{% 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("404Jump");
  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?404Jump=1
        var url = "/" + browerLang.substr(0, idx) + "_" + browerLang.substr(idx + 1).toUpperCase() + "/404.html?404Jump=1&from="+from;
        window.location.href=url;
      }else{       // /zh/404.html?404Jump=3
        var url = "/" + browerLang + "/404.html?404Jump=3&from="+from;
        window.location.href=url;
      }
    }else if(jump == "1"){ // /zh-CN/404.html?404Jump=2
      var url = "/" + browerLang.substr(0, idx) + "-" + browerLang.substr(idx + 1).toUpperCase() + "/404.html?404Jump=2&from="+from;
      window.location.href=url;
    }else if(jump == "2"){ // /zh/404.html?404Jump=3
      var url = "/" + browerLang.substr(0, idx) + "/404.html?404Jump=3&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 %}