#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-only
: <<=cut
=head1 NAME

opkg-build - construct an .opk from a directory

=cut
# Carl Worth <cworth@east.isi.edu>
# based on a script by Steve Redler IV, steve@sr-tech.com 5-21-2001
# 2003-04-25 rea@sr.unh.edu
#   Updated to work on Familiar Pre0.7rc1, with busybox tar.
#   Note it Requires: binutils-ar (since the busybox ar can't create)
set -e
set -o pipefail

version=1.0

opkg_extract_value() {
	sed -e "s/^[^:]*:[[:space:]]*//"
}

required_field() {
	field=$1

	value=`grep "^$field:" < $CONTROL/control | opkg_extract_value`
	if [ -z "$value" ]; then
		echo "*** Error: $CONTROL/control is missing field $field" >&2
		return 1
	fi
	echo $value
	return 0
}

disallowed_field() {
	field=$1

	value=`grep "^$field:" < $CONTROL/control | opkg_extract_value`
	if [ -n "$value" ]; then
		echo "*** Error: $CONTROL/control contains disallowed field $field" >&2
		return 1
	fi
	echo $value
	return 0
}

pkg_appears_sane() {
	local pkg_dir=$1

	local owd=`pwd`
	cd $pkg_dir

	PKG_ERROR=0

	tilde_files=`find . -name '*~' -ls -printf '\\\n'`
	if [ -n "$tilde_files" ]; then
	    if [ "$noclean" = "1" ]; then
		echo "*** Warning: The following files have names ending in '~'.
You probably want to remove them: " >&2
		echo -e $tilde_files
		if [ $? -ne 0 ]; then
			echo "*** Error: Fail to list files have names ending in '~'."
			exit 1
		fi
		echo >&2
	    else
		echo "*** Removing the following files: $tilde_files"
		rm -f "$tilde_files"
	    fi
	fi

	large_uid_files=`find . -uid +99 -ls -printf '\\\n' || true`

	if [ "$ogargs" = "" ]  && [ -n "$large_uid_files" ]; then
		echo "*** Warning: The following files have a UID greater than 99.
You probably want to chown these to a system user: " >&2
		echo -e $large_uid_files
		if [ $? -ne 0 ]; then
			echo "*** Error: Fail to list files have a UID greater than 99."
			exit 1
		fi
		echo >&2
	fi
	    

	if [ ! -f "$CONTROL/control" ]; then
		echo "*** Error: Control file $pkg_dir/$CONTROL/control not found." >&2
		cd $owd
		return 1
	fi

	pkg=`required_field Package`
	[ "$?" -ne 0 ] && PKG_ERROR=1

	version=`required_field Version`
	[ "$?" -ne 0 ] && PKG_ERROR=1
	version=`echo $version | sed 's/Version://; s/^.://g;'`

	arch=`required_field Architecture`
	[ "$?" -ne 0 ] && PKG_ERROR=1

	required_field Maintainer >/dev/null
	[ "$?" -ne 0 ] && PKG_ERROR=1

	required_field Description >/dev/null
	[ "$?" -ne 0 ] && PKG_ERROR=1

	disallowed_filename=`disallowed_field Filename`
	[ "$?" -ne 0 ] && PKG_ERROR=1

	if echo $pkg | grep '[^a-z0-9.+-]'; then
		echo "*** Error: Package name $pkg contains illegal characters, (other than [a-z0-9.+-])" >&2
		PKG_ERROR=1;
	fi

	local bad_fields=`sed -ne 's/^\([^[:space:]][^:[:space:]]\+[[:space:]]\+\)[^:].*/\1/p' < $CONTROL/control | sed -e 's/\\n//'`
	if [ -n "$bad_fields" ]; then
		bad_fields=`echo $bad_fields`
		echo "*** Error: The following fields in $CONTROL/control are missing a ':'" >&2
		echo "	$bad_fields" >&2
		echo "opkg-build: This may be due to a missing initial space for a multi-line field value" >&2
		PKG_ERROR=1
	fi

	for script in $CONTROL/preinst $CONTROL/postinst $CONTROL/prerm $CONTROL/postrm; do
		if [ -f $script -a ! -x $script ]; then
			echo "*** Error: package script $script is not executable" >&2
			PKG_ERROR=1
		fi
	done

