/*
 *  DataSet.cs
 *
 *  Copyright 2014 Michael Zillgith
 *
 *  This file is part of libIEC61850.
 *
 *  libIEC61850 is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  libIEC61850 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with libIEC61850.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  See COPYING file for the complete license text.
 */
using System;

using System.Runtime.InteropServices;

using IEC61850.Common;

namespace IEC61850
{
	namespace Client
	{
        /// <summary>
        /// This class is used to represent a data set. It is used to store the values
        /// of a data set.
        /// </summary>
		public class DataSet
		{
			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
			static extern void ClientDataSet_destroy (IntPtr self);

			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
			static extern IntPtr ClientDataSet_getValues (IntPtr self);

			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
			static extern IntPtr ClientDataSet_getReference (IntPtr self);

			[DllImport("iec61850", CallingConvention = CallingConvention.Cdecl)]
			static extern int ClientDataSet_getDataSetSize (IntPtr self);

			private IntPtr nativeObject;
			private MmsValue values = null;
			private string reference = null;

			internal DataSet (IntPtr nativeObject)
			{
				this.nativeObject = nativeObject;
			}

            /// <summary>
            /// Gets the object reference of the data set
            /// </summary>
            /// <returns>
            /// object reference.
            /// </returns>
			public string GetReference ()
			{
				if (reference == null) {
					IntPtr nativeString = ClientDataSet_getReference (nativeObject);

					reference = Marshal.PtrToStringAnsi (nativeString);
				}

				return reference;
			}

            /// <summary>
            /// Gets the values associated with the data set object
            /// </summary>
            /// <description>This function will return the locally stored values associated with the data set.
            /// These are the values received by the last request to the server. A call to this method doesn't
            /// invoke a request to the server! </description>
            /// <returns>
            /// The locally stored values of the data set (as MmsValue instance of type MMS_ARRAY)
            /// </returns>
			public MmsValue GetValues ()
			{
				if (values == null) {
					IntPtr nativeValues = ClientDataSet_getValues (nativeObject);

					values = new MmsValue (nativeValues, false);
				}

				return values;
			}


            /// <summary>
            /// Gets the number of elements of the data set
            /// </summary>
            /// <returns>
            /// the number of elementes (data set members)
            /// </returns>
			public int GetSize ()
			{
				return ClientDataSet_getDataSetSize (nativeObject);
			}

			~DataSet ()
			{
				ClientDataSet_destroy (nativeObject);
			}

			internal IntPtr getNativeInstance ()
			{
				return nativeObject;
			}
		}

	}

}