<?php
/**
 * AKSRT 人机验证（Cloud Captcha）核心。
 *
 * 唯一配置源：option `aksrt_captcha_config`。
 * 闭环契约：
 *   aksrt_get_captcha_config() -> aksrt_is_captcha_enabled_for(scene)
 *   -> aksrt_render_captcha(scene) -> 客户端 AKSRTCaptchaState + token
 *   -> 业务入口 aksrt_require_captcha(scene, $payload) -> proceed/fail。
 *
 * 仅支持云厂商：tencent / aliyun / cloudflare / geetest。
 * 不含本地图形码 / 本地滑块。
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

/**
 * 支持的验证服务商。
 */
function aksrt_captcha_providers(): array {
	return ['tencent', 'aliyun', 'cloudflare', 'geetest'];
}

/**
 * 人机验证场景白名单。
 */
function aksrt_captcha_scenes(): array {
	return [
		'comment'          => __('发表评论', 'aksrt'),
		'login'            => __('用户登录', 'aksrt'),
		'register'         => __('用户注册', 'aksrt'),
		'bind'             => __('绑定第三方', 'aksrt'),
		'bind_phone'       => __('绑定手机', 'aksrt'),
		'lostpassword'     => __('找回密码', 'aksrt'),
		'change_password'  => __('修改密码', 'aksrt'),
		'change_email'     => __('更改邮箱', 'aksrt'),
		'verify_email'     => __('邮箱验证', 'aksrt'),
		'download'         => __('资源下载', 'aksrt'),
		'signin'           => __('每日签到', 'aksrt'),
	];
}

/**
 * 默认配置结构。
 */
function aksrt_captcha_default_config(): array {
	$all_scenes = array_keys(aksrt_captcha_scenes());
	return [
		'enabled'            => false,
		'active_provider'    => '',
		// Positive list: checked scenes require captcha. Default all scenes.
		'enabled_scenarios'  => $all_scenes,
		// Legacy mirror kept for BC consumers / admin summaries.
		'disabled_scenarios' => [],
		'tencent'            => [],
		'aliyun'             => [],
		'cloudflare'         => [],
		'geetest'            => [],
	];
}

/**
 * Sanitize a list of captcha scene keys against the whitelist.
 *
 * @param mixed $raw
 * @return array<int, string>
 */
function aksrt_captcha_sanitize_scene_list($raw): array {
	$list = is_array($raw) ? $raw : [];
	$clean = [];
	foreach ($list as $scene) {
		$scene = sanitize_key((string) $scene);
		if ($scene !== '' && array_key_exists($scene, aksrt_captcha_scenes()) && !in_array($scene, $clean, true)) {
			$clean[] = $scene;
		}
	}
	return array_values($clean);
}

/**
 * 获取人机验证完整配置（规范化，不合并历史脏键）。
 *
 * @return array
 */
function aksrt_get_captcha_config(): array {
	$cfg = get_option('aksrt_captcha_config', []);
	if (!is_array($cfg)) {
		$cfg = [];
	}

	$all_scenes = array_keys(aksrt_captcha_scenes());
	$provider = isset($cfg['active_provider']) ? sanitize_key((string) $cfg['active_provider']) : '';
	if (!in_array($provider, aksrt_captcha_providers(), true)) {
		$provider = '';
	}

	if (array_key_exists('enabled_scenarios', $cfg)) {
		// Explicit positive list (may be empty = no scenes).
		$enabled = aksrt_captcha_sanitize_scene_list($cfg['enabled_scenarios']);
	} else {
		// Legacy: only disabled list stored → all minus disabled.
		$disabled_legacy = aksrt_captcha_sanitize_scene_list($cfg['disabled_scenarios'] ?? []);
		$enabled = array_values(array_diff($all_scenes, $disabled_legacy));
	}
	$disabled = array_values(array_diff($all_scenes, $enabled));

	$result = [
		'enabled'            => !empty($cfg['enabled']),
		'active_provider'    => $provider,
		'enabled_scenarios'  => $enabled,
		'disabled_scenarios' => $disabled,
	];
	foreach (aksrt_captcha_providers() as $p) {
		$result[$p] = isset($cfg[$p]) && is_array($cfg[$p]) ? $cfg[$p] : [];
	}

	return $result;
}

/**
 * 各服务商必填字段。
 */
function aksrt_captcha_required_fields(string $provider): array {
	$map = [
		'tencent'    => ['secret_id', 'secret_key', 'app_id', 'app_secret_key'],
		'aliyun'     => ['region', 'prefix', 'scene_id', 'access_key_id', 'access_key_secret'],
		'cloudflare' => ['site_key', 'secret_key'],
		'geetest'    => ['captcha_id', 'captcha_key'],
	];
	return $map[$provider] ?? [];
}

