#!/usr/bin/env bash
set -euo pipefail

mt -f "${DEVICE}" load
deadline=$(($(date +%s) + 60))
barcode=''
while true; do
    now=$(date +%s)
    if ((now >= deadline)); then
        break
    fi
    remaining=$((deadline - now))
    info=$(timeout "${remaining}s" ./yatm-lto-info -f "${DEVICE}" || true)
    barcode=$(awk '$1 == "Barcode" && $2 == ":" {
        value = $3
        if (length(value) == 8) {
            value = substr(value, 1, 6)
        }
        print value
        exit
    }' <<< "${info}")
    if [[ -n ${barcode} ]]; then
        break
    fi
    now=$(date +%s)
    if ((now >= deadline)); then
        break
    fi
    delay=$((deadline - now))
    if ((delay > 2)); then
        delay=2
    fi
    sleep "${delay}"
done
if [[ -z ${barcode} ]]; then
    echo "Tape barcode is unavailable: ${DEVICE}" >&2
    exit 1
fi
printf '{"barcode":"%s"}\n' "${barcode}" > "${OUT}"