#!/bin/sh
#
#  scratchpkg
#
#  Copyright (c) 2018 by Emmett1  (emmett1.2miligrams@gmail.com)
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#
#  script to remove all packages other than base and any user input
#

parseopt() {
	while [ "$1" ]; do
		case $1 in
			-n) dryrun=1;;
			-y) yes=$1;;
			-h) printhelp; exit 0;;
			*)  pkg="$pkg $1"
		esac
		shift
	done
}

printhelp() {
	cat << EOF
Usage:
  $(basename $0) [options] [packages]
  
Options:
  -n  dry-run
  -y  dont ask user confirmation
  -h  print this help msg
  
EOF
}

error=0

parseopt "$@"

echo "Calculate packages to keep..."
keep=$(scratch deplist base $pkg | awk '{print $2}')

echo "Calculate selected packages to remove..."
for pkg in $(scratch installed | awk '{print $1}'); do
	echo $keep | tr ' ' '\n' | grep -qx $pkg || {
		remove="$remove $pkg"
	}
done

[ "$remove" ] && {
	[ "$dryrun" = 1 ] && {
		for i in $remove; do
			echo "remove: $i..."
		done
		echo "This is dry-run, no real action is run!"
	} || {
		scratch remove $yes $remove || error=1
	}
} || {
	echo "Already on base, nothing to remove."
}

exit $error