/**
 * 当前服务商必填凭据是否齐全（避免空 captcha_id 打到第三方 403）。
 */
function aksrt_captcha_provider_is_configured(string $provider, array $pcfg = []): bool {
	if (!in_array($provider, aksrt_captcha_providers(), true)) {
		return false;
	}
	$required = aksrt_captcha_required_fields($provider);
	if (empty($required)) {
		return false;
	}
	foreach ($required as $field) {
		if (!isset($pcfg[$field]) || trim((string) $pcfg[$field]) === '') {
			return false;
		}
	}
	return true;
}

/**
 * 指定场景是否启用人机验证。
 *
 * @param string $scene 见 aksrt_captcha_scenes()
 * @return bool
 */
function aksrt_is_captcha_enabled_for($scene): bool {
	$scene = sanitize_key((string) $scene);
	if (!array_key_exists($scene, aksrt_captcha_scenes())) {
		return false;
	}

	$cfg = aksrt_get_captcha_config();
	if (empty($cfg['enabled']) || $cfg['active_provider'] === '') {
		return false;
	}

	$provider = $cfg['active_provider'];
	$pcfg     = $cfg[$provider] ?? [];
	if (!aksrt_captcha_provider_is_configured($provider, $pcfg)) {
		return false;
	}

	$enabled = isset($cfg['enabled_scenarios']) && is_array($cfg['enabled_scenarios'])
			? $cfg['enabled_scenarios']
			: array_values(array_diff(array_keys(aksrt_captcha_scenes()), (array) ($cfg['disabled_scenarios'] ?? [])));

		return in_array($scene, $enabled, true);
}

/**
 * 业务入口统一调用：未启用放行；启用则校验。
 *
 * @param string $scene   场景
 * @param array  $payload 客户端提交的验证字段
 * @return true|string 成功返回 true，失败返回错误信息字符串
 */
function aksrt_require_captcha(string $scene, array $payload = []) {
	if (!aksrt_is_captcha_enabled_for($scene)) {
		return true;
	}
	return aksrt_verify_captcha($payload);
}

/**
 * 后台摘要：enabled / provider / configured / 场景命中状态。
 */
function aksrt_get_captcha_status_summary(): array {
	$cfg      = aksrt_get_captcha_config();
	$provider = $cfg['active_provider'];
	$scenes   = [];
	foreach (aksrt_captcha_scenes() as $key => $label) {
		$scenes[$key] = aksrt_is_captcha_enabled_for($key);
	}
	return [
		'enabled'    => !empty($cfg['enabled']),
		'provider'   => $provider,
		'configured' => $provider !== '' && aksrt_captcha_provider_is_configured($provider, $cfg[$provider] ?? []),
		'scenes'     => $scenes,
	];
}

// ============================================================
// 客户端真实 IP（穿透 CDN / 代理）
// ============================================================

function aksrt_get_client_ip(): string {
	$keys = ['HTTP_X_FORWARDED_FOR', 'HTTP_X_REAL_IP', 'HTTP_CLIENT_IP'];
	foreach ($keys as $key) {
		if (!empty($_SERVER[$key])) {
			$parts = explode(',', (string) $_SERVER[$key]);
			$ip    = trim($parts[0]);
			if (filter_var($ip, FILTER_VALIDATE_IP)) {
				return $ip;
			}
		}
	}
	return isset($_SERVER['REMOTE_ADDR']) ? (string) $_SERVER['REMOTE_ADDR'] : '0.0.0.0';
}

// ============================================================
// 腾讯云 API 3.0 TC3-HMAC-SHA256 签名
// ============================================================

function aksrt_tencent_tc3_sign($secret_id, $secret_key, $service, $timestamp, $date, $action, $version, $payload): array {
	$content_type        = 'application/json; charset=utf-8';
	$host                = 'captcha.tencentcloudapi.com';
	$payload_hash        = hash('sha256', $payload);
	$canonical_headers   = "content-type:{$content_type}\nhost:{$host}\n";
	$signed_headers      = 'content-type;host';
	$canonical_request   = "POST\n/\n\n{$canonical_headers}\n{$signed_headers}\n{$payload_hash}";
	$credential_scope    = "{$date}/{$service}/tc3_request";
	$string_to_sign      = "TC3-HMAC-SHA256\n{$timestamp}\n{$credential_scope}\n" . hash('sha256', $canonical_request);

	$secret_date    = hash_hmac('sha256', $date, 'TC3' . $secret_key, true);
	$secret_service = hash_hmac('sha256', $service, $secret_date, true);
	$secret_signing = hash_hmac('sha256', 'tc3_request', $secret_service, true);
	$signature      = hash_hmac('sha256', $string_to_sign, $secret_signing);

	$authorization = 'TC3-HMAC-SHA256 '
		. "Credential={$secret_id}/{$credential_scope}, "
		. "SignedHeaders={$signed_headers}, "
		. "Signature={$signature}";

	return [
		'Authorization' => $authorization,
		'Content-Type'  => $content_type,
		'Host'          => $host,
		'X-TC-Action'   => $action,
		'X-TC-Timestamp'=> (string) $timestamp,
		'X-TC-Version'  => $version,
		'X-TC-Region'   => '',
	];
}

