#!/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"
}

runremovehooks() {	
	if [ "${#runthishook[@]}" -gt 0 ]; then
		for hook in ${runthishook[@]}; do
			description=$(cat "$hook" | grep ^"# description" | sed 's/\://' | cut -d ' ' -f 3-)
			operation=$(cat "$hook" | grep ^"# operation" | sed 's/\://' | cut -d ' ' -f 3-)
			target=$(cat "$hook" | grep ^"# target" | sed 's/\://' | cut -d ' ' -f 3-)
			if [ -n "$description" ] && [ -n "$operation" ] && [ -n "$target" ]; then
				. $hook
				if [ "`type -t exechook`" = "function" ]; then
					exechook
				fi
			fi
			unset description operation target
			unset -f exechook
		done
	fi	
}

runpreremovehooks() {	
	for hook in $HOOK_DIR/*.hook; do
		[ -f $hook ] || continue
		operation=$(cat "$hook" | grep ^"# operation" | sed 's/\://' | cut -d ' ' -f 3-)
		target=$(cat "$hook" | grep ^"# target" | sed 's/\://' | cut -d ' ' -f 3-)
		if [ "$(echo $operation | grep -w "remove" )" ]; then
			if [ "$(grep $target $INDEX_DIR/$1/.files)" ]; then
				runthishook+=($hook)
			fi
		fi
		unset operation target
	done	
}

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

Options:
  -h, --help            show this help message
      --no-preremove    don't run pre-remove script
      --no-postremove   don't run post-remove script
      --no-hook         skip executing hook
      --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 $1 in
			-h |              --help) SHOWHELP=yes ;;
			-v |           --verbose) VERBOSE_REMOVE=yes ;;
			          --no-preremove) NO_PREREMOVE=yes ;;
				     --no-postremove) NO_POSTREMOVE=yes ;;
			   		       --no-hook) NOHOOK=yes ;;
		                    --root=*) ROOT="${1#*=}" ;;
		                          -*) msg "Invalid option: ($1)"; exit 1 ;;
					               *) RMNAME=$1 ;;
			esac
			shift
		done
	fi	
}

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

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

INDEX_DIR="$ROOT/var/lib/scratchpkg/index"
PKGDEL_DIR="$ROOT/var/lib/scratchpkg"
LOCK_FILE="$PKGDEL_DIR/spkg.lock"
HOOK_DIR="/etc/hooks"
	
# show help page
if [ "$SHOWHELP" ] || [ -z "$RMNAME" ]; then
	help
	ret 0
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

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

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

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

echo "Removing '$name-$version-$release'..."

# source .install script
if [ "$ROOT" = "" ]; then
	if [ -f $INDEX_DIR/$name/.pkginstall ]; then
		source $INDEX_DIR/$name/.pkginstall
	fi
fi
	
if [ ! "$NO_PREREMOVE" ]; then	
	if [ "`type -t pre_remove`" = "function" ]; then
		pre_remove "$version" &>/dev/null
	fi
fi

if [ "$ROOT" = "" ] && [ "$NOHOOK" != "yes" ]; then
	runpreremovehooks $name &>/dev/null
fi

if [ -f "$INDEX_DIR/$name/.bkpfiles" ]; then
	while IFS=' ' read -r line; do
		if [ -e "$ROOT/$line" ] || [ -L "$ROOT/$line" ]; then
			[ "$VERBOSE_REMOVE" = yes ] && echo "<<< $line"
			rm "$ROOT/$line"
		fi
	done < <(tac $INDEX_DIR/$name/.bkpfiles)
fi

while IFS=' ' read -r line; do
	if [ -e "$ROOT/$line" ] || [ -L "$ROOT/$line" ]; then
		[ "$VERBOSE_REMOVE" = yes ] && echo "<<< $line"
		rm "$ROOT/$line"
	fi
done < <(tac $INDEX_DIR/$name/.files | grep -v '/$')

while IFS=' ' read -r line; do
	if [ ! "$(grep -R --exclude-dir="$name" -w "$line" "$INDEX_DIR")" ]; then
		if [ -d "$ROOT/$line" ]; then
			[ "$VERBOSE_REMOVE" = yes ] && echo "<<< $line"
			rmdir "$ROOT/$line"
		fi
	fi
done < <(tac $INDEX_DIR/$name/.files | grep '/$')
	
if [ ! "$NO_POSTREMOVE" ]; then
	if [ "`type -t post_remove`" = "function" ]; then
		post_remove "$version" &>/dev/null
	fi
fi
	
rm -rf $INDEX_DIR/$name

if [ "$ROOT" = "" ] && [ "$NOHOOK" != "yes" ]; then
	runremovehooks
fi

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

ret 0