HtmlElementExtensions.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace HtmlSerializer
{

    public static class HtmlElementExtensions
    {
        public static bool Matches(this HtmlElement el, Selector sel)
        {
            if (sel == null) return false;

            if (!string.IsNullOrEmpty(sel.TagName) &&
                !string.Equals(el.Name, sel.TagName, StringComparison.OrdinalIgnoreCase))
                return false;

            if (!string.IsNullOrEmpty(sel.Id) &&
                !string.Equals(el.Id, sel.Id, StringComparison.Ordinal))
                return false;

            if (sel.Classes != null && sel.Classes.Count > 0)
            {
                foreach (var cls in sel.Classes)
                    if (!el.Classes.Contains(cls)) return false;
            }

            return true;
        }

        public static List<HtmlElement> Query(this HtmlElement root, Selector selector)
        {
            if (root == null || selector == null)
                return new List<HtmlElement>();

            var results = new HashSet<HtmlElement>();
            QueryRecursive(root, selector, results);
            return results.ToList();
        }

        private static void QueryRecursive(HtmlElement context, Selector sel, HashSet<HtmlElement> acc)
        {
            if (context == null || sel == null) return;

            // קבלת כל הצאצאים של context (ללא עצמו)
            var candidates = context.Descendants().Where(e => e != context);

            var matchedHere = candidates.Where(e => e.Matches(sel));

            if (sel.Child == null)
            {
                foreach (var m in matchedHere)
                    acc.Add(m);
                return;
            }

            foreach (var m in matchedHere)
                QueryRecursive(m, sel.Child, acc);
        }
    }

}