#!/usr/bin/env bash

set -euo pipefail

xgit() {
	git -c "user.name=Flake Update Bot" -c "user.email=flake-update-bot@clerie.de" -c "core.pager=cat" "$@"
}

NOW="$(date --utc +%Y-%m-%d-%H-%M)"

xgit status || xgit clone gitea@git.clerie.de:clerie/nixfiles.git .

echo "[!] Download changes"
xgit fetch --all

echo "[!] Chechout remote master"
xgit checkout origin/master

UPDATE_BRANCH="updated-inputs-${NOW}"
echo "[!] Create branch ${UPDATE_BRANCH}"
xgit checkout -b "${UPDATE_BRANCH}"

echo "[!] Update nixpkgs"
nix flake lock --update-input nixpkgs

echo "[!] Commit changes"
xgit add flake.lock

xgit commit -m "Update nixpkgs ${NOW}" || true

xgit diff --name-status origin/updated-inputs "${UPDATE_BRANCH}"

echo "[!] biep"
if xgit diff --quiet origin/updated-inputs "${UPDATE_BRANCH}"
then
	echo "[!] Nothing changed, removing branch"
	xgit branch -D "${UPDATE_BRANCH}"
	exit 0
fi

echo "[!] Publish ${UPDATE_BRANCH}"
xgit push --set-upstream origin "${UPDATE_BRANCH}"

echo "[!] Merge ${UPDATE_BRANCH} into updated-inputs"
xgit checkout updated-inputs
xgit merge -s ort -X theirs "${UPDATE_BRANCH}" -m "Update from ${UPDATE_BRANCH}"

echo "[!] Publish updated-inputs"
xgit push origin updated-inputs