#!/bin/bash
# Copyright (C) CZ.NIC, z.s.p.o. and contributors
# SPDX-License-Identifier: GPL-2.0-or-later
# For more information, see <https://www.knot-dns.cz/>

set -ueo pipefail

ROOT_PATH="$(dirname "$(realpath "$0")")/../src/contrib/libngtcp2/ngtcp2"
NGTCP2_GIT="https://github.com/ngtcp2/ngtcp2"

if [ $# != 1 ]; then
	printf 'expected single arg - git tag name to which to upgrade\n'
	exit 1
fi

clonedir="$(mktemp -d)"
trap 'rm -rf "$clonedir"; printf "error encountered - aborting\n"' ERR

cur_version=v"$(sed -En 's/^.*NGTCP2_VERSION[^"]*"([0-9.]+)"/\1/p' "${ROOT_PATH}/version.h")"

git clone --branch="$1" "$NGTCP2_GIT" "${clonedir}/ngtcp2" 2>/dev/null

cd "${clonedir}/ngtcp2"
function getfiles() {
	git diff --name-only --diff-filter="$1" "$2" "$3" \
		| grep -E '(crypto|lib|third-party)/' \
		| xargs -r realpath >"$4" || true
}
getfiles "A" "$cur_version" "$1" "../added"
getfiles "D" "$cur_version" "$1" "../deleted"
getfiles "ad" "$cur_version" "$1" "../changed"

# generate new version.h
autoreconf -if >/dev/null 2>&1
./configure --enable-lib-only --with-gnutls >/dev/null 2>&1
cp ./lib/includes/ngtcp2/version.h "${ROOT_PATH}"

cd "$ROOT_PATH"

# delete files deleted in new version
while IFS=$'\n' read -r line; do
	find . -type f -name "$(basename "$line")" | xargs -r rm -f
done <"${clonedir}/deleted"

# update changed files
find . -type f | while IFS=$'\n' read -r line; do
	base="$(basename "$line")"
	match="$(grep -Em1 '(^|/)'"$base"'$' "${clonedir}/changed" || true)"
	if [ -n "$match" ]; then
		cp "$match" "$line"
	fi
done

# ngtcp2_crypto.h is the only non-unique filename, so we deal with it separately
# ugly - I'm aware ;p
cp "${clonedir}/ngtcp2/lib/ngtcp2_crypto.h" ./lib/ngtcp2_crypto.h
cp "${clonedir}/ngtcp2/crypto/includes/ngtcp2/ngtcp2_crypto.h" ./ngtcp2_crypto.h

newfiles="$(wc -l <"${clonedir}/added")"
if [ "$newfiles" -gt 0 ]; then
	printf "%s new file(s) were added between %s and %s; add these manually if desired:\n" \
		"$newfiles" "$cur_version" "$1"
	cut -d'/' -f'5-' "${clonedir}/added" | xargs -r printf "\t%s\n"
	mkdir NEWFILES
	xargs <"$clonedir"/added -I{} mv {} ./NEWFILES
fi

rm -rf "$clonedir"
