<?php
/**
 * 登录接口  POST /api/auth/login.php
 * 入参：username / password / slider_token（滑块验证通过后的token）
 * 出参（成功）：{ code:0, msg:'登录成功', data:{ real_name, role_name, permissions } }
 *
 * 批次1 安全加固（REV-1/REV-8）：
 *   - 密码 bcrypt（password_hash）优先校验；存量 sha1 用户登录命中后平滑升级
 *   - 登录限流（15分钟内同 IP+账号失败≥5 次锁定）
 *   - 登录成功后 session_regenerate_id 防会话固定
 *   - 经 Api::boot 统一走 CSRF + 安全 Session
 */
require_once __DIR__ . '/../common/Api.php';

$pdo = Api::boot(['public' => true]);

$username    = trim($_POST['username'] ?? '');
$password    = (string)($_POST['password'] ?? '');
$sliderToken = trim($_POST['slider_token'] ?? '');
$ip          = $_SERVER['REMOTE_ADDR'] ?? '0.0.0.0';

// 滑块验证：前端 slider.js 拖动通过后生成的 token，服务端校验非空且格式合法
if ($sliderToken === '' || strlen($sliderToken) < 10) {
    Response::error('请先完成滑块验证');
}
if ($username === '' || $password === '') {
    Response::error('请输入账号和密码');
}

// 登录限流（fail-open）
checkLoginThrottle($username, $ip);

$stmt = $pdo->prepare(
    "SELECT u.*, r.role_name, r.permissions
     FROM system_users u
     LEFT JOIN system_roles r ON r.id = u.role_id
     WHERE u.username = ? LIMIT 1"
);
$stmt->execute([$username]);
$user = $stmt->fetch();

// 密码校验：bcrypt 优先；旧版无盐 sha1 校验通过后即时平滑升级为 bcrypt
$authOk = false;
if ($user) {
    if (password_verify($password, (string)$user['password'])) {
        $authOk = true;
    } elseif (hash_equals((string)$user['password'], sha1($password))) {
        $authOk = true;
        $pdo->prepare("UPDATE system_users SET password = ? WHERE id = ?")
            ->execute([password_hash($password, PASSWORD_DEFAULT), (int)$user['id']]);
    }
}
if (!$authOk) {
    recordLoginAttempt($username, $ip, false);
    Response::error('账号或密码错误');
}
if ((int)$user['is_active'] !== 1) {
    recordLoginAttempt($username, $ip, false);
    Response::error('账号已被禁用，请联系管理员');
}

recordLoginAttempt($username, $ip, true);

// 更新最后登录时间/IP
$upd = $pdo->prepare("UPDATE system_users SET last_login_time = NOW(), last_login_ip = ? WHERE id = ?");
$upd->execute([$ip, $user['id']]);

// 会话固定防护：登录成功后重新生成 session id（保留已有 CSRF Token）
session_regenerate_id(true);

$_SESSION['user_id']     = (int)$user['id'];
$_SESSION['username']    = $user['username'];
$_SESSION['real_name']   = $user['real_name'] ?? $user['username'];
$_SESSION['role_id']     = (int)$user['role_id'];
$_SESSION['role_name']   = $user['role_name'] ?? '';
$_SESSION['permissions'] = json_decode($user['permissions'] ?? '[]', true) ?: [];

// 操作日志
logAction((int)$user['id'], $user['username'], 'login', 'auth', 'system_users', (int)$user['id'], ['ip' => $ip]);

Response::success([
    'real_name'   => $_SESSION['real_name'],
    'role_name'   => $_SESSION['role_name'],
    'permissions' => $_SESSION['permissions'],
    'csrf_token'  => csrfToken(),
], '登录成功');