<?php

// Replace these placeholders before running the example.
$apiUrl = 'https://your-domain.example/api/v1';
$apiKey = 'YOUR_API_KEY';

function apiRequest(string $apiUrl, string $apiKey, array $parameters): array
{
    $parameters['key'] = $apiKey;

    $handle = curl_init($apiUrl);
    curl_setopt_array($handle, [
        CURLOPT_POST           => true,
        CURLOPT_POSTFIELDS     => http_build_query($parameters),
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_CONNECTTIMEOUT => 10,
        CURLOPT_TIMEOUT        => 30,
        CURLOPT_SSL_VERIFYPEER => true,
        CURLOPT_SSL_VERIFYHOST => 2,
        CURLOPT_HTTPHEADER     => ['Accept: application/json'],
    ]);

    $body = curl_exec($handle);
    if ($body === false) {
        $message = curl_error($handle);
        curl_close($handle);
        throw new RuntimeException('API request failed: ' . $message);
    }
    curl_close($handle);

    $response = json_decode($body, true);
    if (!is_array($response)) {
        throw new RuntimeException('The API returned invalid JSON.');
    }
    if (isset($response['error'])) {
        throw new RuntimeException((string) $response['error']);
    }

    return $response;
}

try {
    // 1. Get the current service list and select a service ID.
    $services = apiRequest($apiUrl, $apiKey, [
        'action' => 'services',
    ]);

    // 2. Place an order. Use a real service ID from the response above.
    $newOrder = apiRequest($apiUrl, $apiKey, [
        'action'   => 'add',
        'service'  => 1,
        'link'     => 'https://www.example.com/profile',
        'quantity' => 100,
    ]);

    // 3. Check the order later using the returned local order ID.
    $status = apiRequest($apiUrl, $apiKey, [
        'action' => 'status',
        'order'  => $newOrder['order'],
    ]);

    // 4. Read the reseller balance.
    $balance = apiRequest($apiUrl, $apiKey, [
        'action' => 'balance',
    ]);

    print_r([
        'services' => $services,
        'order'    => $newOrder,
        'status'   => $status,
        'balance'  => $balance,
    ]);
} catch (Throwable $exception) {
    echo $exception->getMessage();
}

/*
 * Refill example:
 * $refill = apiRequest($apiUrl, $apiKey, [
 *     'action' => 'refill',
 *     'order'  => 1242,
 * ]);
 *
 * Refill status example:
 * $refillStatus = apiRequest($apiUrl, $apiKey, [
 *     'action' => 'refill_status',
 *     'refill' => $refill['refill'],
 * ]);
 *
 * Keep the API key on your server. Do not put it in browser JavaScript,
 * mobile app source code, public repositories, or user-facing URLs.
 */