#!/usr/bin/env bash
# from https://github.com/0atman/noboilerplate/blob/main/scripts/38-nixos.md#dont-use-nix-env
# docstring=quick edit (or ling xD) for nixos config
set -E -o pipefail
shopt -s failglob
export LC_ALL=C.UTF8

INITIAL_PWD="$(pwd)"
PROJECT="$HOME/Projects/NixOS"
GIT_PATTERN="." # "*.nix"


exit_with_new_shell() {
  # check if already in directory
  [[ "$INITIAL_PWD" = "$PROJECT" ]] && printf '>>> already in directory\n' && exit 0

  printf '\n'
  printf '>>> opening a new \"%s\" shell\n' "$(basename "$SHELL")"
  printf '>>> cwd: %s\n' "$(pwd)"
  "$SHELL"
  exit 0
}

cd "$PROJECT" || exit 1
nvim

# check if there are changes at all
[[ -z "$(git diff -U0 "$GIT_PATTERN")" ]] && echo ">>> no changes, exiting ..." && exit_with_new_shell

# only then do auto formating
printf ">>> auto formating ..."
nix fmt . &> /dev/null
printf " DONE!\n"

# and then show the user a diff
git diff -U0 "$GIT_PATTERN" # as a seperate command so we get nice colors and pager

printf ">>> Do you want to rebuild NixOS? [y/N]\n"
printf "<<< " && read -r YESNO
if ! [[ "${YESNO,,}" == "y" ]]; then
  exit_with_new_shell
fi

git add "$GIT_PATTERN"

printf ">>> Rebuilding NixOS\n"
sudo nixos-rebuild switch | tee nixos-switch.log || (
  grep --color error nixos-switch.log && false)
gen=$(nixos-rebuild list-generations | grep current)
git commit -am "$gen"

exit_with_new_shell