# Download the proto files for your LND version
curl -o lightning.proto https://raw.githubusercontent.com/lightningnetwork/lnd/master/lnrpc/lightning.proto

# Install dependencies (JavaScript)
npm install @grpc/grpc-js @grpc/proto-loader

// Subscribe to a single invoice's state changes via gRPC
$invoiceHashHex = getenv('INVOICE_HASH_HEX') ?: '<invoice_hash_in_hex>';
$invoiceClient = new InvoicesClient($grpcHost, $opts);

// Prepare request with the invoice RHash (as raw bytes)
$invoiceReq = new Invoicesrpc\SubscribeSingleInvoiceRequest();
$invoiceReq->setRHash(hex2bin($invoiceHashHex));

// Initiate the RPC stream
$invoiceStream = $invoiceClient->SubscribeSingleInvoice($invoiceReq);
echo "Subscribed to invoice {$invoiceHashHex} (single invoice stream).\n";

// Read streamed Invoice updates
while (true) {
    /** @var Lnrpc\Invoice $invoiceUpdate */
    $invoiceUpdate = $invoiceStream->read();
    if ($invoiceUpdate === null) {
        // Stream ended (invoice reached a final state and stream closed)
        echo "Invoice stream closed by server.\n";
        break;
    }
    // Log the invoice's current state and amount paid
    $state = $invoiceUpdate->getState();  // e.g., 0=OPEN, 1=SETTLED, 2=CANCELED
    $settledFlag = $invoiceUpdate->getSettled();  // boolean
    echo "🔔 Invoice update: state=" . ($settledFlag ? 'SETTLED' : 'OPEN') 
         . ", amount_paid_sat=" . $invoiceUpdate->getAmtPaidSat() . PHP_EOL;
    if ($settledFlag || $state === \Lnrpc\Invoice\InvoiceState::CANCELED) {
        // Stop if invoice is settled or canceled
        echo "Invoice is now final (settled or canceled). Ending subscription.\n";
        break;
    }
}

// Subscribe to all invoice add/settle events via gRPC
$lightningClient = new LightningClient($grpcHost, $opts);
$subReq = new Lnrpc\InvoiceSubscription();  // empty request = subscribe from latest
// (Optionally, set add_index and/or settle_index on $subReq to resume from a specific point)

$invoiceStream = $lightningClient->SubscribeInvoices($subReq);
echo "Subscribed to all invoice events.\n";

// Stream all invoice updates continuously
while (true) {
    $invoice = $invoiceStream->read();
    if ($invoice === null) {
        echo "Invoice event stream closed.\n";
        break;
    }
    $hashHex = bin2hex($invoice->getRHash()); 
    $stateStr = $invoice->getSettled() ? 'settled' : ($invoice->getState() === \Lnrpc\Invoice\InvoiceState::CANCELED ? 'canceled' : 'open');
    echo "📣 Invoice #{$invoice->getAddIndex()} ({$hashHex}): {$stateStr}, value={$invoice->getValueSat()} sat\n";
    // (Process invoice data as needed; this loop continues indefinitely)
}

// Track a single payment's progress via gRPC
$paymentHashHex = getenv('PAYMENT_HASH_HEX') ?: '<payment_hash_in_hex>';
$routerClient = new RouterClient($grpcHost, $opts);

$trackReq = new Routerrpc\TrackPaymentRequest();
$trackReq->setPaymentHash(hex2bin($paymentHashHex));
$trackReq->setNoInflightUpdates(false);  // set true to only get final update

$paymentStream = $routerClient->TrackPaymentV2($trackReq);
echo "Tracking payment {$paymentHashHex} (gRPC)...\n";

// Read payment status updates
while (true) {
    /** @var Lnrpc\Payment $payment */
    $payment = $paymentStream->read();
    if ($payment === null) {
        echo "Payment stream closed by server.\n";
        break;
    }
    $status = $payment->getStatus();  // an enum of type PaymentStatus
    // Map status to human-readable form:
    $statusName = ['UNKNOWN', 'IN_FLIGHT', 'SUCCEEDED', 'FAILED'][$status] ?? $status;
    echo "💱 Payment update: status={$statusName}";
    if ($statusName === 'SUCCEEDED') {
        $preimage = bin2hex($payment->getPaymentPreimage());
        echo ", preimage={$preimage}\n";
        echo "✅ Payment succeeded, amount_sent={$payment->getValueSat()} sat, total_fee={$payment->getFeeSat()} sat\n";
        break;
    } elseif ($statusName === 'FAILED') {
        echo "\n❌ Payment failed (failure reason: {$payment->getFailureReason()}).\n";
        break;
    } else {
        echo " (still in flight)\n";
        // continue loop for more intermediate updates (e.g. HTLC attempts)
    }
}

// Subscribe to updates for all in-flight payments via gRPC
$routerClient = new RouterClient($grpcHost, $opts);
$streamReq = new Routerrpc\TrackPaymentsRequest();
$streamReq->setNoInflightUpdates(false);  // set true to only get final outcomes

$paymentsStream = $routerClient->TrackPayments($streamReq);
echo "Subscribed to all payments stream.\n";

while (true) {
    /** @var Lnrpc\Payment $payment */
    $payment = $paymentsStream->read();
    if ($payment === null) {
        echo "Payments stream closed (no more data).\n";
        break;
    }
    $hashHex = $payment->getPaymentHash();
    $status = $payment->getStatus();
    $statusName = ['UNKNOWN','IN_FLIGHT','SUCCEEDED','FAILED'][$status] ?? $status;
    echo "📤 Payment {$payment->getPaymentIndex()} (hash={$hashHex}): {$statusName}";
    if ($statusName === 'SUCCEEDED') {
        echo " (sent {$payment->getValueSat()} sat, fee {$payment->getFeeSat()} sat)";
    } elseif ($statusName === 'FAILED') {
        echo " (failed: reason={$payment->getFailureReason()})";
    }
    echo PHP_EOL;
    // (The loop continues to stream updates for all ongoing/new payments)
}