#!/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="Cache bootstrap stage"
USAGE="${PROGRAM} {restore|save} [--force]"

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

_ACTION="${1}"
shift

# Check architecture
Check_crossarchitectures

if ! In_list "bootstrap" ${LB_CACHE_STAGES}; then
	exit 0
fi

# Set non-default stage file name
# Note, this (plus the applicable extension added below) must match that used in `bootstrap_debootstrap`
STAGE_FILE="bootstrap_cache.${_ACTION}"

case "${_ACTION}" in
	restore)
		# Checking stage file
		Check_stagefile "${STAGE_FILE}"

		if [ -d cache/bootstrap ]
		then
			Echo_message "Restoring bootstrap stage from cache..."

			# Acquire lock file
			Acquire_lockfile

			# Removing old chroot
			rm -rf chroot

			# Catch failure condition.
			# The installer stage, if not 'none' or 'live' needs to copy cached
			# bootstrap packages, and will error if these do not exist. This
			# could be the case if bootstrap is cached but the packages were
			# wiped from the cache. This detects this condition and if it is the
			# case, ignores the cached bootstrap, forcing it to be rebuilt thus
			# re-caching the packages.
			if ! In_list "${LB_DEBIAN_INSTALLER}" live none &&
			   ! ls cache/packages.bootstrap/*.deb > /dev/null 2>&1
			then
				Echo_message "Cached bootstrap packages required but missing, ignoring cached bootstrap to force rebuild."
				exit 0
			fi

			# Restoring old cache
			cp -a cache/bootstrap chroot

			# Creating stage file
			Create_stagefile "${STAGE_FILE}"
			Create_stagefile "bootstrap"

			exit 0
		fi
		;;

	save)
		Echo_message "Saving bootstrap stage to cache..."

		# Checking stage file
		Check_stagefile "${STAGE_FILE}"

		# Acquire lock file
		Acquire_lockfile

		rm -rf cache/bootstrap

		mkdir -p cache

		cp -a chroot cache/bootstrap

		# Creating stage file
		Create_stagefile "${STAGE_FILE}"
		;;

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