#!/bin/bash
#
#   repo-remove : remove a package entry from a given repo database file
#  
#   Copyright (c) 2007 Dan McGee <dan@archlinux.org>
#  
#   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 2 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, write to the Free Software
#   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 
#   USA.

myver='3.0.0'

FORCE=0
REPO_DB_FILE=""

DB_COMPRESSION="gz" #TODO this is gross
DB_CHECKSUMS=(md5)
TMP_DIR=""

# print usage instructions
usage() {
	echo "repo-remove $myver"
	echo
	echo "usage: repo-remove <path-to-db> <packagename> ..."
	echo
	echo "repo-remove will update a package database by removing the package name"
	echo "specified on the command line from the given repo database. Multiple"
	echo "packages to remove can be specified on the command line."
	echo
	echo "Example:"
	echo "  repo-remove /path/to/repo.db.tar.gz kernel26"
	echo
}

# test if a file is a repository DB
test_repo_db_file () {
	if [ -f "$REPO_DB_FILE" ]; then
		[ "$(tar tf "$REPO_DB_FILE" | grep -c "/desc")" -gt 0 ] || return 1
	else
		true
	fi
}

# remove existing entries from the DB
db_remove_entry()
{
	cd $gstmpdir

	# remove any other package in the DB with same name
	for existing in *; do
		if [ "${existing%-*-*}" = "$1" ]; then
			echo ":: removing existing package '$existing'"
			rm -rf $existing
		fi
	done
} # end db_remove_entry

# PROGRAM START

# check for help flags
if [ "$1" = "-h" -o "$1" = "--help" ]; then
	usage
	exit 0
fi

# check for correct number of args
if [ $# -lt 2 ]; then
	usage
	exit 1
fi

# main routine
if [ $# -gt 1 ]; then
	gstmpdir=$(mktemp -d /tmp/gensync.XXXXXXXXXX) || (\
	echo "cannot create temp directory for database building"; \
	exit 1)

	success=0
	# parse arguements
	for arg in $@; do
		if [ -z "$REPO_DB_FILE" ]; then
			REPO_DB_FILE="$(readlink -f $arg)"
			if ! test_repo_db_file; then
				echo "error: repository file '$REPO_DB_FILE' is not a proper pacman db"
				exit 1
			elif [ -f "$REPO_DB_FILE" ]; then
				echo ":: extracting database to a temporary location"
				tar xf "$REPO_DB_FILE" -C "$gstmpdir"
			fi
		else
			echo ":: searching for package '$arg'"

			this_dir="$(pwd)"
			if db_remove_entry "$arg"; then
				success=1
			else
			echo "error: package matching '$arg' not found"
			fi
			cd $this_dir
		fi
	done

	# if all operations were a success, rezip database
	if [ "$success" = "1" ]; then
		echo ":: creating updated database file ${REPO_DB_FILE}"
		cd $gstmpdir
		if [ -n "$(ls)" ]; then
			[ -f "${REPO_DB_FILE}.old" ] && rm "${REPO_DB_FILE}.old"
			[ -f "$REPO_DB_FILE" ] && mv "$REPO_DB_FILE" "${REPO_DB_FILE}.old"
			case "$DB_COMPRESSION" in
				gz) tar c * | gzip -9 >$REPO_DB_FILE ;;
				bz2) tar c * | bzip2 -9 >$REPO_DB_FILE ;;
				*) echo "warning: no compression set"
				tar c * >$REPO_DB_FILE;;
			esac
		fi
	else
		echo ":: no packages modified, nothing to do"
	fi
fi

# remove the temp directory used to unzip
[ -d "$gstmpdir" ] && rm -rf $gstmpdir

# vim: set ts=2 sw=2 noet: