#!/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.cortexAtool" $CONF_FILE`

    export BRANCH=$BSP_VER
    export KER_SRC=linux-imx
    export KER_PATH=$PRJ_PATH/$KER_SRC
    export DRV_PATH=$TOP_PATH/drivers/${BOARD}

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

    if [[ $BOARD =~ mx6ull ]] ; then
        export ARCH=arm
    else
        export ARCH=arm64
    fi
}

function build_kernel()
{
    defconfig=${BOARD}_defconfig
    patch_file=$PRJ_PATH/patches/$BOARD/${KER_SRC}-$BSP_VER.patch

    cd $PRJ_PATH

    if [ -d $KER_PATH ] ; then
        pr_info "linux kernel source code fetched already"
    else
        pr_info "start fetch linux kernel source code"

        if [[ $BSP_URL =~ github.com ]] ; then
            git clone $BSP_URL/$KER_SRC.git -b $BRANCH --depth=1
        else
            mkdir -p $TARBALL_PATH

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

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

    cd $KER_PATH

    if [ ! -s arch/$ARCH/configs/$defconfig -a -s $patch_file ] ; then
        pr_warn "do patch for $KER_SRC now..."
        patch -p1 < $patch_file
    fi

    pr_warn "start build $KER_SRC"

    if [ ! -s .config ] ; then
        make ${defconfig}
    fi

    make -j ${JOBS}
}

function do_install()
{
    pr_info "start install linux kernel images"

    cd $KER_PATH

    if [ -d $PRFX_PATH ] ; then
        rm -rf $PRFX_PATH/*
    fi

    mkdir -p $PRFX_PATH/overlays

    # Install system image and device tree binaries

    if [[ $BOARD =~ 6ull ]] ; then
        set -x
        cp -f arch/${ARCH}/boot/zImage $PRFX_PATH
        cp -f arch/${ARCH}/boot/dts/${BOARD}.dtb $PRFX_PATH
        if [ -d arch/${ARCH}/boot/dts/${BOARD} ] ; then
            cp -f arch/${ARCH}/boot/dts/${BOARD}/*.dtbo $PRFX_PATH/overlays
        fi
        set +x
    else
        set -x
        cp -f arch/${ARCH}/boot/Image $PRFX_PATH
        cp -f arch/${ARCH}/boot/dts/freescale/${BOARD}.dtb $PRFX_PATH
        if [ -d arch/${ARCH}/boot/dts/${BOARD} ] ; then
            cp -f arch/${ARCH}/boot/dts/${BOARD}/*.dtbo $PRFX_PATH/overlays
        fi
        set +x
    fi

    # Install kernel modules
    make modules_install INSTALL_MOD_PATH=$PRFX_PATH INSTALL_MOD_STRIP=1

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

    if [[ -n "$INST_PATH" && -w $INST_PATH ]] ; then
        pr_info "install linux kernel to '$INST_PATH'"
        cp -f $PRFX_PATH/*Image $INST_PATH
        cp -f $PRFX_PATH/${BOARD}.dtb $INST_PATH
    fi
}

function build_driver()
{
    if [ ! -d $DRV_PATH ] ; then
        return 0;
    fi

    pr_info "start ${BOARD} linux drivers"

    if [ -d $DRV_PATH ] ; then
        cd $DRV_PATH && ./build.sh
    fi

    cd $PRJ_PATH
}

function do_build()
{
    cd $PRJ_PATH

    build_kernel

    do_install

    build_driver
}

function do_clean()
{
    cd $PRJ_PATH

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

    if [ -d $DRV_PATH ] ; then
        cd $DRV_PATH && ./build.sh -c
    fi

    cd
}

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

export_env

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

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

do_build