#!/bin/sh
set -eu

LIVE_DIR=${LIVE_DIR:-/run/s6-rc}
STATE_DIR=${STATE_DIR:-/etc/s6-rc}
SOURCE_DIR=${SOURCE_DIR:-/etc/s6-rc/src}

new_dir="$STATE_DIR"/"_$(date +%s)"

main() {
        local old
        old="$(find "$STATE_DIR" -maxdepth 1 -name '_[0-9]*' -print)"

        # compile new db
        s6-rc-compile "$new_dir" "$SOURCE_DIR"

        # switch to new db (if there's an active tree)
        test -e "$LIVE_DIR" && s6-rc-update -v2 -l "$LIVE_DIR" -b "$new_dir"

        # swap current db
        s6-ln -snf "$new_dir" "$STATE_DIR"/compiled

        # cleanup old db
        # NOTE: needs to be unquoted for expansion to work
        rm -rf -- $old
}

command -v s6-ln >/dev/null 2>&1 || exit 1

main || rm -rf "$new_dir"