// ==UserScript==
// @name         Meta AI Auto Year-of-Birth (Virtualized Robust)
// @namespace    https://meta.ai/
// @version      4.0
// @description  Reliably sets 1995 for year of birth on meta.ai, handling virtualized dropdowns and preventing self-interruptions.
// @match        https://www.meta.ai/*
// @grant        none
// ==/UserScript==

(function () {
  'use strict';

  const STORAGE_KEY = '__metaai_birthyear_selected__';
  let runningLock = false; // Prevent re-entrancy

  if (sessionStorage.getItem(STORAGE_KEY)) return;

  function showToast(message, duration = 1200) {
    let toast = document.createElement('div');
    toast.textContent = message;
    Object.assign(toast.style, {
      position: 'fixed',
      bottom: '40px',
      left: '50%',
      transform: 'translateX(-50%)',
      background: '#1a1a1a',
      color: '#fff',
      padding: '7px 20px',
      borderRadius: '6px',
      fontSize: '15px',
      opacity: 0.93,
      zIndex: 2147483646,
      boxShadow: '0 2px 12px rgba(0,0,0,.22)',
      fontFamily: 'system-ui,sans-serif',
      pointerEvents: 'none'
    });
    document.body.appendChild(toast);
    setTimeout(() => (toast.style.opacity = '0'), duration - 250);
    setTimeout(() => toast.remove(), duration);
  }

  function fireAllClicks(el) {
    if (!el) return;
    ['mousedown', 'mouseup', 'click'].forEach(type =>
      el.dispatchEvent(new MouseEvent(type, {bubbles: true, cancelable: true, view: window})));
  }

  // Wait for a specific condition (returns truthy), with polling and timeout
  function waitFor(condition, timeout = 3000, pollInterval = 65) {
    return new Promise((resolve, reject) => {
      const deadline = Date.now() + timeout;
      (function poll() {
        let result = condition();
        if (result) return resolve(result);
        if (Date.now() > deadline) return reject(new Error('Timeout waiting for element'));
        setTimeout(poll, pollInterval);
      })();
    });
  }

  // Scroll year listbox to try to force 1995 to render, if virtualized
  function forceScrollYearListboxTo(yearStr) {
    // Find any popup/virtualized year scroller (with role="listbox")
    const yearValue = parseInt(yearStr, 10);
    const listboxes = document.querySelectorAll('div[role="listbox"]');
    for (const lb of listboxes) {
      // Try scrolling to the right offset
      // For Meta, years usually decrease from top to bottom
      const minYear = 1920, maxYear = new Date().getFullYear();
      if(lb.scrollHeight > lb.clientHeight) {
        const totalYears = maxYear - minYear + 1;
        let percent = (maxYear - yearValue) / totalYears;
        if (percent < 0) percent = 0; if (percent > 1) percent = 1;
        lb.scrollTop = lb.scrollHeight * percent;
      }
    }
  }

  async function selectYear(yearStr = "1995") {
    // 1. Find the dialog
    let dialog = Array.from(document.querySelectorAll('[role="dialog"]')).find(dlg =>
      dlg.textContent.match(/welcome to meta ai/i) ||
      dlg.textContent.match(/providing your birthday/i)
    );
    if (!dialog) return false;

    // 2. Find the year dropdown button inside dialog
    let yearBtn = Array.from(dialog.querySelectorAll('div[role="button"],button')).find(
      btn => /year/i.test(btn.textContent) || /^\d{4}$/.test(btn.textContent.trim())
    );
    if (!yearBtn) return false;

    // 3. Open the dropdown (if not already showing a listbox, open it)
    fireAllClicks(yearBtn);

    // 4. Wait for the listbox to appear in the DOM
    await waitFor(() => document.querySelector('div[role="listbox"]'), 2000).catch(()=>{});
    let yearOption = null;

    // 5. Try find the option for 1995, scrolling if needed (for up to 2.5s)
    const maxTries = 25;
    for (let i = 0; i < maxTries; ++i) {
      // In case the dropdown closes, re-open
      if (!document.querySelector('div[role="listbox"]')) fireAllClicks(yearBtn);
      forceScrollYearListboxTo(yearStr);
      yearOption = Array.from(document.querySelectorAll('div[role="listbox"] span, div[role="listbox"] div'))
        .find(e => e.textContent.trim() === yearStr && e.offsetParent !== null);
      if (yearOption) break;
      await new Promise(r => setTimeout(r, 100));
    }
    // Try <div role="option"> also, for robustness
    if (!yearOption) {
      yearOption = Array.from(document.querySelectorAll('div[role="option"]')).find(
        el => el.textContent.trim() === yearStr && el.offsetParent !== null
      );
    }

    // 6. Click the year if found
    if (yearOption) {
      fireAllClicks(yearOption);
      showToast('Set year to ' + yearStr);
      // Wait for the yearBtn to show 1995 as the value
      for (let confirmTries = 0; confirmTries < 10; confirmTries++) {
        await new Promise(r => setTimeout(r, 80));
        if (yearBtn.textContent.includes(yearStr)) break;
      }
      return true;
    } else {
      showToast('Could NOT find year ' + yearStr, 2000);
      return false;
    }
  }

  // Try to select year and continue
  async function trySelectYearAndContinue() {
    if (sessionStorage.getItem(STORAGE_KEY)) return;
    if (runningLock) return;
    runningLock = true;
    try {
      const yearOK = await selectYear("1995");
      if (!yearOK) {
        runningLock = false;
        return;
      }
      // Find dialog and Continue button after setting year
      let dialog = Array.from(document.querySelectorAll('[role="dialog"]')).find(dlg =>
        dlg.textContent.match(/welcome to meta ai/i) ||
        dlg.textContent.match(/providing your birthday/i)
      );
      if (!dialog) {
        runningLock = false;
        return;
      }
      // Wait for Continue to be enabled (max 2.5s)
      let continueBtn = null;
      for (let i = 0; i < 25; ++i) {
        continueBtn = Array.from(dialog.querySelectorAll('div[role="button"],button'))
          .find(btn => /continue/i.test(btn.textContent) && !btn.getAttribute('aria-disabled'));
        if (continueBtn) break;
        await new Promise(r => setTimeout(r, 100));
      }
      if (continueBtn) {
        fireAllClicks(continueBtn);
        showToast("Continuing...");
        sessionStorage.setItem(STORAGE_KEY, '1');
      } else {
        showToast("Could not find enabled Continue button", 2000);
      }
    } finally {
      runningLock = false;
    }
  }

  // Mutation observer setup
  const observer = new MutationObserver(() => {
    trySelectYearAndContinue();
  });
  observer.observe(document.body, { childList: true, subtree: true });

  // Also attempt on load (in case dialog already present)
  setTimeout(trySelectYearAndContinue, 400);

})();