#region Copyright (c) 2011-2023 Technosoftware GmbH. All rights reserved
//-----------------------------------------------------------------------------
// Copyright (c) 2011-2023 Technosoftware GmbH. All rights reserved
// Web: https://www.technosoftware.com 
// 
// The source code in this file is covered under a dual-license scenario:
//   - Owner of a purchased license: SCLA 1.0
//   - GPL V3: everybody else
//
// SCLA license terms accompanied with this source code.
// See SCLA 1.0: https://technosoftware.com/license/Source_Code_License_Agreement.pdf
//
// GNU General Public License as published by the Free Software Foundation;
// version 3 of the License are accompanied with this source code.
// See https://technosoftware.com/license/GPLv3License.txt
//
// This source code 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.
//-----------------------------------------------------------------------------
#endregion Copyright (c) 2011-2023 Technosoftware GmbH. All rights reserved

#region Using Directives
using System;
using System.Runtime.InteropServices;

using Technosoftware.DaAeHdaClient.Ae;
using Technosoftware.DaAeHdaClient.Da;
#endregion

#pragma warning disable 0618

namespace Technosoftware.DaAeHdaClient.Com.Ae
{
    /// <summary>
    /// Defines COM marshalling/unmarshalling functions for AE.
    /// </summary>
    internal class Interop
    {
        /// <summary>
        /// Converts a standard FILETIME to an OpcRcw.Ae.FILETIME structure.
        /// </summary>
        internal static OpcRcw.Ae.FILETIME Convert(FILETIME input)
        {
            var output = new OpcRcw.Ae.FILETIME();
            output.dwLowDateTime = input.dwLowDateTime;
            output.dwHighDateTime = input.dwHighDateTime;
            return output;
        }

        /// <summary>
        /// Converts an OpcRcw.Ae.FILETIME to a standard FILETIME structure.
        /// </summary>
        internal static FILETIME Convert(OpcRcw.Ae.FILETIME input)
        {
            var output = new FILETIME();
            output.dwLowDateTime = input.dwLowDateTime;
            output.dwHighDateTime = input.dwHighDateTime;
            return output;
        }

        /// <summary>
        /// Converts the HRESULT to a system type.
        /// </summary>
        internal static OpcResult GetResultID(int input)
        {
            // must check for this error because of a code collision with a DA code.
            if (input == Result.E_INVALIDBRANCHNAME)
            {
                return OpcResult.Ae.E_INVALIDBRANCHNAME;
            }

            return Technosoftware.DaAeHdaClient.Com.Interop.GetResultID(input);
        }

        /// <summary>
        /// Unmarshals and deallocates a OPCEVENTSERVERSTATUS structure.
        /// </summary>
        internal static OpcServerStatus GetServerStatus(ref IntPtr pInput, bool deallocate)
        {
            OpcServerStatus output = null;

            if (pInput != IntPtr.Zero)
            {
                var status = (OpcRcw.Ae.OPCEVENTSERVERSTATUS)Marshal.PtrToStructure(pInput, typeof(OpcRcw.Ae.OPCEVENTSERVERSTATUS));

                output = new OpcServerStatus();

                output.VendorInfo = status.szVendorInfo;
                output.ProductVersion = string.Format("{0}.{1}.{2}", status.wMajorVersion, status.wMinorVersion, status.wBuildNumber);
                output.MajorVersion = status.wMajorVersion;
                output.MinorVersion = status.wMinorVersion;
                output.BuildNumber = status.wBuildNumber;

                output.ServerState = (OpcServerState)status.dwServerState;
                output.StatusInfo = null;
                output.StartTime = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(status.ftStartTime));
                output.CurrentTime = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(status.ftCurrentTime));
                output.LastUpdateTime = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(status.ftLastUpdateTime));

                if (deallocate)
                {
                    Marshal.DestroyStructure(pInput, typeof(OpcRcw.Ae.OPCEVENTSERVERSTATUS));
                    Marshal.FreeCoTaskMem(pInput);
                    pInput = IntPtr.Zero;
                }
            }

            return output;
        }

        /// <summary>
        /// Converts a NodeType value to the OPCAEBROWSETYPE equivalent.
        /// </summary>
        internal static OpcRcw.Ae.OPCAEBROWSETYPE GetBrowseType(TsCAeBrowseType input)
        {
            switch (input)
            {
                case TsCAeBrowseType.Area: return OpcRcw.Ae.OPCAEBROWSETYPE.OPC_AREA;
                case TsCAeBrowseType.Source: return OpcRcw.Ae.OPCAEBROWSETYPE.OPC_SOURCE;
            }

            return OpcRcw.Ae.OPCAEBROWSETYPE.OPC_AREA;
        }

        /// <summary>
        /// Converts an array of ONEVENTSTRUCT structs to an array of EventNotification objects.
        /// </summary>
        internal static TsCAeEventNotification[] GetEventNotifications(OpcRcw.Ae.ONEVENTSTRUCT[] input)
        {
            TsCAeEventNotification[] output = null;

            if (input != null && input.Length > 0)
            {
                output = new TsCAeEventNotification[input.Length];

                for (var ii = 0; ii < input.Length; ii++)
                {
                    output[ii] = GetEventNotification(input[ii]);
                }
            }

