#!/usr/bin/env bash

SKIP_FILES="(CMakeLists.txt|.cmake|CMakePresets.json|Makefile.am|configure.ac)$"

if [ ! -d "$1" ]; then
	echo "$1 is not a directory"
	exit 1
fi

COMMIT="$2"
if [ -z "$2" ]; then
	echo "2nd parameter must be a commit id. Not given, so assuming 'HEAD'"
	COMMIT="HEAD"
fi

if [ -z "${TCG_TPM_HOME}" ]; then
	echo "TCG_TPM_HOME must be set to the TCG TPM repo checkout."
	exit 1
fi

if [ ! -d "${TCG_TPM_HOME}" ]; then
	echo "TCG_TPM_HOME must point to a directory."
	exit 1
fi

set -x
LIBTPMS_ROOT="$PWD"

pushd "${TCG_TPM_HOME}" >/dev/null || exit 1

git checkout "${COMMIT}" || exit 1

for fname in $(git diff-tree --no-commit-id --name-only "${COMMIT}" -r); do
	if [[ $(basename "${fname}") =~ ${SKIP_FILES} ]]; then
		continue
	fi
	mkdir -p "$(dirname "${LIBTPMS_ROOT}/${1}/${fname}")"
	touch "${LIBTPMS_ROOT}/${1}/${fname}"
	meld "${fname}" "${LIBTPMS_ROOT}/${1}/${fname}"
	if [ $(stat -c%s "${LIBTPMS_ROOT}/${1}/${fname}") -eq 0 ]; then
		rm -f "${LIBTPMS_ROOT}/${1}/${fname}"
	fi
done