#!/bin/sh -eu

show_error() {
    echo "$@" >&2
}

sync_hostname() {
    MAPPER_IFACE='xyz.openbmc_project.ObjectMapper'
    MAPPER_PATH='/xyz/openbmc_project/object_mapper'
    INVENTORY_PATH='/xyz/openbmc_project/inventory'
    BMC_ITEM_IFACE='xyz.openbmc_project.Inventory.Item.Bmc'

    BMC_ITEM_PATH=$(busctl --no-pager --verbose call \
                            ${MAPPER_IFACE} \
                            ${MAPPER_PATH} \
                            ${MAPPER_IFACE} \
                            GetSubTree sias \
                            ${INVENTORY_PATH} 0 1 ${BMC_ITEM_IFACE} \
                        2>/dev/null | grep ${INVENTORY_PATH} || true)

    # '     STRING "/xyz/openbmc_project/inventory/system/chassis/bmc";'
    BMC_ITEM_PATH=${BMC_ITEM_PATH#*\"}
    BMC_ITEM_PATH=${BMC_ITEM_PATH%\"*}

    BMC_ITEM_SERVICE=$(mapper get-service \
                                ${BMC_ITEM_PATH} 2>/dev/null || true)

    if [[ -z "${BMC_ITEM_SERVICE}" ]]; then
        echo "No BMC item found in the Inventory. Is VPD EEPROM empty?" >&2
        return
    fi

    BMC_SN=$(busctl get-property ${BMC_ITEM_SERVICE} \
                            ${BMC_ITEM_PATH} \
                            ${BMC_ITEM_IFACE} SerialNumber)
    # 's "002B0DH1000"'
    BMC_SN=${BMC_SN#*\"}
    BMC_SN=${BMC_SN%\"*}

    hostnamectl set-hostname {MACHINE}-${BMC_SN}
}

[ "$(hostname)" = "{MACHINE}" ] && sync_hostname

systemctl disable first-boot-set-hostname.service