{% block body %}
{% if session['logged_in'] %}

You're logged in already! <a href="/logout">Logout</a>.

{% else %}
<meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=0.5, maximum-scale=3.0, user-scalable=yes" />
<link rel="stylesheet" href="static/css/login_service.css">
<script src="static/js/jquery.js"></script>
    <script>
        function signup() {
            let username = $("#username").val();
            let password = $("#password").val();
            let password2 = $("#password2").val();
            if (username === "" || password === "" || password2 === ""){
                alert('输入不能为空!');
                return false;
            }
            if (password !== password2) {
                alert('确认密码与输入密码不一致！');
                return false;
            }
            if (password.length < 4) {
                alert('密码过于简单。(密码长度至少4位)');
                return false;
            }
            $.post("/signup", {'username': username, 'password': password},
                function (response) {
                    if (response.status === '0') {
                        alert('用户名'+username+'已经被注册。');
                        window.location.href = "/signup";
                    } else if (response.status === '1') {
                        alert('用户名密码验证失败。');
                        window.location.href = "/signup";
                    } else if (response.status === '2') {
                        let f = confirm("恭喜，你已成功注册，你的用户名是"+username+'.\n点击“确认”开始使用，或点击“取消”返回首页');
                        if (f) {
                            window.location.href = '/'+username+'/userpage';
                        } else {
                            window.location.href = '/';
                        }
                    } else if (response.status === '3') {
                        alert(response.warn);
                    }
                }
            )
            return false;
        }
    </script>
<p>{{ get_flashed_messages()[0] | safe }}</p>


<div class="container">

  <section class="signin-heading">
    <h1>Sign Up</h1>
  </section>

  <p><input type="username" id="username" placeholder="输入用户名" class="username"></p>
  <p><input type="password" id="password" placeholder="输入密码" class="password"></p>
  <p><input type="password" id="password2" placeholder="确认密码" class="password" ></p>
  <button type="button" class="btn" onclick="signup()">注册</button>

</div>
  
{% endif %}
{% endblock %}