<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Sms;

defined('ABSPATH') || exit;

class SMSSignatureHelper {

    /**
     * 生成签名并发起请求
     *
     * @param string $accessKeyId     AccessKeyId
     * @param string $accessKeySecret AccessKeySecret
     * @param string $domain          API 域名
     * @param array  $params          API 参数
     * @param bool   $https           是否使用 HTTPS
     * @return array|\WP_Error
     */
    public function request(string $accessKeyId, string $accessKeySecret, string $domain, array $params, bool $https = true) {
        $apiParams = array_merge([
            'SignatureMethod'  => 'HMAC-SHA1',
            'SignatureNonce'   => uniqid((string) mt_rand(0, 0xffff), true),
            'SignatureVersion' => '1.0',
            'AccessKeyId'      => $accessKeyId,
            'Timestamp'        => gmdate('Y-m-d\TH:i:s\Z'),
            'Format'           => 'JSON',
        ], $params);

        ksort($apiParams);

        $sortedQueryString = '';
        foreach ($apiParams as $key => $value) {
            $sortedQueryString .= '&' . $this->encode($key) . '=' . $this->encode((string) $value);
        }

        $stringToSign = 'POST&%2F&' . $this->encode(substr($sortedQueryString, 1));
        $sign = base64_encode(hash_hmac('sha1', $stringToSign, $accessKeySecret . '&', true));
        $signature = $this->encode($sign);

        $url = ($https ? 'https' : 'http') . "://{$domain}/";
        $body = "Signature={$signature}{$sortedQueryString}";

        return $this->fetchContent($url, $body);
    }

    /**
     * URL 编码（对齐阿里云规范）
     */
    private function encode(string $str): string {
        $res = rawurlencode($str);
        $res = str_replace('+', '%20', $res);
        $res = str_replace('*', '%2A', $res);
        $res = str_replace('%7E', '~', $res);
        return $res;
    }

    /**
     * 发送 HTTP POST 请求
     *
     * @return array|\WP_Error
     */
    private function fetchContent(string $url, string $body) {
        $response = wp_remote_post($url, [
            'timeout' => 10,
            'headers' => [
                'Content-Type'  => 'application/x-www-form-urlencoded',
                'x-sdk-client'  => 'php/2.0.0',
            ],
            'body'    => $body,
        ]);

        if (is_wp_error($response)) {
            return $response;
        }

        $content = wp_remote_retrieve_body($response);
        $decoded = json_decode($content, true);

        return is_array($decoded) ? $decoded : ['raw' => $content];
    }
}