/**
 * Task descriptions: line breaks and bold, and nothing else.
 *
 * Whoever writes a recipe pastes from the PDF of the technical sheet, and the text
 * used to arrive flattened - every line run into the next, every emphasis lost, to
 * be put back by hand each time. Two conventions carry it now: a newline is a line
 * break, **like this** is bold.
 *
 * No HTML is stored or trusted. The text is escaped first and the only tags in the
 * result are the ones produced here, so a description that contains <script> shows
 * those characters and does nothing. The server-side filter (rich_text in app.py)
 * follows exactly these rules, so a description reads the same whether the page
 * was rendered by Flask or by Alpine.
 */
(function (global) {
  'use strict';

  function escapeHtml(text) {
    return String(text)
      .replace(/&/g, '&amp;')
      .replace(/</g, '&lt;')
      .replace(/>/g, '&gt;')
      .replace(/"/g, '&quot;')
      .replace(/'/g, '&#39;');
  }

  /* Escaped text, then the two tags we add ourselves. Order matters: escaping
     after the substitution would turn our own <strong> into visible text. */
  function richText(value) {
    if (!value) return '';
    return escapeHtml(value)
      .replace(/\*\*([\s\S]+?)\*\*/g, '<strong>$1</strong>')
      .replace(/\n/g, '<br>');
  }

  /* Wrap whatever is selected in a textarea in ** **, the way a B button does.
     Dispatching 'input' is what keeps x-model in step: assigning to value alone
     changes the DOM and leaves Alpine with the old string. */
  function wrapSelectionBold(el) {
    if (!el) return;
    var start = el.selectionStart;
    var end = el.selectionEnd;
    var text = el.value || '';
    el.value = text.slice(0, start) + '**' + text.slice(start, end) + '**' + text.slice(end);
    el.dispatchEvent(new Event('input', { bubbles: true }));
    el.focus();
    // Leave the cursor around the same words, now inside the markers.
    el.selectionStart = start + 2;
    el.selectionEnd = end + 2;
  }

  global.richText = richText;
  global.wrapSelectionBold = wrapSelectionBold;
})(window);