#!/bin/bash

let FORCE_REBUILD=0
KERNEL_REBUILD_ARGS=""

[ -f /etc/gentoo-upgrade.conf ] && source /etc/gentoo-upgrade.conf

# available parameters
eval set -- "`getopt -o h,q --long help,force-rebuild,mrproper,quiet -- \"$@\"`"

while true ; do
    case "$1" in
        -h|--help)
            echo "Usage: kernel-getlast.sh [keys]..."
            echo "Keys:"
            echo -e "-h, --help\t\t\tShow this help and exit."
            echo -e "--force-rebuild\t\t\tForce to rebuild kernel even if no new versions found."
            echo -e "--mrproper\t\t\tClean kernel sources before rebuild."
            echo -e "-q, --quiet\t\t\tMake kernel configuration non-interactive."
            echo
            echo -e "This program works on any GNU/Linux with GNU Baurne's shell"
            echo -e "Report bugs to <mecareful@gmail.com>"
            exit 0
            ;;
        --force-rebuild) let FORCE_REBUILD=1 ; shift ;;
        --mrproper) KERNEL_REBUILD_ARGS="$KERNEL_REBUILD_ARGS --mrproper" ; shift ;;
        -q|--quiet) KERNEL_REBUILD_ARGS="$KERNEL_REBUILD_ARGS --silent" ; shift ;;
        --) shift ; break ;;
        *) echo "Internal error!" ; exit -1 ;;
    esac
done

current_kernel_src=`kernel-config list | grep \* | cut -d" " -f6`
if [ "" == "$current_kernel_src" ]; then
    current_kernel_src=`readlink -f /usr/src/linux`
    current_kernel_src=${current_kernel_src##*/}
fi
[ "" == "$current_kernel_src" ] && echo "Cann't determine current kernel sources ;-(" && exit -1

kernel_regex=`echo -n $current_kernel_src  | sed 's~[0-9]*\.[0-9]*\.[0-9]*~[0-9]*\.[0-9]*\.[0-9]*~ ; s~-r[0-9]*$~~; s~$~\\\(-r[0-9]\\\)\\\?~'`
[ "" == "$kernel_regex" ] && echo "kernel_regex build failed ;-(" && exit -1

new_kernel=`kernel-config list | cut -d" " -f6 | grep ^$kernel_regex$ | sort -V | tail -n1`
[ "" == "$new_kernel" ] && echo "Couldn't find appropriate new kernel version ;-(" && exit -1
echo new_kernel=$new_kernel

# remounting file systems ro->rw
for fs in $RW_REMOUNT; do
    if [[ "$fs" =~ ^/+usr/*$ || "$fs" =~ ^/+boot/*$ ]]; then
        echo "remounting $fs -> rw"
        mount -o remount,rw $fs
        [ 0 -ne $? ] && echo "mount -o remount,rw $fs failed ;-( =======" && exit -1
    fi
done

kernel-config set $new_kernel
[ 0 -ne $? ] && echo "kernel-config set $new_kernel failed ;-(" && exit -1

kernel-clean.sh
[ 0 -ne $? ] && echo "kernel-clean.sh failed ;-(" && exit -1

vmlinuz_file=/boot/`echo $new_kernel | sed 's~^linux~vmlinuz~'`
[ "" == "$vmlinuz_file" ] && echo "vmlinuz_file == \"\"" && exit -1

vmlinuz_file_x86_64=/boot/`echo $new_kernel | sed 's~^linux~vmlinuz~'`-x86_64
[ "" == "$vmlinuz_file_x86_64" ] && echo "vmlinuz_file_x86_64 == \"\"" && exit -1

march=`uname -m`
genkernel_file=/boot/`echo $new_kernel | sed "s~^linux~kernel-genkernel-${march}~"`
echo vmlinuz_file=$vmlinuz_file
echo vmlinuz_file_x86_64=$vmlinuz_file_x86_64
echo genkernel_file=$genkernel_file
[ "" == "$genkernel_file" ] && echo "genkernel_file == \"\"" && exit -1
if [[ ! -f "$vmlinuz_file" && ! -f "$vmlinuz_file_x86_64" && ! -f "$genkernel_file" || 1 -eq $FORCE_REBUILD ]]; then
    kernel-rebuild.sh $KERNEL_REBUILD_ARGS
    [ 0 -ne $? ] && echo "kernel-rebuild.sh $KERNEL_REBUILD_ARGS failed" && exit -1
fi

# remounting file systems rw->ro
for fs in $RO_REMOUNT; do
    if [[ "$fs" =~ ^/+usr/*$ || "$fs" =~ ^/+boot/*$ ]]; then
        echo "remounting $fs -> ro"
        mount -o remount,ro -force $fs
        [ 0 -ne $? ] && echo "mount -o remount,ro -force $fs failed ;-( =======" && exit -1
    fi
done

exit 0