#!/bin/sh

packages() {
	awk '
BEGIN		{ FS = ": " }
/^Package:/	{ pkg = $2 }
/^Version:/	{ version = $2 }
/^$/		{ print(pkg, version) }
' "$@"
}

CSSU_LISTS="/var/lib/apt/lists/repository.maemo.org_community_*_Packages /var/lib/apt/lists/repository.maemo.org_community-testing_*_Packages /var/lib/apt/lists/maemo.merlin1991.at_cssu_community-devel_*_Packages /var/lib/apt/lists/maemo.merlin1991.at_cssu_community-thumb_*_Packages"

if test "$(id -u)" != "0"; then
	echo "You must be root to run this script"
	exit 1
fi

echo "Checking system packages. Please wait... (this can take a lot of time)"
echo

rm -f /var/tmp/cssu-packages
touch /var/tmp/cssu-packages
rm -f /var/tmp/cssu-lists
touch /var/tmp/cssu-lists
for file in $CSSU_LISTS; do
	if ! test -f $file; then continue; fi
	echo $file >> /var/tmp/cssu-lists
	sed -n 's/Package: //p' $file >> /var/tmp/cssu-packages
done
sort -u /var/tmp/cssu-packages > /var/tmp/cssu-packages.new
mv /var/tmp/cssu-packages.new /var/tmp/cssu-packages

dpkg --get-selections | awk '/install$/{print $1}' | sort -u | comm -12 - /var/tmp/cssu-packages > /var/tmp/cssu-packages.new
grep -v '^community-ssu-enabler$' /var/tmp/cssu-packages.new > /var/tmp/cssu-packages

rm -f /var/tmp/version-packages
touch /var/tmp/version-packages
for file in /var/lib/apt/lists/*_Packages; do
	if ! test -f $file; then continue; fi
	if grep -q "^$file\$" /var/tmp/cssu-lists; then continue; fi
	packages $file >> /var/tmp/version-packages
done
sort -u /var/tmp/version-packages > /var/tmp/version-packages.new
mv /var/tmp/version-packages.new /var/tmp/version-packages

rm -f /var/tmp/install-packages
touch /var/tmp/install-packages
rm -f /var/tmp/remove-packages
touch /var/tmp/remove-packages
while read package; do
	max=0
	for version in $(grep "^$package " /var/tmp/version-packages | sed 's/.* //'); do
		if dpkg --compare-versions $max lt $version 1>/dev/null 2>&1; then
			max=$version
		fi
	done
	if test "$max" = "0"; then
		echo "$package" >> /var/tmp/remove-packages
	else
		if test $(dpkg-query -W -f \${Version} $package) != "$max"; then
			echo "$package=$max" >> /var/tmp/install-packages
		fi
	fi
done < /var/tmp/cssu-packages

rm -f /var/tmp/cssu-packages /var/tmp/cssu-lists /var/tmp/version-packages

meta=mp-fremantle-generic-pr
for num in 002 003 004 203 204 205 206 207 208 210; do
	if dpkg -l "*-$num" 2>/dev/null | grep -q '^ii'; then
		meta=mp-fremantle-$num-pr
		break
	fi
done

echo "Remove packages:"
cat /var/tmp/remove-packages
echo

echo "Install packages:"
cat /var/tmp/install-packages
echo

echo "Remove metapackage:"
if dpkg -l mp-fremantle-community-pr 2>/dev/null | grep -q '^ii'; then
	echo "mp-fremantle-community-pr"
fi
echo

echo "Install metapackage:"
if ! dpkg -l $meta 2>/dev/null | grep -q '^ii'; then
	echo $meta >> /var/tmp/install-packages
	echo $meta
fi
echo

if test "$1" == "--check"; then exit 0; fi

echo "This script will uninstall Community SSU and downgrade Maemo 5 to last Nokia version."
echo "See above changes, do you want to continue? (yes/no)"

read REPLY

if test "$REPLY" != "yes"; then
	echo "Canceling..."
	exit 0
fi

echo
echo "==== Removing packages ===="
dpkg -P --force-all $(cat /var/tmp/remove-packages)

echo
echo "==== Downgrading packages ===="
apt-get -y --force-yes install $(cat /var/tmp/install-packages)

echo
echo "Done."
echo "Now you need to restart device."
read REPLY