<?php
require_once 'config.php';
require_once 'vendor/autoload.php'; // PHPMailer

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

// ===== 用户相关函数 =====

/**
 * 用户注册
 */
function registerUser($username, $email, $password, $inviteCode = null) {
    $pdo = getDB();
    
    // 检查用户名是否已存在
    $stmt = $pdo->prepare("SELECT id FROM users WHERE username = ?");
    $stmt->execute([$username]);
    if ($stmt->fetch()) {
        return ['success' => false, 'message' => '用户名已被使用'];
    }
    
    // 检查邮箱是否已存在
    $stmt = $pdo->prepare("SELECT id FROM users WHERE email = ?");
    $stmt->execute([$email]);
    if ($stmt->fetch()) {
        return ['success' => false, 'message' => '邮箱已被注册'];
    }
    
    $pdo->beginTransaction();
    try {
        $hashedPassword = password_hash($password, PASSWORD_DEFAULT);
        $verificationToken = bin2hex(random_bytes(32));
        $inviteCodeGen = strtoupper(substr(bin2hex(random_bytes(6)), 0, 8));
        
        // 处理邀请
        $invitedBy = null;
        if ($inviteCode) {
            $stmt = $pdo->prepare("SELECT id FROM users WHERE invite_code = ?");
            $stmt->execute([$inviteCode]);
            $inviter = $stmt->fetch();
            if ($inviter) {
                $invitedBy = $inviter['id'];
            }
        }
        
        // 创建用户
        $stmt = $pdo->prepare("INSERT INTO users (username, email, password, invite_code, invited_by, verification_token) VALUES (?, ?, ?, ?, ?, ?)");
        $stmt->execute([$username, $email, $hashedPassword, $inviteCodeGen, $invitedBy, $verificationToken]);
        $userId = $pdo->lastInsertId();
        
        // 如果是邀请注册，给邀请人加积分
        if ($invitedBy) {
            // 增加邀请人积分
            $stmt = $pdo->prepare("UPDATE users SET credits = credits + ? WHERE id = ?");
            $stmt->execute([INVITE_CREDIT, $invitedBy]);
            
            // 记录邀请日志
            $stmt = $pdo->prepare("INSERT INTO invite_logs (inviter_id, invitee_id, credits_earned) VALUES (?, ?, ?)");
            $stmt->execute([$invitedBy, $userId, INVITE_CREDIT]);
        }
        
        $pdo->commit();
        
        // 发送验证邮件
        sendVerificationEmail($email, $username, $verificationToken);
        
        return ['success' => true, 'message' => '注册成功！请查收验证邮件'];
        
    } catch (Exception $e) {
        $pdo->rollBack();
        return ['success' => false, 'message' => '注册失败: ' . $e->getMessage()];
    }
}

/**
 * 用户登录
 */
function loginUser($username, $password) {
    $pdo = getDB();
    
    $stmt = $pdo->prepare("SELECT * FROM users WHERE username = ? OR email = ?");
    $stmt->execute([$username, $username]);
    $user = $stmt->fetch();
    
    if (!$user) {
        return ['success' => false, 'message' => '用户不存在'];
    }
    
    if (!$user['is_verified']) {
        return ['success' => false, 'message' => '请先验证邮箱'];
    }
    
    if (!password_verify($password, $user['password'])) {
        return ['success' => false, 'message' => '密码错误'];
    }
    
    $_SESSION['user_id'] = $user['id'];
    $_SESSION['username'] = $user['username'];
    $_SESSION['is_admin'] = $user['is_admin'];
    
    return ['success' => true, 'message' => '登录成功'];
}

/**
 * 发送验证邮件（修复乱码问题）
 */
function sendVerificationEmail($email, $username, $token) {
    $mail = new PHPMailer(true);
    
    try {
        $mail->isSMTP();
        $mail->Host = SMTP_HOST;
        $mail->SMTPAuth = true;
        $mail->Username = SMTP_USERNAME;
        $mail->Password = SMTP_PASSWORD;
        $mail->SMTPSecure = SMTP_SECURE;
        $mail->Port = SMTP_PORT;
        
        // 设置字符编码 - 解决乱码问题
        $mail->CharSet = 'UTF-8';
        $mail->Encoding = 'base64';
        
