#!/usr/bin/env bash

set -euo pipefail

readonly SYSTEMD_CONFIG="/lib/systemd/system/iota.service"
readonly SCRIPT_NAME=$(basename $0)

function get_latest_github_release {
  curl -s https://api.github.com/repos/iotaledger/iri/releases/latest | jq "[.assets][0][0].name" --raw-output
}

function get_download_url {
  curl -s https://api.github.com/repos/iotaledger/iri/releases/latest | jq "[.assets][0][0].browser_download_url"
}

function get_installed_version {
  raw=`grep -v "^#" $SYSTEMD_CONFIG | grep -v "^$" | grep -o -P '(?<=iri-).*(?=.jar)'`
  echo "iri-$raw.jar"
}

log() {
  echo "$@"
  logger -p user.notice -t $SCRIPT_NAME "$@"
}

function v_is_digit {
  tr -cd 0-9 <<<"$@"
}

function update_iri {
  log "New IRI release $latest detected! Updating installed version $installed to the latest release $latest"
  sh -c "sudo rm -f iri-$latest.jar" &&
  sh -c "sudo -u iota wget -qO /home/iota/node/$latest $(get_download_url)" &&
  sed -i -e "s/$installed/$latest/" $SYSTEMD_CONFIG &&
  systemctl daemon-reload &&
  systemctl restart iota
}

function main {
  local latest="$(get_latest_github_release)"
  local installed="$(get_installed_version)"

  if [ "$latest" != "$installed" ] && [ $(v_is_digit ${latest}) ] && [ $(v_is_digit ${installed}) ]; then
    update_iri
  fi
}

main