using System;
using System.IO;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;

namespace ScreenToGif.Util
{
    public static class UiElementExtensions
    {
        public static T XamlClone<T>(this T original) where T : class
        {
            if (original == null)
                return null;

            object clone;
            using (var stream = new MemoryStream())
            {
                XamlWriter.Save(original, stream);
                stream.Seek(0, SeekOrigin.Begin);
                clone = XamlReader.Load(stream);
            }

            return clone as T;
        }

        //public static T Clone<T>(this T source)
        //{
        //    var sb = new StringBuilder();
        //    var writer = XmlWriter.Create(sb, new XmlWriterSettings
        //    {
        //        Indent = true,
        //        ConformanceLevel = ConformanceLevel.Fragment,
        //        OmitXmlDeclaration = true,
        //        NamespaceHandling = NamespaceHandling.OmitDuplicates,
        //    });

        //    var mgr = new XamlDesignerSerializationManager(writer);
        //    mgr.XamlWriterMode = XamlWriterMode.Expression;

        //    XamlWriter.Save(source, mgr);

        //    return null; // sb.ToString();
        //}

        public static T DeepClone<T>(this T source) where T : UIElement
        {
            var type = source.GetType();

            var result = Activator.CreateInstance(type) as T;

            CopyProperties(source, result, type);
            DeepCopyChildren(source, result);

            return result;
        }

        private static void DeepCopyChildren<T>(T source, T result) where T : UIElement
        {
            // Deep copy children.
            var sourcePanel = source as Panel;

            if (sourcePanel == null) return;

            var resultPanel = result as Panel;

            if (resultPanel == null) return;

            foreach (UIElement child in sourcePanel.Children)
            {
                var childClone = DeepClone(child);
                resultPanel.Children.Add(childClone);
            }
        }

        private static void CopyProperties<T>(T source, T result, Type type) where T : UIElement
        {
            //Copy all properties.
            var properties = type.GetRuntimeProperties();

            foreach (var property in properties)
            {
                if (property.Name == "Name") continue;

                if (!property.CanWrite || !property.CanRead) continue;

                var sourceProperty = property.GetValue(source);

                if (sourceProperty is UIElement element)
                {
                    var propertyClone = element.DeepClone();
                    property.SetValue(result, propertyClone);
                }
                else
                {
                    try
                    {
                        property.SetValue(result, sourceProperty);
                    }
                    catch (Exception ex)
                    {
                        System.Diagnostics.Debug.WriteLine(ex);
                    }
                }
            }
        }
    }
}