        $mail->setFrom(SMTP_FROM_EMAIL, SMTP_FROM_NAME);
        $mail->addAddress($email, $username);
        $mail->isHTML(true);
        
        $verifyLink = SITE_URL . "/verify.php?token=" . $token;
        $mail->Subject = '验证邮箱 - ' . SITE_NAME;
        
        // 邮件正文 - 使用完整的HTML模板
        $mail->Body = '
        <!DOCTYPE html>
        <html>
        <head>
            <meta charset="UTF-8">
            <meta name="viewport" content="width=device-width, initial-scale=1.0">
            <title>邮箱验证</title>
            <style>
            	@import url("https://cdn.jsdmirror.com/gh/willow-god/Sharding-fonts/Yozai-Medium/result.min.css");
                body { font-family: "Yozai Medium"; background: #f6f8fa; padding: 40px 20px; }
                .container { max-width: 560px; margin: 0 auto; background: #ffffff; border-radius: 12px; padding: 40px; box-shadow: 0 8px 32px rgba(0,0,0,0.08); }
                .header { text-align: center; margin-bottom: 30px; }
                .header h1 { color: #24292f; font-size: 24px; margin: 0; }
                .header .sub { color: #57606a; font-size: 14px; }
                .content { color: #24292f; line-height: 1.8; }
                .btn { display: block; padding: 12px 32px; background: #0969da; color: #ffffff !important; text-decoration: none; border-radius: 6px; font-weight: 600; margin: 20px 0; }
                .btn:hover { background: #0550ae; }
                .footer { margin-top: 30px; padding-top: 20px; border-top: 1px solid #d0d7de; font-size: 12px; color: #57606a; text-align: center; }
                .link-box { background: #f6f8fa; padding: 12px 16px; border-radius: 6px; word-break: break-all; font-size: 13px; color: #57606a; border: 1px solid #d0d7de; }
                .highlight { color: #0969da; font-weight: 600; }
            </style>
        </head>
        <body>
            <div class="container">
                <div class="header">
                    <h1>📧 ' . SITE_NAME . '</h1>
                    <p class="sub">验证您的邮箱地址</p>
                </div>
                <div class="content">
                    <p>您好，<strong>' . htmlspecialchars($username) . '</strong>：</p>
                    <p>感谢您注册 <strong>' . SITE_NAME . '</strong>！请点击下方按钮验证您的邮箱地址：</p>
                    <p style="text-align: center;">
                        <a href="' . $verifyLink . '" class="btn">✅ 验证邮箱</a>
                    </p>
                    <p style="color: #57606a; font-size: 14px;">如果按钮无法点击，请复制以下链接到浏览器打开：</p>
                    <div class="link-box">' . $verifyLink . '</div>
                    <p style="margin-top: 20px; font-size: 14px; color: #57606a;">
                        ⏰ 此链接 <span class="highlight">24 小时</span> 内有效。<br>
                        🔒 如果您没有注册 ' . SITE_NAME . '，请忽略并删除此邮件。
                    </p>
                </div>
                <div class="footer">
                    <p>' . SITE_NAME . ' · 安全可靠 · 免费二级域名分发</p>
                    <p style="margin-top: 4px;">© ' . date('Y') . ' ' . SITE_NAME . ' · 由 ❤️ 驱动</p>
                </div>
            </div>
        </body>
        </html>
        ';
        
        $mail->AltBody = "欢迎注册 " . SITE_NAME . "！\n\n" .
                         "您好，" . $username . "：\n\n" .
                         "请访问以下链接验证您的邮箱地址：\n" .
                         $verifyLink . "\n\n" .
                         "此链接 24 小时内有效。\n\n" .
                         "如果您没有注册 " . SITE_NAME . "，请忽略并删除此邮件。";
        
        $mail->send();
        return true;
        
    } catch (Exception $e) {
        error_log("邮件发送失败: " . $e->getMessage());
        return false;
    }
}