/**
 * 阿里云 OpenAPI POP Signature v1.0 (HMAC-SHA1)。
 */
function aksrt_aliyun_afs_sign(array $params, string $secret): string {
	ksort($params);
	$canonicalized = '';
	foreach ($params as $k => $v) {
		$canonicalized .= '&' . rawurlencode((string) $k) . '=' . rawurlencode((string) $v);
	}
	$string_to_sign = 'POST&%2F&' . rawurlencode(substr($canonicalized, 1));
	return base64_encode(hash_hmac('sha1', $string_to_sign, $secret . '&', true));
}

// ============================================================
// 服务端二次校验
// ============================================================

/**
 * 校验客户端提交的人机验证字段。
 *
 * @param array $post_data 客户端字段（captcha_verified + 厂商 token）
 * @return true|string 成功返回 true，失败返回错误信息
 */
function aksrt_verify_captcha($post_data) {
	$cfg = aksrt_get_captcha_config();
	if (empty($cfg['enabled']) || $cfg['active_provider'] === '') {
		return true;
	}

	$provider  = $cfg['active_provider'];
	$pcfg      = $cfg[$provider] ?? [];
	$client_ip = aksrt_get_client_ip();

	// 客户端验证字段（前端写入 captcha_verified=1 表示用户已完成交互）
	if (($post_data['captcha_verified'] ?? '') !== '1') {
		return __('人机验证失败', 'aksrt');
	}

	switch ($provider) {
		case 'tencent':
			$result = aksrt_verify_tencent($pcfg, $post_data, $client_ip);
			break;
		case 'cloudflare':
			$result = aksrt_verify_cloudflare($pcfg, $post_data, $client_ip);
			break;
		case 'geetest':
			$result = aksrt_verify_geetest($pcfg, $post_data);
			break;
		case 'aliyun':
			$result = aksrt_verify_aliyun($pcfg, $post_data);
			break;
		default:
			return true;
	}

	return $result === true ? true : ($result ?: __('人机验证失败', 'aksrt'));
}

/**
 * 腾讯云 Captcha 2.0（DescribeCaptchaResult + TC3-HMAC-SHA256）。
 *
 * @return true|string
 */
function aksrt_verify_tencent(array $pcfg, array $post_data, string $client_ip) {
	$ticket  = (string) ($post_data['tencent_ticket'] ?? '');
	$randstr = (string) ($post_data['tencent_randstr'] ?? '');
	if ($ticket === '' || $randstr === '') {
		return __('缺少验证参数', 'aksrt');
	}
	if (str_starts_with($ticket, 'trerror_')) {
		return __('验证码 SDK 异常，请刷新页面重试（容灾票据）', 'aksrt');
	}

	$secret_id  = (string) ($pcfg['secret_id'] ?? '');
	$secret_key = (string) ($pcfg['secret_key'] ?? '');
	if ($secret_id === '' || $secret_key === '') {
		return __('验证码配置不完整：缺少云 API 密钥 (SecretId/SecretKey)', 'aksrt');
	}

	$timestamp = time();
	$date      = gmdate('Y-m-d', $timestamp);
	$payload   = wp_json_encode([
		'CaptchaType'  => 9,
		'CaptchaAppId' => (int) ($pcfg['app_id'] ?? 0),
		'AppSecretKey' => (string) ($pcfg['app_secret_key'] ?? ''),
		'Ticket'       => $ticket,
		'Randstr'      => $randstr,
		'UserIp'       => $client_ip,
	]);

	$headers = aksrt_tencent_tc3_sign($secret_id, $secret_key, 'captcha', $timestamp, $date, 'DescribeCaptchaResult', '2019-07-22', $payload);

	$curl_headers = [];
	foreach ($headers as $k => $v) {
		$curl_headers[] = "{$k}: {$v}";
	}

	$ch = curl_init('https://captcha.tencentcloudapi.com/');
	curl_setopt_array($ch, [
		CURLOPT_POST           => true,
		CURLOPT_RETURNTRANSFER => true,
		CURLOPT_TIMEOUT        => 10,
		CURLOPT_POSTFIELDS     => $payload,
		CURLOPT_HTTPHEADER     => $curl_headers,
		CURLOPT_SSL_VERIFYPEER => false,
		CURLOPT_FOLLOWLOCATION => false,
	]);
	$response_body = curl_exec($ch);
	$curl_error    = curl_error($ch);
	curl_close($ch);

	if ($curl_error) {
		return '验证码服务请求失败: ' . $curl_error;
	}

	$body = json_decode((string) $response_body, true);
	if (isset($body['Response']['Error'])) {
		$err = $body['Response']['Error'];
		return '腾讯 API 调用失败: ' . ($err['Message'] ?? $err['Code'] ?? '未知错误');
	}

