// Pure helpers of the workspace: quoting paths for a shell, what a dropped
// file does where it lands, sizes. No DOM here, so node can test them.
(function (root) {
  'use strict';
  function shellQuote(p) { return "'" + String(p).replace(/'/g, "'\\''") + "'"; }
  function shellQuoteAll(ps) { return ps.map(shellQuote).join(' '); }
  const same = (a, b) => a.kind === b.kind && a.id === b.id;
  // dropAction says what dropping item on target does: a transfer between
  // file panes, paths pasted into a terminal of the same place, nothing on
  // its own folder, or a refusal with the reason.
  function dropAction(item, target) {
    if (target.kind === 'term') {
      return same(item.source, target.source) ? {kind: 'paste'}
        : {kind: 'deny', reason: 'Нельзя: файл на ' + item.source.label + ', а терминал на ' + target.source.label};
    }
    if (same(item.source, target.source) && target.dir === item.dir) return {kind: 'none'};
    return {kind: 'transfer'};
  }
  function fmtSize(n) {
    if (n < 1024) return n + ' B';
    if (n < 1048576) return (n / 1024).toFixed(1) + ' K';
    if (n < 1073741824) return (n / 1048576).toFixed(1) + ' M';
    return (n / 1073741824).toFixed(1) + ' G';
  }
  // scope gives a module timers, requests and listeners that end with it;
  // once ended it starts nothing new (a request's late answer cannot set a
  // timer going again).
  function scope() {
    let ended = false;
    const timers = new Set(), offs = [], ac = new AbortController();
    return {
      timeout(fn, ms) { if (ended) return 0; const id = setTimeout(() => { timers.delete(id); fn(); }, ms); timers.add(id); return id; },
      interval(fn, ms) { if (ended) return 0; const id = setInterval(fn, ms); timers.add(id); return id; },
      clear(id) { clearTimeout(id); clearInterval(id); timers.delete(id); },
      fetch(url, opt) {
        const o = Object.assign({credentials: 'same-origin'}, opt || {});
        // A request with its own signal ends on either.
        o.signal = o.signal && AbortSignal.any ? AbortSignal.any([o.signal, ac.signal]) : (o.signal || ac.signal);
        return fetch(url, o);
      },
      on(target, ev, fn, opt) { target.addEventListener(ev, fn, opt); offs.push(() => target.removeEventListener(ev, fn, opt)); },
      signal: ac.signal,
      end() { ended = true; timers.forEach(id => { clearTimeout(id); clearInterval(id); }); timers.clear(); offs.forEach(f => f()); ac.abort(); }
    };
  }

  // parseActions finds what an assistant's answer asks the panel to do:
  // closed ``` blocks headed run [machine], read|ls [machine:]path or
  // write [machine:]path (its body the file's text).
  function parseActions(text) {
    const out = [], re = /```(run|read|ls|write|search|fetch)([^\n]*)\n([\s\S]*?)```/g;
    for (let m; (m = re.exec(text));) {
      const kind = m[1], head = m[2].trim(), body = m[3].replace(/\n$/, '');
      if (kind === 'run') { out.push({kind, machine: head, path: '', body}); continue; }
      if (kind === 'search' || kind === 'fetch') { out.push({kind, machine: '', path: '', body: (head + '\n' + body).trim()}); continue; }
      const c = head.indexOf(':');
      const machine = c > 0 && !head.startsWith('/') ? head.slice(0, c) : '';
      out.push({kind, machine, path: machine ? head.slice(c + 1) : head, body: kind === 'write' ? body : ''});
    }
    return out;
  }
  // md turns an assistant's text (no ``` blocks - those are drawn apart)
  // into HTML: headings, lists, quotes, bold, italic, `code` and http(s)
  // links. Everything is escaped first, so nothing else gets through.
  const escH = v => String(v).replace(/[&<>"]/g, c => ({'&': '&amp;', '<': '&lt;', '>': '&gt;', '"': '&quot;'}[c]));
  function mdInline(t) {
    const codes = [];
    t = t.replace(/`([^`\n]+)`/g, (_, c) => { codes.push(c); return '\u0000' + (codes.length - 1) + '\u0000'; });
    t = escH(t)
      .replace(/\*\*([^*\n]+)\*\*/g, '<b>$1</b>')
      .replace(/(^|[^*\w])\*([^*\n]+)\*(?!\w)/g, '$1<i>$2</i>')
      .replace(/(^|\W)_([^_\n]+)_(?!\w)/g, '$1<i>$2</i>')
      .replace(/\[([^\]\n]+)\]\(((?:[^()\s]|\([^()\s]*\))+)\)/g, (_, txt, url) => /^https?:\/\//i.test(url.replace(/&amp;/g, '&'))
        ? '<a href="' + url + '" target="_blank" rel="noopener">' + txt + '</a>' : txt);
    return t.replace(/\u0000(\d+)\u0000/g, (_, i) => '<code>' + escH(codes[+i]) + '</code>');
  }
  function md(text) {
    const out = [];
    let para = [], list = null;
    const flush = () => {
      if (para.length) out.push('<p>' + para.map(mdInline).join('<br>') + '</p>');
      para = [];
      if (list) { out.push('<' + list.tag + '>' + list.items.map(x => '<li>' + mdInline(x) + '</li>').join('') + '</' + list.tag + '>'); list = null; }
    };
    for (const line of String(text).split('\n')) {
      let m;
      if (!line.trim()) { flush(); continue; }
      if ((m = /^#{1,6}\s+(.*)$/.exec(line))) { flush(); out.push('<h4>' + mdInline(m[1]) + '</h4>'); continue; }
      if (/^\s*(-{3,}|\*{3,})\s*$/.test(line)) { flush(); out.push('<hr>'); continue; }
      if ((m = /^>\s?(.*)$/.exec(line))) { flush(); out.push('<blockquote>' + mdInline(m[1]) + '</blockquote>'); continue; }
      const ul = /^\s*[-*•]\s+(.*)$/.exec(line), ol = /^\s*\d+[.)]\s+(.*)$/.exec(line);
      if (ul || ol) {
        const tag = ul ? 'ul' : 'ol';
        if (para.length || (list && list.tag !== tag)) flush();
        if (!list) list = {tag, items: []};
        list.items.push((ul || ol)[1]);
        continue;
      }
      if (list) flush();
      para.push(line);
    }
    flush();
    return out.join('');
  }
  const api = {shellQuote, shellQuoteAll, dropAction, fmtSize, scope, parseActions, md};
  if (typeof module !== 'undefined') module.exports = api; else root.WSUtil = api;
})(this);