	if [ -f $CONTROL/conffiles ]; then
		for cf in `cat $CONTROL/conffiles`; do
			if [ ! -f ./$cf ]; then
				echo "*** Error: $CONTROL/conffiles mentions conffile $cf which does not exist" >&2
				PKG_ERROR=1
			fi
		done
	fi

	cd $owd
	return $PKG_ERROR
}

###
# opkg-build "main"
###
ogargs=""
outer=ar
noclean=0
opkext=0
compressor=gzip
zipargs="-9n"
compressorargs=""

# Determine if tar supports the --format argument by checking the help output.
#
# This is needed because:
#    - Busybox tar doesn't support '--format'
#    - On some Linux distros, tar now defaults to posix format if '--format'
#      isn't explicitly specified
#    - Opkg doesn't currently support posix format archives
#
# It's easier to check for mention of the '--format' option than to detect the
# tar implementation and maintain a list of which support '--format'.
tarformat=""
if tar --help 2>&1 | grep -- "--format" > /dev/null;
then
    tarformat="--format=gnu"
fi

compressor_ext() {
    case $1 in
	gzip|pigz)
	    echo gz
	    ;;
	bzip2)
	    echo bz2
	    ;;
	xz)
	    echo xz
	    ;;
	lz4)
	    echo lz4
	    ;;

	*)
	    echo "*** Error: unsupported compression scheme: $1" >&2
	    exit 1
	    ;;
    esac
}

: <<=cut
=head1 SYNOPSIS

B<opkg-build> [B<-c>] [B<-C>] [B<-Z> I<compressor>] [B<-a>] [B<-O>] [B<-o> I<owner>] [B<-g> I<group>] I<pkg_directory> [I<destination_directory>]

=cut

usage="Usage: $0 [-c] [-C] [-Z compressor] [-a] [-O] [-o owner] [-g group] <pkg_directory> [<destination_directory>]"
while getopts "a:cCg:ho:vOZ:" opt; do
    case $opt in
	o ) owner=$OPTARG
	    ogargs="--owner=$owner"
	    ;;
	O ) opkext=1
	    ;;
	g ) group=$OPTARG
	    ogargs="$ogargs --group=$group"
	    ;;
	c ) outer=tar
	    ;;
	C ) noclean=1
	    ;;
	Z ) compressor=$OPTARG
	    ;;
	a ) compressorargs=$OPTARG
	    ;;
	v ) echo $version
	    exit 0
	    ;;
	h )
	    echo $usage  >&2
	    exit 0
	    ;;
	\? )
	    echo $usage  >&2
    esac
done

cext=$(compressor_ext $compressor)

# pgzip requires -T to avoid timestamps on the gzip archive
if gzip --help 2>&1 | grep -- "-T" > /dev/null; then
	zipargs="-9nT"
fi

if [ compressorargs = "" ] ; then
	if [ $compressor = "gzip" ] ; then
		compressorargs=$zipargs
	elif [ $compressor = "pigz" ] ; then
		if $compressor --help 2>&1 | grep -- "-T" > /dev/null; then
			compressorargs="-9nT"
		fi
	fi
fi

tsortargs=
if tar --help 2>&1 | grep -- "--sort=" > /dev/null; then
	tsortargs="--sort=name"
fi

shift $(($OPTIND - 1))

# continue on to process additional arguments

case $# in
1)
	dest_dir=$PWD
	;;
2)
	dest_dir=$2
	if [ "$dest_dir" = "." -o "$dest_dir" = "./" ] ; then
	    dest_dir=$PWD
	else
		mkdir -p "$dest_dir"
	fi
	;;
*)
	echo $usage >&2
	exit 1 
	;;
esac

pkg_dir=$1

if [ ! -d $pkg_dir ]; then
	echo "*** Error: Directory $pkg_dir does not exist" >&2
	exit 1
fi

