(function(){
  function buildTokens(rawQuery) {
    const q = (rawQuery || '').trim();
    if (!q) return [];
    // Normalize punctuation to spaces, trim non-alphanumerics at ends, dedupe
    const tokens = q
      .replace(/[,_;:]+/g, ' ')
      .split(/\s+/)
      .map(t => t.replace(/^[^A-Za-z0-9]+|[^A-Za-z0-9]+$/g, ''))
      .filter(Boolean);
    return Array.from(new Set(tokens));
  }

  function escapeHtml(text) {
    try {
      return (window.htmlSanitizer && window.htmlSanitizer.escape)
        ? window.htmlSanitizer.escape(text)
        : String(text == null ? '' : text);
    } catch (_) {
      return String(text == null ? '' : text);
    }
  }

  function highlight(text, tokens) {
    const value = text == null ? '' : String(text);
    if (!value || !Array.isArray(tokens) || tokens.length === 0) return escapeHtml(value);
    try {
      const source = String(value);
      const haystack = source.toLowerCase();
      const uniqueTokens = Array.from(new Set((tokens || []).map(t => String(t).toLowerCase()).filter(Boolean)));
      const ranges = [];
      uniqueTokens.forEach(t => {
        let from = 0;
        while (from <= haystack.length - t.length && t.length > 0) {
          const idx = haystack.indexOf(t, from);
          if (idx === -1) break;
          ranges.push([idx, idx + t.length]);
          from = idx + 1; // allow overlapping matches shift by 1
        }
      });
      if (ranges.length === 0) return escapeHtml(source);
      // Merge overlapping/adjacent ranges
      ranges.sort((a, b) => a[0] - b[0] || a[1] - b[1]);
      const merged = [];
      let [curStart, curEnd] = ranges[0];
      for (let i = 1; i < ranges.length; i++) {
        const [s, e] = ranges[i];
        if (s <= curEnd) {
          // overlap or adjacency
          curEnd = Math.max(curEnd, e);
        } else {
          merged.push([curStart, curEnd]);
          [curStart, curEnd] = [s, e];
        }
      }
      merged.push([curStart, curEnd]);
      // Build output with escaping of text segments
      let out = '';
      let pos = 0;
      merged.forEach(([s, e]) => {
        if (pos < s) out += escapeHtml(source.slice(pos, s));
        out += '<strong>' + escapeHtml(source.slice(s, e)) + '</strong>';
        pos = e;
      });
      if (pos < source.length) out += escapeHtml(source.slice(pos));
      return out;
    } catch (_) {
      return escapeHtml(String(text));
    }
  }

  function formatSnippet(snippet, tokens) {
    if (!snippet) return '';
    let html = String(snippet);
    try {
      const hasStrong = /<\s*strong\b/i.test(html);
      if (!hasStrong) {
        html = highlight(html, Array.isArray(tokens) ? tokens : []);
      }
      if (window.htmlSanitizer && typeof window.htmlSanitizer.sanitize === 'function') {
        html = window.htmlSanitizer.sanitize(html);
      }
    } catch (_) {}
    return html;
  }

  window.highlightUtils = {
    buildTokens,
    highlight,
    escape: escapeHtml,
    formatSnippet
  };
})();