/**
 * 验证邮箱
 */
function verifyEmail($token) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT id, username, email FROM users WHERE verification_token = ? AND is_verified = 0");
    $stmt->execute([$token]);
    $user = $stmt->fetch();
    
    if (!$user) {
        // 检查token是否已被使用（已验证）
        $stmt = $pdo->prepare("SELECT id, username FROM users WHERE verification_token = ? AND is_verified = 1");
        $stmt->execute([$token]);
        if ($stmt->fetch()) {
            return ['success' => false, 'message' => '此链接已被使用，请直接登录。'];
        }
        return ['success' => false, 'message' => '无效的验证链接，请检查是否正确复制。'];
    }
    
    // 更新用户状态
    $stmt = $pdo->prepare("UPDATE users SET is_verified = 1, verification_token = NULL WHERE id = ?");
    $stmt->execute([$user['id']]);
    
    return ['success' => true, 'message' => '邮箱验证成功！'];
}

// ===== 积分相关函数 =====

/**
 * 获取用户积分
 */
function getUserCredits($userId) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT credits FROM users WHERE id = ?");
    $stmt->execute([$userId]);
    $result = $stmt->fetch();
    return $result ? $result['credits'] : 0;
}

/**
 * 扣减积分
 */
function deductCredits($userId, $amount) {
    $pdo = getDB();
    
    // 检查积分是否足够
    $stmt = $pdo->prepare("SELECT credits FROM users WHERE id = ?");
    $stmt->execute([$userId]);
    $user = $stmt->fetch();
    
    if (!$user || $user['credits'] < $amount) {
        return ['success' => false, 'message' => '剩余的积分不足。'];
    }
    
    $stmt = $pdo->prepare("UPDATE users SET credits = credits - ? WHERE id = ?");
    $stmt->execute([$amount, $userId]);
    
    return ['success' => true, 'message' => '扣减成功！'];
}

/**
 * 添加积分
 */
function addCredits($userId, $amount, $reason = '') {
    $pdo = getDB();
    $stmt = $pdo->prepare("UPDATE users SET credits = credits + ? WHERE id = ?");
    $stmt->execute([$amount, $userId]);
    return ['success' => true];
}

// ===== 签到相关函数 =====

/**
 * 签到
 */
function signIn($userId) {
    $pdo = getDB();
    $today = date('Y-m-d');
    
    // 检查今天是否已签到
    $stmt = $pdo->prepare("SELECT id FROM sign_in_logs WHERE user_id = ? AND sign_in_date = ?");
    $stmt->execute([$userId, $today]);
    if ($stmt->fetch()) {
        return ['success' => false, 'message' => '今日已经签到过了。'];
    }
    
    $pdo->beginTransaction();
    try {
        // 记录签到
        $stmt = $pdo->prepare("INSERT INTO sign_in_logs (user_id, sign_in_date, credits_earned) VALUES (?, ?, ?)");
        $stmt->execute([$userId, $today, SIGN_IN_CREDIT]);
        
        // 增加积分
        $stmt = $pdo->prepare("UPDATE users SET credits = credits + ? WHERE id = ?");
        $stmt->execute([SIGN_IN_CREDIT, $userId]);
        
        $pdo->commit();
        return ['success' => true, 'message' => '签到成功！获得 ' . SIGN_IN_CREDIT . ' 积分', 'credits' => SIGN_IN_CREDIT];
        
    } catch (Exception $e) {
        $pdo->rollBack();
        return ['success' => false, 'message' => '签到失败: ' . $e->getMessage()];
    }
}

/**
 * 检查今天是否已签到
 */
function hasSignedInToday($userId) {
    $pdo = getDB();
    $today = date('Y-m-d');
    $stmt = $pdo->prepare("SELECT id FROM sign_in_logs WHERE user_id = ? AND sign_in_date = ?");
    $stmt->execute([$userId, $today]);
    return (bool)$stmt->fetch();
}

/**
 * 获取签到统计
 */
function getSignInStats($userId) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT COUNT(*) as total, SUM(credits_earned) as total_credits FROM sign_in_logs WHERE user_id = ?");
    $stmt->execute([$userId]);
    return $stmt->fetch();
}

// ===== 域名相关函数 =====

/**
 * 获取用户域名数量
 */
function getUserDomainCount($userId) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT COUNT(*) as count FROM domains WHERE user_id = ? AND status = 1");
    $stmt->execute([$userId]);
    $result = $stmt->fetch();
    return $result ? $result['count'] : 0;
}

