#!/bin/sh -e
# initramfs local-premount script for fixrtc

PREREQ=""

# Output pre-requisites
prereqs()
{
	echo "$PREREQ"
}

case "$1" in
prereqs)
	prereqs
	exit 0
	;;
esac

# use the fixrtc cmdline option in your bootloader to
# automatically set the hardware clock to the date of
# the last mount of your root filesystem to avoid fsck
# to get confused by the superblock being in the future

BROKEN_CLOCK=""
ROOTDEV=""
# System partition is currently used by ubuntu touch only
SYSTEMPART=""

# shellcheck disable=SC2013
for x in $(cat /proc/cmdline); do
	case ${x} in
	root=*)
		value=${x#*=}

		# Find the device node path depending on the form of root= :
		case ${value} in
		UUID=*)
			ROOTDEV=/dev/disk/by-uuid/${value#UUID=}
			;;
		LABEL=*)
			ROOTDEV=/dev/disk/by-label/${value#LABEL=}
			;;
		*)
			ROOTDEV=${value}
			;;
		esac
	;;
	systempart=*)
		value=${x#*=}

		# Find the device node path depending on the form of root= :
		case ${value} in
		UUID=*)
			SYSTEMPART=/dev/disk/by-uuid/${value#UUID=}
			;;
		LABEL=*)
			SYSTEMPART=/dev/disk/by-label/${value#LABEL=}
			;;
		*)
			SYSTEMPART=${value}
			;;
		esac
		# if systempart= is defined we do not want root=/dev/ram
		# been taken into account
		[ "$ROOTDEV" = "/dev/ram" ] && ROOTDEV=""
	;;
	fixrtc)
		BROKEN_CLOCK=1
	;;
	esac
done

# Touch devices might not have a valid 'root', so use system part if available
if [ -z "$ROOTDEV" ] && [ -n "$SYSTEMPART" ]; then
	ROOTDEV=$SYSTEMPART
fi

if [ -n "$BROKEN_CLOCK" ] && [ -n "$ROOTDEV" ]; then
	# need udev settle for /dev/disk/by-* symlinks to be added
	udevadm settle

	wait-for-root "$ROOTDEV" "${ROOTDELAY:-180}" >/dev/null

	ROOTDISK=$(readlink -f "$ROOTDEV")

	MOUNTDATESTR=$(dumpe2fs -h "$ROOTDISK" 2>/dev/null|grep "Last mount time")
	# Trim whitespace for busybox
	MOUNTDATE="${MOUNTDATESTR#*:}"
	MOUNTDATE="${MOUNTDATE#"${MOUNTDATE%%[![:space:]]*}"}"

	CREATEDATESTR=$(dumpe2fs -h "$ROOTDISK" 2>/dev/null|grep "Filesystem created") || true
	# Trim whitespace for busybox
	CREATEDATE="${CREATEDATESTR#*:}"
	CREATEDATE="${CREATEDATE#"${CREATEDATE%%[![:space:]]*}"}"

	# Hide stderr to avoid ugly message:
	#  can't open '/dev/misc/rtc': No such file or directory
	# on pi2 (and possible more PIs) where there is no /dev/rtc of
	# any kind. We still need to keep this call because we use
	# fixrtc on all armhf images.
	hwclock -s 2>/dev/null || true

	# make sure we're also compatible with busybox, if available
	DATE="/bin/date -D%c"
	date -D%c 2>/dev/null 2>&1 || DATE=/bin/date

	if [ "$MOUNTDATE" = "n/a" ]; then
		# some versions of mkfs set n/a now, date is not happy with this so
		# let us use some half way sane epoch instead
		MOUNTDATE="Fri Jan 1 00:00:00 1999"
	fi
	TIMESTR=$MOUNTDATE
	TIME=$(${DATE} --utc --date "${TIMESTR}" +%s)

	CURTIME=$(${DATE} --utc +%s)

	# in case the created time is newer than last mount, use that instead
	if [ -n "$CREATEDATE" ]; then
		CREATETIME=$(${DATE} --utc --date "${CREATEDATE}" +%s)
		if [ "$CREATETIME" -gt "$TIME" ]; then
			TIMESTR=$CREATEDATE
			TIME=$CREATETIME
		fi
	fi

	if [ "$TIME" -gt "$CURTIME" ]; then
		${DATE} --set="${TIMESTR} 1 minute" >/dev/null 2>&1
	fi
fi

# This script is best-effort.  If we couldn't fudge the clock as desired,
# just try to carry on boot anyway:
# It will probably fail, but we won't have made the situation any worse.
exit 0
