using System;
using System.Xml;
using System.Collections;
using System.Collections.Generic;

namespace oodb.mapping
{
    public class ListMapping : NaiveMapping
    {
        public FlatTypeMapping ElementMapping { get; }

        public ListMapping(OODB oodb, Type type)
            : base(oodb, type)
        {
            ElementMapping = OODB.GetFlatTypeMapping(type.GetGenericArguments()[0]);
        }

        public override object FromXml(XmlElement xmlValue)
        {
            if (!NativeType.FullName.Equals(xmlValue.GetAttribute("Type")))
                throw new ArgumentException("Type != NativeType", nameof(xmlValue));

            IList list = Activator.CreateInstance(typeof(List<>).MakeGenericType(ElementMapping.NativeType)) as IList;
            foreach (XmlNode elementNode in xmlValue.ChildNodes)
            {
                if ((elementNode is XmlElement) && ((((XmlElement)elementNode).Name.Equals("Value"))))
                {
                    list.Add(ElementMapping.FromXml(elementNode as XmlElement));
                }
            }

            return list;
        }

        public override XmlElement ToXml(XmlDocument xmlDocument, object value)
        {
            XmlElement valueElement = CreateEmptyValueElement(xmlDocument);

            IList list = value as IList;

            for (int n = 0; n < list.Count; n++)
            {
                valueElement.AppendChild(ElementMapping.ToXml(xmlDocument, list[n]));
            }

            return valueElement;
        }

        public override string ToText(object value)
        {
            throw new NotImplementedException();
        }

        public override object FromText(string text)
        {
            throw new NotImplementedException();
        }
    }

}