/**
 * 检查用户是否可以添加域名
 */
function canAddDomain($userId) {
    $count = getUserDomainCount($userId);
    if ($count >= MAX_DOMAINS_PER_USER) {
        return ['success' => false, 'message' => '您的域名数量已达到最大域名数量限制 (' . MAX_DOMAINS_PER_USER . '个)。'];
    }
    
    $credits = getUserCredits($userId);
    if ($credits < CREDIT_PER_DOMAIN) {
        return ['success' => false, 'message' => '积分不足，需要 ' . CREDIT_PER_DOMAIN . ' 积分'];
    }
    
    return ['success' => true];
}

/**
 * 验证子域名是否合法
 */
function validateSubdomain($subdomain) {
    // 不能为空
    if (empty($subdomain)) {
        return ['success' => false, 'message' => '子域名不能为空。'];
    }
    
    // 长度至少3个字符
    if (strlen($subdomain) < 3) {
        return ['success' => false, 'message' => '子域名长度至少 3 个字符。'];
    }
    
    // 不能超过 20 个字符
    if (strlen($subdomain) > 20) {
        return ['success' => false, 'message' => '子域名长度不能超过 20 个字符。'];
    }
    
    // 只能包含小写字母、数字和连字符
    if (!preg_match('/^[a-z0-9\-]+$/', $subdomain)) {
        return ['success' => false, 'message' => '子域名只能包含小写字母、数字和连字符。'];
    }
    
    // 不能以连字符开头或结尾
    if (preg_match('/^-|-$/', $subdomain)) {
        return ['success' => false, 'message' => '子域名不能以连字符开头或结尾。'];
    }
    
    // 不能包含连续的连字符
    if (strpos($subdomain, '--') !== false) {
        return ['success' => false, 'message' => '子域名不能包含连续的连字符。'];
    }
    
    // 不能是保留关键字
    $reserved = ['www', 'mail', 'ftp', 'smtp', 'pop3', 'imap', 'admin', 'root', 'test', 'demo', 'api', 'dev', 'prod', 'stage', 'local', 'git', 'store', 'assets', 'image', 'bbs', 'help', 'forum'];
    if (in_array(strtolower($subdomain), $reserved)) {
        return ['success' => false, 'message' => '该子域名前缀已被禁用，请使用其他前缀。'];
    }
    
    return ['success' => true];
}

/**
 * 验证记录值格式
 */
function validateRecordValue($type, $value) {
    $type = strtoupper($type);
    
    switch ($type) {
        case 'A':
            if (!filter_var($value, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
                return ['success' => false, 'message' => 'A 记录需要有效的 IPv4 地址。'];
            }
            break;
            
        case 'AAAA':
            if (!filter_var($value, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
                return ['success' => false, 'message' => 'AAAA 记录需要有效的 IPv6 地址。'];
            }
            break;
            
        case 'CNAME':
            if (!preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/i', $value)) {
                return ['success' => false, 'message' => 'CNAME 记录需要有效的域名。'];
            }
            break;
            
        case 'MX':
            if (!preg_match('/^\d+\s+([a-z0-9\-]+\.)+[a-z]{2,}$/i', $value)) {
                return ['success' => false, 'message' => 'MX 记录格式: 优先级 域名 (10 mail.example.com)。'];
            }
            break;
            
        case 'NS':
            if (!preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/i', $value)) {
                return ['success' => false, 'message' => 'NS 记录需要有效的域名。'];
            }
            break;
            
        case 'TXT':
            if (strlen($value) > 255) {
                return ['success' => false, 'message' => 'TXT 记录值不能超过 255 个字符。'];
            }
            break;
            
        case 'SRV':
            // SRV记录格式: 优先级 权重 端口 目标域名
            $parts = preg_split('/\s+/', trim($value));
            if (count($parts) != 4) {
                return ['success' => false, 'message' => 'SRV 记录格式: 优先级 权重 端口 目标域名 (10 5 5060 sip.example.com)。'];
            }
            
