#!@BASH_SHELL@
#
#   bacman: recreate a package from a running system
#   This script rebuilds an already installed package using metadata
#   stored into the pacman database and system files
#
#   (c) 2008 - locci <carlocci_at_gmail_dot_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 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, see <http://www.gnu.org/licenses/>.
#

readonly progname="bacman"
readonly progver="0.2.1"

#
# User Friendliness
#
function usage(){
    echo "This program recreates a package using pacman's db and system files"
    echo "Usage:   $progname <installed package name>"
    echo "Example: $progname kernel26"
}

if [ $# -ne 1 ] ; then
    usage
    exit 1
fi

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

if [ "$1" = "--version" -o "$1" = "-v" ]; then
    echo "$progname version $progver"
    echo "Copyright (C) 2008 locci"
    exit 0
fi

#
# Fakeroot support
#
if [ $EUID -gt 0 ]; then
    if [ -f /usr/bin/fakeroot ]; then
        echo "Entering fakeroot environment"
        export INFAKEROOT="1"
        /usr/bin/fakeroot -u -- $0 $1
        exit $?
    else
        echo "WARNING: installing fakeroot or running ${progname} as root is required to"
        echo "         preserve the ownership permissions of files in some packages"
        echo ""
    fi
fi

#
# Setting environmental variables
#
if [ ! -r @sysconfdir@/pacman.conf ]; then
    echo "ERROR: unable to read @sysconfdir@/pacman.conf"
    exit 1
fi

eval $(awk '/DBPath/ {print $1$2$3}' @sysconfdir@/pacman.conf)
pac_db="${DBPath:-@localstatedir@/lib/pacman/}/local"

if [ ! -r @sysconfdir@/makepkg.conf ]; then
    echo "ERROR: unable to read @sysconfdir@/makepkg.conf"
    exit 1
fi

source "@sysconfdir@/makepkg.conf"
if [ -r ~/.makepkg.conf ]; then
    source ~/.makepkg.conf
fi

pkg_arch=${CARCH:-'unknown'}
pkg_dest="${PKGDEST:-$PWD}"
pkg_pkger=${PACKAGER:-'Unknown Packager'}

pkg_name="$1"
pkg_dir="$(echo $pac_db/$pkg_name-[0-9]*)"
pkg_namver="${pkg_dir##*/}"

#
# Checks everything is in place
#
if [ ! -d "$pac_db" ] ; then
    echo "ERROR: pacman database directory ${pac_db} not found"
    exit 1
fi

if [ ! -d "$pkg_dir" ] ; then
    echo "ERROR: package ${pkg_name} not found in pacman database"
    exit 1
fi

#
# Begin
#
echo Package: ${pkg_namver}
work_dir=$(mktemp -d -p /tmp)
cd "$work_dir" || exit 1

#
# File copying
#
echo "Copying package files..."

cat "$pkg_dir"/files |
while read i; do
    if [ -z "$i" ] ; then
        continue
    fi

    if [[ "$i" =~ %[A-Z]*% ]] ; then
        current=$i
        continue
    fi

    case $current in
        %FILES%)
            ret=0
            if [ -e "/$i" ]; then
                bsdtar -cnf - "/$i" 2> /dev/null | bsdtar -xpf -

                # Workaround to bsdtar not reporting a missing file as an error
                if [ ! -e "$work_dir/$i" -a ! -L "$work_dir/$i" ]; then
                    echo ""
                    echo "ERROR: unable to add /$i to the package"
                    echo "       If your user does not have permssion to read this file then"
                    echo "       you will need to run $progname as root"
                    rm -rf "$work_dir"
                    exit 1
                fi
            else
                echo ""
                echo "WARNING: package file /$i is missing"
                echo ""
            fi


        ;;
    esac
done

ret=$?
if [ $ret -ne 0 ]; then
    rm -rf "$work_dir"
    exit 1
fi

pkg_size=$(du -sk | awk '{print $1 * 1024}')

