/* Dona Markdown V1 : rendu DOM sécurisé, sans injection de HTML depuis Hermes.
 * Nécessite uniquement les API standard du navigateur (aucun CDN).
 */
(() => {
  'use strict';

  function normalize(value) {
    return String(value ?? '')
      .replace(/\r\n?/g, '\n')
      .replace(/\u00a0/g, ' ')
      .replace(/&#(?:x20|32);| /gi, ' ')
      .replace(/\\\n/g, '\n')
      // Certains formats rééchappent les délimiteurs Markdown en \\* ou \\`.
      .replace(/\\([*`_])/g, '$1');
  }
  function element(tag, parent, cls) {
    const node = document.createElement(tag);
    if (cls) node.className = cls;
    parent.appendChild(node);
    return node;
  }
  function appendInline(parent, input, depth = 0) {
    const str = String(input ?? '');
    if (!str || depth > 5) { parent.appendChild(document.createTextNode(str)); return; }
    const tokens = /`([^`\n]+)`|\*\*([^*\n]+?)\*\*|__([^_\n]+?)__|~~([^~\n]+?)~~|\[([^\]\n]+)\]\((https?:\/\/[^\s)]+)\)|\*([^*\n]+?)\*|_([^_\n]+?)_/g;
    let last = 0, m;
    while ((m = tokens.exec(str)) !== null) {
      if (m.index > last) parent.appendChild(document.createTextNode(str.slice(last, m.index)));
      if (m[1] !== undefined) element('code', parent).textContent = m[1];
      else if (m[2] !== undefined || m[3] !== undefined) appendInline(element('strong', parent), m[2] ?? m[3], depth + 1);
      else if (m[4] !== undefined) appendInline(element('del', parent), m[4], depth + 1);
      else if (m[5] !== undefined) {
        const a = element('a', parent);
        a.textContent = m[5];
        a.href = m[6]; // Seulement http(s), filtré par la regexp.
        a.rel = 'noopener noreferrer';
        a.target = '_blank';
      }
      else if (m[7] !== undefined || m[8] !== undefined) appendInline(element('em', parent), m[7] ?? m[8], depth + 1);
      last = tokens.lastIndex;
    }
    if (last < str.length) parent.appendChild(document.createTextNode(str.slice(last)));
  }
  function render(target, value, options = {}) {
    if (!target || typeof target.replaceChildren !== 'function') return;
    const source = normalize(value);
    const fragment = document.createDocumentFragment();
    if (options.inline) {
      appendInline(fragment, source);
      target.replaceChildren(fragment);
      return;
    }
    const lines = source.split('\n');
    let paragraph = [];
    let codeLines = null;
    let lists = [];
    function flushParagraph() {
      if (!paragraph.length) return;
      const p = element('p', fragment);
      paragraph.forEach((line, i) => {
        if (i) p.appendChild(document.createElement('br'));
        appendInline(p, line);
      });
      paragraph = [];
    }
    for (let index = 0; index < lines.length; index++) {
      const line = lines[index];
      const trimmed = line.trim();
      if (codeLines !== null) {
        if (/^\s*```\s*$/.test(line)) {
          const pre = element('pre', fragment);
          element('code', pre).textContent = codeLines.join('\n');
          codeLines = null;
        } else codeLines.push(line);
        continue;
      }
      if (/^\s*```(?:[\w+-]+)?\s*$/.test(line)) {
        flushParagraph(); lists = []; codeLines = []; continue;
      }
      if (!trimmed) { flushParagraph(); lists = []; continue; }
      const list = line.match(/^(\s*)([-*+]|\d+[.)])\s+(.+)$/);
      if (list) {
        flushParagraph();
        const indent = list[1].replace(/\t/g, '    ').length;
        const type = /\d/.test(list[2][0]) ? 'ol' : 'ul';
        while (lists.length && (indent < lists[lists.length - 1].indent ||
          (indent === lists[lists.length - 1].indent && type !== lists[lists.length - 1].type))) lists.pop();
        if (!lists.length || indent > lists[lists.length - 1].indent) {
          const parent = lists.length && lists[lists.length - 1].lastItem
            ? lists[lists.length - 1].lastItem : fragment;
          const node = element(type, parent);
          lists.push({node, type, indent, lastItem: null});
        }
        const current = lists[lists.length - 1];
        current.lastItem = element('li', current.node);
        appendInline(current.lastItem, list[3]);
        continue;
      }
      lists = [];
      const heading = line.match(/^\s*(#{1,6})\s+(.+)$/);
      if (heading) {
        flushParagraph();
        appendInline(element('h' + Math.min(heading[1].length + 2, 6), fragment), heading[2]);
        continue;
      }
      const quote = line.match(/^\s*>\s?(.*)$/);
      if (quote) {
        flushParagraph();
        appendInline(element('blockquote', fragment), quote[1]);
        continue;
      }
      if (/^\s*(?:-{3,}|\*{3,})\s*$/.test(line)) {
        flushParagraph(); element('hr', fragment); continue;
      }
      paragraph.push(line.trim());
    }
    if (codeLines !== null) { const pre = element('pre', fragment); element('code', pre).textContent = codeLines.join('\n'); }
    flushParagraph();
    target.replaceChildren(fragment);
  }
  window.DonaMarkdown = Object.freeze({ render, normalize });
})();