#!/bin/sh

. /lib/functions.sh
. /lib/functions/system.sh
. /usr/share/libubox/jshn.sh

# initialize defaults
export MTD_ARGS=""
export MTD_CONFIG_ARGS=""
export INTERACTIVE=0
export VERBOSE=1
export SAVE_CONFIG=1
export SAVE_OVERLAY=0
export SAVE_OVERLAY_PATH=
export SAVE_PARTITIONS=1
export SAVE_INSTALLED_PKGS=0
export SKIP_UNCHANGED=0
export CONF_IMAGE=
export CONF_BACKUP_LIST=0
export CONF_BACKUP=
export CONF_RESTORE=
export NEED_IMAGE=
export HELP=0
export FORCE=0
export TEST=0
export UMOUNT_ETCBACKUP_DIR=0

# parse options
while [ -n "$1" ]; do
	case "$1" in
		-i) export INTERACTIVE=1;;
		-v) export VERBOSE="$(($VERBOSE + 1))";;
		-q) export VERBOSE="$(($VERBOSE - 1))";;
		-n) export SAVE_CONFIG=0;;
		-c) export SAVE_OVERLAY=1 SAVE_OVERLAY_PATH=/etc;;
		-o) export SAVE_OVERLAY=1 SAVE_OVERLAY_PATH=/;;
		-p) export SAVE_PARTITIONS=0;;
		-k) export SAVE_INSTALLED_PKGS=1;;
		-u) export SKIP_UNCHANGED=1;;
		-b|--create-backup) export CONF_BACKUP="$2" NEED_IMAGE=1; shift;;
		-r|--restore-backup) export CONF_RESTORE="$2" NEED_IMAGE=1; shift;;
		-l|--list-backup) export CONF_BACKUP_LIST=1;;
		-f) export CONF_IMAGE="$2"; shift;;
		-F|--force) export FORCE=1;;
		-T|--test) export TEST=1;;
		-h|--help) export HELP=1; break;;
		-*)
			echo "Invalid option: $1" >&2
			exit 1
		;;
		*) break;;
	esac
	shift;
done

export CONFFILES=/tmp/sysupgrade.conffiles
export CONF_TAR=/tmp/sysupgrade.tgz
export ETCBACKUP_DIR=/etc/backup
export INSTALLED_PACKAGES=${ETCBACKUP_DIR}/installed_packages.txt

IMAGE="$1"

[ -z "$IMAGE" -a -z "$NEED_IMAGE" -a $CONF_BACKUP_LIST -eq 0 -o $HELP -gt 0 ] && {
	cat <<EOF
Usage: $0 [<upgrade-option>...] <image file or URL>
       $0 [-q] [-i] [-c] [-u] [-o] [-k] <backup-command> <file>

upgrade-option:
	-f <config>  restore configuration from .tar.gz (file or url)
	-i           interactive mode
	-c           attempt to preserve all changed files in /etc/
	-o           attempt to preserve all changed files in /, except those
	             from packages but including changed confs.
	-u           skip from backup files that are equal to those in /rom
	-n           do not save configuration over reflash
	-p           do not attempt to restore the partition table after flash.
	-k           include in backup a list of current installed packages at
	             $INSTALLED_PACKAGES
	-T | --test
	             Verify image and config .tar.gz but do not actually flash.
	-F | --force
	             Flash image even if image checks fail, this is dangerous!
	-q           less verbose
	-v           more verbose
	-h | --help  display this help

backup-command:
	-b | --create-backup <file>
	             create .tar.gz of files specified in sysupgrade.conf
	             then exit. Does not flash an image. If file is '-',
	             i.e. stdout, verbosity is set to 0 (i.e. quiet).
	-r | --restore-backup <file>
	             restore a .tar.gz created with sysupgrade -b
	             then exit. Does not flash an image. If file is '-',
	             the archive is read from stdin.
	-l | --list-backup
	             list the files that would be backed up when calling
	             sysupgrade -b. Does not create a backup file.

EOF
	exit 1
}

[ -n "$IMAGE" -a -n "$NEED_IMAGE" ] && {
	cat <<-EOF
		-b|--create-backup and -r|--restore-backup do not perform a firmware upgrade.
		Do not specify both -b|-r and a firmware image.
	EOF
	exit 1
}

