PHP集成Walmart Returns API指南：认证、请求与常见错误解决

<?php

// 辅助函数：生成UUID v4 (GUID)
function generateUuidV4() {
    return sprintf( '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
        mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ),
        mt_rand( 0, 0xffff ),
        mt_rand( 0, 0x0fff ) | 0x4000,
        mt_rand( 0, 0x3fff ) | 0x8000,
        mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff )
    );
}

// --- 配置信息 ---
// 替换为您的实际Client ID和Secret Key
define('CLIENT_ID', 'YOUR_CLIENT_ID');
define('SECRET_KEY', 'YOUR_SECRET_KEY');

$getTokenUrl = 'https://marketplace.walmartapis.com/v3/token';

$client_id = CLIENT_ID;
$secret_key = SECRET_KEY;
$authorization_key = base64_encode($client_id . ":" . $secret_key);

// 为令牌请求生成GUID作为WM_QOS.CORRELATION_ID
$correlation_id_token = generateUuidV4(); 

$tokenHeaders = array(
    'Authorization: Basic ' . $authorization_key,
    'WM_SVC.NAME: Walmart Marketplace',
    'WM_QOS.CORRELATION_ID: ' . $correlation_id_token,
    'Content-Type: application/x-www-form-urlencoded',
    'Accept: application/json' // 明确请求JSON响应
);

$postFields = 'grant_type=client_credentials';

$ch = curl_init(); // 初始化cURL会话

curl_setopt_array($ch, array(
    CURLOPT_URL => $getTokenUrl,
    CURLOPT_RETURNTRANSFER => true, // 将cURL执行的结果以字符串返回，而不是直接输出
    CURLOPT_ENCODING => '',
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30, // 设置合理的超时时间
    CURLOPT_FOLLOWLOCATION => true, // 允许cURL跟随"Location:"头部的重定向
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_POSTFIELDS => $postFields,
    CURLOPT_HTTPHEADER => $tokenHeaders,
));

$tokenResponseRaw = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE); // 获取HTTP响应码

if (curl_errno($ch)) {
    echo 'cURL Error (Token Request): ' . curl_error($ch) . "\n";
    exit;
}

if ($httpCode !== 200) {
    echo "Token API Error (HTTP $httpCode): " . $tokenResponseRaw . "\n";
    exit;
}

$tokenData = json_decode($tokenResponseRaw, true);

$accessToken = '';
if (isset($tokenData['access_token'])) {
    $accessToken = $tokenData['access_token'];
    echo "Access Token obtained successfully: " . $accessToken . "\n";
} else {
    echo "Failed to get access token: " . $tokenResponseRaw . "\n";
    exit;
}

// 此时，$accessToken 变量包含了您后续API请求所需的访问令牌。
// curl_close($ch); // 不关闭，以便在后续请求中重用cURL句柄
?>

<?php
// ... (以上获取访问令牌的代码) ...

// --- Step 2: Access Walmart Returns API ---

$returnsApiUrl = 'https://marketplace.walmartapis.com/v3/returns';
// 您可以根据需要添加查询参数，例如：
// $returnsApiUrl .= '?status=Created&createdStartDate=2023-01-01T00:00:00Z';

// 为退货API请求生成一个新的GUID
$correlation_id_returns = generateUuidV4(); 

$returnsHeaders = array(
    'WM_SEC.ACCESS_TOKEN: ' . $accessToken, // 正确的访问令牌头部
    'WM_QOS.CORRELATION_ID: ' . $correlation_id_returns, // 使用GUID
    'WM_SVC.NAME: Walmart Marketplace',
    'Accept: application/json', // 请求JSON响应
    // 'Cookie' 头部通常不必要，除非API文档特别说明
);

// 重新配置cURL句柄以进行退货API请求
curl_setopt_array($ch, array(
    CURLOPT_URL => $returnsApiUrl,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => '',
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_FOLLOWLOCATION => true,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => 'GET',
    CURLOPT_POSTFIELDS => '', // GET请求通常没有请求体
    CURLOPT_HTTPHEADER => $returnsHeaders,
));

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

if (curl_errno($ch)) {
    echo '