#!/usr/bin/env bash

help () {
  echo 'dchr-run <chroot-dir> [command]'
  echo 'https://dchr.dc09.ru'
}

clean () {
  echo '-- Cleaning up'
  umount "$1/proc"
  umount "$1/sys"
  umount "$1/dev"
  umount "$1/run"
}

error () {
  echo -e '-- \e[1;31mError\e[0m -- see output above'
  exit 1 # `trap` in main() calls cleanup function
}

setup () {
  echo '-- Mounting'
  mount -t proc /proc "$1/proc" || error
  mount -t sysfs /sys "$1/sys" || error
  mount -o bind /dev "$1/dev" || error
  mount -o bind /run "$1/run"
}

runcmd () {
  echo -e '-- \e[1;32mOK\e[0m -- running chroot'
  chrdir="$1"
  shift
  chrcmd=("$@")
  chroot "$chrdir" "${chrcmd[@]}"
}

main () {
  [[ "$1" == "--help" || "$1" == "" ]] && help && exit 0

  chrdir=$(readlink -f "$1")
  shift

  trap "clean \"$chrdir\"" EXIT

  setup "$chrdir"
  runcmd "$chrdir" "$@"
  exit $?
}

sourced () {
  [ -n "$ZSH_VERSION"  ] && [[ "$ZSH_EVAL_CONTEXT" =~ :file ]] && return 0
  [ -n "$BASH_VERSION" ] && [[ "$0" != "$BASH_SOURCE" ]] && return 0
  return 1
}

sourced || main "$@"