using System;

using System.Collections.Generic;

using System.Text;

using System.Linq;

using System.Xml.Serialization;

using System.Xml;

using System.Xml.Linq;

using System.IO;

using System.Data;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

using System.IO.Compression;

​

    // https://stackoverflow.com/questions/51467120/how-to-serialize-a-class-that-may-only-have-unique-instances

    public sealed class MyClassDTO

    {

        public string Name { get; set; }

​

        public static implicit operator MyClassDTO(MyClass obj) => obj == null ? null : new MyClassDTO { Name = obj.Name };

​

        public static implicit operator MyClass(MyClassDTO dto) => dto == null ? null : MyClass.Parse(dto.Name);

    }

​

    public sealed class MyClass

    {

        private static readonly Dictionary<string, MyClass> Cache;

​

        static MyClass()

        {

            Cache = new Dictionary<string, MyClass>()

            {

                { "one", new MyClass("one") { OtherRuntimeData = "other runtime data 1" } },

                { "two", new MyClass("two") { OtherRuntimeData = "other runtime data 2" } },

            };

        }

​

        // XmlSerializer required parameterless constructor.

        private MyClass() => throw new NotImplementedException();

​

        private MyClass(string name) => this.Name = name;

​

        public string Name { get; }

​

        public string OtherRuntimeData { get; set; }

​

        public static MyClass Parse(string from) => Cache[from];

        public static IEnumerable<MyClass> Instances => Cache.Values;

    }

​

    public class RootObject

    {

        // Technique taken from https://stackoverflow.com/questions/3280362/most-elegant-xml-serialization-of-color-structure

        [XmlElement(Type=typeof(MyClassDTO))]

        public MyClass MyClass { get; set; }

    }

​

    public class TestClass

    {

        public static void Test()

        {

            var root = new RootObject { MyClass = MyClass.Instances.Last() };

​

            var xml = root.GetXml(true);

            Console.WriteLine(xml);

            var root2 = xml.LoadFromXml<RootObject>();

            Assert.IsTrue(object.ReferenceEquals(root.MyClass, root2.MyClass));

            Console.WriteLine("\n{0} successfully round-tripped.", nameof(root.MyClass));           

        }

    }

​

    public static class XmlSerializationHelper

    {

        public static T LoadFromXml<T>(this string xmlString, XmlSerializer serial = null)

        {

            serial = serial ?? new XmlSerializer(typeof(T));

            using (var reader = new StringReader(xmlString))

            {

                return (T)serial.Deserialize(reader);

            }

        }

​

        public static string GetXml<T>(this T obj, bool omitStandardNamespaces)

        {

            return obj.GetXml(null, omitStandardNamespaces);

        }

        public static string GetXml<T>(this T obj, XmlSerializer serializer = null, bool omitStandardNamespaces = false)

        {

            XmlSerializerNamespaces ns = null;

            if (omitStandardNamespaces)

            {

                ns = new XmlSerializerNamespaces();

                ns.Add("", ""); // Disable the xmlns:xsi and xmlns:xsd lines.

            }           

            using (var textWriter = new StringWriter())

            {

                var settings = new XmlWriterSettings() { Indent = true }; // For cosmetic purposes.

                using (var xmlWriter = XmlWriter.Create(textWriter, settings))

                    (serializer ?? new XmlSerializer(obj.GetType())).Serialize(xmlWriter, obj, ns);

                return textWriter.ToString();

            }

        }

        public static string GetOuterXml(this XmlNode node, bool indent = true)

        {

            if (node == null)

                return null;

            using (var textWriter = new StringWriter())

            {

                var settings = new XmlWriterSettings

                {

                    Indent = indent,

                    OmitXmlDeclaration = true,

                };

                using (var xmlWriter = XmlWriter.Create(textWriter, settings))

                {

                    node.WriteTo(xmlWriter);

                }

                return textWriter.ToString();

            }

        }

    }

    public static class XmlAssert

    {

        // https://weblogs.asp.net/marianor/easy-way-to-compare-two-xmls-for-equality

        // https://stackoverflow.com/questions/7318157/best-way-to-compare-xelement-objects

        // Adapted from the answer https://stackoverflow.com/a/14463137 by https://stackoverflow.com/users/1102100/robjohnson

        public static void AreEqual(

            XElement expected,

            XElement actual)

        {

            Assert.IsTrue(XNode.DeepEquals(Normalize(expected), Normalize(actual)));

        }

​

        private static XElement Normalize(XElement element)

        {

            if (element.HasElements)

            {

                return new XElement(

                    element.Name,

                    element.Attributes()

                           .OrderBy(a => a.Name.ToString()),

                    element.Elements()

                           .OrderBy(a => a.Name.ToString())

                           .Select(e => Normalize(e)));

​

            }

​

            if (element.IsEmpty)

            {

                return new XElement(

                    element.Name,

                    element.Attributes()

                           .OrderBy(a => a.Name.ToString()));

            }

​

            return new XElement(element.Name, element.Attributes()

                .OrderBy(a => a.Name.ToString()), element.Value);

        }

    }

    public class AssertionFailedException : System.Exception

    {

        public AssertionFailedException() : base() { }

​

        public AssertionFailedException(string s) : base(s) { }

    }

​

    public static class Assert

    {

        public static void IsTrue(bool value)

        {

            IsTrue(value, "failed");

        }

​

        public static void IsTrue(bool value, string message)

        {

            if (value == false)

                throw new AssertionFailedException(message ?? "failed");

        }

    }

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Roslyn 2.0 Compiler; Environment version: " + Environment.Version);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Uncaught exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

    }

​