	$resp         = $body['Response'] ?? [];
	$captcha_code = (int) ($resp['CaptchaCode'] ?? 0);
	if ($captcha_code === 1) {
		return true;
	}

	$messages = [
		0   => '验证未通过',
		7   => 'Randstr 不合法',
		8   => 'Ticket 已过期（有效期 5 分钟）',
		9   => 'Ticket 被重复使用',
		15  => 'Ticket 不合法（解密失败）',
		16  => 'CaptchaAppId 与 Ticket 不匹配',
		21  => '票据校验异常（风控拦截）',
		100 => '参数校验失败（AppId/SecretKey/Ticket 不匹配）',
	];
	$msg = $resp['CaptchaMsg'] ?? ($messages[$captcha_code] ?? '未知错误');
	return '腾讯验证失败: ' . $msg . " (CaptchaCode: {$captcha_code})";
}

/**
 * Cloudflare Turnstile siteverify。
 *
 * @return true|string
 */
function aksrt_verify_cloudflare(array $pcfg, array $post_data, string $client_ip) {
	$token = (string) ($post_data['cf_turnstile_response'] ?? '');
	if ($token === '' || strlen($token) < 10) {
		return __('缺少验证参数', 'aksrt');
	}

	$secret = (string) ($pcfg['secret_key'] ?? '');
	$bodies = [
		['secret' => $secret, 'response' => $token],
		['secret' => $secret, 'response' => $token, 'remoteip' => $client_ip],
	];

	$body = [];
	foreach ($bodies as $attempt) {
		$resp = wp_remote_post('https://challenges.cloudflare.com/turnstile/v0/siteverify', [
			'timeout' => 10,
			'body'    => $attempt,
		]);
		if (is_wp_error($resp)) {
			continue;
		}
		$body = json_decode(wp_remote_retrieve_body($resp), true);
		if (!empty($body['success'])) {
			return true;
		}
	}

	$codes = isset($body['error-codes']) && is_array($body['error-codes']) ? implode(', ', $body['error-codes']) : '未知错误';
	return 'Cloudflare 验证失败: ' . $codes;
}

/**
 * 极验 GeeTest v4 validate。
 *
 * @return true|string
 */
function aksrt_verify_geetest(array $pcfg, array $post_data) {
	$lot_number     = (string) ($post_data['geetest_lot_number'] ?? '');
	$captcha_output = (string) ($post_data['geetest_captcha_output'] ?? '');
	$pass_token     = (string) ($post_data['geetest_pass_token'] ?? '');
	$gen_time       = (string) ($post_data['geetest_gen_time'] ?? '');
	if ($lot_number === '' || $captcha_output === '' || $pass_token === '') {
		return __('缺少验证参数', 'aksrt');
	}

	$captcha_key = (string) ($pcfg['captcha_key'] ?? '');
	$sign_token  = hash_hmac('sha256', $lot_number, $captcha_key);

	$resp = wp_remote_post('https://gcaptcha4.geetest.com/validate', [
		'timeout' => 10,
		'body'    => [
			'captcha_id'     => (string) ($pcfg['captcha_id'] ?? ''),
			'lot_number'     => $lot_number,
			'captcha_output' => $captcha_output,
			'pass_token'     => $pass_token,
			'gen_time'       => $gen_time,
			'sign_token'     => $sign_token,
		],
	]);

	if (is_wp_error($resp)) {
		return '验证请求失败: ' . $resp->get_error_message();
	}

	$body = json_decode(wp_remote_retrieve_body($resp), true);
	if (!empty($body['result']) && $body['result'] === 'success') {
		return true;
	}
	$reason = $body['reason'] ?? ($body['msg'] ?? '未知错误');
	return '极验验证失败: ' . $reason;
}

/**
 * 阿里云 CAPTCHA 2.0 V3 (VerifyIntelligentCaptcha)。
 *
 * @return true|string
 */
function aksrt_verify_aliyun(array $pcfg, array $post_data) {
	$captcha_verify_param = (string) ($post_data['aliyun_captcha_verify_param'] ?? '');
	if ($captcha_verify_param === '') {
		return __('缺少验证参数 (captchaVerifyParam)', 'aksrt');
	}

	$region   = (string) ($pcfg['region'] ?? 'cn');
	$endpoint = $region === 'sgp'
		? 'captcha.ap-southeast-1.aliyuncs.com'
		: 'captcha.cn-shanghai.aliyuncs.com';

	$params = [
		'AccessKeyId'        => (string) ($pcfg['access_key_id'] ?? ''),
		'Action'             => 'VerifyIntelligentCaptcha',
		'Format'             => 'JSON',
		'SignatureMethod'    => 'HMAC-SHA1',
		'SignatureVersion'   => '1.0',
		'SignatureNonce'     => uniqid('', true),
		'Timestamp'          => gmdate('Y-m-d\TH:i:s\Z'),
		'Version'            => '2023-03-05',
		'CaptchaVerifyParam' => $captcha_verify_param,
	];
	if (!empty($pcfg['scene_id'])) {
		$params['SceneId'] = (string) $pcfg['scene_id'];
	}
	$params['Signature'] = aksrt_aliyun_afs_sign($params, (string) ($pcfg['access_key_secret'] ?? ''));

