using System;
using System.Xml;
using Deltares.Geotechnics;
using Deltares.Geotechnics.SurfaceLines;
using Deltares.Standard.IO;
using Deltares.Standard.Reflection;

namespace Deltares.Stability
{
    /// <summary>
    /// This factory creates a SurfaceLine instance if it is required by the XML definition
    /// This factory exists for backwards compatibility for SurfaceLine2 refactoring
    /// </summary>
    public class SurfaceLineInstanceFactory : IClassInstanceFactory
    {
        /// <summary>
        /// This method will return true for a <see cref="SurfaceLine2"/> type, false otherwise
        /// </summary>
        /// <param name="type">The type for which is checked whether this class can handle it.</param>
        /// <returns>Returns true for <see cref="SurfaceLine2"/> type, false otherwise</returns>
        public bool CanHandle(Type type)
        {
            return type == typeof(SurfaceLine2);
        }

        /// <summary>
        /// Creates an instance of <see cref="SurfaceLine"/> if the XMLNode is representing an old
        /// <see cref="SurfaceLine"/> instance. If it is a new <see cref="SurfaceLine2"/>, a <c>null</c> is returned
        /// so the usual instance creation can take place.
        /// </summary>
        /// <param name="type">The type which would be initialized</param>
        /// <param name="node">The XML node which contains information about the serialized instance</param>
        /// <returns>An instance of SurfaceLine if the <paramref name="node"/> is a serialized 
        /// SurfaceLine, <c>null</c> otherwise.</returns>
        public object CreateInstance(Type type, XmlNode node)
        {
            var attribute =
                node.Attributes[StaticReflection.GetMemberName<SurfaceLine2>(x => x.GeometryMustIncludePoint_Xml)];

            return null == attribute ? new SurfaceLine() : null;
        }
    }
}