$session = $sdk->generateQrLogin('POS Terminal #1', $shopId);

echo $session['session_id'];   // Unique session ID
echo $session['qr_code'];      // Deep link for QR code
echo $session['expires_at'];   // Expiration time (5 min)

// Generate QR image URL using Loyalty.lt API
$qrImageUrl = "https://api.loyalty.lt/qr?data=" 
    . urlencode($session['qr_code']) . "&size=250";

echo "<img src='{$qrImageUrl}' alt='Scan to login'>";

// Poll every 2 seconds until authenticated or expired
$maxAttempts = 150; // 5 minutes
$attempt = 0;

while ($attempt < $maxAttempts) {
    $status = $sdk->pollQrLogin($session['session_id']);
    
    switch ($status['status']) {
        case 'authenticated':
            $user = $status['user'];
            $token = $status['token'];
            echo "Welcome, " . $user['name'];
            break 2;
            
        case 'scanned':
            echo "QR scanned, waiting for confirmation...";
            break;
            
        case 'expired':
            echo "Session expired";
            break 2;
    }
    
    sleep(2);
    $attempt++;
}

// Get Ably token for real-time updates
$ablyToken = $sdk->getAblyToken($session['session_id']);

// Use with Ably PHP client
echo $ablyToken['token'];
echo $ablyToken['channel'];

$session = $sdk->generateQrCardSession('POS Terminal', $shopId);

echo $session['session_id'];
echo $session['qr_code'];
echo $session['expires_at'];

// Display QR using Loyalty.lt API
$qrUrl = "https://api.loyalty.lt/qr?data=" 
    . urlencode($session['qr_code']) . "&size=250";

// Poll for customer identification
while (true) {
    $result = $sdk->pollQrCardStatus($session['session_id']);
    
    if ($result['status'] === 'completed') {
        $card = $result['card_data'];
        
        echo "Customer: " . $card['user']['name'];
        echo "Card: " . $card['card_number'];
        echo "Points: " . $card['points_balance'];
        
        // Process transaction
        $sdk->createTransaction([
            'card_id' => $card['id'],
            'amount' => $orderTotal,
            'points' => (int) $orderTotal,
            'type' => 'earn',
        ]);
        
        break;
    }
    
    if ($result['status'] === 'expired') {
        // Regenerate QR
        break;
    }
    
    sleep(2);
}

$sdk->sendAppLink(
    '+37060000000',  // Phone number
    $shopId,         // Shop ID (required)
    'Jonas',         // Optional customer name
    'lt'             // Language (lt/en)
);

<?php

use LoyaltyLt\SDK\LoyaltySDK;
use LoyaltyLt\SDK\Exceptions\LoyaltySDKException;

class POSController
{
    private LoyaltySDK $sdk;
    private ?array $currentCustomer = null;
    private ?array $qrSession = null;
    
    public function __construct()
    {
        $this->sdk = new LoyaltySDK([
            'apiKey' => env('LOYALTY_API_KEY'),
            'apiSecret' => env('LOYALTY_API_SECRET'),
        ]);
    }
    
    public function startCustomerIdentification(): array
    {
        $this->qrSession = $this->sdk->generateQrCardSession('POS');
        
        return [
            'qr_url' => "https://api.loyalty.lt/qr?data=" 
                . urlencode($this->qrSession['qr_code']) . "&size=300",
            'session_id' => $this->qrSession['session_id'],
            'expires_at' => $this->qrSession['expires_at'],
        ];
    }
    
    public function checkCustomerStatus(): ?array
    {
        if (!$this->qrSession) return null;
        
        $result = $this->sdk->pollQrCardStatus($this->qrSession['session_id']);
        
        if ($result['status'] === 'completed') {
            $this->currentCustomer = $result['card_data'];
            return $this->currentCustomer;
        }
        
        return null;
    }
    
    public function processCheckout(float $total): array
    {
        if (!$this->currentCustomer) {
            throw new \Exception('No customer identified');
        }
        
        $pointsToAward = (int) ($total * 10); // 10 points per €1
        
        $transaction = $this->sdk->createTransaction([
            'card_id' => $this->currentCustomer['id'],
            'amount' => $total,
            'points' => $pointsToAward,
            'type' => 'earn',
            'description' => 'Purchase',
            'reference' => 'POS-' . time(),
        ]);
        
        return [
            'transaction_id' => $transaction['id'],
            'points_awarded' => $pointsToAward,
            'customer' => $this->currentCustomer['user']['name'],
        ];
    }
}