#!/bin/sh -e

PREREQS=""

prereqs()
{
	echo "$PREREQS"
}

case "$1" in
	prereqs)
		prereqs
		exit 0
	;;
esac

# find the disk to install to
find_target()
{
	SRC=$1
	
	for f in /sys/block/[sh]d[a-z]; do
		bdev=$(basename $f)
		if [ "$bdev" = "$SRC" ]; then
			continue
		fi
		# the first block device that's not root?  take it!
		echo "$bdev"
		break
	done
}

do_install()
{
	echo
	echo
	echo
	echo "Starting installer!"
	if [ ! -d /root/etc ]; then
		echo "Error: /root doesn't appear to have a valid filesystem mounted!"
		sleep 9999999999
	fi

	ROOT_SRC=$(grep ' /root ' /proc/mounts | cut -d' ' -f1)
	ROOT_SRC=$(readlink -f $ROOT_SRC | sed 's/.*\/\([hs]d[a-z]\)[0-9]\+$/\1/')

	TARGET=$(find_target "$ROOT_SRC")

	if [ -z "$TARGET" ]; then
		echo "Error: couldn't find drive to install to!"
		sleep 9999999999
	fi

	# don't keep fs mounted while copying it
	umount /root
	
	# wait 15s for user realize that they've made a mistake
	echo "Copying data from [$ROOT_SRC]  =>  [$TARGET]"
	echo "IF THIS IS INCORRECT, REBOOT NOW OR YOU WILL LOSE DATA!  (waiting 15s)"
	sleep 15

	echo "Too late, starting copy..."
	# ideally, we'll resize the filesystem/partitions later..
	dd if=/dev/$ROOT_SRC of=/dev/$TARGET bs=4k

	echo "Done.  Remove installer media."
	while [ -d /sys/block/$ROOT_SRC ]; do
		sleep 1
	done
	reboot
}

for x in $(cat /proc/cmdline); do
	case $x in
	installer)
		do_install
		;;
	esac
done