using System;
using System.Xml;
using System.Xml.Linq;

namespace Umbraco.Core
{
	/// <summary>
	/// Extension methods for xml objects
	/// </summary>
	internal static class XmlExtensions
	{
		public static T AttributeValue<T>(this XmlNode xml, string attributeName)
		{
			if (xml == null) throw new ArgumentNullException("xml");
			if (xml.Attributes == null) return default(T);

			if (xml.Attributes[attributeName] == null)
				return default(T);

			var val = xml.Attributes[attributeName].Value;
			var result = val.TryConvertTo<T>();
			if (result.Success)
				return result.Result;

			return default(T);
		}

        public static XElement GetXElement(this XmlNode node)
        {
            XDocument xDoc = new XDocument();
            using (XmlWriter xmlWriter = xDoc.CreateWriter())
                node.WriteTo(xmlWriter);
            return xDoc.Root;
        }

        public static XmlNode GetXmlNode(this XElement element)
        {
            using (XmlReader xmlReader = element.CreateReader())
            {
                XmlDocument xmlDoc = new XmlDocument();
                xmlDoc.Load(xmlReader);
                return xmlDoc.FirstChild;
            }
        }

        public static XmlNode GetXmlNode(this XElement element, XmlDocument xmlDoc)
        {
            using (XmlReader xmlReader = element.CreateReader())
            {
                xmlDoc.Load(xmlReader);
                return xmlDoc.DocumentElement;
            }
        }
	}
}