#!/bin/bash
CAT=`type -p cat`
GREP=`type -p grep`
AWK=`type -p awk`
SFDISK=`type -p sfdisk`
PARTED=`type -p parted`
MOUNT=`type -p mount`
MKDIR=`type -p mkdir`
SWAPON=`type -p swapon`
MKFSEXT3=`type -p mkfs.ext3`
MKFSXFS=`type -p mkfs.xfs`
MKSWAP=`type -p mkswap`
LS=`type -p ls`

get_swap_size() {

	ramkb=`$CAT /proc/meminfo | $GREP MemTotal | $AWK {'print $2'}`
	let swap_size=2*$ramkb/1024+16

}

remove_removable() {

revindex=0
element_count=${#disks[@]}

while [ "$revindex" -lt "$element_count" ]
	do
	s=${disks[$revindex]#/dev/}
	s=${s//:/}
	removable=`$CAT /sys/block/$s/removable`
	[ $removable -gt 0 ] && unset disks[$revindex]
	revindex+=1
	done

}


get_devices() {
	
	get_swap_size
	disks=(`$SFDISK -s | $GREP dev | $AWK {'print $1'}`)
	remove_removable
	numdisks=0
	sizes=()
	for disk in ${disks[@]};do
		numdisks=$((numdisks+1))
		let sizes[$numdisks-1]=`$SFDISK -s | $GREP $disk | $AWK {'print $2'}`/1024
	done

[ ${#disks[@]} -eq 0 ] && echo 'No disc found :,( I am giving up'; exit 255
[ ${#disks[@]} -gt 2 ] && echo 'More than 2 disks found, I can/will use only the first two :-('; exit 127
let smallestdisk=2048+2048+100+$swap_size
[ ${sizes[0]} -lt $smallestdisk ] && echo 'First disk size is smaller than $smallestdisk :-/ manual install required'; exit 13

}

wipe_device() {

	hd_part=${$1#/dev/}
	partitions=(`$LS /dev/ | $GREP $hd_part.`)
	if  [[ ${#partitions[@]} -gt 0 ]]
	then
		index=1
		elements=${#partitions[@]}
		while [ "$index" -lt "$elements"+1 ]
		do
			$PARTED -s $1 rm $index
			index+=1
		 done
	fi
}

partition_single() {
	exit
	dev=${disks[0]//:/}
	echo "Destroying partitions on device $dev ..."
	wipe_device $dev
	echo "Creating a new partition table on $dev ..."
	$SFDISK $dev -uM -L <<-EOT
	0,100,L,*
	,$swap_size,S
	,2048,L
	,,L
	EOT

	echo "Formating partitions on $dev ..."
	$MKFSEXT3 ${dev}1
	$MKSWAP -v1 ${dev}2
	$MKFSXFS -f ${dev}3
	$MKFSXFS -f ${dev}4

	echo "Mounting partitions on $dev ..."
	$MOUNT ${dev}3 /mnt/target
	$MKDIR -p /mnt/target/{boot,data}
	[ $double ] && $MKDIR -p /mnt/target/backup
	$MOUNT ${dev}1 /mnt/target/boot
	$MOUNT ${dev}4 /mnt/target/data
	$SWAPON ${dev}2 

}
partition_double() {
	
	double=1
	partition_single
	dev2=${disks[1]//:/}
	echo "Creating a new partition table on $dev2 ..."
	$SFDISK $dev2
	echo "Formating partitions on $dev2 ..." 
	$MKFSXFS -f ${dev2}1
	echo "Mounting partitions on $dev2 ..."
	$MOUNT ${dev2}1 /mnt/target/backup

}
main() {

	get_devices
	[ ${#disks[@]} -eq 1 ] && partition_single
	[ ${#disks[@]} -ge 2 ] && partition_double
}
main