#!/usr/bin/env bash

# SPDX-FileCopyrightText: 2022 Caleb La Grange <thonkpeasant@protonmail.com>
# SPDX-FileCopyrightText: 2023 Leah Rowe <leah@libreboot.org>
# SPDX-License-Identifier: GPL-3.0-only

name=""
revision=""
location=""
url=""
bkup_url=""
tmp_dir=""

main()
{
	if [ -z "${1+x}" ]; then
		err 'Error: name not set'
	fi

	name=${1}

	read_config
	verify_config

	clone_project

	# clean in case of failure
	rm -rf ${tmp_dir} >/dev/null 2>&1 || exit 1
}

read_config()
{
	awkstr=" /\{.*${name}.*}{/ {flag=1;next} /\}/{flag=0} flag { print }"
	while read -r line ; do
		set ${line} >/dev/null 2>&1
		case ${line} in
			rev:*)
			revision=${2}
			;;
			loc:*)
			location=${2}
			;;
			url:*)
			url=${2}
			;;
			bkup_url:*)
			bkup_url=${2}
			;;
		esac
	done <<< $(eval "awk '${awkstr}' resources/git/revisions")
}

verify_config()
{
	if [ -z "${revision+x}" ]; then
		err 'Error: revision not set'
	elif [ -z "${location+x}" ]; then
		err 'Error: location not set'
	elif [ -z "${url+x}" ]; then
		err 'Error: url not set'
	fi
}

clone_project()
{
	tmp_dir=$(mktemp -dt "${name}_XXXXX")

	git clone ${url} ${tmp_dir} || git clone ${bkup_url} ${tmp_dir} \
			|| err "ERROR: could not download ${name}"

	(
	cd ${tmp_dir} || exit 1
	git reset --hard ${revision} || err "Cannot reset revision"
	)

	patch_project

	if [ -d "${location}" ]; then
		rm -Rf ${location} || exit 1
	fi
	mv ${tmp_dir} ${location} && return 0

	printf "ERROR: Could not copy temp file to destination.\n"
	err " ${tmp_dir} > ${location} check permissions"
}

patch_project()
{
	patchdir="resources/${name}/patches"

	for patchfile in ${PWD}/${patchdir}/*.patch ; do
		if [ ! -f "${patchfile}" ]; then
			continue
		fi
		(
		cd ${tmp_dir} || exit 1
		git am ${patchfile} || err "Cannot patch project: $name"
		)
	done
}

usage()
{
	cat <<- EOF
	Usage: ./gitclone [name]

	Options:
	name: Module name as specified in resources/git/revisions
	EOF
}

err()
{
	printf "${@}\n"
	usage
	exit 1
}

main $@