#
# .PKGINFO stuff
#
echo Generating .PKGINFO metadata...
echo "# Generated by $progname $progver"    > .PKGINFO
if [ "$INFAKEROOT" = "1" ]; then
    echo "# Using $(fakeroot -v)"    >> .PKGINFO
fi
echo "# $(LC_ALL=C date)"            >> .PKGINFO
echo "#"                    >> .PKGINFO

cat "$pkg_dir"/{desc,files} |
while read i; do
    if [[ -z "$i" ]]; then
        continue;
    fi

    if [[ "$i" =~ %[A-Z]*% ]] ; then
        current=$i
        continue
    fi

    case "$current" in
        # desc
        %NAME%)
            echo "pkgname = $i"    >> .PKGINFO
        ;;
        %VERSION%)
            echo "pkgver = $i"    >> .PKGINFO
        ;;
        %DESC%)
            echo "pkgdesc = $i"    >> .PKGINFO
        ;;
        %URL%)
            echo "url = $i"    >> .PKGINFO
        ;;
        %LICENSE%)
            echo "license = $i"    >> .PKGINFO
        ;;
        %ARCH%)
            echo "arch = $i"    >> .PKGINFO
        ;;
        %BUILDDATE%)
            echo "builddate = $(date -u "+%s")"    >> .PKGINFO
        ;;
        %PACKAGER%)
            echo "packager = $pkg_pkger"        >> .PKGINFO
        ;;
        %SIZE%)
            echo "size = $pkg_size"        >> .PKGINFO
        ;;
        %GROUPS%)
            echo "group = $i"    >> .PKGINFO
        ;;
        %REPLACES%)
            echo "replaces = $i"    >> .PKGINFO
        ;;
        %DEPENDS%)
            echo "depend = $i"   >> .PKGINFO
        ;;
        %OPTDEPENDS%)
            echo "optdepend = $i" >> .PKGINFO
        ;;
        %CONFLICTS%)
            echo "conflict = $i" >> .PKGINFO
        ;;
        %PROVIDES%)
            echo "provides = $i"  >> .PKGINFO
        ;;

        # files
        %BACKUP%)
            # strip the md5sum after the tab
            echo "backup = ${i%%$'\t'*}"   >> .PKGINFO
        ;;
    esac
done

comp_files=".PKGINFO"

if [ -f "$pkg_dir/install" ] ; then
    cp "$pkg_dir/install" "$work_dir/.INSTALL"
    comp_files+=" .INSTALL"
fi
if  [ -f $pkg_dir/changelog ] ; then
    cp "$pkg_dir/changelog" "$work_dir/.CHANGELOG"
    comp_files+=" .CHANGELOG"
fi

#
# Fixes owner:group and permissions for .PKGINFO, .CHANGELOG, .INSTALL
#
chown root:root "$work_dir"/{.PKGINFO,.CHANGELOG,.INSTALL} 2> /dev/null
chmod 644 "$work_dir"/{.PKGINFO,.CHANGELOG,.INSTALL} 2> /dev/null

#
# Generate the package
#
echo "Generating the package..."

case "$PKGEXT" in
	*tar.gz)  EXT=${PKGEXT%.gz} ;;
	*tar.bz2) EXT=${PKGEXT%.bz2} ;;
	*tar.xz)  EXT=${PKGEXT%.xz} ;;
	*tar)     EXT=${PKGEXT} ;;
	*) echo "WARNING: '%s' is not a valid archive extension." \
	"$PKGEXT" ; EXT=$PKGEXT ;;
esac

pkg_file="$pkg_dest/$pkg_namver-$pkg_arch${PKGEXT}"
ret=0

# when fileglobbing, we want * in an empty directory to expand to
# the null string rather than itself
shopt -s nullglob
# TODO: Maybe this can be set globally for robustness
shopt -s -o pipefail
bsdtar -cf - $comp_files * |
case "$PKGEXT" in
    *tar.gz)  gzip -c -f -n ;;
    *tar.bz2) bzip2 -c -f ;;
    *tar.xz)  xz -c -z - ;;
    *tar)     cat ;;
esac > ${pkg_file} || ret=$?

if [ $ret -ne 0 ]; then
    echo "ERROR: unable to write package to $pkg_dest"
    echo "       Maybe the disk is full or you do not have write access"
    rm -rf "$work_dir"
    exit 1
fi

rm -rf "$work_dir"

echo Done

exit 0

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