            $priority = intval($parts[0]);
            $weight = intval($parts[1]);
            $port = intval($parts[2]);
            $target = strtolower(trim($parts[3]));
            
            if ($priority < 0 || $priority > 65535) {
                return ['success' => false, 'message' => '优先级必须是 0-65535 之间的数字。'];
            }
            if ($weight < 0 || $weight > 65535) {
                return ['success' => false, 'message' => '权重必须是 0-65535 之间的数字。'];
            }
            if ($port < 0 || $port > 65535) {
                return ['success' => false, 'message' => '端口必须是 0-65535 之间的数字。'];
            }
            if ($target !== '.' && !preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/', $target)) {
                return ['success' => false, 'message' => '无效的目标域名，请输入有效的域名或用 . 表示空。'];
            }
            break;
            
        default:
            return ['success' => false, 'message' => '不支持的记录类型。'];
    }
    
    return ['success' => true];
}

/**
 * 获取记录类型列表
 */
function getRecordTypes() {
    return [
        'A' => 'IPv4 地址',
        'AAAA' => 'IPv6 地址',
        'CNAME' => '域名别名',
        'MX' => '邮件交换 (优先级 域名)',
        'NS' => '域名服务器',
        'TXT' => '文本记录',
        'SRV' => '服务定位 (优先级 权重 端口 目标)'
    ];
}

/**
 * 获取记录类型的示例值
 */
function getRecordTypeExample($type) {
    $examples = [
        'A' => '192.168.1.1',
        'AAAA' => '2001:db8::1',
        'CNAME' => 'example.com',
        'MX' => '10 mail.example.com',
        'NS' => 'ns1.example.com',
        'TXT' => 'v=spf1 include:example.com ~all',
        'SRV' => '10 5 5060 sip.example.com'
    ];
    return $examples[$type] ?? '';
}

/**
 * 获取记录类型的格式说明
 */
function getRecordTypeHint($type) {
    $hints = [
        'A' => 'IPv4 地址，例如: 192.168.1.1',
        'AAAA' => 'IPv6 地址，例如: 2001:db8::1',
        'CNAME' => '目标域名，例如: example.com',
        'MX' => '格式: 优先级 域名，例如: 10 mail.example.com',
        'NS' => '域名服务器，例如: ns1.example.com',
        'TXT' => '任意文本，例如: v=spf1 include:example.com ~all',
        'SRV' => '格式: 优先级 权重 端口 目标域名，例如: 10 5 5060 sip.example.com'
    ];
    return $hints[$type] ?? '';
}

/**
 * 添加域名（扣除积分）
 */
function addDomain($userId, $mainDomain, $subdomain, $type, $value) {
    // 检查权限
    $canAdd = canAddDomain($userId);
    if (!$canAdd['success']) {
        return $canAdd;
    }
    
    // 验证子域名
    $subdomainValidation = validateSubdomain($subdomain);
    if (!$subdomainValidation['success']) {
        return $subdomainValidation;
    }
    
    // 验证记录值
    $valueValidation = validateRecordValue($type, $value);
    if (!$valueValidation['success']) {
        return $valueValidation;
    }
    
    // 检查主域名是否支持
    $mainDomains = getMainDomains();
    if (!in_array($mainDomain, $mainDomains)) {
        return ['success' => false, 'message' => '不支持的主域名。'];
    }
    
    $pdo = getDB();
    
    // 检查数据库中是否已存在
    $stmt = $pdo->prepare("SELECT id FROM domains WHERE main_domain = ? AND subdomain = ? AND status = 1");
    $stmt->execute([$mainDomain, $subdomain]);
    if ($stmt->fetch()) {
        return ['success' => false, 'message' => '该域名已存在。'];
    }
    
    $pdo->beginTransaction();
    
    try {
        // 先尝试添加到 Cloudflare
        $cfResult = addCloudflareRecord($mainDomain, $subdomain, $type, $value);
        if (!$cfResult['success']) {
            return ['success' => false, 'message' => '添加失败: ' . $cfResult['message']];
        }
        
        // 扣减积分
        $stmt = $pdo->prepare("UPDATE users SET credits = credits - ? WHERE id = ? AND credits >= ?");
        $stmt->execute([CREDIT_PER_DOMAIN, $userId, CREDIT_PER_DOMAIN]);
        if ($stmt->rowCount() === 0) {
            throw new Exception('积分不足');
        }
        
