#!/bin/bash

usage() {
  cat <<EOF
Usage:
  $(basename "$0") [OPTION...]

Options:
  -h  Print this help
  -i  Path to SSH identity file

EOF
}

while getopts i:h opt; do
  case "$opt" in
    i)
      identityFile="${OPTARG}"
      ;;
    h)
      usage
      exit 0
      ;;
    \?)
      usage >&2
      exit 64
      ;;
  esac
done

shift $((OPTIND - 1))

if [ -z ${identityFile} ]; then
  echo "missing option: -i is required" >&2
  usage >&2
  exit 64
fi

if [ -z $(type -P "scp") ] || [ -z $(type -P "ssh") ]; then
  echo "SSH needs to be installed" >&2
  exit 64
fi

echo "Please open $(tput bold)https://nixos.org/download#nixos-amazon$(tput sgr0) and follow the
instructions to launch an EC2 instance.

$(tput bold)Note: it's recommended to use a disk size of >=20GB.$(tput sgr0)"
echo

read -p "Domain or IP of launched EC2 instance: " host

echo
echo "$(tput bold)Copying configuration to ${host}...$(tput sgr0)"
scp -i "${identityFile}" ./configuration.nix root@"${host}":/etc/nixos/configuration.nix

echo "$(tput bold)Building system...$(tput sgr0)"
ssh -i "${identityFile}" root@"${host}" "nixos-rebuild switch --upgrade"