0822用户登录、注册、退出

用户登录、注册、退出，我们主要是为了演示 cookie 和 session 的使用方法。

$action = strtolower($_GET['action']);
switch ($action){
    case 'login':
        if($_SERVER['REQUEST_METHOD'] === 'POST'){
            $email = $_POST['email'];
            $password= sha1($_POST['password']);
            //echo $password;
            //die ($email);
            $result = array_filter($users, function ($user) use ($email,$password){
               return $user['email'] === $email && $user['password'] === $password;
            });
            //
            if (count($result) === 1){
                $_SESSION['user'] = serialize(array_pop($result));
                exit ('<script>alert("验证通过");location.href="index.php"</script>');
            }
            exit ('请求类型错误');
        }
    case 'logout':
        if (isset($_SESSION['user'])){
            session_destroy();
            exit ('<script>alert("退出成功");location.href="index.php"</script>');
        }
    case 'register':
        $email = $_POST['email'];
        $name= $_POST['name'];
        $password= sha1($_POST['p2']);
        $register_time = time();
        $sql = <<< SQL
            INSERT `user`
            SET `name` = ?,
                `email` = ?,
                `password` = ?,
                `register_time` = ?;
        SQL;
        $stmt = $db->prepare($sql);
        $data = [$name,$email,$password, $register_time];
        if ($stmt->execute($data)) {
            if ($stmt->rowCount() > 0) {
                $sql = 'SELECT * FROM `user` WHERE `id` = ' . $db->lastInsertId();
                $stmt = $db->prepare($sql);
                $stmt->execute();
                $newUser = $stmt->fetch(PDO::FETCH_ASSOC);
                $_SESSION['user'] = serialize($newUser);
                exit ('<script>alert("注册成功");location.href="index.php"</script>');
            }else{
                exit ('<script>alert("注册失败");location.href="register.php"</script>');
            }
        }else{
            print_r($stmt->errorInfo());
        }
    default;
    exit('参数非法或未定义操作');
}