using System.Collections.Generic;
using System.Xml;
using XNeedle.Parser.Elements;

namespace XNeedle.Transformation
{
    public class Rule : Part
    {
        public required string XPathSelector { get; set; }
        public required IEnumerable<Part> Body;

        public void Transform(XmlDocument xml)
        {
            var context = new Context();
            context.Node = xml.DocumentElement;
            Operate(context);
        }

        public override void Operate(Context ctx)
        {
            if(ctx.Node is null)
            {
                return;
            }
            var nodes = ctx.Node.SelectNodes(XPathSelector);
            if(nodes is null)
            {
                return;
            }
            foreach (XmlNode n in nodes)
            {
                var loopCtx = ctx.Clone();
                loopCtx.Node = n;
                foreach (var b in Body)
                {
                    b.Operate(loopCtx);
                }
            }
        }
    }
}