#!/bin/bash

# this project absolute path
PRJ_PATH=$(cd $(dirname "${BASH_SOURCE[0]}") && pwd)

# top project absolute path
TOP_PATH=$(realpath $PRJ_PATH/..)

# binaries build prefix install path
PRFX_PATH=$PRJ_PATH/install

# binaries finally install path if needed
#INST_PATH=/tftp

# download taballs path
TARBALL_PATH=$PRJ_PATH/tarballs

# config file path
CONF_FILE=$TOP_PATH/config.json

# shell script will exit once get command error
set -e

#+-------------------------+
#| Shell script functions  |
#+-------------------------+

function pr_error() {
	echo -e "\033[40;31m $1 \033[0m"
}

function pr_warn() {
	echo -e "\033[40;33m $1 \033[0m"
}

function pr_info() {
	echo -e "\033[40;32m $1 \033[0m"
}

# decompress a packet to destination path
function do_unpack()
{
	tarball=$1
	dstpath=`pwd`

	if [[ $# == 2 ]] ; then
		dstpath=$2
	fi

	pr_info "decompress $tarball => $dstpath"

	mkdir -p $dstpath
	case $tarball in
		*.tar.gz)
			tar -xzf $tarball -C $dstpath
			;;

		*.tar.bz2)
			tar -xjf $tarball -C $dstpath
			;;

		*.tar.xz)
			tar -xJf $tarball -C $dstpath
			;;

		*.tar.zst)
			tar -I zstd -xf $tarball -C $dstpath
			;;

		*.tar)
			tar -xf $tarball -C $dstpath
			;;

		*.zip)
			unzip -qo $tarball -d $dstpath
			;;

		*)
			pr_error "decompress Unsupport packet: $tarball"
			return 1;
			;;
	esac
}

# parser configure file and export environment variable
function export_env()
{
	export BOARD=`jq -r ".bsp.board" $CONF_FILE | tr 'A-Z' 'a-z'`
	export BSP_VER=`jq -r ".bsp.version" $CONF_FILE | tr 'A-Z' 'a-z'`
	export BSP_URL=`jq -r ".bsp.giturl" $CONF_FILE`
	export CROSS_COMPILE=`jq -r ".bsp.crosstool" $CONF_FILE`

	export DEF_CONFIG=${BOARD}_defconfig
	export IMG_KER=linuxrom-${BOARD}.itb

	export JOBS=`cat /proc/cpuinfo | grep processor | wc -l`
	export ARCH=arm

	export SRCS="linux-at91"
}

function do_fetch()
{
	cd $PRJ_PATH

	for src in $SRCS
	do
		if [ -d $src ] ; then
			pr_info "$src source code fetched already"
			continue
		fi

		pr_info "start fetch $src source code"
		mkdir -p $TARBALL_PATH

		# Download source code packet
		if [ ! -s $TARBALL_PATH/$src.tar.xz ] ; then
			wget $BSP_URL/at91/bsp/$BSP_VER/$src.tar.xz -P $TARBALL_PATH
		fi

		# decompress source code packet
		do_unpack $TARBALL_PATH/$src.tar.xz

		# do patch if patch file exist
		patch_file=$PRJ_PATH/patches/$BOARD/$src-$BSP_VER.patch
		if [ -s $patch_file ] ; then
			pr_warn "do patch for $src now..."
			cd $src
			patch -p1 < $patch_file
			cd -
		fi
	done
}

function build_kernel()
{
	SRC=linux-at91

	pr_warn "start build $SRC"
	cd $PRJ_PATH/${SRC}

	if [ ! -f .config ] ; then
		make $DEF_CONFIG ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE}
	fi

	make -j${JOBS} ARCH=${ARCH} CROSS_COMPILE=${CROSS_COMPILE}

	pr_info "mkimage -f linuxrom-${BOARD}.its ${IMG_KER}"
	${TOP_PATH}/bootloader/u-boot-at91/tools/mkimage -f linuxrom-${BOARD}.its ${IMG_KER} > /dev/null
	chmod a+x ${IMG_KER}

	set -x
	cp ${IMG_KER} $PRFX_PATH/
	set +x
}

function do_build()
{
	cd $PRJ_PATH
	mkdir -p $PRFX_PATH

	build_kernel
}

function do_install()
{
	cd $PRJ_PATH

	echo ""
	pr_info "linux kernel installed to '$PRFX_PATH'"
	ls $PRFX_PATH && echo ""

	if [[ -n "$INST_PATH" && -w $INST_PATH ]] ; then
		pr_info "install linux images to '$INST_PATH'"
		cp $PRFX_PATH/* $INST_PATH
	fi
}

function do_clean()
{
	for d in $SRCS
	do
		rm -rf $PRJ_PATH/$d
	done

	rm -rf $PRJ_PATH/tarballs
	rm -rf $PRFX_PATH
}

#+-------------------------+
#| Shell script body entry |
#+-------------------------+

cd $PRJ_PATH

export_env

if [[ $# == 1 && $1 == -c ]] ;then
	pr_warn "start clean linux kernel"
	do_clean
	exit;
fi

pr_warn "start build linux kernelel for ${BOARD}"

do_fetch

do_build

do_install