#!/bin/bash
SERIAL_NUM="UNKNOWN"
BACKUP_SERIAL="UNKNOWN_BACKUP"

if [ -f /home/bitcoin/.mynode/mynode_serial ]; then
    BACKUP_SERIAL=$(cat /home/bitcoin/.mynode/mynode_serial)
else
    # Backup, use eth0 mac (some are duplicate?)
    if [ -f /sys/class/net/eth0/address ]; then
        MAC=$(cat /sys/class/net/eth0/address)
        BACKUP_SERIAL=$(echo "${MAC//:}")
    else
        BACKUP_SERIAL="UNKNOWN_BACKUP_SERIAL"
    fi
fi


if [ -f /sys/firmware/devicetree/base/serial-number ]; then
    SERIAL_NUM=$(tr -d '\0' </sys/firmware/devicetree/base/serial-number)
else
    SERIAL_NUM=$(cat /proc/cpuinfo | grep Serial | cut -d ' ' -f 2)
    if [[ "$SERIAL_NUM" == "" ]]; then
        # Caution - dmidecode seem to cause issues on some platforms (used on VM)
        SERIAL_NUM=$(sudo dmidecode | grep UUID | cut -d ' ' -f 2)
        if [[ "$SERIAL_NUM" == "03000200-0400-0500-0006-000700080009" ]]; then
             # Some mini PCs return this hard coded value
            SERIAL_NUM=$BACKUP_SERIAL
        fi
    elif [[ "$SERIAL_NUM" == "0000000000000000" ]]; then
        # RockPro64 returns 0s (base serial-num should work now)
        SERIAL_NUM=$BACKUP_SERIAL
    fi
fi

echo $SERIAL_NUM