#!/bin/bash

# parameters and default values
CONFIG="releng"
ARCH="i686"
DATE=$(date +%Y.%m.%d)
MIRROR_DIR="/srv/http/mirror/mirror.archlinux32.org"
TORRENT_SERVER="archlinux32.org"
TORRENT_USER="hefur"
HEFUR_DIR="/var/lib/hefurd"

base_dir=$(
  readlink -e "${0%/*}"
)

usage() {
  >&2 echo ""
  >&2 echo "build-torrent: seed torrents for Archlinux32 ISOs"
  >&2 echo ""
  >&2 echo "possible options:"
  >&2 echo "  -h|--help:       show this help and exit."
  >&2 echo "  --arch           architecture of the ISO, default is '$ARCH'."
  >&2 echo "  --date           date of the ISO for, default is '$DATE'."
  >&2 echo "  --mirror-dir     where are the ISOs stored on the mirror, default is '$MIRROR_DIR'."
  >&2 echo "  --torrent-server the name of the server hosting torrents with hefurd, default is '$TORRENT_SERVER'."
  >&2 echo "  --torrent-user   the user hefurd is running as, default is '$TORRENT_USER'."
  >&2 echo "  --magnet-link    retrieve magnet link of an already published torrent."
  [ -z "$1" ] && exit 1 || exit "$1"
}

# fail on first error
set -e

# cleanup hook
tmp_dir="$(mktemp -d)"
cleanup() {
  if [ "${no_cleanup}" = 0 ]; then  
    if mountpoint -q "${tmp_dir}"; then
      sudo umount "${tmp_dir}"
    fi
    rm -rf --one-file-system "${tmp_dir}"
  fi
}
trap cleanup EXIT

eval set -- "$(
  getopt -o h \
  --long help \
  --long arch: \
  --long date: \
  --long mirror-dir: \
  --long torrent-server: \
  --long torrent-user: \
  --long magnet-link \
  -n "$(basename "$0")" -- "$@" || \
  echo usage
)"

arch="$ARCH"
date="$DATE"
mirror_dir="$MIRROR_DIR"
iso="${iso}"
torrent_server="$TORRENT_SERVER"
torrent_user="$TORRENT_USER"
hefur_dir="$HEFUR_DIR"
magnet_link=0

while [ $# -gt 0 ]; do
  case "$1" in
    '--arch')
      shift
      arch="$1"
    ;;
    '--date')
      shift
      date="$1"
    ;;
    '--mirror-dir')
      shift
      mirror_dir="$1"
    ;;
    '--torrent-server')
      shift
      torrent_server="$1"
    ;;
    '--torrent-user')
      shift
      torrent_user="$1"
    ;;
    '--magnet-link')
      magnet_link=1
    ;;
    '--help'|'-h')
      usage 0
    ;;
    '--')
      shift
      break
    ;;
    *)
      >&2 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

archiso_dir="$mirror_dir/archisos"
iso="archlinux32-$date-$arch.iso"

# retrieve the magnet link (for publishing on the webpage)
if [ $magnet_link = 1 ]; then
	magnet_link="$(transmission-show --magnet "$archiso_dir/${iso}.torrent")"
  echo "$magnet_link"
  exit 0
fi

declare -a available_mirrors
mirrorlist="$(cat /etc/pacman.d/mirrorlist32 | grep Server | cut -d '=' -f 2 | sed -e 's/\s//g;s_$arch/$repo_archisos/_')"
available_mirrors=($mirrorlist)

if [ ! -f "$archiso_dir/${iso}" ] ; then
  >&2 echo "'${iso}' not found."
  exit 1
fi

# create web seed as the list of all mirrors and create the torrent
# file, announce it on the torrent server
function join_by { local IFS="$1"; shift; echo "$*"; }
web_seed="$(join_by ',' "${available_mirrors[@]}")"
torrent_file="${iso}.torrent"

rm -f "${archiso_dir}/${torrent_file}"
mktorrent --announce=http://${torrent_server}:6969/announce \
  --web-seed="${web_seed}" \
  --output="${archiso_dir}/${torrent_file}" \
  "${archiso_dir}/${iso}"

# I have to go over port 9586, copying manually ATM
#scp -P "${torrent_ssh_port}" "${archiso_dir}/${torrent_file}" "${torrent_user}@${torrent_server}:${hefur_dir}"

exit 0