#!/bin/bash
#
#  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/>.
#

trap "interrupted" SIGHUP SIGINT SIGQUIT SIGTERM

export LC_ALL=C

interrupted() {
	echo
	ret 1
}

msg() {
	echo -e "==> $1"
}

msg2() {
	echo -e " -> $1"
}

msgerr() {
	echo -e "==> ERROR: $1"
}

msgwarn() {
	echo -e "==> WARNING: $1"
}

help() {	
	cat << EOF	
Usage:
  $(basename $0) [ <options> <package name> ]

Options:
  -h, --help            show this help message
  -v, --verbose         print removed files
      --no-preremove    don't run pre-remove script
      --no-postremove   don't run post-remove script
      --root=<path>     remove package from custom root directory
      
EOF
}

extract_opt() {
	for opt in $@; do
		case $opt in
			  --*) OPTS+=($opt) ;;
			   -*) for (( i=1; i<${#opt}; i++ )); do OPTS+=(-${opt:$i:1}); done ;;
			    *) OPTS+=($opt) ;;
		esac
	done
	echo ${OPTS[@]}
}

parse_opts() {	
	if [ -z "$1" ]; then
		SHOWHELP=yes
	else
		while [ "$1" ]; do
			case $1 in
			-h |              --help) SHOWHELP=yes ;;
			-v |           --verbose) VERBOSE_REMOVE="-v" ;;
			          --no-preremove) NO_PREREMOVE=yes ;;
				     --no-postremove) NO_POSTREMOVE=yes ;;
		                    --root=*) ROOT_DIR="${1#*=}" ;;
		                          -*) msg "Invalid option: ($1)"; exit 1 ;;
					               *) RMNAME=$1 ;;
			esac
			shift
		done
	fi	
}

ret() {
	# remove lock file on exit
	rm -f $LOCK_FILE $reserve $dirs $remove $files
	exit $1
}

isinstalled() {
	if [ -s $INDEX_DIR/$1/.pkginfo ] && grep -q $1 $INDEX_DIR/$1/.pkginfo; then
		return 0
	else
		return 1
	fi
}
	
parse_opts $(extract_opt $@)

INDEX_DIR="$ROOT_DIR/var/lib/scratchpkg/index"
LOCK_FILE="$ROOT_DIR/var/lib/scratchpkg/spkg.lock"

# disable pre/post remove script when remove from custom root location
if [ "$ROOT_DIR" != "" ]; then
	NO_PREREMOVE=yes
	NO_POSTREMOVE=yes
fi
	
# show help page
if [ "$SHOWHELP" ] || [ -z "$RMNAME" ]; then
	help
	ret 0
fi

# check for root access
if [ "$UID" != "0" ]; then
	echo "Removing package need root access!"
	ret 1
fi

# check for lock file
if [ -f $LOCK_FILE ]; then
	msgerr "Cant install/remove package simultaneously."
	msgerr "remove '$LOCK_FILE' if no install/remove package process running."
	exit 1
else
	touch $LOCK_FILE
	if [ "$?" != 0 ]; then
		msgerr "Cant create lock file in '$LOCK_FILE'"
		exit 1
	fi
fi

if ! isinstalled $RMNAME; then
	msgerr "Package '$RMNAME' not installed."
	ret 1
fi

name=$(grep ^name $INDEX_DIR/$RMNAME/.pkginfo | cut -d " " -f3-)
version=$(grep ^version $INDEX_DIR/$RMNAME/.pkginfo | cut -d " " -f3-)
release=$(grep ^release $INDEX_DIR/$RMNAME/.pkginfo | cut -d " " -f3-)

if [ -z $name ] && [ -z $version ] && [ -z $release ]; then
	msgerr "Package '$RMNAME' not installed but exist in database."
	ret 1
fi

# create list for reserve and remove (dirs and files)
reserve=$(mktemp) || { msgerr "Failed create tmp files"; ret 1; }
remove=$(mktemp)  || { msgerr "Failed create tmp files"; ret 1; }
dirs=$(mktemp)    || { msgerr "Failed create tmp files"; ret 1; }
files=$(mktemp)   || { msgerr "Failed create tmp files"; ret 1; }

grep '/$' $INDEX_DIR/*/.files | grep -v $INDEX_DIR/$name | awk -F : '{print $2}' | sort | uniq > $reserve
grep '/$' $INDEX_DIR/$name/.files > $remove
grep -Fxv -f $reserve $remove | tac > $dirs
grep -v '/$' $INDEX_DIR/$name/.files | tac >> $files

echo "remove: $name-$version-$release..."

# pre-remove script
if [ ! "$NO_PREREMOVE" ] && [ -f $INDEX_DIR/$name/.pkginstall ]; then
	pushd "$ROOT_DIR"/ >/dev/null
		sh $INDEX_DIR/$name/.pkginstall pre-remove "$version"
	popd >/dev/null
fi

# remove files and dirs
pushd "$ROOT_DIR"/ >/dev/null
	[ -s $files ] && xargs -a $files -d'\n' rm $VERBOSE_REMOVE
	[ -s $dirs ]  && xargs -a $dirs -d'\n' rmdir $VERBOSE_REMOVE
popd >/dev/null

rm -f $reserve $dirs $remove $files

# post-remove script	
if [ ! "$NO_POSTREMOVE" ] && [ -f $INDEX_DIR/$name/.pkginstall ]; then
	pushd "$ROOT_DIR"/ >/dev/null
		sh $INDEX_DIR/$name/.pkginstall post-remove "$version"
	popd >/dev/null
fi

# remove from database
rm -rf $INDEX_DIR/$name

# running ldconfig
if [ -x "$ROOT_DIR"/sbin/ldconfig ]; then
	"$ROOT_DIR"/sbin/ldconfig -r "$ROOT_DIR"/
fi

ret 0