        // 添加域名到数据库
        $stmt = $pdo->prepare("INSERT INTO domains (user_id, main_domain, subdomain, record_type, record_value) VALUES (?, ?, ?, ?, ?)");
        $stmt->execute([$userId, $mainDomain, $subdomain, $type, $value]);
        
        $pdo->commit();
        return ['success' => true, 'message' => '域名添加成功！消耗 ' . CREDIT_PER_DOMAIN . ' 积分'];
        
    } catch (Exception $e) {
        $pdo->rollBack();
        // 如果数据库失败，尝试删除 Cloudflare 记录
        deleteCloudflareRecord($mainDomain, $subdomain);
        return ['success' => false, 'message' => '添加失败: ' . $e->getMessage()];
    }
}

/**
 * 获取用户的域名列表
 */
function getUserDomains($userId) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT * FROM domains WHERE user_id = ? AND status = 1 ORDER BY created_at DESC");
    $stmt->execute([$userId]);
    return $stmt->fetchAll();
}

/**
 * 删除域名
 */
function deleteDomain($userId, $domainId) {
    $pdo = getDB();
    
    // 检查域名是否属于该用户
    $stmt = $pdo->prepare("SELECT main_domain, subdomain FROM domains WHERE id = ? AND user_id = ? AND status = 1");
    $stmt->execute([$domainId, $userId]);
    $domain = $stmt->fetch();
    
    if (!$domain) {
        return ['success' => false, 'message' => '该域名不存在。'];
    }
    
    // 从 Cloudflare 删除
    deleteCloudflareRecord($domain['main_domain'], $domain['subdomain']);
    
    // 软删除
    $stmt = $pdo->prepare("UPDATE domains SET status = 0 WHERE id = ?");
    $stmt->execute([$domainId]);
    
    return ['success' => true, 'message' => '域名删除成功。'];
}

// ===== Cloudflare API函数 =====

/**
 * 获取域名配置
 */
function getDomainConfig($mainDomain) {
    global $DOMAINS_CONFIG;
    return $DOMAINS_CONFIG[$mainDomain] ?? null;
}

/**
 * 添加Cloudflare记录（最终修复SRV - 使用正确的字段名）
 */
function addCloudflareRecord($mainDomain, $subdomain, $type, $value) {
    $config = getDomainConfig($mainDomain);
    if (!$config) {
        error_log("Cloudflare 错误: 未找到域名配置 - {$mainDomain}");
        return ['success' => false, 'message' => '未找到域名配置'];
    }
    
    $fullDomain = strtolower($subdomain) . '.' . strtolower($mainDomain);
    $type = strtoupper($type);
    
    // 检查记录是否已存在
    $ch = curl_init('https://api.cloudflare.com/client/v4/zones/' . $config['zone_id'] . '/dns_records?name=' . urlencode($fullDomain) . '&type=' . $type);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $config['api_token']
    ]);
    curl_setopt($ch, CURLOPT_TIMEOUT, 10);
    
    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    
    if ($httpCode === 200) {
        $result = json_decode($response, true);
        if ($result && $result['success'] && !empty($result['result'])) {
            error_log("Cloudflare 记录已存在 - {$fullDomain}");
            return ['success' => false, 'message' => '该记录已存在。'];
        }
    }
    
    // 构建请求数据 - 基础字段
    $data = [
        'type' => $type,
        'name' => $fullDomain,
        'ttl' => 300,
        'proxied' => false  // 必须明确设置为 false
    ];
    
    // 根据记录类型处理值
    switch ($type) {
        case 'A':
            if (!filter_var($value, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
                return ['success' => false, 'message' => '无效的 IPv4 地址。'];
            }
            $data['content'] = $value;
            break;
            
        case 'AAAA':
            if (!filter_var($value, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
                return ['success' => false, 'message' => '无效的 IPv6 地址。'];
            }
            $data['content'] = $value;
            break;
            
        case 'CNAME':
            $value = strtolower(trim($value));
            if (!preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/', $value)) {
                return ['success' => false, 'message' => '无效的域名格式。'];
            }
            $data['content'] = $value;
            break;
            
