#!/bin/bash

set_bootloader() {
	if [ "x$BOOTLOADER" == 'xgrub' ]
	then
		set_grub_bootloader
	else
		return 0
	fi
}

set_grub_bootloader() {
	local GRUB_CONF='/boot/grub/grub.conf'

	print_info 1 ''
	print_info 1 "Adding kernel to $GRUB_CONF..."

	# Extract block device information from /etc/fstab
	local GRUB_ROOTFS=$(awk '/[[:space:]]\/[[:space:]]/ { print $1 }' /etc/fstab)
	local GRUB_BOOTFS=$(awk '/^[^#].+[[:space:]]\/boot[[:space:]]/ { print $1 }' /etc/fstab)

	# If /boot is not defined in /etc/fstab, it must be the same as /
	[ "x$GRUB_BOOTFS" == 'x' ] && GRUB_BOOTFS=$GRUB_ROOTFS

	# Read GRUB device map
	echo ${tmp}
	if [ ! -d ${tmp} ]
	then
		mkdir ${tmp}
	fi

	grub --batch --device-map=${tmp}/grub.map <<EOF >/dev/null
quit
EOF

	# Get the GRUB mapping for our device
	local GRUB_BOOT_DISK1=$(echo $GRUB_BOOTFS | sed -e 's#\(/dev/.\+\)[[:digit:]]\+#\1#')
	echo ${GRUB_BOOT_DISK1}
	local GRUB_BOOT_DISK=$(awk '{if ($2 == "'$GRUB_BOOT_DISK1'") {gsub(/(\(|\))/, "", $1); print $1;}}' ${tmp}/grub.map)

	local GRUB_BOOT_PARTITION=$(echo $GRUB_BOOTFS | sed -e 's#/dev/.\+\([[:digit:]]\+\)#\1#')
	if [ ! -d ${tmp} ]
	then
		rm -r ${tmp}
	fi
	echo ${GRUB_ROOTFS}
	
	echo ${GRUB_BOOTFS}
	echo ${GRUB_BOOT_DISK}
	echo ${GRUB_BOOT_PARTITION}
	
	# Create grub configuration directory and file if it doesn't exist.
	[ ! -e `basename $GRUB_CONF` ] && mkdir -p `basename $GRUB_CONF`

	if [ ! -e $GRUB_CONF ]
	then
		if [ "${GRUB_BOOT_DISK}" = '' -o "${GRUB_BOOT_PARTITION}" = '' ]
		then
			print_error 1 'Error! /boot/grub/grub.conf does not exist and the correct settings can\'t be automatically detected.'
			print_error 1 'Please manually create your /boot/grub/grub.conf file.'
		else
			# grub.conf doesn't exist - create it with standard defaults
			touch $GRUB_CONF
			echo 'default 0' >> $GRUB_CONF
			echo 'timeout 5' >> $GRUB_CONF
			echo >> $GRUB_CONF

			# Add grub configuration to grub.conf	
			echo "# Genkernel generated entry, see GRUB documentation for details" >> $GRUB_CONF
			echo "title=Gentoo Linux ($KV)" >> $GRUB_CONF
			echo -e "\troot ($GRUB_BOOT_DISK,$GRUB_BOOT_PARTITION)" >> $GRUB_CONF
			if [ "${BUILD_INITRD}" -eq '0' ]
			then
				echo -e "\tkernel /kernel-$KV root=$GRUB_ROOTFS" >> $GRUB_CONF
			else
				echo -e "\tkernel /kernel-$KV root=/dev/ram0 init=/linuxrc real_root=$GRUB_ROOTFS" >> $GRUB_CONF
				echo -e "\tinitrd /initrd-$KV" >> $GRUB_CONF
			fi
			echo >> $GRUB_CONF
		fi
	else
		# grub.conf already exists; so...
		# ... Clone the first boot definition and change the version.
		cp $GRUB_CONF $GRUB_CONF.bak
		awk 'BEGIN { RS="" ; FS="\n" ; OFS="\n" ; ORS="\n\n" } 
			NR == 2 {
				ORIG=$0;
				sub(/\(.+\)/,"(" KV ")",$1);
				sub(/kernel-[[:alnum:][:punct:]]+/, "kernel-" KV, $3);
				sub(/initrd-[[:alnum:][:punct:]]+/, "initrd-" KV, $4);
				print RS $0; 
				print RS ORIG;}
			NR != 2 { print RS $0; }' KV=$KV $GRUB_CONF.bak > $GRUB_CONF
	fi
}