#! /bin/sh
# Check that the root filesystem is large enough to hold /rofs.
. /lib/partman/lib/base.sh

db_get partman-auto/method
if [ "$RET" = loop ]; then
	# Wubi does some of its own checks which help defend against this,
	# and the delay imposed by this check looks particularly weird in
	# Wubi.
	exit 0
fi

# Fudge factors
rootfudge=200000000 # 200MB
bootmultfudge=3

partitions=
rofssum=0
rootrofssize=
rootsize=

parts=$(
for dev in $DEVICES/*; do
    [ -d "$dev" ] || continue
    cd $dev
    open_dialog PARTITIONS
    while { read_line num id size type fs path name; [ "$id" ]; }; do
	[ "$fs" != free ] || continue
	[ -f "$id/method" ] || continue
	[ -f "$id/acting_filesystem" ] || continue
        [ -f "$id/mountpoint" ] || continue
        mountpoint="$(cat "$id/mountpoint")"
	echo "$mountpoint,$size"
    done
    close_dialog
done | sort
)

seen=
for part in $parts; do
	mountpoint="${part%,*}"
	size="${part#*,}"
	if [ "$mountpoint" = "/" ]; then
		if [ -e /cdrom/casper/filesystem.size ]; then
			rofssize="$(cat /cdrom/casper/filesystem.size)"
		else
			rofssize="$(du -s --block-size=1 /rofs | cut -f1)"
		fi
		rootrofssize="$rofssize"
		rootsize="$size"
	else
		[ -d "/rofs$mountpoint" ] || continue
		rofssize="$(du -s --block-size=1 /rofs$mountpoint | cut -f1)"
		if [ "$mountpoint" = "/boot" ]; then
			rofssize="$(expr $rofssize \* $bootmultfudge)"
		else
			# general fudge factor: add 20% for luck
			rofssize="$(expr $rofssize \* 12 / 10)"
		fi
		if ! longint_le $rofssize $size ; then
			partitions="${partitions:+$partitions, }$mountpoint $(longint2human $rofssize)"
		fi

		# Make sure that no parent of $mountpoint has been added to
		# $rofssum yet, otherwise we'll produce an invalid size.
		d="$(dirname $mountpoint)"
		found=
		if [ -n "$seen" ]; then
			while :; do
				if [ "$d" = / ]; then
					break
				fi
				if echo "$seen" | grep -wqs "$d"; then
					found=1
					break
				fi
				d="$(dirname $d)"
			done
		fi
		if [ -z "$found" ]; then
			rofssum="$(expr $rofssum + $rofssize)"
			seen="$seen $mountpoint"
		fi
	fi
done

if [ -n "$rootrofssize" ]; then
    rofs=$(expr $rootrofssize - $rofssum + $rootfudge)
    if ! longint_le $rofs $rootsize ; then
        partitions="/ $(longint2human $rofs)${partitions:+, $partitions}"
    fi
fi

if [ -n "$partitions" ]; then
    partitions="$(echo "$partitions" | sed -e 's/, /\n/g')"
    db_capb escape
    db_reset ubiquity/partition-too-small
    db_subst ubiquity/partition-too-small PARTITIONS "$(printf %s "$partitions" | debconf-escape -e)"
    db_capb
    db_input critical ubiquity/partition-too-small || true
    db_go || true
    db_get ubiquity/partition-too-small
    if [ "$RET" = true ]; then
        exit 1
    fi
fi

exit 0