#!/bin/bash
set -e

if [ $(id -u) -ne 0 ]; then
	echo 'must be root (sudo)'
	exit 1
fi

echo 'detecting Ubuntu version'
osver=`/usr/bin/lsb_release -r | /usr/bin/cut -f2`
if [ "$osver" == "18.04" ]; then
	echo 'detected Ubuntu 18.04 (bionic)'
	echo 'performing step 1: upgrade to Ubuntu 20.04 (focal)'

	echo 'updating package list'
	/usr/bin/apt update

	echo 'upgrading installed packages'
	DEBIAN_FRONTEND=noninteractive /usr/bin/apt -y upgrade

	echo 'autoremoving unused packages'
	/usr/bin/apt -y autoremove

	echo 'upgrading operating system'
	DEBIAN_FRONTEND=noninteractive /usr/bin/do-release-upgrade

	echo 'upgrade complete'
elif [ "$osver" == "22.04" ]; then
	echo 'detected Ubuntu 20.04 (bionic)'

	if [ -f /etc/apt/sources.list.d/lsfilter.list ]; then
		n=`/bin/grep 'deb ' /etc/apt/sources.list.d/lsfilter.list | /bin/grep -v '^#' | /usr/bin/wc -l`
		if [ $n -ne 0 ]; then
			echo 'upgraded system already initialized'
			echo 'nothing to do'
			exit 0
		fi
	fi

	echo 'performing step 2: initialize upgraded system'
	if [ -f /etc/apt/sources.list.d/lsfilter.list ]; then
		echo 'cleaning up custom package repositories'
		/usr/local/bin/lspkg --remove-all-repos
	fi

	echo 'adding custom package repository'
	/usr/local/bin/lspkg --add-repo production

	echo 'updating custom package repository list'
	if [ -f /tmp/lsfilter.list ]; then
		/bin/rm -v /tmp/lsfilter.list
	fi

	/bin/cat /etc/apt/sources.list.d/lsfilter.list | /bin/sed 's/ bionic / focal /' > /tmp/lsfilter.list
	/bin/cp -v /tmp/lsfilter.list /etc/apt/sources.list.d/lsfilter.list

	echo 'updating package list'
	/usr/bin/apt update

	echo 'upgrading installed packages'
	DEBIAN_FRONTEND=noninteractive /usr/bin/apt -y upgrade
else
	echo "unsupported Ubuntu version $osver"
	exit 1
fi