<!DOCTYPE html>
<html lang="ru">
<head>
  <meta charset="UTF-8">
  <title>Проверка браузера</title>
  <style>
    body {
      background: linear-gradient(90deg, rgba(255, 255, 255, 1) 0%, rgba(101, 118, 198, 1) 100%);
      display: flex;
      width: 100vw;
      height: 100vh;
      justify-content: center;
      font-family: "Arial", serif;
      font-size: 3vh;
      color: #050b2c;
      margin: 0;
      padding: 0;
      overflow: hidden;
    }

    body.success {
      background: linear-gradient(90deg, rgba(255, 255, 255, 1) 0%, rgb(122, 198, 101) 100%);
    }

    body.error {
      background: linear-gradient(90deg, rgba(255, 255, 255, 1) 0%, rgb(178, 110, 138) 100%);
    }

    .loader {
      display: flex;
      align-items: center;
      flex-direction: column;
      margin-top: 30vh;
      text-align: center;
    }

    .loader-image {
      position: relative;
      display: flex;
      width: 100%;
      justify-content: center;
    }

    .preloader {
      width: 100px;
      height: 100px;
      transition: 0.3s ease-in-out;
      border-radius: 50%;
      border: 4px solid white;
      animation-name: loader;
      animation-duration: 3s;
      animation-iteration-count: infinite;
      position: absolute;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      margin: 0 auto;
    }

    @keyframes loader {
      0% {
        transform: scale(1);
      }

      50% {
        transform: scale(0.5);
      }

      100% {
        transform: scale(1);
      }
    }
  </style>
</head>
<body>
<div class="loader">
  <div class="loader-info">
    <h1 class="loader-header">Идет проверка вашего браузера</h1>
    <p class="loader-text">Пожалуйста подождите...</p>
    <div id="result"></div>
  </div>
  <div class="loader-image">
    <div class="preloader"></div>
  </div>

  <script type="text/javascript">
    const {cookieCodeName, code, id, checkPassUrl, reportUrl, passTimeout} = {"cookieCodeName":"ANTI_DDOS_CODE","id":"/Hqe7X8n+j+ej4aZPJ9hoXiJ3k46h5xjD0i0YAI9XRs=","code":"kFbIiPtyfUXObXW1ZJXlkfKKL4nQQw3jXL+vObGRS8I=","checkPassUrl":"","reportUrl":"/anti-ddos/report","passTimeout":8000};
    setTimeout(createRedirect, 100);

    async function createRedirect(){
      try{
        if( !cookieCodeName ) throw new Error(`No cookieCodeName in data`);

        const ret = await fetch('/anti-ddos/code', {
          method: 'post',
        });
        const json = await ret.json();
        const code = json.code;
        if( !code ) throw new Error(`no code`);

        document.cookie = `${cookieCodeName}=${encodeURIComponent(code)}; path=/`;

        if(checkPassUrl){
          const checkRet = await fetch(checkPassUrl)
          const url = checkRet.url;
          const isAntiddosRedirect = new URL(url).pathname.startsWith('/anti-ddos/');
          //if( checkRet.redirected ){
          if( isAntiddosRedirect ){
            throw new Error('checkPassUrl returned redirect.');
          }
        }

        setTimeout(() => returnBack(), 100);

      }catch(err){
        document.querySelector('.loader-image').style.display = 'none';
        document.querySelector('.loader-text').style.display = 'none';
        document.querySelector('#result').textContent = 'Упс что-то прошло не так. Попробуйте позже.';
        document.body.classList.add('error');
        await sendErrorReport('phase1', err);
      }
    }

    function sendErrorReport(phase, err){
      const formData = new FormData();
      formData.append('id', id);
      formData.append('code', code);
      formData.append('phase', phase);
      formData.append('error', String(err));
      return fetch(reportUrl, {
        method: 'POST',
        headers: {'Content-Type': 'application/x-www-form-urlencoded'},
        body: new URLSearchParams(formData).toString(),
      });
    }

    function returnBack(){
      const params = new URLSearchParams(location.search);
      let returnUrl = params.get('return_url') ?? '/';

      if( returnUrl.startsWith('/anti-ddos/') ) returnUrl = '/';

      const url = new URL(location.href);
      url.search = '';
      url.pathname = returnUrl;

      document.querySelector('.loader-text').style.display = 'none';
      document.querySelector('#result').textContent = 'Доступ разрешен. Сейчас вас должно перенаправить на сайт.';
      document.body.classList.add('success');

      location.replace(url.origin + returnUrl + location.hash);

      setTimeout(() => notifyTooLong(), passTimeout);

      //console.log(returnUrl);
      //const button = document.createElement('button');
      //button.textContent = `Продолжить`;
      //button.onclick = returnBack;
      //document.querySelector('.info').appendChild(button);
    }

    function notifyTooLong(){
      sendErrorReport('phase2', new Error('too long'));
      document.querySelector('#result').textContent = 'Доступ разрешен. Но сайт отвечает слишком долго. Попробуйте подождать еще, или вернуться позже.';
    }
  </script>
</div>
</body>
</html>