#!/usr/bin/env sh

#  helper script: create code trees based on git revision, with patches
#  (currently used for downloading coreboot, seabios and u-boot)
#
#	Copyright (C) 2014-2016,2020,2021,2023 Leah Rowe <info@minifree.org>
#	Copyright (C) 2022 Alper Nebi Yasak <alpernebiyasak@gmail.com>
#	Copyright (C) 2022 Ferass El Hafidi <vitali64pmemail@protonmail.com>
#
#	This program is free software: you can redistribute it and/or modify
#	it under the terms of the GNU General Public License as published by
#	the Free Software Foundation, either version 3 of the License, or
#	(at your option) any later version.
#
#	This program is distributed in the hope that it will be useful,
#	but WITHOUT ANY WARRANTY; without even the implied warranty of
#	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#	GNU General Public License for more details.
#
#	You should have received a copy of the GNU General Public License
#	along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

[ "x${DEBUG+set}" = 'xset' ] && set -v
set -u -e

. "include/err.sh"

_target=""
tree=""
rev=""
project=""
cfgsdir=""

main()
{
	rm -f "${cfgsdir}"/*/seen || err_rm_seen "main 1"

	printf "Downloading %s and (if available) applying patches\n" \
	    ${project}

	[ -z "${1}" ] && err "project name not specified"
	project="${1}"
	cfgsdir="config/${project}"
	[ -d "${cfgsdir}" ] || err "unsupported project name"
	shift 1

	targets=$(./build command options "${cfgsdir}")
	[ $# -gt 0 ] && targets=$@
	[ -z "${targets}" ] && \
	    err "No targets available for project: ${project}"

	for x in ${targets}; do
		rm -f "${cfgsdir}"/*/seen || err_rm_seen "main 2"
		download_for_target "${x}" || \
		    err "${project}/${target}: cannot download source tree"
	done

	rm -f "${cfgsdir}"/*/seen || err_rm_seen "main 3"
}

download_for_target()
{
	_target="${1}"
	tree="undefined"
	rev="undefined"

	fetch_config "${_target}" || \
	    err "download_for_target: ${project}/${_target}: bad target.cfg"

	rm -f "${cfgsdir}"/*/seen || err_rm_seen "download_for_target"

	if [ -d "${project}/${tree}" ]; then
		printf "REMARK: download/%s %s: exists. Skipping.\n" \
		    "${project}" "${tree}" 1>&2
		[ "${tree}" != "${_target}" ] && \
			printf "(for target: '%s}')\n" "${_target}" 1>&2
		return 0
	fi

	fetch_from_upstream || \
	    err "download_for_target: cannot fetch: ${project}"
	prepare_new_tree "${_target}" "${tree}" "${rev}" || \
	    err "download_for_target: cannot create tree: ${project}/${tree}"
}

fetch_config()
{
	_target=${1}

	while true; do
		rev="undefined"
		tree="undefined"

		check_config_for_target "${_target}" || return 1

		# This is to override $rev and $tree
		. "${cfgsdir}/${_target}/target.cfg" || \
		    err "fetch_config: no \"${cfgsdir}/${_target}/target.cfg\""

		if [ "${_target}" != "${tree}" ]; then
			_target="${tree}"
			continue
		elif [ "${tree}" = "undefined" ]; then
			printf "ERROR (fetch_config): download/%s:" 1>&2
			printf " tree name undefined for '%s\n'" \
			    "${project}" "${_target}" 1>&2
			return 1
		elif [ "${rev}" = "undefined" ]; then
			printf "ERROR (fetch_config): download/%s:" 1>&2
			printf " commit ID undefined for '%s'\n" \
			    "${project}" "${_target}" 1>&2
			return 1
		else
			break
		fi
	done
}

check_config_for_target()
{
	_target=${1}

	if [ ! -f "${cfgsdir}/${_target}/target.cfg" ]; then
		printf "ERROR: download/%s: target.cfg does not" \
		    "${project}" 1>&2
		printf " exist for '%s'\n" "${_target}" 1>&2
		return 1
	elif [ -f "${cfgsdir}/${_target}/seen" ]; then
		printf "ERROR: download/%s: logical loop:" "${project}" 1>&2
		printf " '%s' target.cfg refers to another tree," "${_target}" \
		    1>&2
		printf " which ultimately refers back to '%s'." "${_target}" \
		    1>&2
		return 1
	fi
	touch "${cfgsdir}/${_target}/seen" || \
	    err "${project}/${_target}: touch \"${cfgsdir}/${_target}/seen\""
}

fetch_from_upstream()
{
	[ -d "${project}" ] || mkdir -p "${project}" || return 1
	[ -d "${project}" ] || return 1
	[ -d "${project}/${project}" ] && return 0

	./update project repo ${project} || return 1
}

prepare_new_tree()
{
	target=${1}
	tree=${2}
	rev=${3}

	printf "Preparing %s tree: %s\n" ${project} ${tree}
	[ "${tree}" != "${target}" ] && \
		printf "(for target, %s)\n" "${target}"

	cp -R "${project}/${project}" "${project}/${tree}" || \
	    err "${project}/${tree}: cannot copy source tree"
	(
	cd "${project}/${tree}" || err "cannot cd to ${project}/${tree}"
	git reset --hard ${rev} || \
	    err "cannot reset ${project} revision for tree, ${tree}"
	git submodule update --init --checkout || \
	    err "cannot update ${project} submodules for tree, ${tree}"

	for patch in "../../${cfgsdir}/${tree}/patches/"*.patch; do
		[ -f "${patch}" ] || continue
		if ! git am "${patch}"; then
			git am --abort || \
			    err "${project}/${tree}: FAILED: git am --abort"
			err "cannot patch: ${project}/${tree}"
		fi
	done

	# extra.sh can be used for anything
	# but should *only* be a last resort
	if [ -f "../../${cfgsdir}/${tree}/extra.sh" ]; then
		"../../${cfgsdir}/${tree}/extra.sh" || \
		    err "prepare_new_tree ${project}/${tree}: extra.sh: error"
	fi
	)
}

err_rm_seen()
{
	err "${1}: ${project}/${target}: cannot rm: \"${cfgsdir}/*/seen\""
}

main $@