#!/bin/bash

#set -o xtrace
set -u
set -o pipefail

UMASK="$(umask)"

final-local () {
  if [[ -z "$(ls -A ${TEMPF})" ]]; then
    rmdir "${TEMPF}"
  else
    if [[ $KEEP == "true" ]]; then
      mv "${FOLDER}" "${NEWFL}"
    else
      rm -rf "${FOLDER}"
    fi
    mv "${TEMPF}" "${FOLDER}"
  fi
}

final-remote () {
  if [[ -z "$(ls ${TEMPF})" ]]; then
    rmdir "${TEMPF}"
  else
    sudo scp -r "${TEMPF}" "${ADDR}:/srv/backup/${TEMPF}" || exit 1
    if [[ $KEEP == "true" ]]; then
      sudo ssh "${ADDR}" "cd /srv/backup; mv \"${FOLDER}\" \"${NEWFL}\""
    else
      sudo ssh "${ADDR}" "cd /srv/backup; rm -rf \"${FOLDER}\""
    fi
    sudo scp -r "${TEMPF}" "${ADDR}:/srv/backup" && rm -rf "${TEMPF}"
    sudo ssh "${ADDR}" "cd /srv/backup; mv \"${TEMPF}\" \"${FOLDER}\""
  fi
}

cprompt () {
  if [[ $UNATTENDED == "true" ]]; then return; fi
  read -r -s -N 1 -p "Continue [Enter]?"
  if [[ $REPLY != $'\n' ]]; then
    printf "\n"
    printf "  Script stopped!\n"
    if [[ $SEND == "true" ]]; then
      final-remote
    else 
      final-local
    fi
    exit
  fi
}

usage () {
  printf "v2b.sh <option> [ <prefix> ]\n"
  printf "  <prefix> only backup volumes with this prefix\n"
  printf "  option: k (keep existing backups)\n"
  printf "  option: p (remove prefix from tar archive file name\n"
  printf "  option: u (unattended backup)\n"
  printf "  option: s <address> (send backup directly to remote address via ssh)\n"
}

SEND="false"
ADDR=""
REMOVE="false"
KEEP="false"
UNATTENDED="false"

OUTPUT=""
while getopts ':s:pku' OPT; do
  case $OPT in
    s) SEND="true"; ADDR="${OPTARG}"; OUTPUT="${OUTPUT}  Option: SEND BACKUPS\n";;
    p) REMOVE="true"; OUTPUT="${OUTPUT}  Option: RESTART AFTER\n";;
    r) KEEP="true"; OUTPUT="${OUTPUT}  Option: KEEP EXISTING BACKUPS\n";;
    u) UNATTENDED="true"; OUTPUT="${OUTPUT}  Option: UNATTENDED BACKUP\n";;
    \?) usage; exit;;
  esac
done
shift $((OPTIND -1))

if [[ $SEND == "true" ]]; then
  FOLDER="_$(hostname -f)_"
else
  FOLDER="_vols_"
fi

if [[ $# > 0 ]]; then
  VOLUMES="$(sudo docker volume ls -q |grep "${1}")"
else
  VOLUMES="$(sudo docker volume ls -q)"
fi

if [[ -z $VOLUMES ]]; then
  printf "Cannot find volumes spec: ${1}_\n"
  exit 1
fi

if [[ $SEND == "true" ]]; then
  if sudo ssh "${ADDR}" test -d "/srv/backup/${FOLDER}"; then
    LASTF="$(sudo ssh "${ADDR}" ls -d --format=single-column ${FOLDER}* |tail -n1)"
  else
    LASTF="${FOLDER}"
  fi
else
  if [[ -d ${FOLDER} ]]; then
    LASTF="$(ls -d --format=single-column ${FOLDER}* |tail -n1)"
  else
    LASTF="${FOLDER}"
  fi
fi

INDEX="$((( ${LASTF#${FOLDER}} + 0 )))"
NEWFL="${FOLDER}$(printf "%05d" $((( ${INDEX} + 1 ))))"
TEMPF="$(mktemp -dt -p $PWD XXXXXXXXXXXXXXX)"

for VOL in ${VOLUMES}; do
  if [[ $REMOVE == "true" ]]; then
    TAR="${VOL#${1}_}.tar.bz2"
  else
    TAR="${VOL}.tar.bz2"
  fi
  printf "${VOL} --> ${TEMPF}/${TAR}\n"
  cprompt
  sudo docker run --rm --log-driver none \
    -v "${VOL}:/volume" \
    -v "${TEMPF}:/backup" \
    loomchild/volume-backup backup -v "${TAR}"
  sudo chmod 400 "${TEMPF}/${TAR}"
done

if [[ $SEND == "true" ]]; then
  final-remote
else 
  final-local
fi

set +o xtrace