{% extends "page_base.html" %}

{% block title %}
    <title>{% if title %}{{ title }} - {% else %}404{% trans %}Page not found{% endtrans %}
        - {% endif %}{{ site_name }}</title>
{% endblock %}

{% block head_end %}
    <script>
        function getQueryVariable(variable) {
            var query = window.location.search.substring(1);
            var vars = query.split("&");
            for (var i = 0; i < vars.length; i++) {
                var pair = vars[i].split("=");
                if (pair[0] == variable) {
                    return pair[1];
                }
            }
            return (false);
        }

        var jump = getQueryVariable("jump");
        var from = getQueryVariable("from");
        var pageLang = a = document.getElementsByTagName("html")[0].lang.toLowerCase(); // en -> zh-cn
        var browerLang = (navigator.language || navigator.browserLanguage).toLowerCase();    // zh-cn
        if (!from) {
            from = document.referrer;
        }
        if (pageLang && browerLang != pageLang) {
            var idx = browerLang.indexOf("-");
            if (!jump) {
                if (idx > 0) { // zh-cn, jump to /zh_CN/404.html?jump=1
                    var url = "/" + browerLang.substr(0, idx) + "_" + browerLang.substr(idx + 1).toUpperCase() + "/404.html?jump=1&from=" + from;
                    window.location.href = url;
                } else {       // /zh/404.html?jump=5
                    var url = "/" + browerLang + "/404.html?jump=5&from=" + from;
                    window.location.href = url;
                }
            } else if (jump == "1") { // /zh-CN/404.html?jump=2
                var url = "/" + browerLang.substr(0, idx) + "-" + browerLang.substr(idx + 1).toUpperCase() + "/404.html?jump=2&from=" + from;
                window.location.href = url;
            } else if (jump == "2") { // /zh-cn/404.html?jump=3
                var url = "/" + browerLang.substr(0, idx) + "-" + browerLang.substr(idx + 1).toLowerCase() + "/404.html?jump=3&from=" + from;
                window.location.href = url;
            } else if (jump == "3") { // /zh_cn/404.html?jump=4
                var url = "/" + browerLang.substr(0, idx) + "_" + browerLang.substr(idx + 1).toLowerCase() + "/404.html?jump=4&from=" + from;
                window.location.href = url;
            } else if (jump == "4") { // /zh/404.html?jump=5
                var url = "/" + browerLang.substr(0, idx) + "/404.html?jump=5&from=" + from;
                window.location.href = url;
            }
        }
    </script>
{% endblock %}

{% block content %}
    {% block title_404 %}
        <h1 style="width: 100%; text-align: center;">404 {% trans %}Page not found{% endtrans %}</h1>
    {% endblock %}
    {% block body_404 %}
        {{ body|safe }}
    {% endblock %}
    {% block btn_404 %}
        <div style="text-align:center;padding:1em;">
            <a class="btn" id="previous_btn">{% trans %}Return to previous page{% endtrans %}</a> <a class="btn"
                                                                                                     href="/">
            {% trans %}Home{% endtrans %}</a>
        </div>
        <script>
            var btn = document.getElementById("previous_btn");
            btn.onclick = function () {
                if (from.indexOf("/404.html") >= 0) {
                    from = "/";
                }
                window.location.href = from;
            };
        </script>
    {% endblock %}
{% endblock %}