#!/bin/sh

__dest=/
__pb_mount_dir=/var/petitboot/mnt/dev/
__plugin_basedir=/tmp/
plugin_file=pb-plugin.cpio.gz
plugin_meta=pb-plugin.conf
plugin_meta_dir=etc/preboot-plugins/
plugin_meta_path=$plugin_meta_dir$plugin_meta
plugin_wrapper_dir=/var/lib/pb-plugins/bin

usage()
{
	cat <<EOF
Usage: $0 <command>

Where <command> is one of:
  install <FILE|URL> - install plugin from FILE/URL
  scan               - look for available plugins on attached devices
  create <DIR>       - create a new plugin archive from DIR
EOF
}

is_url()
{
	local url tmp
	url=$1
	tmp=${url#*://}
	[ "$url" != "$tmp" ]
}

download()
{
	local url file proto
	url=$1
	file=$2
	proto=${url%://*}

	case "$proto" in
	http)
		wget -O - "$url" > $file
		;;
	ftp)
		ncftpget -c "$url" > $file
		;;
	*)
		echo "error: Unsuported protocol $proto" >&2
		false
	esac
}

plugin_info()
{
	local title
	if [ "$PLUGIN_VENDOR" ]
	then
		title="$PLUGIN_VENDOR: $PLUGIN_NAME"
	else
		title="$PLUGIN_NAME"
	fi

	echo "$title"
	echo "  (version $PLUGIN_VERSION)"
}

do_wrap()
{
	local base binary dir

	base=$1
	binary=$2
	shift 2

	for dir in etc dev sys proc var
	do
		[ -e "$base/$dir" ] || mkdir -p "$base/$dir"
	done

	cp /etc/resolv.conf $base/etc
	mount -o bind /dev $base/dev
	mount -o bind /sys $base/sys
	mount -o bind /proc $base/proc
	mount -o bind /var $base/var

	chroot "$base" "$binary" "$@"

	umount $base/dev
	umount $base/sys
	umount $base/proc
	umount $base/var
}

__create_wrapper()
{
	local base binary wrapper

	base=$1
	binary=$2
	wrapper=$plugin_wrapper_dir/$(basename $binary)

	mkdir -p $plugin_wrapper_dir

	cat <<EOF > $wrapper
#!/bin/sh

exec $(realpath $0) __wrap '$base' '$binary' "\$@"
EOF

	chmod a+x $wrapper
}

do_install()
{
	local url name file __dest

	url=$1

	if [ -z "$url" ]
	then
		echo "error: install requires a file/URL argument." >&2
		exit 1
	fi

	name=${url##*/}

	if is_url "$url"
	then
		file=$(mktemp)
		trap "rm '$file'" EXIT
		download "$url" "$file"
		if [ $? -ne 0 ]
		then
			echo "error: failed to download $url" >&2
			exit 1
		fi
	else
		file=$url
		if [ ! -r "$file" ]
		then
			echo "error: $file doesn't exist or is not readable" >&2
			exit 1
		fi
	fi

        echo "File '$name' has the following sha256 checksum:"
	echo
	sha256sum "$file" | cut -f1 -d' '
	echo
	echo "Do you want to install this plugin? (y/N)"
	read resp

	case $resp in
	[yY]|[yY][eE][sS])
		;;
	*)
		echo "Cancelled"
		exit 0
		;;
	esac

	__dest=$(mktemp -d)
	gunzip -c "$file" | ( cd $__dest && cpio -i -d)

	if [ $? -ne 0 ]
	then
		echo "error: Failed to extract archive $url, exiting"
		rm -rf $__dest
		exit 1
	fi

	. $__dest/$plugin_meta_path

	for binary in ${PLUGIN_EXECUTABLES}
	do
		__create_wrapper "$__dest" "$binary"
	done

	echo "Plugin installed"
	plugin_info
}

do_scan()
{
	local found dev plugin_path __meta_tmp
	found=0
	for mnt in $__pb_mount_dir/*
	do
		dev=$(basename $mnt)
		plugin_path="$mnt/$plugin_file"

