//-----------------------------------------------------------------------
// <copyright file="IProtocolMessageWithExtensions.cs" company="Andrew Arnott">
//     Copyright (c) Andrew Arnott. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------

namespace DotNetOpenAuth.Messaging {
	using System;
	using System.Collections.Generic;
	using System.Diagnostics.Contracts;

	/// <summary>
	/// A protocol message that supports adding extensions to the payload for transmission.
	/// </summary>
	[ContractClass(typeof(IProtocolMessageWithExtensionsContract))]
	public interface IProtocolMessageWithExtensions : IProtocolMessage {
		/// <summary>
		/// Gets the list of extensions that are included with this message.
		/// </summary>
		/// <remarks>
		/// Implementations of this interface should ensure that this property never returns null.
		/// </remarks>
		IList<IExtensionMessage> Extensions { get; }
	}

	/// <summary>
	/// Code contract for the <see cref="IProtocolMessageWithExtensions"/> interface.
	/// </summary>
	[ContractClassFor(typeof(IProtocolMessageWithExtensions))]
	internal abstract class IProtocolMessageWithExtensionsContract : IProtocolMessageWithExtensions {
		/// <summary>
		/// Prevents a default instance of the <see cref="IProtocolMessageWithExtensionsContract"/> class from being created.
		/// </summary>
		private IProtocolMessageWithExtensionsContract() {
		}

		#region IProtocolMessageWithExtensions Members

		/// <summary>
		/// Gets the list of extensions that are included with this message.
		/// </summary>
		/// <remarks>
		/// Implementations of this interface should ensure that this property never returns null.
		/// </remarks>
		IList<IExtensionMessage> IProtocolMessageWithExtensions.Extensions {
			get {
				Contract.Ensures(Contract.Result<IList<IExtensionMessage>>() != null);
				throw new NotImplementedException();
			}
		}

		#endregion

		#region IProtocolMessage Members

		/// <summary>
		/// Gets the level of protection this message requires.
		/// </summary>
		MessageProtections IProtocolMessage.RequiredProtection {
			get { throw new NotImplementedException(); }
		}

		/// <summary>
		/// Gets a value indicating whether this is a direct or indirect message.
		/// </summary>
		MessageTransport IProtocolMessage.Transport {
			get { throw new NotImplementedException(); }
		}

		#endregion

		#region IMessage Members

		/// <summary>
		/// Gets the version of the protocol or extension this message is prepared to implement.
		/// </summary>
		/// <remarks>
		/// Implementations of this interface should ensure that this property never returns null.
		/// </remarks>
		Version IMessage.Version {
			get {
				throw new NotImplementedException();
			}
		}

		/// <summary>
		/// Gets the extra, non-standard Protocol parameters included in the message.
		/// </summary>
		/// <remarks>
		/// Implementations of this interface should ensure that this property never returns null.
		/// </remarks>
		IDictionary<string, string> IMessage.ExtraData {
			get {
				throw new NotImplementedException();
			}
		}

		/// <summary>
		/// Checks the message state for conformity to the protocol specification
		/// and throws an exception if the message is invalid.
		/// </summary>
		/// <remarks>
		/// 	<para>Some messages have required fields, or combinations of fields that must relate to each other
		/// in specialized ways.  After deserializing a message, this method checks the state of the
		/// message to see if it conforms to the protocol.</para>
		/// 	<para>Note that this property should <i>not</i> check signatures or perform any state checks
		/// outside this scope of this particular message.</para>
		/// </remarks>
		/// <exception cref="ProtocolException">Thrown if the message is invalid.</exception>
		void IMessage.EnsureValidMessage() {
			throw new NotImplementedException();
		}

		#endregion
	}
}