#!/usr/bin/env bash
#
# SPDX-License-Identifier: GPL-2.0
#
# Copyright (c) 2013-2026 Igor Pecovnik, igor@armbian.com
#
# This file is a part of the Armbian Build Framework
# https://github.com/armbian/build/

# Functions:

# compile_atf
# compile_uboot
# compile_kernel
# compile_firmware
# compile_xilinx_bootgen
# grab_version
# advanced_patch
# process_patch_file
# overlayfs_wrapper

grab_version() {
	local ver=()
	ver[0]=$(grep "^VERSION" "${1}"/Makefile | head -1 | awk '{print $(NF)}' | grep -oE '^[[:digit:]]+' || true)
	ver[1]=$(grep "^PATCHLEVEL" "${1}"/Makefile | head -1 | awk '{print $(NF)}' | grep -oE '^[[:digit:]]+' || true)
	ver[2]=$(grep "^SUBLEVEL" "${1}"/Makefile | head -1 | awk '{print $(NF)}' | grep -oE '^[[:digit:]]+' || true)
	ver[3]=$(grep "^EXTRAVERSION" "${1}"/Makefile | head -1 | awk '{print $(NF)}' | grep -oE '^-rc[[:digit:]]+' || true)
	ver[4]=$(if [ -f localversion-next ]; then echo $(cat localversion-next); fi || true)
	echo "${ver[0]:-0}${ver[1]:+.${ver[1]}}${ver[2]:+.${ver[2]}}${ver[3]}${ver[4]}"
	return 0
}

# overlayfs_wrapper <operation> <workdir> <description>
#
# <operation>: wrap|cleanup
# <workdir>: path to source directory
# <description>: suffix for merged directory to help locating it in /tmp
# return value: new directory
#
# Assumptions/notes:
# - Ubuntu Xenial host
# - /tmp is mounted as tmpfs
# - there is enough space on /tmp
# - UB if running multiple compilation tasks in parallel
# - should not be used with CREATE_PATCHES=yes
#
overlayfs_wrapper() {
	local operation="$1"
	if [[ $operation == wrap ]]; then
		local srcdir="$2"
		local description="$3"
		mkdir -p /tmp/overlay_components/ /tmp/armbian_build/
		local tempdir workdir mergeddir
		tempdir=$(mktemp -d --tmpdir="/tmp/overlay_components/") # @TODO: WORKDIR? otherwise uses host's root disk, which might be small
		workdir=$(mktemp -d --tmpdir="/tmp/overlay_components/")
		mergeddir=$(mktemp -d --suffix="_$description" --tmpdir="/tmp/armbian_build/")
		mount -t overlay overlay -o lowerdir="$srcdir",upperdir="$tempdir",workdir="$workdir" "$mergeddir"
		# this is executed in a subshell, so use temp files to pass extra data outside
		echo "$tempdir" >> /tmp/.overlayfs_wrapper_cleanup
		echo "$mergeddir" >> /tmp/.overlayfs_wrapper_umount
		echo "$mergeddir" >> /tmp/.overlayfs_wrapper_cleanup
		echo "$mergeddir"
		return
	fi
	if [[ $operation == cleanup ]]; then
		if [[ -f /tmp/.overlayfs_wrapper_umount ]]; then
			for dir in $(< /tmp/.overlayfs_wrapper_umount); do
				[[ $dir == /tmp/* ]] && umount -l "$dir" > /dev/null 2>&1
			done
		fi
		if [[ -f /tmp/.overlayfs_wrapper_cleanup ]]; then
			for dir in $(< /tmp/.overlayfs_wrapper_cleanup); do
				[[ $dir == /tmp/* ]] && rm -rf "$dir"
			done
		fi
		rm -f /tmp/.overlayfs_wrapper_umount /tmp/.overlayfs_wrapper_cleanup
	fi
}