#!/bin/sh

## live-build(7) - System Build Scripts
## Copyright (C) 2016-2020 The Debian Live team
## Copyright (C) 2006-2015 Daniel Baumann <mail@daniel-baumann.ch>
##
## This program comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
## This is free software, and you are welcome to redistribute it
## under certain conditions; see COPYING for details.


set -e

# Including common functions
[ -e "${LIVE_BUILD}/scripts/build.sh" ] && . "${LIVE_BUILD}/scripts/build.sh" || . /usr/lib/live/build.sh

# Setting static variables
DESCRIPTION="Manage /usr/sbin/policy-rc.d"
USAGE="${PROGRAM} {install|remove} [--force]"

# Processing arguments and configuration files
Init_config_data "${@}"

_ACTION="${1}"
shift

# Requiring stage file
Require_stagefiles config bootstrap

policy_rcd_contents="$(cat <<EOF
#!/bin/sh
echo "All runlevel operations denied by policy" >&2
exit 101
EOF
)"

case "${_ACTION}" in
	install)
		Echo_message "Configuring file /usr/sbin/policy-rc.d"

		# Checking stage file
		Check_stagefile

		# Acquire lock file
		Acquire_lockfile

		if [ -e chroot/usr/sbin/policy-rc.d ]
		then
			if [ -e /etc/alternatives/policy-rc.d ]
			then
				# Install an alternative for policy-rc.d
				echo "${policy_rcd_contents}" > chroot/usr/sbin/policy-rc.d.live-build
				Chroot chroot update-alternatives --install /usr/sbin/policy-rc.d policy-rc.d /usr/sbin/policy-rc.d.live-build 1000
				chmod 0755 chroot/usr/sbin/policy-rc.d.live-build
			else
				# Save policy-rc.d file
				Chroot chroot dpkg-divert --rename --quiet --add /usr/sbin/policy-rc.d

				# Create policy-rc.d file
				echo "${policy_rcd_contents}" > chroot/usr/sbin/policy-rc.d
				chmod 0755 chroot/usr/sbin/policy-rc.d
			fi
		fi

		# Creating stage file
		Create_stagefile
		;;

	remove)
		Echo_message "Deconfiguring file /usr/sbin/policy-rc.d"

		# Checking stage file
		Ensure_stagefile_exists

		# Acquire lock file
		Acquire_lockfile

		alternatives_query_policyrcd="$(
			Chroot chroot update-alternatives --query policy-rc.d \
				| grep 'Value:' \
				| cut -d' ' -f2
		)"
		if [ "${alternatives_query_policyrcd}" = '/usr/sbin/policy-rc.d.live-build' ]
		then
			# Remove the live-build alternative for policy-rc.d
			Chroot chroot update-alternatives --remove policy-rc.d /usr/sbin/policy-rc.d.live-build
			rm -f chroot/usr/sbin/policy-rc.d.live-build
		elif [ -e chroot/usr/sbin/policy-rc.d.distrib ]
		then
			# Remove custom policy-rc.d file
			rm -f chroot/usr/sbin/policy-rc.d

			# Restore policy-rc.d file
			Chroot chroot dpkg-divert --rename --quiet --remove /usr/sbin/policy-rc.d
		fi

		# Removing stage file
		Remove_stagefile
		;;

	*)
		Echo_error "Invalid action parameter: '${_ACTION}'"
		Usage --fail
		;;
esac