# CONTROL is second so that it takes precedence
CONTROL=
[ -d $pkg_dir/DEBIAN ] && CONTROL=DEBIAN
[ -d $pkg_dir/CONTROL ] && CONTROL=CONTROL
if [ -z "$CONTROL" ]; then
	echo "*** Error: Directory $pkg_dir has no CONTROL subdirectory." >&2
	exit 1
fi

if ! pkg_appears_sane $pkg_dir; then
	echo >&2
	echo "opkg-build: Please fix the above errors and try again." >&2
	exit 1
fi

tmp_dir=$dest_dir/IPKG_BUILD.$$
mkdir $tmp_dir

build_date="${SOURCE_DATE_EPOCH:-$(date +%s)}"

mtime_args=""
# --clamp-mtime requires tar > 1.28. Only use it if SOURCE_DATE_EPOCH is set, to avoid having a generic case dependency on tar > 1.28.
# this setting will make sure files generated at build time have consistent mtimes, for reproducible builds.
if [ ! -z "$SOURCE_DATE_EPOCH"  ]; then
    mtime_args="--mtime=@$build_date --clamp-mtime"
fi

export LANG=C
export LC_ALL=C
( cd $pkg_dir/$CONTROL && find . -type f | sort > $tmp_dir/control_list )
( cd $pkg_dir && find . -path ./$CONTROL -prune -o -path . -o -print  | sort > $tmp_dir/file_list )
( cd $pkg_dir && tar $ogargs $tsortargs --no-recursion $mtime_args -c $tarformat -T $tmp_dir/file_list | $compressor $compressorargs > $tmp_dir/data.tar.$cext )
( cd $pkg_dir/$CONTROL && tar $ogargs $tsortargs --no-recursion --mtime=@$build_date -c $tarformat -T $tmp_dir/control_list | gzip $zipargs > $tmp_dir/control.tar.gz )
rm $tmp_dir/file_list
rm $tmp_dir/control_list

echo "2.0" > $tmp_dir/debian-binary

if [ $opkext -eq 1 ]; then 
	pkg_file=$dest_dir/${pkg}_${version}_${arch}.opk
else
	pkg_file=$dest_dir/${pkg}_${version}_${arch}.ipk
fi

rm -f $pkg_file
if [ "$outer" = "ar" ] ; then
  ( cd $tmp_dir && ar -crfD $pkg_file ./debian-binary ./control.tar.gz ./data.tar.$cext )
else
  ( cd $tmp_dir && tar -c $tsortargs --mtime=@$build_date $tarformat ./debian-binary ./control.tar.gz ./data.tar.$cext | gzip $zipargs > $pkg_file )
fi

rm $tmp_dir/debian-binary $tmp_dir/data.tar.$cext $tmp_dir/control.tar.gz
rmdir $tmp_dir

echo "Packaged contents of $pkg_dir into $pkg_file"

exit 0
: <<=cut
=head1 DESCRIPTION

B<opkg-build> creates an opkg package from a filesystem tree stored in I<pkg_directory>. I<pkg_directory> must have a B<CONTROL> directory, which contains the control information files, including the control file itself. This directory will I<not> appear in the binary package's filesystem archive, but instead the files in it will be put in the binary package's control information area.

B<opkg-build> will read B<CONTROL/control> file and parse it. It will check it for syntax errors and other problems, and it will stop if it finds any.

If no I<destination_directory> is specified, B<opkg-build> will write the package into a file in the current directory. The name of the package file will be I<package>B<_>I<version>B<_>I<arch>B<.ipk>.

If the archive to be created already exists, it will be overwritten.

=head1 OPTIONS

A summary of options is included below.

=over

=item B<-c>

Generate a binary package in an older B<tar> format.

=item B<-C>

Stop with an error if any files ending with B<~> are found. The default behaviour is to remove such files.

=item B<-Z> I<compressor>

Specify which compression type to use when building a package. Allowed values are B<gzip>, B<pigz>, B<bzip2>, B<lz4> and B<xz> (default is B<gzip>).

=item B<-a> I<compressor-args>

Specify the arguments used by the compressor. Overrides the default values.

=item B<-O>

Use B<.opk> extension. By default, B<.ipk> is used.

=item B<-o> I<owner>

Force I<owner> as the owner of all files in the package.

=item B<-g> I<group>

Force I<group> as the group of all files in the package.

=back

=head1 FILES

B<opkg-build> creates a temporary directory named B<IPKG_BUILD.>I<$$> in the destination directory (where I<$$> stands for the PID of the running B<opkg-build>). There currently isn't a way to override this.

For compatibility with Debian's B<dpkg-deb>, the directory with control files can also be named B<DEBIAN>. If both B<DEBIAN> and B<CONTROL> directories present, B<CONTROL> takes the precedence.

=head1 AUTHORS

This manual page was written by Andrew Shadura based on the manual page of B<dpkg-deb>.

=cut
