/*********************************************************************/
/*                                                                   */
/*                     AgentService Framework                        */
/*                       www.agentservice.it                         */
/*                                                                   */
/* Copyright (C) 2007 l.i.d.o. - DIST, University of Genoa, Italy    */
/* GNU Lesser General Public License                                 */
/*                                                                   */
/* This library is free software; you can redistribute it and/or     */
/* modify it under the terms of the GNU Lesser General Public        */
/* License as published by the Free Software Foundation,             */
/* version 2.1 of the License.                                       */
/*                                                                   */
/* This library is distributed in the hope that it will be useful,   */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of    */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU */
/* Lesser General Public License for more details.                   */
/*                                                                   */
/* You should have received a copy of the GNU Lesser General Public  */
/* License along with this library; if not, write to the             */
/* Free Software Foundation, Inc., 59 Temple Place - Suite 330,      */
/* Boston, MA  02111-1307, USA.                                      */
/*                                                                   */
/*********************************************************************/
using System;
using System.IO;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters;
using System.Runtime.Serialization.Formatters.Binary;

namespace AgentService.Platform.MTS
{
	/// <summary>
	/// Class MessageBodyItem. Represent an item of the message's body.
	/// </summary>
	[Serializable]
    [DataContract]
	public class MessageBodyItem/* : ISerializable*/
	{
		/// <summary>
		/// Item's identifier
		/// </summary>
		protected string identifier;
		/// <summary>
		/// Gets the item's identifier
		/// </summary>
		[DataMember]
        public string Identifier
		{
			get
			{
				return this.identifier;
			}
            set
            {
                identifier = value;
            }
		}

		/// <summary>
		/// The class type of the istance
		/// </summary>
		protected System.Type type;
		/// <summary>
		/// Gets the type of the item
		/// </summary>
        public System.Type Type
		{
			get
			{
				return this.type;
			}
            set
            {
                type = value;
            }
		}
		/// <summary>
		/// BodyItem's instance
		/// </summary>
		protected object instance;
		/// <summary>
		/// Gets the instance of the body's item
		/// </summary>
        public object Instance
		{
			get
			{
				return this.instance;
			}

			set
			{

                if (value.GetType().Equals(this.type))
                {
                    this.instance = value;
                }
                else
                {
                    throw new ArgumentException("Cannot assign an object: type mismatch.", "Instance");
                }
			}
		}

        /// <summary>
        /// A string containing the istance type
        /// </summary>
        [DataMember]
        public String TypeString
        {
            get
            {
                return type.FullName;
            }
            set
            {
                Type t = System.Type.GetType(value);
                if (t != null) this.type = t;
            }
        }

        /// <summary>
        /// A string that contains the serialized object
        /// </summary>
        [DataMember]
        public String InstanceString
        {
            get
            {
                MemoryStream mem = new MemoryStream();
                CompactFormatter.CompactFormatterPlus cfp = new CompactFormatter.CompactFormatterPlus();
                cfp.Serialize(mem, this.instance);
                mem.Close();
                byte[] b = mem.ToArray();
                return Convert.ToBase64String(b);
            }
            set
            {
                byte[] b = Convert.FromBase64String(value);
                MemoryStream ms = new MemoryStream(b);
                ms.Position = 0;
                CompactFormatter.CompactFormatterPlus cfp = new CompactFormatter.CompactFormatterPlus();
                this.instance = cfp.Deserialize(ms);
                ms.Close();
                this.type = this.instance.GetType();
            }
        }
			
		/// <summary>
		/// Constructs a MessageBodyItem.
		/// </summary>
		public MessageBodyItem()
		{
			this.identifier = null;
			this.type = null;
			this.instance = null;
		}

		/// <summary>
		/// Constructs a MEssagBodyItem with the given identifier, type, and istance.
		/// </summary>
		/// <param name="identifier">Item's Identifier</param>
		/// <param name="type">Type of the istance</param>
		/// <param name="instance">The object item's istance</param>		
		public MessageBodyItem(string identifier, System.Type type, object instance)
		{
			if (type.IsSerializable == false)
				throw new System.ArgumentException("the type of the item is not serializable", "type");

			if (type.IsInstanceOfType(instance) == false)
				throw new System.ArgumentException("the instance is not of the provided type", "instance");

			this.identifier = identifier;
			this.type = type;
			this.instance = instance;
		}

		/// <summary>
		/// Deserialization Constructor.
		/// </summary>
		/// <param name="info">SerializeInfo</param>
		/// <param name="context">The context in which deserializing</param>
		public MessageBodyItem(SerializationInfo info, StreamingContext context) 
		{
			identifier = (string)info.GetValue("identifier", typeof(string));
			type = (System.Type)info.GetValue("type", typeof(System.Type));
			instance = (object)info.GetValue("instance",typeof(object));
		}
			
		/// <summary>
		/// Serialization function.
		/// </summary>
		/// <param name="info">SerializeInfo</param>
		/// <param name="context">The context in which deserializing</param>
		public virtual void GetObjectData(SerializationInfo info, StreamingContext context)
		{
			info.AddValue("identifier", this.identifier);
			info.AddValue("type", this.type);
			info.AddValue("instance", this.instance);
		}

	} 
}