#!/bin/bash
set -e

function get_random() {
	local number=0
	while [ "$number" -le 20 ]
	do
	  	number=$RANDOM
	    let "number %= 50" 
	done

	echo $number
}

	 file=$(mktemp -u --tmpdir=.  vgfile.XXXX)
	 group=$(mktemp -u testgrp-XXXX)
	 thingroup=$(mktemp -u thingrp-XXXX)
	 mntpath=$(mktemp -d --tmpdir=. mntdir-XXXX)
	 volume_name=$(mktemp -u testvol-XXXX)
	 volume_size=200M
	 truncate ${file} --size 10G
	 loopdev=$(losetup -f --show ${file})
	 pvcreate --metadatasize 1M ${loopdev}
	 vgcreate ${group} -s 1MiB ${loopdev}
	 pe_size=$(vgdisplay "/dev/${group}" | grep 'PE Size' | awk '{print $3}')
	 thin_size=$(echo "$(vgdisplay "/dev/${group}" | grep 'Free  PE' | awk '{print $5}')*${pe_size}-180" | bc -l) 
	 lvcreate --ignoreactivationskip -Z n -L ${thin_size}M -T "/dev/${group}/${thingroup}" 
	 lvcreate --ignoreactivationskip -V${volume_size} -T "${group}/${thingroup}" -n "${volume_name}"
	 mkfs.ext4 /dev/$group/$volume_name
	 sync
	 vgchange -Kan $group
	 losetup -d $loopdev

echo "Volume created, doing work"
for i in {1..10}; do 
	echo "Doing iteration $i"
	loopdev=$(losetup -f --show ${file})
	vgchange -Kay $group
	if ! mount /dev/$group/$volume_name $mntpath; then 
		echo "kor"
		exit 1
	fi
	rm -rf $mntpath/*
	dd if=/dev/urandom of=$mntpath/$(mktemp -u tmpfile.XXXX) bs=$(get_random)M count=1
	umount $mntpath
	vgchange -Kan $group
	losetup -d $loopdev

done