#!/bin/bash
#
#   pacman-uncage
#
#   Copyright (c) 2002-2006 by Andrew Rose <rose.andrew@gmail.com>
#   I used Judds pacman-optimise as a framework.
#
#   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='2.9.9'
dbroot="/var/lib/pacman"
tmproot="/var/lib/pacman.new"
pacmandb="/var/lib/pacman.db"
pacmanlog=$(pacman -Qv | grep "Log File" | cut -d ":" -f2)

usage() {
    echo "pacman-uncage $myver"
    echo "usage: $0 [pacman_db_root]"
    echo
    echo "pacman-uncage returns your pacman db to the generic style."
    echo
}

die() {
    echo "pacman-uncage: $*" >&2
    exit 1
}

die_r() {
    rm -f /tmp/pacman.lck
    die $*
}

if [[ "$1" != "" ]]; then
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        usage
        exit 0
    fi
    dbroot=$1
fi

[[ $(id -u) != 0 ]] && die "You must be root to uncage the database"

# added by wain: make sure pacmandb is mounted
if ! mount -l | grep $dbroot >/dev/null; then
    die "Pacmandb must be mounted"
fi

# make sure pacman isn't running
[[ -f /tmp/pacman.lck ]] && die "Pacman lockfile was found.  Cannot run while pacman is running."
[[ ! -d $dbroot ]] && die "$dbroot does not exist or is not a directory"

# don't let pacman run while we do this
touch /tmp/pacman.lck

# write to pacman.log
echo "[ $(date '+%Y-%m-%d %H:%M ')] Pacman-cage [cmd] >> Starting and preparing pacmandb uncaging process ..." >> $pacmanlog

# step 1: sum the old db
echo "==> md5sum'ing the old database..."
find $dbroot -type f | sort | xargs md5sum >/tmp/pacsums.old

echo "==> copying pacman.db contents back, note: the time needed to get a brew is now."
mkdir $tmproot
cp -a $dbroot/. $tmproot

echo "==> unmounting old dbroot and moving new one in"
umount $dbroot
rmdir $dbroot
mv $tmproot $dbroot

echo "==> md5sum'ing the new database..."
find $dbroot -type f | sort | xargs md5sum >/tmp/pacsums.new

echo "==> checking integrity..."
diff /tmp/pacsums.old /tmp/pacsums.new &>/dev/null
if [[ $? != 0 ]]; then
    # failed, move the old one back into place
    rm -rf $dbroot
    mkdir $dbroot
    mount -o loop $pacmandb $dbroot
    echo "[ $(date '+%Y-%m-%d %H:%M ')] Pacman-cage [cmd] >> Something went wrong. $pacmandb remounted to $dbroot." >> $pacmanlog
    die_r "integrity check FAILED, reverting to old database"
fi

echo "==> Removing old pacman.db"
rm $pacmandb

rm -f /tmp/pacman.lck /tmp/pacsums.old /tmp/pacsums.new

echo "[ $(date '+%Y-%m-%d %H:%M ')] Pacman-cage [cmd] >> Pacman database has been uncaged." >> $pacmanlog
echo
echo "Finished.  Your pacman database has been uncaged! Welcome home."
echo

exit 0