#!/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}"

        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 || 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