#!/bin/sh

__dest=/
__pb_mount_dir=/var/petitboot/mnt/dev/
plugin_dev_meta=pb-plugin.conf
plugin_installed_meta_dir=/etc/preboot-plugins/

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
  list                - list currently-installed plugins
  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_install()
{
	local url

	url=$1

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

	if [ ! -d "$__dest" ]
	then
		echo "error: destination directory '$__dest' doesn't exist" >&2
		exit 1
	fi

	if [ ! -w "$__dest" ]
	then
		echo "error: destination directory isn't writeable" >&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 into the pre-boot environment? (y/N)"
	read resp

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

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

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

do_scan()
{
	local found
	found=0
	for mnt in $__pb_mount_dir/*
	do
		dev=$(basename $mnt)
		metafile="$mnt/$plugin_dev_meta"
		[ -e "$metafile" ] || continue
		(
			. $metafile
			printf "Plugin found on %s:\n" $dev
			plugin_info
			printf "\n"
			printf "To install this plugin, run:\n"
			printf "  $0 install $mnt/$PLUGIN_FILE\n"
			printf "\n"
		)
		found=1
	done

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

do_list()
{
	local found
	found=0
	for meta in $plugin_installed_meta_dir/*
	do
		[ -e "$meta" ] || continue
		[ $found = 0 ] && printf "Installed plugins:\n"
		found=1
		(
			. $meta
			plugin_info
			echo
		)
	done

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

guided_meta()
{
	local vendorname vendorshortname
	local pluginname pluginnhortname
	local version date
	local dir

	dir=$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

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

	mkdir -p $dir

	cat <<EOF > $dir/$vendorshortname-$pluginshortname
PLUGIN_VENDOR='$vendorname'
PLUGIN_NAME='$pluginname'
PLUGIN_VERSION='$version'
PLUGIN_DATE='$date'
EOF

}

do_create()
{
	local src found 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_dir_abs="$src/$plugin_installed_meta_dir"
	found=0
	for meta in $meta_dir_abs/*
	do
		[ -e "$meta" ] || continue
		found=$(($found+1))
		meta_file=$meta
	done

	if [ $found = 0 ]
	then
		echo "No plugin metadata file found. " \
			"Would you like to create one? (Y/n)"
		read resp
		case "$resp" in
		[nN]|[nN][oO])
			echo "Cancelled, exiting"
			exit 1
			;;
		esac
		guided_meta $meta_dir_abs || exit
		meta_file=$meta_dir_abs/*
	fi

	if [ $found -gt 1 ]
	then
		echo "error: Multiple metadata files found in $meta_dir_abs" >&2
		exit 1
	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

	) || exit 1

	outfile=pb-plugin.cpio.gz

	(
		cd $src
		find -mindepth 1 | cpio -o -Hnewc -v
	) | gzip -c > pb-plugin.cpio.gz

	cp $meta_file $plugin_dev_meta
	echo "PLUGIN_FILE='$outfile'" >> $plugin_dev_meta

	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
  
Metadata in:
  $plugin_dev_meta

If you rename $outfile (or distribute it in a non-root directory), then
also update the PLUGIN_FILE variable in $plugin_dev_meta.
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
	(
		echo "PLUGIN_NAME=test"
		echo "PLUGIN_VERSION=1"
		echo "PLUGIN_FILE=data/pb-plugin.cpio.gz"
	) > $mnt_dir/$plugin_dev_meta

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

test_empty_scan()
{
	do_scan | grep -q "No plugins"
}

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

	test_tmpdir="$tests_tmpdir/$n"
	mkdir "$test_tmpdir"
	__test_dest="$test_tmpdir/base"
	mkdir "$__test_dest"
	[ -d "$__test_dest" ] || exit 1
	__dest=$__test_dest
}

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 $@
	;;
list)
	shift
	do_list $@
	;;
create)
	shift
	do_create $@
	;;
__test)
	shift
	do_tests $@
	;;
"")
	echo "error: Missing command" >&2
	usage
	exit 1
	;;
*)
	echo "Invalid command: $s" >&2
	usage
	exit 1
esac