using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Xml;

namespace NTERA.Engine.Compiler
{
	[DebuggerDisplay("{Type}")]
	public class ExecutionNode : IEnumerable<ExecutionNode>
	{
		public string Type { get; set; }

		public Dictionary<string, string> Metadata { get; set; } = new Dictionary<string, string>();

		public string Anchor { get; set; }

		public Marker Symbol { get; set; }

		public ExecutionNode[] SubNodes { get; set; } = new ExecutionNode[0];

		public ExecutionNode this[string type]
		{
			get { return SubNodes.First(x => x.Type == type); }
		}

		public ExecutionNode this[int index]
		{
			get => SubNodes[index];
			set => SubNodes[index] = value;
		}

		public void WriteXml(XmlWriter writer)
		{
			writer.WriteStartElement(Type);

			foreach (var kv in Metadata)
				writer.WriteAttributeString(kv.Key, kv.Value);

			foreach (var node in SubNodes)
				node.WriteXml(writer);

			writer.WriteEndElement();
		}

		public IEnumerator<ExecutionNode> GetEnumerator()
		{
			return ((IEnumerable<ExecutionNode>)SubNodes).GetEnumerator();
		}

		IEnumerator IEnumerable.GetEnumerator()
		{
			return SubNodes.GetEnumerator();
		}
	}
}