#! /bin/bash

#  This script is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License version 2 as
#  published by the Free Software Foundation.
#
#  See the COPYING and AUTHORS files for more details.

: ${QUILT_DIR=/usr/share/quilt}

if ! [ -r $QUILT_DIR/scripts/patchfns ]
then
	echo "Cannot read library $QUILT_DIR/scripts/patchfns" >&2
	exit 1
fi
. $QUILT_DIR/scripts/patchfns
cd ${SUBDIR:-.}

usage() {
	echo "Usage: ${0##*/} [--fuzz=N] specfile"
	exit 1
}

options=$(getopt -o v --long sourcedir:,fuzz: -n "${0##*/}" -- "$@") || exit

eval set -- "$options"

sourcedir=

while true
do
	case "$1" in
	-v)
		verbose=1
		shift ;;
	--sourcedir)
		sourcedir=${2%/}/
		shift 2 ;;
	--fuzz)
		# Only works with rpm 4.6 and later
		DEFINE_FUZZ="%define _default_patch_fuzz $2"
		shift 2 ;;
	--)
		shift
		break ;;
	esac
done

[ "${sourcedir:0:1}" = / ] || sourcedir=$PWD/$sourcedir

specfile=$1
if [ $# -ne 1 -o ! -f "$specfile" ]
then
	usage
fi
if [ "${specfile:0:1}"  = / ]
then
	specdir=$(dirname "$specfile")
	specfile=${specfile##*/}
else
	specdir=$PWD
fi

tmpdir="$(gen_tempfile -d ${VARTMPDIR:-/var/tmp}/${0##*/})"
mkdir -p $tmpdir || exit 1
add_exit_handler "rm -rf $tmpdir"
mkdir -p $tmpdir/build
mkdir -p $tmpdir/bin

# Redirect file descriptors
# 5 is used in verbose mode, 4 in non-verbose mode, and 2 for both (real errors)
if [ -n "$verbose" ]
then
	exec 3>&1 5>&2 4>/dev/null
else
	exec 3>&1 4>&2 5>/dev/null
fi

# create md5 sums, also for uncompressed files
echo -n "### md5sum: " >&4
shopt -s nullglob
for file in $sourcedir/*
do
	basename=${file##*/}
	case "$basename" in
		ready|bigpack|MD5SUMS|MD5SUMS.meta|*.spec|*.changes)
			continue
			;;
	esac
	[ -f "$file" ] || continue
	echo -n "." >&4
	echo "md5sum < $file" >&5
	set -- $(md5sum < "$file")
	echo "$1 $basename"

	case "$file" in
		*.lzma)
			# file doesn't reliably recognize lzma-compressed files
			filetype="lzma"
			;;
		*.xz)
			# old versions of file don't know about xz-compressed
			# files
			filetype="xz"
			;;
		*)
			filetype="$(file -b "$file")"
			;;
	esac

	case "$filetype" in
		compress*|gzip*)
			echo -n "g" >&4
			echo "gzip -cd $file | md5sum" >&5
			set -- $(gzip -cd "$file" | md5sum)
			echo "$1 $basename"
			;;
		bzip2*)
			echo -n "b" >&4
			echo "bzip2 -cd $file | md5sum" >&5
			set -- $(bzip2 -cd "$file" | md5sum)
			echo "$1 $basename"
			;;
		xz*|XZ*)
			echo -n "x" >&4
			echo "xz -cd $file | md5sum" >&5
			set -- $(xz -cd "$file" | md5sum)
			echo "$1 $basename"
			;;
		lzma*)
			echo -n "l" >&4
			echo "lzma -cd $file | md5sum" >&5
			set -- $(lzma -cd "$file" | md5sum)
			echo "$1 $basename"
			;;
	esac
done > $tmpdir/md5sums
echo >&4
shopt -u nullglob

# wrapper script for patch and tar
cat <<-'EOF' > $tmpdir/bin/wrapper
	#! /bin/bash

	# find original data file by md5sum
	original_file() {
		local file=$1 md5sum

		set -- $(md5sum < $file)
		md5sum=$1
		while read md5sum_ file_
		do
			if [ "$md5sum" = "$md5sum_" ]
			then
				echo ${file_#\*}
				return 0
			fi
		done < $tmpdir/md5sums

