/***********************************************************************
 * 
 *  Copyright (C) 2005-2006 Novell, Inc. Inc. All Rights Reserved.
 *
 *  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
 *  Library 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, Novell, Inc.
 * 
 *  To contact Novell about this file by physical or electronic mail, 
 *  you may find current contact information at www.novell.com.
 * 
 ***********************************************************************/

using System;
using System.IO;
using AppModule.InterProcessComm;

namespace AppModule.NamedPipes {
	#region Comments
	/// <summary>
	/// An abstract class, which defines the methods for creating named pipes 
	/// connections, reading and writing data.
	/// </summary>
	/// <remarks>
	/// This class is inherited by 
	/// <see cref="AppModule.NamedPipes.ClientPipeConnection">ClientPipeConnection</see> 
	/// and <see cref="AppModule.NamedPipes.ServerPipeConnection">ServerPipeConnection</see> 
	/// classes, used for client and server applications respectively, which communicate
	/// using NamesPipes.
	/// </remarks>
	#endregion
	public abstract class APipeConnection : IInterProcessConnection {
		#region Comments
		/// <summary>
		/// A <see cref="AppModule.NamedPipes.PipeHandle">PipeHandle</see> object containing
		/// the native pipe handle.
		/// </summary>
		#endregion
		protected PipeHandle Handle = new PipeHandle();
		#region Comments
		/// <summary>
		/// The name of the named pipe.
		/// </summary>
		/// <remarks>
		/// This name is used for creating a server pipe and connecting client ones to it.
		/// </remarks>
		#endregion
		protected string Name;
		#region Comments
		/// <summary>
		/// Boolean field used by the IDisposable implementation.
		/// </summary>
		#endregion
		protected bool disposed = false;
		#region Comments
		/// <summary>
		/// The maximum bytes that will be read from the pipe connection.
		/// </summary>
		/// <remarks>
		/// This field could be used if the maximum length of the client message
		/// is known and we want to implement some security, which prevents the
		/// server from reading larger messages.
		/// </remarks>
		#endregion
		protected int maxReadBytes;
		#region Comments
		/// <summary>
		/// Reads a message from the pipe connection and converts it to a string
		/// using the UTF8 encoding.
		/// </summary>
		/// <remarks>
		/// See the <see cref="AppModule.NamedPipes.NamedPipeWrapper.Read">NamedPipeWrapper.Read</see>
		/// method for an explanation of the message format.
		/// </remarks>
		/// <returns>The UTF8 encoded string representation of the data.</returns>
		#endregion
		public string Read() {
			CheckIfDisposed();
			return NamedPipeWrapper.Read(Handle, maxReadBytes);
		}
		#region Comments
		/// <summary>
		/// Reads a message from the pipe connection.
		/// </summary>
		/// <remarks>
		/// See the <see cref="AppModule.NamedPipes.NamedPipeWrapper.ReadBytes">NamedPipeWrapper.ReadBytes</see>
		/// method for an explanation of the message format.
		/// </remarks>
		/// <returns>The bytes read from the pipe connection.</returns>
		#endregion
		public byte[] ReadBytes() {
			CheckIfDisposed();
			return NamedPipeWrapper.ReadBytes(Handle, maxReadBytes);
		}
		#region Comments
		/// <summary>
		/// Writes a string to the pipe connection/
		/// </summary>
		/// <param name="text">The text to write.</param>
		#endregion
		public void Write(string text) {
			CheckIfDisposed();
			NamedPipeWrapper.Write(Handle, text);
		}
		#region Comments
		/// <summary>
		/// Writes an array of bytes to the pipe connection.
		/// </summary>
		/// <param name="bytes">The bytes array.</param>
		#endregion
		public void WriteBytes(byte[] bytes) {
			CheckIfDisposed();
			NamedPipeWrapper.WriteBytes(Handle, bytes);
		}
		#region Comments
		/// <summary>
		/// Closes the pipe connection.
		/// </summary>
		#endregion
		public abstract void Close();
		#region Comments
		/// <summary>
		/// Connects a pipe connection.
		/// </summary>
		#endregion
		public abstract void Connect();
		#region Comments
		/// <summary>
		/// Disposes a pipe connection by closing the underlying native handle.
		/// </summary>
		#endregion
		public void Dispose() {
			Dispose(true);
			GC.SuppressFinalize(this);
		}
		#region Comments
		/// <summary>
		/// Disposes a pipe connection by closing the underlying native handle.
		/// </summary>
		/// <param name="disposing">A boolean indicating how the method is called.</param>
		#endregion
		protected void Dispose(bool disposing) {
			if(!this.disposed) {
				NamedPipeWrapper.Close(this.Handle);
			}
			disposed = true;         
		}
		#region Comments
		/// <summary>
		/// Checks if the pipe connection is disposed.
		/// </summary>
		/// <remarks>
		/// This check is done before performing any pipe operations.
		/// </remarks>
		#endregion
		public void CheckIfDisposed() {
			if(this.disposed) {
				throw new ObjectDisposedException("The Pipe Connection is disposed.");
			}
		}
		#region Comments
		/// <summary>
		/// Gets the pipe connection state from the <see cref="AppModule.NamedPipes.PipeHandle">PipeHandle</see> 
		/// object.
		/// </summary>
		/// <returns>The pipe connection state.</returns>
		#endregion
		public InterProcessConnectionState GetState() {
			CheckIfDisposed();
			return this.Handle.State;
		}
		#region Comments
		/// <summary>
		/// Retrieved the operating system native handle for the pipe connection.
		/// </summary>
		#endregion
		public int NativeHandle {
			get {
				CheckIfDisposed();
				return (int)this.Handle.Handle;
			}
		}
		public int GetLocalUserID(ref int lowPart, ref int highPart, ref string sSIDString)
		{							
			return ImpersonateWrapper.GetLocalUserID(this.Handle, ref lowPart, ref highPart, ref sSIDString);				
		}
	}	
}