#! /bin/sh -e

. /usr/share/debconf/confmodule

chroot_has () {
	PATH="$CHROOT_PATH" /bin/search-path "$1"
}

chroot_run () {
	db_subst rescue/shell/title DEVICE "$RESCUE_ROOTDEV"
	start-shell rescue/shell/title chroot /target "$@"
}

# Work out a sensible $PATH with respect to /target.
CHROOT_PATH=
OLD_IFS="$IFS"
IFS=:
for element in $PATH; do
	# Only include absolute elements.
	if [ "${element#/}" != "$element" ]; then
		CHROOT_PATH="${CHROOT_PATH:+$CHROOT_PATH:}/target$element"
	fi
done
IFS="$OLD_IFS"

shell_failed () {
	db_capb
	db_subst rescue/shell/run-failed SHELL "$*"
	db_subst rescue/shell/run-failed DEVICE "$RESCUE_ROOTDEV"
	db_input critical rescue/shell/run-failed
	db_go || true
	db_capb backup
}

if chroot_has bash; then
	chroot_run 'bash -i' || shell_failed 'bash -i'
elif [ -f /target/bin/sh ] && [ -x /target/bin/sh ]; then
	chroot_run /bin/sh -i || shell_failed '/bin/sh -i'
elif chroot_has sash; then
	chroot_run sash || shell_failed sash
elif chroot_has busybox; then
	# Try this last even though busybox is useful, since it might fail
	# due to a missing sh applet.
	chroot_run busybox sh || shell_failed 'busybox sh'
else
	db_capb
	db_subst rescue/shell/not-found DEVICE "$RESCUE_ROOTDEV"
	db_input critical rescue/shell/not-found
	db_go || true
	db_capb backup
fi

exit 0