		# Try harder
		if ! [ -e $tmpdir/more-md5sums ]
		then
			( cd $RPM_BUILD_DIR
			find . -type f \
			| sed -e 's:^.\/::' \
			| xargs md5sum \
			) > $tmpdir/more-md5sums
		fi
		
		while read md5sum_ file_
		do
			if [ "$md5sum" = "$md5sum_" ]
			then
				echo ${file_#\*}
				return 0
			fi
		done < $tmpdir/more-md5sums

		return 1
	}

	# Extract a command line option with or without argument
	cmdline_option() {
		local letter=$1 no_arg=$2
		shift

		while [ $# -ne 0 ]
		do
			if [ "${1:0:2}" = -$letter ]
			then
				if [ -z "$no_arg" ]
				then
					[ "$1" = -$letter ] && set -- "$1$2"
				fi
				echo $1
				break
			fi
			shift
		done
	}

	# Extract the -p option from the command line
	strip_option() {
		set -- $(cmdline_option p "$@")
		[ "$1" != -p1 ] && echo $1
	}

	# Extract the -R option from the command line
	reverse_option() {
		set -- $(cmdline_option R no_arg "$@")
		echo $1
	}

	patch_opt_d() {
		local subdir=$(cmdline_option d "$@")
		[ -z "$subdir" ] || echo "${subdir:2}"

	}

	patch_input_file() {
		while [ $# -gt 0 ]; do
			case "$1" in
			-i|--input)
				if [ $# -ge 2 ]; then
					echo "$2"
					return
				fi
				;;
			-i*)
				echo "${1#-i}"
				return
				;;
			--input=*)
				echo "${1#--input=}"
				return
				;;
			esac
			shift
		done
		return 1
	}

	tar_input_file() {
		case "$1" in
		*C*f*)
			echo "$3"
			;;
		*f*)
			echo "$2"
			;;
		esac
	}

	tar_opt_C() {
		case "$1" in
		*C*f*)
			echo "$2"
			return ;;
		esac
	}

	tmpdir=${RPM_BUILD_DIR%/*}
	rm -f $tmpdir/data
	case "${0##*/}" in
	patch)
		inputfile=$(patch_input_file "$@")
		;;
	tar)
		inputfile=$(tar_input_file "$@")
		# For tar, file - means read from stdin
		[ "$inputfile" = "-" ] && inputfile=
		;;
	esac
	if [ -z "$inputfile" ]; then
	    # put data from stdin into tmpfile
	    cat > $tmpdir/data
	fi

	unpackfile="$(original_file ${inputfile:-$tmpdir/data})"
	if [ -n "$unpackfile" ]
	then
		case "${0##*/}" in
		patch)
			echo -n p >&4
			subdir=$(patch_opt_d "$@")
			if [ -n "$subdir" ]
			then
				dir=$(cd "$subdir" && echo $PWD)
			else
				dir=$PWD
			fi
			dir=${dir/$RPM_BUILD_DIR}
			dir=${dir##/}
			dir=${dir// /\\ }
			echo "${0##*/} ${dir:-.} $unpackfile" \
			     $(strip_option "$@") $(reverse_option "$@") >&3
			;;
		tar)
			echo -n t >&4
			subdir=$(tar_opt_C "$@")
			if [ -n "$subdir" ]
			then
				dir=$(cd "$subdir" && echo $PWD)
			else
				dir=$PWD
			fi
			dir=${dir/$RPM_BUILD_DIR}
			dir=${dir##/}
			dir=${dir// /\\ }
			echo "${0##*/} ${dir:-.} $unpackfile" >&3
			;;
		esac
	fi

	PATH=${PATH#*:}
	if [ -n "$inputfile" ]; then
	    ${0##*/} "$@"
	else
	    ${0##*/} "$@" < $tmpdir/data
	fi
EOF

chmod 755 $tmpdir/bin/wrapper
# If $TMPDIR is mounted with noexec, rpmbuild won't be able to execute
# our wrapper script
if [ ! -x $tmpdir/bin/wrapper ]
then
	printf "Cannot execute %s; filesystem mounted with noexec?\n" \
	       $tmpdir/bin/wrapper >&2
 	printf "Setting %s in ~/.quiltrc may help\n" "VARTMPDIR" >&2
	exit 1
fi

ln -s wrapper $tmpdir/bin/patch
ln -s wrapper $tmpdir/bin/tar

# let rpm do all the dirty specfile stuff ...
echo -n "### rpmbuild: " >&4

export PATH="$tmpdir/bin:$PATH"
rpmbuild --eval "%define _sourcedir $sourcedir" \
	 --eval "%define _specdir   $specdir" \
	 --eval "%define _builddir  $tmpdir/build" \
	 --eval "%define __patch    $tmpdir/bin/patch" \
	 --eval "%define __tar      $tmpdir/bin/tar" \
	 --eval "$DEFINE_FUZZ" \
	 --nodeps \
	 -bp "$specdir/$specfile" < /dev/null >&5 2>&5
status=$?
echo >&4
exit $status
### Local Variables:
### mode: shell-script
### End:
# vim:filetype=sh