        case 'MX':
            $parts = preg_split('/\s+/', trim($value));
            if (count($parts) != 2) {
                return ['success' => false, 'message' => 'MX 记录格式: 优先级 域名 (例如: 10 mail.example.com)。'];
            }
            if (!is_numeric($parts[0]) || intval($parts[0]) < 0 || intval($parts[0]) > 65535) {
                return ['success' => false, 'message' => '优先级必须是 0-65535 之间的数字。'];
            }
            $domain = strtolower(trim($parts[1]));
            if (!preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/', $domain)) {
                return ['success' => false, 'message' => '无效的邮件服务器域名。'];
            }
            $data['priority'] = intval($parts[0]);
            $data['content'] = $domain;
            break;
            
        case 'NS':
            $value = strtolower(trim($value));
            if (!preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/', $value)) {
                return ['success' => false, 'message' => '无效的域名服务器地址。'];
            }
            $data['content'] = $value;
            break;
            
        case 'TXT':
            if (strlen($value) > 255) {
                return ['success' => false, 'message' => 'TXT 记录值不能超过 255 字符。'];
            }
            $data['content'] = $value;
            break;
            
        case 'SRV':
            // ===== SRV记录特殊处理 =====
            $parts = preg_split('/\s+/', trim($value));
            if (count($parts) != 4) {
                return ['success' => false, 'message' => 'SRV 记录格式: 优先级 权重 端口 目标域名 (例如: 10 5 5060 sip.example.com)'];
            }
            
            $priority = intval($parts[0]);
            $weight = intval($parts[1]);
            $port = intval($parts[2]);
            $target = strtolower(trim($parts[3]));
            
            // 验证数值范围
            if ($priority < 0 || $priority > 65535) {
                return ['success' => false, 'message' => '优先级必须是 0-65535 之间的数字。'];
            }
            if ($weight < 0 || $weight > 65535) {
                return ['success' => false, 'message' => '权重必须是 0-65535 之间的数字。'];
            }
            if ($port < 0 || $port > 65535) {
                return ['success' => false, 'message' => '端口必须是 0-65535 之间的数字。'];
            }
            
            // 验证目标域名
            if ($target !== '.' && !preg_match('/^([a-z0-9\-]+\.)+[a-z]{2,}$/', $target)) {
                return ['success' => false, 'message' => '无效的目标域名，请输入有效的域名或用 . 表示空。'];
            }
            
            // ===== 重要：SRV 记录使用不同的字段名 =====
            // Cloudflare SRV API 要求使用这些字段名：
            // - priority, weight, port, target (不是 content!)
            $data['priority'] = (int)$priority;
            $data['weight'] = (int)$weight;
            $data['port'] = (int)$port;
            $data['target'] = (string)$target;  // 关键：使用 target 而不是 content
            $data['proxied'] = false;
            
            error_log("SRV 数据: priority={$priority}, weight={$weight}, port={$port}, target={$target}");
            break;
            
        default:
            return ['success' => false, 'message' => '不支持的记录类型'];
    }
    
    // 记录请求数据用于调试
    error_log("Cloudflare 请求数据: " . json_encode($data));
    
    $ch = curl_init('https://api.cloudflare.com/client/v4/zones/' . $config['zone_id'] . '/dns_records');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $config['api_token']
    ]);
    curl_setopt($ch, CURLOPT_TIMEOUT, 30);
    
    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    $curlError = curl_error($ch);
    curl_close($ch);
    
    // 记录响应
    error_log("Cloudflare 响应: HTTP {$httpCode}");
    error_log("Cloudflare 响应内容: " . $response);
    
    if ($curlError) {
        error_log("Cloudflare CURL 错误: " . $curlError);
        return ['success' => false, 'message' => 'CURL 错误: ' . $curlError];
    }
    
    if ($httpCode === 200) {
        $result = json_decode($response, true);
        if ($result && $result['success']) {
            error_log("Cloudflare 添加成功: {$fullDomain}");
            return ['success' => true, 'message' => '添加成功'];
        } else {
            $errorMsg = '未知错误';
            if (isset($result['errors']) && !empty($result['errors'])) {
                $errorMsg = $result['errors'][0]['message'] ?? 'API错误';
                if (isset($result['errors'][0]['error_chain'])) {
                    foreach ($result['errors'][0]['error_chain'] as $chain) {
                        if (isset($chain['message'])) {
                            $errorMsg .= ' - ' . $chain['message'];
                        }
                    }
                }
            }
            error_log("Cloudflare API 错误: " . $errorMsg);
            return ['success' => false, 'message' => 'Cloudflare 错误: ' . $errorMsg];
        }
    }
    