		[ -e "$plugin_path" ] || continue

		# extract plugin metadata to a temporary directory
		__meta_tmp=$(mktemp -d)
		[ -d $__meta_tmp ] || continue
		gunzip -c "$plugin_path" |
			(cd $__meta_tmp &&
				cpio -i -d $plugin_meta_path 2>/dev/null)
		if ! [ $? = 0 -a -e "$plugin_path" ]
		then
			rm -rf $__meta_tmp
			continue
		fi

		(
			. $__meta_tmp/$plugin_meta_path

			printf "Plugin found on %s:\n" $dev
			plugin_info
			printf "\n"
			printf "To run this plugin:\n"
			printf "  $0 run $plugin_path\n"
			printf "\n"
		)
		rm -rf $__meta_tmp
		found=1
	done

	if [ "$found" = 0 ]
	then
		echo "No plugins found"
	fi
}

guided_meta()
{
	local vendorname vendorshortname
	local pluginname pluginnhortname
	local version date executable
	local file

	file=$1

cat <<EOF

Enter the vendor company / author name. This can contain spaces.
(eg. 'Example Corporation')
EOF
	read vendorname
cat <<EOF

Enter the vendor shortname. This should be a single-word abbreviation, in all
lower-case. This is only used in internal filenames.

Typically, a stock-ticker name is used for this (eg 'exco')
EOF
	read vendorshortname

cat <<EOF

Enter the descriptive plugin name. This can contain spaces, but should only be
a few words in length (eg 'RAID configuration utility')
EOF
	read pluginname

cat <<EOF

Enter the plugin shortname. This should not contain spaces, but hyphens are
fine (eg 'raid-config'). This is only used in internal filnames.
EOF
	read pluginshortname


cat <<EOF

Enter the plugin version. This should not contain spaces (eg 1.2):
EOF
	read version

cat <<EOF

Enter the full path (within the plugin root) to the plugin executable file(s).
These will be exposed as wrapper scripts, to be run from the standard petitboot
shell environment (eg, /usr/bin/my-raid-config).

If multiple executables are provided, separate with a space.
EOF
	read executables

	date=$(date +%Y-%m-%d)

	mkdir -p $(dirname $file)

	cat <<EOF > $file
PLUGIN_VENDOR='$vendorname'
PLUGIN_NAME='$pluginname'
PLUGIN_VERSION='$version'
PLUGIN_DATE='$date'
PLUGIN_EXECUTABLES='$executables'
EOF

}

do_create()
{
	local src meta_dir_abs meta_file
	src=$1

	if [ -z "$src" ]
	then
		echo "error: missing source directory" >&2
		usage
		exit 1
	fi

	if [ ! -d "$src" ]
	then
		echo "error: source directory missing" >&2
		exit 1
	fi

	meta_file=$src/$plugin_meta_path

	if [ ! -e $meta_file ]
	then
		echo "No plugin metadata file found. " \
			"Would you like to create one? (Y/n)"
		read resp
		case "$resp" in
		[nN]|[nN][oO])
			echo "Cancelled, exiting"
			exit 1
			;;
		esac
		guided_meta $meta_file || exit
	fi

	# Sanity check metadata file
	(
		. $meta_file
		if [ ! -n "$PLUGIN_VENDOR" ]
		then
			echo "error: no PLUGIN_VENDOR defined in metadata" &>2
			exit 1
		fi
		if [ ! -n "$PLUGIN_NAME" ]
		then
			echo "error: no PLUGIN_NAME defined in metadata" &>2
			exit 1
		fi
		if [ ! -n "$PLUGIN_VERSION" ]
		then
			echo "error: no PLUGIN_VERSION defined in metadata" &>2
			exit 1
		fi
		if [ ! -n "$PLUGIN_DATE" ]
		then
			echo "error: no PLUGIN_DATE defined in metadata" &>2
			exit 1
		fi
		if [ ! -n "$PLUGIN_EXECUTABLES" ]
		then
			echo "error: no PLUGIN_EXECUTABLES defined in metadata"\				&>2
			exit 1
		fi

