#!/bin/sh

set -e

config="${HOME}/.config"
local_rc="${PWD}/config/.zshrc"
local_env="${PWD}/config/.zshenv"
local_funcs="${PWD}/config/zsh-functions"
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 zsh 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/zsh 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 "${config}/zsh"; then
    mkdir "${config}/zsh"
  fi
}

_remove_zsh() {
  echo "Removing ~/.config/zsh directory..." >&2
  test -e "${HOME}/.zshenv" && rm "${HOME}/.zshenv"
  test -d "${config}/zsh" && rm -r "${config}/zsh"
}

_uninstall_zsh() {
  echo "Uninstalling zsh configuration..." >&2
  test -e "${HOME}/.zshenv" && rm "${HOME}/.zshenv"
  test -e "${config}/zsh/.zshrc" && rm "${config}/zsh/.zshrc"
  test -e "${config}/zsh/zsh-functions" && rm "${config}/zsh/zsh-functions"
}

_link_zsh() {
  echo "Linking zsh configuration..." >&2
  ln -sfv "${local_env}" "${HOME}"
  ln -sfv "${local_rc}" "${config}/zsh"
  ln -sfv "${local_funcs}" "${config}/zsh"
}

_copy_zsh() {
  echo "Copying zsh configuration..." >&2
  cp "${local_env}" "${HOME}"
  cp "${local_rc}" "${config}/zsh"
  cp "${local_funcs}" "${config}/zsh"
}

_install_zsh() {
  _make_dirs
  # copy if in copy mode.
  test "$copy" -eq 0 && _copy_zsh && return 0
  # link if in link mode.
  test "$link" -eq 0 && _link_zsh && return 0
  # we don't know what to do error.
  echo "Neither link or copy option was set, see --help for usage." >&2
  exit 1
}

# -------------- main -------------------
main() {
  _parse_options "$@"

  # check if in remove mode.
  test "$remove" -eq 0 && _remove_zsh && exit "$?"
  # check if in uninstall mode.
  test "$uninstall" -eq 0 && _uninstall_zsh && exit "$?"
  # install
  _install_zsh
}

main "$@"