#! /usr/bin/env bash

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

	if ! [ -e $tmpdir/md5sums ]
	then
		echo >&4
		create_md5sums "$RPM_SOURCE_DIR" $tmpdir/md5sums
		echo -n "### rpmbuild: " >&4
	fi

	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 $QUILT_SETUP_PREFIX${file_#\*}
			return 0
		fi
	done < $tmpdir/more-md5sums

	# Return md5sum and error if we can't match the file
	echo $md5sum
	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
	# Modern option format
	-*)
		while [ $# -gt 0 ]
		do
			case "$1" in
			# Extract the file name (long option)
			--file)
				echo "$2"
				return
				;;
			--file=*)
				echo "${1#--file=}"
				return
				;;
			# Skip other long options
			--*)
				shift
				;;
			# Extract the file name (short option)
			-*f)
				echo "$2"
				return
				;;
			-f*)
				echo "${1#-f}"
				return
				;;
			# Skip other short options and parameters
			*)
				shift
				;;
			esac
		done
		;;
	# Legacy option format (must always come first)
	*C*f*)
		echo "$3"
		return
		;;
	*f*)
		echo "$2"
		return
		;;
	?*)
		# Eat legacy options and try again
		until [ $# -eq 0 -o "${1:0:1}" = "-" ]
		do
			shift
		done
		tar_input_file "$@"
		return
		;;
	esac
	return 1
}

unzip_input_file()
{
	while [ $# -gt 0 ]
	do
		case "$1" in
		-*)
			shift
			;;
		*)
			echo "$1"
			return
			;;
		esac
	done
	return 1
}

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

pwd_to_dir()
{
	local subdir=$1 dir

	if [ -n "$subdir" ]
	then
		dir=$(cd "$subdir" && echo $PWD)
	else
		dir=$PWD
	fi
	dir=${dir/$RPM_BUILD_DIR}
	dir=${dir##/}
	dir=${dir// /\\ }

	echo "$dir"
}

# Who were we called as?
command=${0##*/}

PATH=${PATH#*:}
# If we are called too early, pass through without processing
[ -n "$RPM_BUILD_DIR" ] || exec $command "$@"

tmpdir=${RPM_BUILD_DIR%/*}
case $command in
patch)
	echo -n p >&4
	inputfile=$(patch_input_file "$@")
	;;
tar)
	echo -n t >&4
	[ -n "$QUILT_SETUP_FAST" ] && exec tar "$@"
	inputfile=$(tar_input_file "$@")
	# For tar, file - means read from stdin
	[ "$inputfile" = "-" ] && inputfile=
	;;
unzip)
	echo -n Z >&4
	[ -n "$QUILT_SETUP_FAST" ] && exec unzip "$@"
	inputfile=$(unzip_input_file "$@")
	;;
esac

# If the file was not passed as a parameter, try to identify stdin
if [ -n "$QUILT_SETUP_FAST" -a -z "$inputfile" ]
then
	inputfile=$(readlink /proc/self/fd/0)
	[ "${inputfile:0:1}" = / -a -f "$inputfile" ] || inputfile=
fi

if [ -n "$inputfile" ]
then
	if [ "${inputfile:0:1}" = / ]
	then
		unpackfile=${inputfile/$RPM_SOURCE_DIR}
	else
		unpackfile=$QUILT_SETUP_PREFIX$(dir_to_dir "$RPM_BUILD_DIR" "$inputfile")
	fi
else
	if [ -n "$QUILT_SETUP_FAST" ]
	then
		# In fast mode we can read from stdin directly, we won't let
		# patch apply the patch anyway
		md5sum=$(md5sum)
	else
		# put data from stdin into tmpfile
		cat > $tmpdir/data
		md5sum=$(md5sum < $tmpdir/data)
	fi

	unpackfile=$(original_file $md5sum)
	if [ $? -ne 0 ]
	then
		# Report problem to the caller
		echo -n "?" >&4
		printf "Warning: no match for file with md5sum %s\n" \
		       $unpackfile >&2
		unpackfile="#$unpackfile"
	fi
fi

case $command in
patch)
	subdir=$(patch_opt_d "$@")
	dir=$(pwd_to_dir $subdir)
	echo "patch ${dir:-.} $unpackfile" \
	     $(strip_option "$@") $(reverse_option "$@") >&3
	;;
tar)
	subdir=$(tar_opt_C "$@")
	dir=$(pwd_to_dir $subdir)
	echo "tar ${dir:-.} $unpackfile" >&3
	;;
unzip)
	dir=$(pwd_to_dir)
	echo "unzip ${dir:-.} $unpackfile" >&3
	;;
esac

# In fast mode, we don't actually apply patches
[ -n "$QUILT_SETUP_FAST" ] && exit 0

if [ -n "$inputfile" ]
then
	exec $command "$@"
else
	exec $command "$@" < $tmpdir/data
fi