(function () {
  'use strict';

  const MASTER_KEY = 'enabled';

  async function isEnabled() {
    const { enabled } = await browser.storage.local.get(MASTER_KEY);
    return enabled !== false;
  }

  function autoAcceptPrivacy() {
    const modal = document.getElementById('myModal');
    if (!modal) return;
    const checkbox = document.getElementById('Confirmation');
    const submit = document.getElementById('Submit');
    if (checkbox && !checkbox.checked) checkbox.click();
    if (submit) submit.click();
  }

  function watchPrivacyModal() {
    autoAcceptPrivacy();
    const observer = new MutationObserver(() => autoAcceptPrivacy());
    observer.observe(document.body, { childList: true, subtree: true });
    setTimeout(() => observer.disconnect(), 30000);
  }

  async function autoLogin() {
    const { profiles } = await browser.storage.local.get('profiles');
    const active = (profiles || []).find((p) => p.enabled);
    if (!active) return;
    const userField = document.querySelector(
      'input[name="UserName"], input[name="username"], input[id="UserName"], input[id="username"]'
    );
    const passField = document.querySelector('input[type="password"]');
    if (!userField || !passField) return;
    userField.value = active.username;
    passField.value = active.password;
    userField.dispatchEvent(new Event('input', { bubbles: true }));
    passField.dispatchEvent(new Event('input', { bubbles: true }));
    const form = userField.closest('form') || passField.closest('form');
    if (!form) return;
    setTimeout(() => {
      const submitBtn = form.querySelector('input[type="submit"], button[type="submit"]');
      if (submitBtn) submitBtn.click();
      else form.submit();
    }, 300);
  }

  async function fetchCourseDescription(courseCode, academicPeriod, academicYear, token) {
    const body = new URLSearchParams();
    body.set('Courses', courseCode);
    body.set('AcademicPeriod', academicPeriod);
    body.set('AcademicYear', academicYear);
    body.set('AjaxFormVM.Controller', 'CourseSchedule');
    body.set('AjaxFormVM.Action', 'CourseScheduleOffered');
    body.set('AjaxFormVM.ResultTargetId', 'CourseScheduleOfferedList');
    body.set('AjaxFormVM.LinkToReturn', '');
    body.set('AjaxFormVM.LinkToReturnTargetId', '');
    body.set('AjaxFormVM.FormHeader', 'Choose term to view courses offered');
    body.set('AjaxFormVM.FormHeaderIcon', '');
    body.set('AjaxFormVM.FormId', 'CourseScheduleCourseScheduleOffered');
    body.set('AjaxFormVM.ShowCloseButton', 'True');
    body.set('AjaxFormVM.PreventAutoUpdateTarget', 'True');
    body.set('AjaxFormVM.CloseModalAfterSubmit', 'False');
    body.set('AjaxFormVM.AjaxFormType', 'Search');
    body.set('AjaxFormVM.FormNoteLocation', '');
    body.set('AjaxFormVM.SubmitButton.FaIcon', '');
    body.set('AjaxFormVM.SubmitButton.ButtonText', '');
    body.set('AjaxFormVM.SubmitButton.ButtonSize', '');
    body.set('__RequestVerificationToken', token);
    const resp = await fetch('/CourseSchedule/CourseScheduleOffered?Length=14', {
      method: 'POST',
      headers: {
        'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8',
        'X-Requested-With': 'XMLHttpRequest'
      },
      body: body.toString(),
      credentials: 'same-origin'
    });
    if (!resp.ok) throw new Error('Offered courses request failed: ' + resp.status);
    const html = await resp.text();
    const courses = ISMIStools.parseOfferedCourses(html);
    const match = courses.find((c) => c.courseCode === courseCode);
    return match ? match.description : '';
  }

  function extractTotalUnits(text) {
    const m = /Total Units:\s*([\d.]+)/i.exec(text);
    return m ? m[1] : '';
  }

  async function scrapeStudyLoad() {
    const table = document.querySelector('table.table-forum');
    if (!table) throw new Error('No study load table found on this page.');
    const courses = ISMIStools.parseStudyLoadTable(table.outerHTML);
    if (!courses.length) throw new Error('No courses found in study load table.');

    const periodEl = document.getElementById('AcademicPeriod');
    const yearEl = document.getElementById('AcademicYear');
    const tokenEl = document.querySelector('input[name="__RequestVerificationToken"]');
    const academicPeriod = periodEl ? periodEl.value : '';
    const academicYear = yearEl ? yearEl.value : '';
    const token = tokenEl ? tokenEl.value : '';

    const uniqueCodes = [...new Set(courses.map((c) => c.courseCode))];
    const descMap = {};
    for (const code of uniqueCodes) {
      try {
        descMap[code] = await fetchCourseDescription(code, academicPeriod, academicYear, token);
      } catch (e) {
        descMap[code] = '';
      }
    }
    courses.forEach((c) => { c.description = descMap[c.courseCode] || ''; });

    let header = {};
    try {
      const resp = await fetch('/Manage/Student', { credentials: 'same-origin' });
      if (!resp.ok) throw new Error('Profile request failed: ' + resp.status);
      const html = await resp.text();
      header = ISMIStools.parseProfilePage(html);
    } catch (e) {
      header = {};
    }

    const totalUnits = extractTotalUnits(document.body.innerText);
    return { header, courses, totalUnits };
  }

  browser.runtime.onMessage.addListener((msg, sender, sendResponse) => {
    if (msg && msg.type === 'scrape-study-load') {
      scrapeStudyLoad()
        .then((data) => sendResponse({ ok: true, data }))
        .catch((err) => sendResponse({ ok: false, error: String((err && err.message) || err) }));
      return true; // async response
    }
  });

  (async function init() {
    if (!(await isEnabled())) return;
    watchPrivacyModal();
    if (/\/Account\/Login/i.test(location.href)) autoLogin();
  })();
})();