	$resp = wp_remote_post('https://' . $endpoint . '/', [
		'timeout' => 10,
		'body'    => $params,
	]);

	if (is_wp_error($resp)) {
		return '验证请求失败: ' . $resp->get_error_message();
	}

	$body = json_decode(wp_remote_retrieve_body($resp), true);
	if (!empty($body['Success'])) {
		$verify_result = $body['Result']['VerifyResult'] ?? false;
		if ($verify_result === true) {
			return true;
		}
		$code_messages = [
			'F001' => '疑似攻击请求，风险策略不通过',
			'F002' => '验证参数为空',
			'F003' => '验证参数格式不合法',
			'F004' => '测试模式配置为不通过',
			'F005' => '场景 ID 不合法',
			'F006' => '场景 ID 与配置不匹配',
			'F008' => '验证数据重复提交',
			'F009' => '检测到虚拟设备环境',
			'F010' => '同 IP 访问频率超限',
			'F011' => '同设备访问频率超限',
			'F012' => 'SceneID 与前端配置不一致',
			'F014' => '无初始化记录或已过期（20 分钟）',
			'F015' => '验证交互不通过',
			'F018' => 'CaptchaVerifyParam 重复使用',
			'F019' => '验证请求超时（90 秒）',
			'F020' => 'CaptchaVerifyParam 与场景 ID 不匹配',
		];
		$verify_code = (string) ($body['Result']['VerifyCode'] ?? '');
		return '阿里云 V3 验证失败: ' . ($code_messages[$verify_code] ?? '未知错误 (' . ($verify_code ?: 'N/A') . ')');
	}

	return '阿里云 V3 验证失败: ' . ($body['Message'] ?? '未知错误');
}

// ============================================================
// 前端渲染（挂载点 + 内联 SDK + AKSRTCaptchaState）
// ============================================================

/**
 * 渲染人机验证挂载点。未启用场景直接返回。
 */
function aksrt_render_captcha($scene = 'comment') {
	$scene = sanitize_key((string) $scene);
	if (!aksrt_is_captcha_enabled_for($scene)) {
		return;
	}

	$cfg      = aksrt_get_captcha_config();
	$provider = $cfg['active_provider'];
	$pcfg     = $cfg[$provider] ?? [];

	if (!aksrt_captcha_provider_is_configured($provider, $pcfg)) {
		if (current_user_can('manage_options')) {
			echo '<div class="aksrt-captcha-misconfig" style="font-size:12px;color:#d03050;margin:8px 0;">';
			echo esc_html(sprintf(
				/* translators: %s: captcha provider key */
				__('人机验证服务商「%s」已启用但凭据未配齐，前台已跳过渲染。请到「功能&权限 → 人机验证」补全配置。', 'aksrt'),
				$provider
			));
			echo '</div>';
		}
		return;
	}

	$uid = 'aksrt-captcha-' . $scene . '-' . wp_unique_id();
	$vid = 'captcha_verified_' . $scene . '_' . wp_unique_id();

	$js_config = [
		'provider' => $provider,
		'scene'    => $scene,
		'uid'      => $uid,
		'vid'      => $vid,
		'tc'       => ['app_id' => (string) ($pcfg['app_id'] ?? '')],
		'cf'       => [
			'site_key' => (string) ($pcfg['site_key'] ?? ''),
			'theme'    => (string) ($pcfg['theme'] ?? 'auto'),
			'size'     => (string) ($pcfg['size'] ?? 'normal'),
		],
		'gt'       => [
			'captcha_id' => trim((string) ($pcfg['captcha_id'] ?? '')),
			'product'    => (string) ($pcfg['product'] ?? 'bind'),
		],
		'al'       => [
			'region'   => (string) ($pcfg['region'] ?? 'cn'),
			'prefix'   => (string) ($pcfg['prefix'] ?? ''),
			'scene_id' => (string) ($pcfg['scene_id'] ?? ''),
		],
	];

	$token_fields = ['cf_turnstile_response', 'tencent_ticket', 'tencent_randstr', 'tencent_sid',
		'geetest_lot_number', 'geetest_captcha_output', 'geetest_pass_token', 'geetest_gen_time',
		'aliyun_captcha_verify_param'];
	$token_fields_json = wp_json_encode($token_fields, JSON_UNESCAPED_UNICODE);
	?>
<div class="aksrt-captcha-wrap" data-provider="<?php echo esc_attr($provider); ?>" data-scene="<?php echo esc_attr($scene); ?>">
	<div id="<?php echo esc_attr($uid); ?>" class="aksrt-captcha-box" style="display:none"></div>
	<input type="hidden" name="captcha_verified" id="<?php echo esc_attr($vid); ?>" value="0">
</div>
<link rel="stylesheet" href="<?php echo esc_url(AKSRT_URI . '/assets/css/shared/captcha.css'); ?>">
<script>(function(){
var C=<?php echo wp_json_encode($js_config, JSON_UNESCAPED_UNICODE); ?>;
var TOKEN_FIELDS=<?php echo $token_fields_json; ?>;
var root=window.AKSRTCaptchaState=window.AKSRTCaptchaState||{loaders:{}, scenes:{}};

