(function (window) {
  'use strict';

  var STUDY_VERSION = 'S-2026.2';
  var CONSENT_VERSION = 'research-consent-2026-10-17-v2';
  var API_ROOT = '/api/research-v2';

  function cleanSession(value) {
    return /^[A-Za-z0-9_.:-]{1,100}$/.test(value || '') ? value : 'public-self-guided';
  }

  function sessionId() {
    var params = new URLSearchParams(window.location.search);
    var explicit = params.get('session') || params.get('game_session_id');
    if (explicit) {
      var selected = cleanSession(explicit);
      try { window.localStorage.setItem('makigra_research_active_session:' + STUDY_VERSION, selected); } catch (error) {}
      return selected;
    }
    try { return cleanSession(window.localStorage.getItem('makigra_research_active_session:' + STUDY_VERSION) || 'public-self-guided'); }
    catch (error) { return 'public-self-guided'; }
  }

  function storageKey() {
    return 'makigra_research_case_token:' + STUDY_VERSION + ':' + sessionId();
  }

  function randomToken() {
    var bytes = new Uint8Array(32);
    window.crypto.getRandomValues(bytes);
    return Array.prototype.map.call(bytes, function (byte) {
      return byte.toString(16).padStart(2, '0');
    }).join('');
  }

  function existingToken() {
    try {
      var token = window.localStorage.getItem(storageKey()) || '';
      return /^[a-f0-9]{64}$/.test(token) ? token : '';
    } catch (error) {
      return '';
    }
  }

  function token(create) {
    var value = existingToken();
    if (!value && create) {
      value = randomToken();
      try {
        window.localStorage.setItem(storageKey(), value);
      } catch (error) {
        throw new Error('Браузер не разрешил сохранить исследовательскую сессию. Разрешите локальное хранилище и повторите.');
      }
    }
    return value;
  }

  function submissionToken() {
    return randomToken();
  }

  async function request(path, body) {
    var controller = new window.AbortController();
    var timer = window.setTimeout(function () { controller.abort(); }, 20000);
    var response;
    try { response = await window.fetch(API_ROOT + path, {
      method: 'POST',
      credentials: 'same-origin',
      headers: { 'Content-Type': 'application/json', 'Accept': 'application/json' },
      body: JSON.stringify(body),
      signal: controller.signal
    }); } catch (error) {
      throw new Error(error.name === 'AbortError' ? 'Сервер не ответил вовремя. Проверьте соединение и повторите отправку: сохранённые ответы не продублируются.' : 'Нет связи с сервером. Проверьте интернет и повторите отправку.');
    } finally { window.clearTimeout(timer); }
    var result;
    try {
      result = await response.json();
    } catch (error) {
      throw new Error('Сервер вернул некорректный ответ.');
    }
    if (!response.ok || !result.ok) {
      throw new Error(result.error || 'Сервис исследования временно недоступен.');
    }
    return result;
  }

  async function status() {
    var value = token(false);
    if (!value) {
      return { ok: true, has_case: false, status: { T0: null, T1: null, T2: null } };
    }
    return request('/status.php', {
      browser_token: value,
      game_session_id: sessionId(),
      study_version: STUDY_VERSION
    });
  }

  async function submit(wave, formVersion, answers, source) {
    return request('/submit.php', {
      browser_token: token(wave === 'T0'),
      submission_token: submissionToken(),
      game_session_id: sessionId(),
      study_version: STUDY_VERSION,
      form_version: formVersion,
      wave: wave,
      answers: answers,
      source: source || 'public',
      research_consent: true,
      consent_version: CONSENT_VERSION,
      website: ''
    });
  }

  function withSession(path) {
    var separator = path.indexOf('?') === -1 ? '?' : '&';
    return path + separator + 'session=' + encodeURIComponent(sessionId());
  }

  window.MakigraResearch = {
    studyVersion: STUDY_VERSION,
    consentVersion: CONSENT_VERSION,
    sessionId: sessionId,
    hasLocalCase: function () { return !!existingToken(); },
    startNew: function () {
      window.localStorage.removeItem(storageKey());
    },
    status: status,
    submit: submit,
    withSession: withSession
  };
}(window));