	) || exit 1

	outfile=$plugin_file

	(
		cd $src
		find -mindepth 1 | cpio -o -Hnewc -v
	) | gzip -c > $outfile

	echo
	echo "Plugin metadata:"
	sed -e 's/^/  /' $meta_file
	echo

	echo "User-visible metadata:"

	(
		. $meta_file
		plugin_info | sed -e 's/^/  /'
	)

	echo


cat <<EOF
Plugin created in:
  $outfile

Ship this file in the top-level-directory of a USB device or CD to have it
automatically discoverable by 'pb-plugin scan'.
EOF
}

test_http_download()
{
	local tmp ref

	tmp=$(mktemp -p $test_tmpdir)
	ref=$(mktemp -p $test_tmpdir)

	echo $RANDOM > $ref

	wget()
	{
		cat $ref
	}

	download http://example.com/test $tmp
	cmp -s "$ref" "$tmp"
}

test_ftp_download()
{
	local tmp ref

	tmp=$(mktemp -p $test_tmpdir)
	ref=$(mktemp -p $test_tmpdir)

	echo $RANDOM > $ref

	ncftpget()
	{
		cat $ref
	}

	download ftp://example.com/test $tmp
	cmp -s "$ref" "$tmp"
}

test_scan()
{
	__pb_mount_dir="$test_tmpdir/mnt"
	mnt_dir="$__pb_mount_dir/sda"
	mkdir -p $mnt_dir/$plugin_meta_dir
	(
		echo "PLUGIN_NAME=test"
		echo "PLUGIN_VERSION=1"
		echo "PLUGIN_EXECUTABLES=/bin/sh"
	) > $mnt_dir/$plugin_meta_path
	(
		cd $mnt_dir;
		find -mindepth 1 | cpio -o -Hnewc 2>/dev/null
	) | gzip -c > $mnt_dir/$plugin_file

	do_scan | grep -q 'test 1'
	rc=$?
}

test_empty_scan()
{
	__pb_mount_dir="$test_tmpdir/mnt"
	mkdir -p $__pb_mount_dir
	do_scan | grep -q "No plugins"
}

test_setup()
{
	n=$(($n+1))

	test_tmpdir="$tests_tmpdir/$n"
	mkdir "$test_tmpdir"
}

test_teardown()
{
	true
}

test_failed=0
do_test()
{
	local tstr op

	tstr="$@"
	op=-eq

	if [ "x$1" = "x!" ]
	then
		op=-ne
		shift
	fi

	test_setup
	( $@ )
	local rc=$?
	test_teardown

	if [ $rc $op 0 ]
	then
		echo PASS: "$tstr"
	else
		echo FAIL: "$tstr"
		test_failed=1
		false
	fi
}

do_tests()
{
	local tests_tmpdir n

	tests_tmpdir=$(mktemp -d)
	n=0

	do_test ! is_url "/test"
	do_test ! is_url "./test"
	do_test ! is_url "../test"
	do_test ! is_url "test"
	do_test is_url "http://example.com/path"
	do_test is_url "git+ssh://example.com/path"
	do_test test_http_download
	do_test test_ftp_download
	do_test test_scan
	do_test test_empty_scan

	if [ $test_failed = 0 ]
	then
		echo "$n tests passed"
	else
		echo "Tests failed"
		false
	fi
	rm -rf "$tests_tmpdir"
}

case "$1" in
install)
	shift
	do_install $@
	;;
scan)
	shift
	do_scan $@
	;;
create)
	shift
	do_create $@
	;;
__wrap)
	shift
	do_wrap $@
	;;
__test)
	shift
	do_tests $@
	;;
"")
	echo "error: Missing command" >&2
	usage
	exit 1
	;;
*)
	echo "Invalid command: $s" >&2
	usage
	exit 1
esac