function loadScriptOnce(key, src, readyCheck){
	if(typeof readyCheck==='function' && readyCheck()){ return Promise.resolve(); }
	if(root.loaders[key]){ return root.loaders[key]; }
	root.loaders[key]=new Promise(function(resolve, reject){
		var existing=document.querySelector('script[data-aksrt-sdk="'+key+'"]');
		if(existing){
			if(typeof readyCheck==='function' && readyCheck()){ resolve(); return; }
			existing.addEventListener('load', function(){ resolve(); }, {once:true});
			existing.addEventListener('error', function(){ reject(new Error(key+' load failed')); }, {once:true});
			return;
		}
		var script=document.createElement('script');
		script.src=src; script.async=true; script.setAttribute('data-aksrt-sdk', key);
		script.onload=function(){ resolve(); };
		script.onerror=function(){ reject(new Error(key+' load failed')); };
		document.head.appendChild(script);
	});
	return root.loaders[key];
}

var box, hField, form=null;
var verified=false;
var pendingAction=null;
var triggerCaptcha=function(){ showTip('验证码加载中，请稍候', '#e67e22'); };

function findForm(){
	form=box.closest('form');
	if(!form&&C.scene==='comment') form=document.getElementById('commentform');
	if(!form&&(C.scene==='login'||C.scene==='register')){
		form=document.getElementById('aksrt-login-form')
			||document.getElementById('aksrt-modal-login-form')
			||document.getElementById('sign-login-form')
			||document.getElementById('aksrt-phone-login-form')
			||document.getElementById('aksrt-modal-register-form')
			||document.getElementById('sign-register-form')
			||document.getElementById('aksrt-phone-register-form')
			||document.querySelector('.auth-form')
			||document.querySelector('.sign-form');
	}
	if(!form&&C.scene==='bind_phone'){
		form=document.getElementById('aksrt-bind-phone-form')
			||document.querySelector('[data-aksrt-bind-phone-form]')
			||document.querySelector('.auth-form');
	}
	return form;
}

function bindSubmit(){
	if(!form) return;
	form.addEventListener('submit', function(e){
		if(verified || hField.value==='1') return;
		e.preventDefault(); e.stopImmediatePropagation();
		pendingAction=null; triggerCaptcha();
	}, true);
}

function setField(name, value){
	var container = form || box;
	var el=container.querySelector('input[name="'+name+'"]');
	if(!el){ el=document.createElement('input'); el.type='hidden'; el.name=name; container.appendChild(el); }
	el.value=value;
}

function resetVerificationState(){
	verified=false;
	hField.value='0';
	var container = form || box;
	TOKEN_FIELDS.forEach(function(n){
		var f=container.querySelector('input[name="'+n+'"]');
		if(f) f.remove();
	});
	if(C.scene==='download'){
		syncDownloadSiblings(false);
	}
}

function syncDownloadSiblings(passed){
	var myContainer=box.closest('[data-aksrt-download-captcha]');
	if(!myContainer) return;
	document.querySelectorAll('[data-aksrt-download-captcha]').forEach(function(target){
		if(target===myContainer) return;
		var tgtH=target.querySelector('input[name="captcha_verified"]');
		if(tgtH) tgtH.value=passed ? '1' : '0';
		TOKEN_FIELDS.forEach(function(name){
			var f=target.querySelector('input[name="'+name+'"]');
			if(f) f.remove();
			if(passed){
				var srcEl=myContainer.querySelector('input[name="'+name+'"]');
				if(srcEl&&srcEl.value!==''){
					var tgtEl=document.createElement('input'); tgtEl.type='hidden'; tgtEl.name=name; target.appendChild(tgtEl);
					tgtEl.value=srcEl.value;
				}
			}
		});
	});
}

function submitNativeForm(){
	if(!form) return;
	if(form.requestSubmit){ form.requestSubmit(); }
	else { HTMLFormElement.prototype.submit.call(form); }
}

function submitForm(){
	verified=true; hField.value='1';
	if(C.scene==='download') syncDownloadSiblings(true);
	if(typeof pendingAction==='function'){
		finishPending(true); return;
	}
	setTimeout(resetVerificationState, 3000);
	submitNativeForm();
}

function showTip(msg, color){
	var t=box.querySelector('.captcha-tip');
	if(!t){ t=document.createElement('div'); t.className='captcha-tip'; t.style.cssText='font-size:12px;margin-top:4px;text-align:left;'; box.appendChild(t); }
	t.style.color=color||'#e74c3c'; t.textContent=msg;
	setTimeout(function(){ if(t.parentNode) t.remove(); }, 4000);
}

