run_as_user() {
	mastodon_dir="/usr/local/www/mastodon"
	_cmd="$@"
	_user="${mastodon_web_user}"
	[ -z "${_user}" ] && _user="${mastodon_stream_user}"
	[ -z "${_user}" ] && _user="${mastodon_workers_user}"
	if [ -n "${_user}" ]; then
		_cmd="su -m ${_user} -c 'cd "${mastodon_dir}" && sh -c \"$_cmd\"'"
	fi
	eval "${_cmd}"
}

query() {
	psql_env="_=1"
	_db_name=$1
	shift
	_sql="$*"
	rc=0

	if [ -n "${mastodon_db_password}" ]; then
		passwd_directory=$(mktemp -d) || exit 1
		passwd_file="${passwd_directory}/.pgpass"
		echo "\*:\*:\*:\*:${mastodon_db_password}" > "${passwd_file}"
		chmod 600 "${passwd_file}"
		psql_env="HOME=${passwd_directory}"
	fi
	if [ -n "${mastodon_db_url}" ]; then
		_psql_cmd="env ${psql_env} psql -qtA \"${mastodon_db_url}\" dbname=\"${_db_name}\""
	elif [ -n "${mastodon_db_name}" ]; then
		_psql_cmd="env ${psql_env} psql -qtA \
			${mastodon_db_user:+-U ${mastodon_db_user} } \
			${mastodon_db_host:+-h ${mastodon_db_host} } \
			${mastodon_db_port:+-p ${mastodon_db_port} } \
			\"${_db_name}\""
	else
		rc=1
	fi
	if [ "$rc" = 0 ]; then
		echo "${_sql}" | run_as_user "${_psql_cmd}" || rc=1
	fi
	if [ -n "${passwd_directory}" -a -d "${passwd_directory}" ]; then
		rm -rf "${passwd_directory}"
	fi
	return $rc
}

db_quick_test() {
	[ -n "${mastodon_db_url}" ] && return 0 # Our connection test would always fail
	out=$(query template1 'select 1') && test "${out}" -eq 1
}

db_schema_version() {
	query "${mastodon_db_name}" 'select max(version) from schema_migrations'
}

check_db_schema() {
	required_schema_version="$1"
	shift
	if db_quick_test; then
		schema_version=$(db_schema_version)
		if [ -n "${schema_version}" ]; then
			if [ "${schema_version}" -eq "${required_schema_version}" ]; then
				return 0
			elif [ "${schema_version}" -lt 20170604144747 ] ; then
				return 4
			else
				return 3
			fi
		else
			return 2
		fi
	else
		return 1
	fi
}

run_rails() {
	if [ -n "${mastodon_db_url}" ]; then
		_rails_cmd="env \
		DATABASE_URL=\"${mastodon_db_url}\" \
		RAILS_ENV=production \
		rails $1"
	else
		_rails_cmd="env \
		${mastodon_db_host+DB_HOST=\"${mastodon_db_host}\"} \
		${mastodon_db_name+DB_NAME=\"${mastodon_db_name}\"} \
		${mastodon_db_port+DB_PORT=\"${mastodon_db_port}\"} \
		${mastodon_db_user+DB_USER=\"${mastodon_db_user}\"} \
		${mastodon_db_password+DB_PASS=\"${mastodon_db_password}\"} \
		RAILS_ENV=production \
		rails $1"
	fi
	run_as_user "${_rails_cmd}"
}

do_schema() {
	check_db_schema 20170913000752
	rc=$?
	case $rc in
	0)	;;
	1)	echo "Cannot connect to Mastodon database"
		return 1
		;;
	2)	run_rails db:setup ;;
	3)	run_rails db:migrate ;;
	4)	run_rails mastodon:maintenance:prepare_for_foreign_keys ;;
	esac
}

check_mastodon() {
	do_schema
}