    // 解析错误响应
    $result = json_decode($response, true);
    if ($result && isset($result['errors'])) {
        $errorMsg = '';
        foreach ($result['errors'] as $error) {
            $errorMsg .= $error['message'] . ' ';
            if (isset($error['error_chain'])) {
                foreach ($error['error_chain'] as $chain) {
                    if (isset($chain['message'])) {
                        $errorMsg .= '- ' . $chain['message'] . ' ';
                    }
                }
            }
        }
        return ['success' => false, 'message' => '请求错误: ' . trim($errorMsg)];
    }
    
    return ['success' => false, 'message' => "HTTP错误: {$httpCode} - " . substr($response, 0, 200)];
}

/**
 * 删除Cloudflare记录（支持SRV）
 */
function deleteCloudflareRecord($mainDomain, $subdomain) {
    $config = getDomainConfig($mainDomain);
    if (!$config) return false;
    
    $fullDomain = $subdomain . '.' . $mainDomain;
    $zoneId = $config['zone_id'];
    $token = $config['api_token'];
    
    // 查询记录ID - 不限定类型，因为SRV记录可能用target字段
    $ch = curl_init('https://api.cloudflare.com/client/v4/zones/' . $zoneId . '/dns_records?name=' . urlencode($fullDomain));
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Content-Type: application/json',
        'Authorization: Bearer ' . $token
    ]);
    
    $response = curl_exec($ch);
    $result = json_decode($response, true);
    curl_close($ch);
    
    if (isset($result['result']) && !empty($result['result'])) {
        $recordId = $result['result'][0]['id'];
        
        $ch = curl_init('https://api.cloudflare.com/client/v4/zones/' . $zoneId . '/dns_records/' . $recordId);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'DELETE');
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            'Content-Type: application/json',
            'Authorization: Bearer ' . $token
        ]);
        
        curl_exec($ch);
        curl_close($ch);
        return true;
    }
    
    return false;
}

// ===== 其他辅助函数 =====

/**
 * 检查是否已登录
 */
function isLoggedIn() {
    return isset($_SESSION['user_id']);
}

/**
 * 检查是否是管理员
 */
function isAdmin() {
    return isset($_SESSION['is_admin']) && $_SESSION['is_admin'] == 1;
}

/**
 * 获取当前用户ID
 */
function getCurrentUserId() {
    return $_SESSION['user_id'] ?? null;
}

/**
 * 获取用户信息
 */
function getUserInfo($userId) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT id, username, email, credits, invite_code, is_admin, created_at FROM users WHERE id = ?");
    $stmt->execute([$userId]);
    return $stmt->fetch();
}

/**
 * 获取邀请统计
 */
function getInviteStats($userId) {
    $pdo = getDB();
    $stmt = $pdo->prepare("SELECT COUNT(*) as count, SUM(credits_earned) as total_credits FROM invite_logs WHERE inviter_id = ?");
    $stmt->execute([$userId]);
    return $stmt->fetch();
}

/**
 * 获取主题
 */
function getTheme() {
    $pdo = getDB();
    try {
        $stmt = $pdo->prepare("SELECT setting_value FROM settings WHERE setting_key = 'theme'");
        $stmt->execute();
        $result = $stmt->fetch();
        return $result ? $result['setting_value'] : 'dark';
    } catch (PDOException $e) {
        return 'dark';
    }
}

/**
 * 切换主题
 */
function toggleTheme() {
    $pdo = getDB();
    $current = getTheme();
    $new = $current === 'dark' ? 'light' : 'dark';
    $stmt = $pdo->prepare("UPDATE settings SET setting_value = ? WHERE setting_key = 'theme'");
    $stmt->execute([$new]);
    return $new;
}

/**
 * 获取所有主域名列表
 */
function getMainDomains() {
    global $DOMAINS_CONFIG;
    return array_keys($DOMAINS_CONFIG);
}
?>