# prevent messages from clobbering the tarball when using stdout
[ "$CONF_BACKUP" = "-" ] && export VERBOSE=0


list_conffiles() {
	awk '
		BEGIN { conffiles = 0 }
		/^Conffiles:/ { conffiles = 1; next }
		!/^ / { conffiles = 0; next }
		conffiles == 1 { print }
	' /usr/lib/opkg/status
}

list_changed_conffiles() {
	# Cannot handle spaces in filenames - but opkg cannot either...
	list_conffiles | while read file csum; do
		[ -r "$file" ] || continue

		echo "${csum}  ${file}" | sha256sum -sc - || echo "$file"
	done
}

add_conffiles() {
	local file="$1"
	( find $(sed -ne '/^[[:space:]]*$/d; /^#/d; p' \
		/etc/sysupgrade.conf /lib/upgrade/keep.d/* 2>/dev/null) \
		\( -type f -o -type l \) $find_filter 2>/dev/null;
	  list_changed_conffiles ) | sort -u > "$file"
	return 0
}

add_overlayfiles() {
	local file="$1"

	local packagesfiles=$1.packagesfiles
	touch "$packagesfiles"

	if [ "$SAVE_OVERLAY_PATH" = / ]; then
		local conffiles=$1.conffiles
		local keepfiles=$1.keepfiles

		list_conffiles | cut -f2 -d ' ' | sort -u > "$conffiles"

		# backup files from /etc/sysupgrade.conf and /lib/upgrade/keep.d, but
		# ignore those aready controlled by opkg conffiles
		find $(sed -ne '/^[[:space:]]*$/d; /^#/d; p' \
			/etc/sysupgrade.conf /lib/upgrade/keep.d/* 2>/dev/null) \
			\( -type f -o -type l \) 2>/dev/null | sort -u |
			grep -h -v -x -F -f $conffiles > "$keepfiles"

		# backup conffiles, but only those changed if '-u'
		[ $SKIP_UNCHANGED = 1 ] &&
			list_changed_conffiles | sort -u > "$conffiles"

		# do not backup files from packages, except those listed
		# in conffiles and keep.d
		{
			find /usr/lib/opkg/info -type f -name "*.list" -exec cat {} \;
			find /usr/lib/opkg/info -type f -name "*.control" -exec sed \
				-ne '/^Alternatives/{s/^Alternatives: //;s/, /\n/g;p}' {} \; |
				cut -f2 -d:
		} |  grep -v -x -F -f $conffiles |
		     grep -v -x -F -f $keepfiles | sort -u > "$packagesfiles"
		rm -f "$keepfiles" "$conffiles"
	fi

	# busybox grep bug when file is empty
	[ -s "$packagesfiles" ] || echo > $packagesfiles

	( cd /overlay/upper/; find .$SAVE_OVERLAY_PATH \( -type f -o -type l \) $find_filter | sed \
		-e 's,^\.,,' \
		-e '\,^/etc/board.json$,d' \
		-e '\,/[^/]*-opkg$,d' \
		-e '\,^/etc/urandom.seed$,d' \
		-e "\,^$INSTALLED_PACKAGES$,d" \
		-e '\,^/usr/lib/opkg/.*,d' \
	) | grep -v -x -F -f $packagesfiles > "$file"

	rm -f "$packagesfiles"

	return 0
}

if [ $SAVE_OVERLAY = 1 ]; then
	[ ! -d /overlay/upper/etc ] && {
		echo "Cannot find '/overlay/upper/etc', required for '-c'" >&2
		exit 1
	}
	sysupgrade_init_conffiles="add_overlayfiles"
else
	sysupgrade_init_conffiles="add_conffiles"
fi

find_filter=""
if [ $SKIP_UNCHANGED = 1 ]; then
	[ ! -d /rom/ ] && {
		echo "'/rom/' is required by '-u'"
		exit 1
	}
	find_filter='( ( -exec test -e /rom/{} ; -exec cmp -s /{} /rom/{} ; ) -o -print )'
fi

include /lib/upgrade

do_save_conffiles() {
	local conf_tar="$1"

	[ -z "$(rootfs_type)" ] && {
		echo "Cannot save config while running from ramdisk." >&2
		ask_bool 0 "Abort" && exit
		rm -f "$conf_tar"
		return 0
	}
	run_hooks "$CONFFILES" $sysupgrade_init_conffiles
	ask_bool 0 "Edit config file list" && vi "$CONFFILES"

	if [ "$SAVE_INSTALLED_PKGS" -eq 1 ]; then
		echo "${INSTALLED_PACKAGES}" >> "$CONFFILES"
		mkdir -p "$ETCBACKUP_DIR"
		# Avoid touching filesystem on each backup
		RAMFS="$(mktemp -d -t sysupgrade.XXXXXX)"
		mkdir -p "$RAMFS/upper" "$RAMFS/work"
		mount -t overlay overlay -o lowerdir=$ETCBACKUP_DIR,upperdir=$RAMFS/upper,workdir=$RAMFS/work $ETCBACKUP_DIR &&
			UMOUNT_ETCBACKUP_DIR=1 || {
				echo "Cannot mount '$ETCBACKUP_DIR' as tmpfs to avoid touching disk while saving the list of installed packages." >&2
				ask_bool 0 "Abort" && exit
			}

