using System;
using System.Collections.Generic;
using System.Text;
using System.Xml.Serialization;
using System.Xml;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.IO;
using System.Security.Permissions;

namespace lib
{
	[Serializable]
	public class SerializableDictionary<TKey, TVal>: Dictionary<TKey, TVal>, IXmlSerializable, ISerializable
	{
		#region Constants
		private const string DictionaryNodeName = "Dictionary";
		private const string ItemNodeName = "Item";
		private const string KeyNodeName = "Key";
		private const string ValueNodeName = "Value";
		#endregion
		#region Constructors
		public SerializableDictionary()
		{
		}

		public SerializableDictionary( IDictionary<TKey, TVal> dictionary )
				: base( dictionary )
		{
		}

		public SerializableDictionary( IEqualityComparer<TKey> comparer )
				: base( comparer )
		{
		}

		public SerializableDictionary( int capacity )
				: base( capacity )
		{
		}

		public SerializableDictionary( IDictionary<TKey, TVal> dictionary, IEqualityComparer<TKey> comparer )
				: base( dictionary, comparer )
		{
		}

		public SerializableDictionary( int capacity, IEqualityComparer<TKey> comparer )
				: base( capacity, comparer )
		{
		}

		#endregion
		#region ISerializable Members

		protected SerializableDictionary( SerializationInfo info, StreamingContext context )
		{
			int itemCount = info.GetInt32("ItemCount");
			for( int i = 0; i < itemCount; i++ )
			{
				KeyValuePair<TKey, TVal> kvp = (KeyValuePair<TKey, TVal>)info.GetValue(String.Format( $"Item{i}" ), typeof(KeyValuePair<TKey, TVal>));
				this.Add( kvp.Key, kvp.Value );
			}
		}


		//[SecurityPermission( SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.SerializationFormatter )]
		void ISerializable.GetObjectData( SerializationInfo info, StreamingContext context )
		{
			info.AddValue( "ItemCount", this.Count );
			int itemIdx = 0;
			foreach( KeyValuePair<TKey, TVal> kvp in this )
			{
				info.AddValue( String.Format( $"Item{itemIdx}" ), kvp, typeof( KeyValuePair<TKey, TVal> ) );
				itemIdx++;
			}
		}

		#endregion
		#region IXmlSerializable Members

		void IXmlSerializable.WriteXml( System.Xml.XmlWriter writer )
		{
			//writer.WriteStartElement(DictionaryNodeName);
			foreach( KeyValuePair<TKey, TVal> kvp in this )
			{
				writer.WriteStartElement( ItemNodeName );
				writer.WriteStartElement( KeyNodeName );
				KeySerializer.Serialize( writer, kvp.Key );
				writer.WriteEndElement();
				writer.WriteStartElement( ValueNodeName );
				ValueSerializer.Serialize( writer, kvp.Value );
				writer.WriteEndElement();
				writer.WriteEndElement();
			}
			//writer.WriteEndElement();
		}

		void IXmlSerializable.ReadXml( System.Xml.XmlReader reader )
		{
			if( reader.IsEmptyElement )
			{
				return;
			}

			// Move past container
			if( !reader.Read() )
			{
				throw new XmlException( "Error in Deserialization of Dictionary" );
			}

			//reader.ReadStartElement(DictionaryNodeName);
			while( reader.NodeType != XmlNodeType.EndElement )
			{
				reader.ReadStartElement( ItemNodeName );
				reader.ReadStartElement( KeyNodeName );
				TKey key = (TKey)KeySerializer.Deserialize(reader);
				reader.ReadEndElement();
				reader.ReadStartElement( ValueNodeName );
				TVal value = (TVal)ValueSerializer.Deserialize(reader);
				reader.ReadEndElement();
				reader.ReadEndElement();
				this.Add( key, value );
				reader.MoveToContent();
			}
			//reader.ReadEndElement();

			reader.ReadEndElement(); // Read End Element to close Read of containing node
		}

		System.Xml.Schema.XmlSchema IXmlSerializable.GetSchema()
		{
			return null;
		}

		#endregion
		#region Private Properties
		protected XmlSerializer ValueSerializer
		{
			get
			{
				if( valueSerializer == null )
				{
					valueSerializer = new XmlSerializer( typeof( TVal ) );
				}
				return valueSerializer;
			}
		}

		private XmlSerializer KeySerializer
		{
			get
			{
				if( keySerializer == null )
				{
					keySerializer = new XmlSerializer( typeof( TKey ) );
				}
				return keySerializer;
			}
		}
		#endregion
		#region Private Members
		private XmlSerializer keySerializer = null;
		private XmlSerializer valueSerializer = null;
		#endregion
	}
}