#!/bin/bash
# 
#   gensync
#  
#   Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.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='2.9.8'

usage() {
  echo "gensync $myver"
  echo "usage: $0 <root> <destfile> [package_directory]"
	echo
	echo "gensync will generate a sync database by reading all PKGBUILD files"
	echo "from <root>.  gensync builds the database in a temporary directory"
	echo "and then compresses it to <destfile>."
	echo
	echo "gensync will calculate md5sums of packages in the same directory as"
	echo "<destfile>, unless an alternate [package_directory] is specified."
	echo
	echo "note: The <destfile> name is important.  It must be of the form"
	echo "      {treename}.db.tar.gz where {treename} is the name of the custom"
	echo "      package repository you configured in /etc/pacman.conf.  The"
	echo "      generated database must reside in the same directory as your"
	echo "      custom packages (also configured in /etc/pacman.conf)"
	echo
	echo "example:  gensync /var/abs/local /home/mypkgs/custom.db.tar.gz"
	echo
  echo
  exit 0
}

die() {
	echo "gensync: $*" >&2
	rm -rf $gstmpdir
	exit 1
}

check_option() {
	local i
	for i in ${options[@]}; do
		local uc=`echo $i | tr [:lower:] [:upper:]`
		local lc=`echo $i | tr [:upper:] [:lower:]`
		if [ "$uc" = "$1" -o "$lc" = "$1" ]; then
			echo $1
			return
		fi
	done
}

get_md5checksum()
{
	if [ "$pkgdir" != "" ]; then
		pkgfile="$pkgdir/$pkgname-$pkgver-$pkgrel.pkg.tar.gz"
	else
		pkgfile="$destdir/$pkgname-$pkgver-$pkgrel.pkg.tar.gz"
	fi
	if [ -f $pkgfile ]; then
		md5line=`md5sum $pkgfile`
		[ ! -z "$md5line" ] && pkgmd5sum=${md5line%  *}
		echo $pkgmd5sum
	fi
	return 0
}

db_write_entry()
{
	unset pkgname pkgver pkgrel pkgdesc force
	unset groups replaces provides depends conflicts options
	source $1 || return 1
	cd $gstmpdir
	mkdir $pkgname-$pkgver-$pkgrel || return 1
	cd $pkgname-$pkgver-$pkgrel
	# desc
	: >desc
	echo "%NAME%" >>desc
	echo "$pkgname" >>desc
	echo "" >>desc
	echo "%VERSION%" >>desc
	echo "$pkgver-$pkgrel" >>desc
	echo "" >>desc
	echo "%DESC%" >>desc
	echo "$pkgdesc" >>desc
	echo "" >>desc
	echo "%CSIZE%" >>desc
	echo "$csize" >>desc
	echo "" >>desc
	if [ ! -z $pkgmd5sum ]; then
		echo "%MD5SUM%" >>desc
		echo "$pkgmd5sum" >>desc
		echo "" >>desc
	fi
	if [ ${#groups[*]} -gt 0 ]; then
		echo "%GROUPS%" >>desc
		for it in "${groups[@]}"; do
			echo "$it" >>desc
		done
		echo "" >>desc
	fi
	if [ ${#replaces[*]} -gt 0 ]; then
		echo "%REPLACES%" >>desc
		for it in "${replaces[@]}"; do
			echo "$it" >>desc
		done
		echo "" >>desc
	fi
	if [ "$force" = "y" -o "$force" = "Y" -o "`check_option FORCE`" ]; then
		echo "%FORCE%" >>desc
		echo "" >>desc
	fi
	# depends
	: >depends
	if [ ${#depends[*]} -gt 0 ]; then
		echo "%DEPENDS%" >>depends
		for it in "${depends[@]}"; do
		  echo "$it" >>depends
		done
		echo "" >>depends
	fi
	if [ ${#conflicts[*]} -gt 0 ]; then
		echo "%CONFLICTS%" >>depends
		for it in "${conflicts[@]}"; do
		  echo "$it" >>depends
		done
		echo "" >>depends
	fi
	if [ ${#provides[*]} -gt 0 ]; then
		echo "%PROVIDES%" >>depends
		for it in "${provides[@]}"; do
		  echo "$it" >>depends
		done
		echo "" >>depends
	fi
	# preserve the modification time
	touch -r $1 desc depends
}

if [ $# -lt 2 ]; then
	usage
	exit 1
fi

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

d=`dirname $1`
rootdir=`cd $d && pwd`/`basename $1`
d=`dirname $2`
destdir=`cd $d && pwd`
destfile="$destdir/`basename $2`"
pkgdir=
if [ "$3" != "" ]; then
	pkgdir=$3
fi
gstmpdir=$(mktemp -d /tmp/gensync.XXXXXXXXXX) || exit 1

[ ! -d $rootdir ] && die "invalid root dir: $rootdir"
echo "gensync: building database entries, generating md5sums..." >&2
cd `dirname $2`
for file in `find $rootdir/* -name PKGBUILD`; do
	source $file || die "errors parsing $file"
	if [ "$pkgdir" != "" ]; then
		pkgfile="$pkgdir/$pkgname-$pkgver-$pkgrel.pkg.tar.gz"
	else
		pkgfile="$destdir/$pkgname-$pkgver-$pkgrel.pkg.tar.gz"
	fi
	if [ -f $pkgfile ]; then
		csize=`du -b $pkgfile | cut -f1`
		pkgmd5sum=`get_md5checksum $pkgfile`
		[ -z $pkgmd5sum ] && die "error generating checksum for $pkgfile"
		db_write_entry $file || die "error writing entry for $file"
	else
		echo "gensync: missing package: $pkgfile" >&2
	fi
done

echo "gensync: compressing to $destfile..." >&2
cd $gstmpdir
tar c * | gzip -9 >$destfile
[ $? -gt 0 ] && die "error writing to $destfile"

rm -rf $gstmpdir
exit 0