#!/usr/bin/env bash

## CONSTANTS

BASE_ARCHIVE_URL='https://git.artcode.re/miaou/miaou-bash/archive'

## FUNCTIONS

function upgrade {
  echo UPGRADE
  execute_miaou_lib self-upgrade
}

function install {
  echo INSTALL

  local latest_tag
  latest_tag=$(curl -s https://git.artcode.re/api/v1/repos/miaou/miaou-bash/tags |
    grep -oPm1 '{"name":".*?",' |
    head -n1 |
    cut -d'"' -f4)
  echo "latest_tag=$latest_tag"

  local tempfile='/tmp/miaou-bash-latest.tar.gz'
  curl -so "$tempfile" "${BASE_ARCHIVE_URL}/${latest_tag}.tar.gz"
  sudo tar -xzf "$tempfile" --directory "$(dirname "$MIAOU_BASH_DIR")"
  rm "$tempfile"
  execute_miaou_lib initiate

  echo "miaou-bash successfully $deployment_type_adjective"
}

function assert_supported_distro {
  if ! grep -E '^ID=debian|^ID_LIKE=debian' /etc/os-release &&
    ! grep -E '^ID=arch|^ID_LIKE=arch' /etc/os-release; then
    local distro
    distro=$(grep -oP '^ID=\K(.*)' /etc/os-release)
    >&2 echo "unsupported GNU/Linux distribution: $distro"
    >&2 echo 'only debian-like OR arch-like currently supported'
    exit 2
  fi
}

function once_installed {
  [[ -v MIAOU_BASH_DIR && -d "$MIAOU_BASH_DIR" &&
    -L /etc/inputrc &&
    "$(readlink /etc/inputrc)" == "$MIAOU_BASH_DIR"/etc/inputrc ]]
}

function execute_miaou_lib {
  sudo -E "$MIAOU_BASH_DIR"/bin/miaou-bash "$MIAOU_BASH_DIR"/lib/"$1".bash
}

function assert_bash {
  if [[ $SHELL != bash ]]; then
    >&2 echo "you are running on SHELL=$SHELL. Bash expected!"
    exit 98
  fi
}

function sudo_root {
  [[ "$UID" -ne 0 ]] && sudo -vp 'SUDO privilege required: '
  true
}
## MAIN

set -Eeuo pipefail
assert_supported_distro
assert_bash
sudo_root

if [[ ! -v MIAOU_BASH_DIR ]]; then
  MIAOU_BASH_DIR=/opt/miaou-bash
  export MIAOU_BASH_DIR
fi

deployment_type_adjective="${1:-installed}" # `miaou-bash --self-upgrade` provides the 'upgrade' term
if once_installed; then upgrade; else install; fi
if [[ $deployment_type_adjective == 'installed' ]]; then
  exec bash -l
fi