//#
//# ORB Helper Utilities
//# $Revision: 1.1 $
//# Copyright 2004 by Eric Y. Theriault
//# All Rights Reserved.
//# http://www.eyt.ca/CORBA
//#
using System;
using System.Runtime.Remoting;
using Ch.Elca.Iiop;
using Ch.Elca.Iiop.Services;
using omg.org.CosNaming;

namespace ca.eyt.corba
{
	/// <summary>
	/// Summary description for ORBHelper.
	/// </summary>
	public class ORBHelper
	{
		/// <summary>
		/// Used for parsing the command line arguments.
		/// </summary>
		private enum State {
			/// <summary>
			/// This is the normal state of the algorithm.
			/// </summary>
			Parsing,
			/// <summary>
			/// When an -ORBInitialHost is seen, this state is enabled.
			/// </summary>
			Host,
			/// <summary>
			/// When an -ORBInitialPort is seen, this state is enabled.
			/// </summary>
			Port,
			/// <summary>
			/// When an -ORBInitRef is seen, this state is enabled.
			/// </summary>
			Reference
		                   };

		///
		/// <summary>Acquires a nameserver reference from the command line.</summary>
		/// <remarks>IIOP.net does not appear to process command-line arguments like
		/// standard CORBA implementations do.  This method is intended to make up for
		/// this lack of functionality.  This assumes that you have registered the
		/// channels.</remarks>
		/// <param name="args">Arguments from the program.  This processes -ORBInitialHost,
		/// -ORBInitialPort, and -ORBInitRef parameters like Java, TAO, and Mico does.</param>
		/// <param name="orb">Initial CORBA Reference.</param>
		/// 
		public static NamingContext resolveNameserviceReference( CorbaInit orb, string [] args )
		{
			String initialHost = "localhost";
			String initialPort = "1050";
			String initialReference = null;
			State state = State.Parsing;
			for ( int i = 0; i < args.Length; ++ i ) 
			{
				// Check the argument; If it is a match, set the state accordingly.
				// If it is not a match, check the state, and copy in the parameters
				// if needed.
				if ( args[i].CompareTo( "-ORBInitialHost" ) == 0 ) 
				{
					if ( state != State.Parsing ) 
					{
						throw new Exception( "State should be Parsing, but it is " + state );
					}
					state = State.Host;
				} 
				else if ( args[i].CompareTo( "-ORBInitialPort" ) == 0 ) 
				{
					if ( state != State.Parsing ) 
					{
						throw new Exception( "State should be Parsing, but it is " + state );
					}
					state = State.Port;
				}
				else if ( args[i].CompareTo( "-ORBInitRef" ) == 0 )  
				{
					if ( state != State.Parsing ) 
					{
						throw new Exception( "State should be Parsing, but it is " + state );
					}
					state = State.Reference;
				}
				else if ( state != State.Parsing ) 
				{
					switch ( state ) 
					{
						case State.Host:
							initialHost = args[i];
							break;

						case State.Port:
							initialPort = args[i];
							break;

						case State.Reference:
							const String ns = "NameService=";
							int index = args[i].IndexOf( ns );
							if ( index == -1 ) {
								throw new Exception( "Initial Reference does not specify a Nameservice: " + args[i] );
							}
							initialReference = args[i].Substring( index + ns.Length );
							break;

						default:
							throw new Exception( "Invalid State: " + state );
					}
					state = State.Parsing;
				}
			}

			// Initialize the initialReference if the other fields are not null.
			if ( initialReference == null && initialHost != null && initialPort != null ) 
			{
				initialReference = String.Format( "corbaloc:iiop:{0}:{1}/NameService", initialHost, initialPort );
			}

			// OK.  Now let's process
			if ( initialReference != null ) 
			{
				return RemotingServices.Connect( typeof( NamingContext ), initialReference ) as NamingContext;
			}
			else 
			{
				// Currently not possible, but...
				throw new Exception( "No naming service specified." );
			}
		}
	}
}