function showLoading(){ box.innerHTML='<div style="text-align:center;padding:20px;color:#9ca3af;">验证码加载中...</div>'; }
function clearLoading(){ box.innerHTML=''; }

function finishPending(ok){
		var action=pendingAction; pendingAction=null;
		if(typeof action==='function'){ action(!!ok); }
	}

	function cancelPending(msg){
		if(msg) showTip(msg, '#e67e22');
		finishPending(false);
	}

	root.scenes[C.scene]={
	verify:function(callback){
		if(verified || hField.value==='1'){
			if(typeof callback==='function') callback(true);
			return;
		}
		pendingAction=(typeof callback==='function')?function(ok){ callback(ok!==false); }:null;
		triggerCaptcha();
	},
	reset:resetVerificationState
};

// ============ 腾讯云 Captcha 2.0 ============
function loadTencent(){
	showLoading();
	loadScriptOnce('tencent', 'https://turing.captcha.qcloud.com/TJCaptcha.js', function(){
		return typeof TencentCaptcha!=='undefined';
	}).then(function(){
		clearLoading();
		var capIns=null;
		triggerCaptcha=function(){
			if(!capIns){
				capIns=new TencentCaptcha(C.tc.app_id, function(res){
					if(res.ret===2){ cancelPending('已取消验证'); return; }
					if(res.ret===0 && res.ticket){
						if(res.ticket.indexOf('trerror_')===0){
							showTip('验证码服务异常，请刷新页面重试', '#e67e22'); return;
						}
						setField('tencent_ticket', res.ticket);
						setField('tencent_randstr', res.randstr);
						setField('tencent_sid', res.sid||'');
						submitForm();
						return;
					}
					if(res.errorCode){
						var errorMap={1001:'验证码组件加载失败',1002:'验证码超时',1006:'验证码配置拉取失败',1008:'验证码页面加载异常',1012:'验证码刷新次数过多',1013:'验证码网络异常'};
						showTip(errorMap[res.errorCode]||('验证码异常(errorCode:'+res.errorCode+')'), '#e74c3c');
					}
				}, {userLanguage:'zh-cn'});
			}
			capIns.show();
		};
	}).catch(function(){ clearLoading(); showTip('验证码组件加载失败，请刷新重试', '#e74c3c'); });
}

// ============ Cloudflare Turnstile（弹窗） ============
function loadCloudflare(){
	var cfWidgetId=null, cfVerifying=false, cfModal=null;

	if(typeof turnstile==='undefined'){
		window['onTurnstileLoad_'+C.uid]=function(){};
		loadScriptOnce('cloudflare', 'https://challenges.cloudflare.com/turnstile/v0/api.js?onload=onTurnstileLoad_'+C.uid+'&render=explicit', function(){
			return typeof turnstile!=='undefined';
		});
	}

	function renderWidget(){
		if(cfWidgetId){ try { turnstile.remove(cfWidgetId); } catch(e) {} cfWidgetId=null; }
		if(typeof turnstile==='undefined'){ setTimeout(renderWidget, 200); return; }
		cfWidgetId=turnstile.render('#modalWidget_'+C.uid, {
			sitekey:C.cf.site_key, theme:C.cf.theme, size:C.cf.size, action:'aksrt-verify',
			callback:function(token){
				if(!cfVerifying) return;
				cfVerifying=false;
				setField('cf_turnstile_response', token);
				closeModal(); submitForm();
			},
			'error-callback':function(){ showTip('验证码失败，请重试', '#e74c3c'); cfWidgetId=null; setTimeout(renderWidget, 500); },
			'expired-callback':function(){ showTip('验证码已过期，请重新验证', '#e67e22'); cfWidgetId=null; setTimeout(renderWidget, 500); }
		});
	}

	function createModal(){
		cfModal=document.createElement('div');
		cfModal.className='aksrt-captcha-modal-overlay';
		cfModal.innerHTML='<div class="aksrt-captcha-modal-backdrop"></div>'+
			'<div class="aksrt-captcha-modal-box"><div class="aksrt-captcha-modal-header">'+
			'<span class="aksrt-captcha-modal-title">人机验证</span>'+
			'<button type="button" class="aksrt-captcha-modal-close">&times;</button></div>'+
			'<div class="aksrt-captcha-modal-body"><p class="aksrt-captcha-modal-hint">请完成验证后继续操作</p>'+
			'<div id="modalWidget_'+C.uid+'" class="aksrt-captcha-modal-widget"></div></div></div>';
		document.body.appendChild(cfModal);
		var cancelFn=function(){ cfVerifying=false; closeModal(); cancelPending('已取消验证'); };
		cfModal.querySelector('.aksrt-captcha-modal-backdrop').addEventListener('click', cancelFn);
		cfModal.querySelector('.aksrt-captcha-modal-close').addEventListener('click', cancelFn);
		renderWidget();
	}

	function closeModal(){
		if(cfWidgetId){ try { turnstile.remove(cfWidgetId); } catch(e) {} cfWidgetId=null; }
		if(cfModal && cfModal.parentNode){ cfModal.parentNode.removeChild(cfModal); }
		cfModal=null;
	}

	triggerCaptcha=function(){
		if(cfVerifying){ showTip('验证码进行中，请稍候', '#e67e22'); return; }
		cfVerifying=true; createModal();
	};
}

