<?php

function postJsonToApi(string $url, array $data, array $headers = []): ?array
{
    $jsonData = json_encode($data);

    if ($jsonData === false) {
        error_log("Failed to encode JSON data for URL: " . $url);
        return null;
    }

    // Default headers
    $defaultHeaders = [
        'Content-Type: application/json',
        'Content-Length: ' . strlen($jsonData),
        // Add Authorization header if needed, e.g.:
        // 'Authorization: Bearer YOUR_API_KEY_HERE'
    ];

    // Merge custom headers, allowing overrides
    $mergedHeaders = array_merge($defaultHeaders, $headers);

    $ch = curl_init($url);

    curl_setopt($ch, CURLOPT_POST, 1); // Set as POST request
    curl_setopt($ch, CURLOPT_POSTFIELDS, $jsonData); // Set JSON data
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true); // Return the response as a string
    curl_setopt($ch, CURLOPT_HTTPHEADER, $mergedHeaders); // Set headers

    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);

    if (curl_errno($ch)) {
        $error_msg = curl_error($ch);
        error_log("cURL Error for URL {$url}: {$error_msg}");
        curl_close($ch);
        return null;
    }

    curl_close($ch);

    if ($httpCode >= 200 && $httpCode < 300) {
        return json_decode($response, true);
    } else {
        error_log("API call to {$url} failed with HTTP code {$httpCode}. Response: {$response}");
        return null;
    }
}

// Example Usage:
// $apiUrl = "https://api.example.com/create-resource"; // Replace with your API endpoint
// $postData = [
//     'name' => 'New Item',
//     'description' => 'This is a description for the new item.',
//     'quantity' => 10
// ];
// $customHeaders = [
//     'X-Custom-Header: MyValue',
//     'Authorization: Bearer YOUR_ACTUAL_API_KEY' // Replace with your actual key
// ];

// $result = postJsonToApi($apiUrl, $postData, $customHeaders);

// if ($result) {
//     echo "Resource created successfully:
";
//     print_r($result);
// } else {
//     echo "Failed to create resource.
";
// }

// You can test with a public API like httpbin.org for POST requests:
// $testApiUrl = "https://httpbin.org/post";
// $testData = ['message' => 'Hello from PHP cURL', 'timestamp' => time()];
// $testResult = postJsonToApi($testApiUrl, $testData);
// if ($testResult) {
//     echo "
Test API call result:
";
//     print_r($testResult);
// }

?>