5sum=0
sha512sum=0
sign_key=0
size=0
kernel_version=0

while [ $# -gt 0 ]; do
  case "$1" in
    '--iso')
      shift
      iso="$1"
      ;;
    '--output-dir')
      shift
      output_dir="$1"
      ;;
    '--check')
      check=1
      ;;
    '--expected-sign-key')
      shift
      expected_sign_key="$1"
      ;;
    '--md5sum')
      md5sum=1
      ;;
    '--sha512sum')
      sha512sum=1
      ;;
    '--sign-key')
      sign_key=1
      ;;
    '--size')
      size=1
      ;;
    '--kernel-version')
      kernel_version=1
      ;;
    '--help'|'-h')
      usage 0
    ;;
    '--')
      shift
      break
    ;;
    *)
      printf 'Whoops, option "%s" is not yet implemented!\n' "$1" >&2
      exit 42
    ;;
  esac
  shift
done

if [ $# -gt 0 ]; then
  >&2 echo 'Too many arguments.'
  exit 2
fi

if [ "${md5sum}" = 1 ]; then
  md5sum="$(
    grep "\s${iso/}\$" "${output_dir}/md5sums" | \
      awk '{print $1}'
  )"
  echo "${md5sum}"
fi

if [ "${sha512sum}" = 1 ]; then
  sha512sum="$(
    grep "\s${iso/}\$" "${output_dir}/sha512sums" | \
      awk '{print $1}'
  )"
  echo "${sha512sum}"
fi

if [ "${sign_key}" = 1 -o "${check}" = 1 ]; then
  sign_keys="$(
    printf '%s\n' $(
      gpg --status-fd=1 --verify "${output_dir}/${iso}.sig" "${output_dir}/${iso}" 2> /dev/null | \
        grep '^\[GNUPG:] VALIDSIG [0-9A-F]\+ ' | \
        cut -d' ' -f3
    ) | \
      sort -u
  )"

  if [ $(echo "${sign_keys}" | grep -c '\S') -ne 1 ]; then
    >&2 echo 'Not exactly one key used for signing the iso:'
    >&2 echo "'${sign_keys}'"
    exit 1
  fi

  sign_key="${sign_keys}"

  if [ "${sign_key}" != "${expected_sign_key}" ]; then
    >&2 printf "Isos are signed with key '%s' instead of '%s'.\n" \
       "${sign_key}" \
       "${expected_sign_key}"
    exit 1
  fi

  if [ "${check}" = 0 ]; then
	echo "${sign_key}"
  fi
fi

if [ "${size}" = 1 ]; then
  size="$(
    printf 'scale=1; %s/1024/1024\n' "$(stat -c'%s' "${output_dir}/${iso}")" | \
      bc
  )"
  echo "${size}"
fi

if [ "${kernel_version}" = 1 -o "${check}" = 1 ]; then
  sudo mount -o loop,ro "${output_dir}/${iso}" "${tmp_dir}"
  kernels="$(
    printf '%s\n' $(
      find "${tmp_dir}/arch" \
        -maxdepth 1 \
        -name 'pkglist.*.txt' \
        -not -name 'pkglist.x86_64.txt' \
        -execdir cat {} \; \
        | sed '
          s/^linux\s\+\([^-]\+-[^-]\+\)$/\1/
          t
          d
        '
      ) | \
      sort -u
  )"
  sudo umount "${tmp_dir}"

  if [ $(echo "${kernels}" | grep -c '\S') -ne 1 ]; then
    >&2 echo 'Not exactly one kernel on the iso:'
    >&2 echo "${kernels}"
    exit 1
  fi
  
  kernel_version="${kernels}"
  if [ "${check}" = 0 ]; then
    echo "${kernel_version}"
  fi
fi

exit 0