// ============ 极验 GeeTest v4 ============
function loadGeetest(){
	showLoading();
	var captchaId=(C.gt && C.gt.captcha_id) ? String(C.gt.captcha_id).trim() : '';
	var product=(C.gt && C.gt.product) ? String(C.gt.product) : 'bind';
	if(!captchaId){
		clearLoading();
		showTip('极验 Captcha ID 未配置，请到后台「功能&权限 → 人机验证」填写并保存', '#e74c3c');
		return;
	}
	function render(){
		clearLoading();
		initGeetest4({captchaId:captchaId, product:product, hideSuccess:true}, function(capIns){
			window['__gt_'+C.uid]=capIns;
			function onSuccess(){
				var result=capIns.getValidate();
				if(!result) return;
				setField('geetest_lot_number', result.lot_number);
				setField('geetest_captcha_output', result.captcha_output);
				setField('geetest_pass_token', result.pass_token);
				setField('geetest_gen_time', result.gen_time);
				submitForm();
			}
			if(product==='bind' || product==='popup'){
				capIns.onReady(function(){}).onSuccess(onSuccess).onClose(function(){});
			}else{
				capIns.appendTo('#'+C.uid).onSuccess(onSuccess).onClose(function(){});
			}
		});
		triggerCaptcha=function(){
			var instance=window['__gt_'+C.uid];
			if(!instance){ showTip('验证码加载中，请稍候再试', '#e67e22'); return; }
			if(product==='bind' || product==='popup'){ instance.showCaptcha(); return; }
			showTip('请先完成人机验证', '#e67e22');
		};
	}
	if(typeof initGeetest4==='undefined'){
		loadScriptOnce('geetest', 'https://static.geetest.com/v4/gt4.js', function(){
			return typeof initGeetest4!=='undefined';
		}).then(render).catch(function(){ clearLoading(); showTip('极验组件加载失败', '#e74c3c'); });
		return;
	}
	render();
}

// ============ 阿里云 CAPTCHA 2.0 V3 ============
function loadAliyun(){
	showLoading();
	window.AliyunCaptchaConfig={ region:C.al.region||'cn', prefix:C.al.prefix };

	function render(){
		clearLoading();
		var captchaIns=null;
		var btn=box.closest('form') ? box.closest('form').querySelector('button[type="submit"], input[type="submit"]') : null;
		window.initAliyunCaptcha({
			SceneId:C.al.scene_id, mode:'popup', element:'#'+C.uid,
			button:btn ? '#' + (btn.id || (function(){ btn.id='aksrt-captcha-btn-'+C.scene; return btn.id; })()) : null,
			success:function(captchaVerifyParam){
				setField('aliyun_captcha_verify_param', captchaVerifyParam);
				submitForm();
			},
			fail:function(result){ showTip('验证码失败: ' + (result || '请重试'), '#e74c3c'); captchaIns=null; },
			getInstance:function(instance){ captchaIns=instance; },
			slideStyle:{width:360, height:40}, language:'cn'
		});
		triggerCaptcha=function(){
			if(captchaIns && captchaIns.show){ captchaIns.show(); return; }
			showTip('验证码组件加载中，请稍候再试', '#e67e22');
		};
	}

	if(typeof window.initAliyunCaptcha==='undefined'){
		loadScriptOnce('aliyun', 'https://o.alicdn.com/captcha-frontend/aliyunCaptcha/AliyunCaptcha.js', function(){
			return typeof window.initAliyunCaptcha!=='undefined';
		}).then(render).catch(function(){ clearLoading(); showTip('验证码组件加载失败，请刷新重试', '#e74c3c'); });
		return;
	}
	render();
}

function loadProvider(){
	switch(C.provider){
		case 'tencent': loadTencent(); break;
		case 'cloudflare': loadCloudflare(); break;
		case 'geetest': loadGeetest(); break;
		case 'aliyun': loadAliyun(); break;
	}
}

function init(){
	box=document.getElementById(C.uid);
	hField=document.getElementById(C.vid);
	if(!box||!hField) return;

	var tries=0;
	(function retryFind(){
		findForm();
		if(!form && ++tries < 10){ setTimeout(retryFind, 150); }
		else {
			if(form) bindSubmit();
			setTimeout(loadProvider, 0);
		}
	})();
}

if(document.readyState==='loading'){ document.addEventListener('DOMContentLoaded', init); }
else { setTimeout(init, 50); }
})();</script>
	<?php
}