#!/bin/sh

set -e

config="${HOME}/.config"
uninstall=1
remove=1
copy=1
link=0

_usage() {
  printf "\n" >&2
  printf "Usage: setup [OPTIONS]\n" >&2
  printf "\n" >&2
  printf "Installs or Uninstalls nvim configuration files.\n" >&2
  printf "\n" >&2
  printf "Options:\n" >&2
  printf "\t-c | --copy      : Copy the configuration files, instead of creating symlinks.\n" >&2
  printf "\t-h | --help      : Print usage information.\n" >&2
  printf "\t-l | --link      : Create symlinks to the configuration files (Default).\n" >&2
  printf "\t-r | --remove    : Removes the entire ~/.config/nvim directory.\n" >&2
  printf "\t-u | --uninstall : Uninstalls configuration files.\n" >&2
  printf "\n" >&2
  printf "If called without the uninstall option then it will install the configuration files.\n" >&2
  printf "The copy and link options are ignored if called with the uninstall or remove option.\n" >&2
  printf "\n" >&2
}

_parse_options() {
  arg=
  while ! test -z "$1"; do
    arg="$1"
    case $arg in
      -c | --copy)
        copy=0
        link=1
        shift;;
      -h | --help)
        _usage
        exit;;
      -l | --link)
        copy=1
        link=0
        shift;;
     -r | --remove)
        remove=0
        shift;;
      -u | --uninstall)
        uninstall=0
        shift;;
      *)
        echo "Unknown option $arg" >&2
        shift;;
    esac
  done
}

_make_dirs() {
  if ! test -d "${config}"; then
    mkdir "${config}"
  fi
  if ! test -d "${config}/nvim"; then
    mkdir "${config}/nvim"
  fi
}

_remove_nvim() {
  echo "Removing nvim configuration..." >&2
  test -d "${config}/nvim" && rm -r "${config}/nvim"
}

_uninstall_nvim() {
  echo "Uninstalling nvim configuration..." >&2
  test -e "${config}/nvim/init.lua" && rm "${config}/nvim/init.lua"
  test -d "${config}/nvim/lua" && rm "${config}/nvim/lua"
}

_link_nvim() {
  echo "Linking nvim configuration..." >&2
  ln -sfv "${PWD}/init.lua" "${config}/nvim"
  ln -sfv "${PWD}/lua" "${config}/nvim"
}

_copy_nvim() {
  echo "Linking nvim configuration..." >&2
  cp "${PWD}/init.lua" "${config}/nvim"
  cp -r "${PWD}/lua" "${config}/nvim"
}

_install_nvim() {
  _make_dirs
  # copy if in copy mode
  test "$copy" -eq 0 && _copy_nvim && exit "$?"
  # link if in link mode
  test "$link" -eq 0 && _link_nvim && exit "$?"
  # else we don't know what to do
  echo "Neither link or copy options were set. Use the --help option" >&2
  exit 1
}

#------------------------------- main ------------------------------

main() {
  _parse_options "$@"

  # check if remove is called first
  test $remove -eq 0 && _remove_nvim && exit "$?"

  # then check if uninstall was called
  test $uninstall -eq 0 && _uninstall_nvim && exit "$?"

  # else install the configuration files
  _install_nvim
  echo "Nvim will need to be started for vim plugins to download."
}

main "$@"