		# Format: pkg-name<TAB>{rom,overlay,unkown}
		# rom is used for pkgs in /rom, even if updated later
		find /usr/lib/opkg/info -name "*.control" \( \
			\( -exec test -f /rom/{} \; -exec echo {} rom \; \) -o \
			\( -exec test -f /overlay/upper/{} \; -exec echo {} overlay \; \) -o \
			\( -exec echo {} unknown \; \) \
			\) | sed -e 's,.*/,,;s/\.control /\t/' > ${INSTALLED_PACKAGES}
	fi

	v "Saving config files..."
	[ "$VERBOSE" -gt 1 ] && TAR_V="v" || TAR_V=""
	tar c${TAR_V}zf "$conf_tar" -T "$CONFFILES" 2>/dev/null
	if [ "$?" -ne 0 ]; then
		echo "Failed to create the configuration backup."
		rm -f "$conf_tar"
		exit 1
	fi

	[ "$UMOUNT_ETCBACKUP_DIR" -eq 1 ] && {
		umount "$ETCBACKUP_DIR"
		rm -rf "$RAMFS"
	}
	rm -f "$CONFFILES"
}

if [ $CONF_BACKUP_LIST -eq 1 ]; then
	run_hooks "$CONFFILES" $sysupgrade_init_conffiles
	[ "$SAVE_INSTALLED_PKGS" -eq 1 ] && echo ${INSTALLED_PACKAGES} >> "$CONFFILES"
	cat "$CONFFILES"
	rm -f "$CONFFILES"
	exit 0
fi

if [ -n "$CONF_BACKUP" ]; then
	do_save_conffiles "$CONF_BACKUP"
	exit $?
fi

if [ -n "$CONF_RESTORE" ]; then
	if [ "$CONF_RESTORE" != "-" ] && [ ! -f "$CONF_RESTORE" ]; then
		echo "Backup archive '$CONF_RESTORE' not found." >&2
		exit 1
	fi

	[ "$VERBOSE" -gt 1 ] && TAR_V="v" || TAR_V=""
	tar -C / -x${TAR_V}zf "$CONF_RESTORE"
	exit $?
fi

type platform_check_image >/dev/null 2>/dev/null || {
	echo "Firmware upgrade is not implemented for this platform." >&2
	exit 1
}

case "$IMAGE" in
	http://*|\
	https://*)
		wget -O/tmp/sysupgrade.img "$IMAGE"
		IMAGE=/tmp/sysupgrade.img
		;;
esac

IMAGE="$(readlink -f "$IMAGE")"

case "$IMAGE" in
	'')
		echo "Image file not found." >&2
		exit 1
		;;
	/tmp/*)	;;
	*)
		v "Image not in /tmp, copying..."
		cp -f "$IMAGE" /tmp/sysupgrade.img
		IMAGE=/tmp/sysupgrade.img
		;;
esac

json_load "$(/usr/libexec/validate_firmware_image "$IMAGE")" || {
	echo "Failed to check image"
	exit 1
}
json_get_var valid "valid"
[ "$valid" -eq 0 ] && {
	if [ $FORCE -eq 1 ]; then
		echo "Image check failed but --force given - will update anyway!" >&2
	else
		echo "Image check failed." >&2
		exit 1
	fi
}

if [ -n "$CONF_IMAGE" ]; then
	case "$(get_magic_word $CONF_IMAGE cat)" in
		# .gz files
		1f8b) ;;
		*)
			echo "Invalid config file. Please use only .tar.gz files" >&2
			exit 1
		;;
	esac
	get_image "$CONF_IMAGE" "cat" > "$CONF_TAR"
	export SAVE_CONFIG=1
elif ask_bool $SAVE_CONFIG "Keep config files over reflash"; then
	[ $TEST -eq 1 ] || do_save_conffiles "$CONF_TAR"
	export SAVE_CONFIG=1
else
	[ $TEST -eq 1 ] || rm -f "$CONF_TAR"
	export SAVE_CONFIG=0
fi

if [ $TEST -eq 1 ]; then
	exit 0
fi

install_bin /sbin/upgraded
v "Commencing upgrade. Closing all shell sessions."

COMMAND='/lib/upgrade/do_stage2'

if [ -n "$FAILSAFE" ]; then
	printf '%s\x00%s\x00%s' "$RAM_ROOT" "$IMAGE" "$COMMAND" >/tmp/sysupgrade
	lock -u /tmp/.failsafe
else
	force_attr=""
	[ $FORCE -eq 1 ] && force_attr="\"force\": true,"
	backup_attr=""
	[ $SAVE_CONFIG -eq 1 ] && backup_attr="\"backup\": $(json_string $CONF_TAR),"
	ubus call system sysupgrade "{
		\"prefix\": $(json_string "$RAM_ROOT"),
		\"path\": $(json_string "$IMAGE"),
		$force_attr
		$backup_attr
		\"command\": $(json_string "$COMMAND"),
		\"options\": {
			\"save_partitions\": $SAVE_PARTITIONS
		}
	}"
fi