            return output;
        }

        /// <summary>
        /// Converts a ONEVENTSTRUCT struct to a EventNotification object.
        /// </summary>
        internal static TsCAeEventNotification GetEventNotification(OpcRcw.Ae.ONEVENTSTRUCT input)
        {
            var output = new TsCAeEventNotification();

            output.SourceID = input.szSource;
            output.Time = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(input.ftTime));
            output.Severity = input.dwSeverity;
            output.Message = input.szMessage;
            output.EventType = (TsCAeEventType)input.dwEventType;
            output.EventCategory = input.dwEventCategory;
            output.ChangeMask = input.wChangeMask;
            output.NewState = input.wNewState;
            output.Quality = new TsCDaQuality(input.wQuality);
            output.ConditionName = input.szConditionName;
            output.SubConditionName = input.szSubconditionName;
            output.AckRequired = input.bAckRequired != 0;
            output.ActiveTime = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(input.ftActiveTime));
            output.Cookie = input.dwCookie;
            output.ActorID = input.szActorID;

            var attributes = Technosoftware.DaAeHdaClient.Com.Interop.GetVARIANTs(ref input.pEventAttributes, input.dwNumEventAttrs, false);

            output.SetAttributes(attributes);

            return output;
        }

        /// <summary>
        /// Converts an array of OPCCONDITIONSTATE structs to an array of Condition objects.
        /// </summary>
        internal static TsCAeCondition[] GetConditions(ref IntPtr pInput, int count, bool deallocate)
        {
            TsCAeCondition[] output = null;

            if (pInput != IntPtr.Zero && count > 0)
            {
                output = new TsCAeCondition[count];

                var pos = pInput;

                for (var ii = 0; ii < count; ii++)
                {
                    var condition = (OpcRcw.Ae.OPCCONDITIONSTATE)Marshal.PtrToStructure(pos, typeof(OpcRcw.Ae.OPCCONDITIONSTATE));

                    output[ii] = new TsCAeCondition();

                    output[ii].State = condition.wState;
                    output[ii].Quality = new TsCDaQuality(condition.wQuality);
                    output[ii].Comment = condition.szComment;
                    output[ii].AcknowledgerID = condition.szAcknowledgerID;
                    output[ii].CondLastActive = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(condition.ftCondLastActive));
                    output[ii].CondLastInactive = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(condition.ftCondLastInactive));
                    output[ii].SubCondLastActive = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(condition.ftSubCondLastActive));
                    output[ii].LastAckTime = Technosoftware.DaAeHdaClient.Com.Interop.GetFILETIME(Convert(condition.ftLastAckTime));

                    output[ii].ActiveSubCondition.Name = condition.szActiveSubCondition;
                    output[ii].ActiveSubCondition.Definition = condition.szASCDefinition;
                    output[ii].ActiveSubCondition.Severity = condition.dwASCSeverity;
                    output[ii].ActiveSubCondition.Description = condition.szASCDescription;

                    // unmarshal sub-conditions.
                    var names = Technosoftware.DaAeHdaClient.Com.Interop.GetUnicodeStrings(ref condition.pszSCNames, condition.dwNumSCs, deallocate);
                    var severities = Technosoftware.DaAeHdaClient.Com.Interop.GetInt32s(ref condition.pdwSCSeverities, condition.dwNumSCs, deallocate);
                    var definitions = Technosoftware.DaAeHdaClient.Com.Interop.GetUnicodeStrings(ref condition.pszSCDefinitions, condition.dwNumSCs, deallocate);
                    var descriptions = Technosoftware.DaAeHdaClient.Com.Interop.GetUnicodeStrings(ref condition.pszSCDescriptions, condition.dwNumSCs, deallocate);

                    output[ii].SubConditions.Clear();

                    if (condition.dwNumSCs > 0)
                    {
                        for (var jj = 0; jj < names.Length; jj++)
                        {
                            var subcondition = new TsCAeSubCondition();

                            subcondition.Name = names[jj];
                            subcondition.Severity = severities[jj];
                            subcondition.Definition = definitions[jj];
                            subcondition.Description = descriptions[jj];

                            output[ii].SubConditions.Add(subcondition);
                        }
                    }

                    // unmarshal attributes.
                    var values = Technosoftware.DaAeHdaClient.Com.Interop.GetVARIANTs(ref condition.pEventAttributes, condition.dwNumEventAttrs, deallocate);
                    var errors = Technosoftware.DaAeHdaClient.Com.Interop.GetInt32s(ref condition.pErrors, condition.dwNumEventAttrs, deallocate);

                    output[ii].Attributes.Clear();

                    if (condition.dwNumEventAttrs > 0)
                    {
                        for (var jj = 0; jj < values.Length; jj++)
                        {
                            var attribute = new TsCAeAttributeValue();

                            attribute.ID = 0;
                            attribute.Value = values[jj];
                            attribute.Result = GetResultID(errors[jj]);

                            output[ii].Attributes.Add(attribute);
                        }
                    }

                    // deallocate structure.
                    if (deallocate)
                    {
                        Marshal.DestroyStructure(pos, typeof(OpcRcw.Ae.OPCCONDITIONSTATE));
                    }

                    pos = (IntPtr)(pos.ToInt64() + Marshal.SizeOf(typeof(OpcRcw.Ae.OPCCONDITIONSTATE)));
                }

                // deallocate array.
                if (deallocate)
                {
                    Marshal.FreeCoTaskMem(pInput);
                    pInput = IntPtr.Zero;
                }
            }

            return output;
        }

        /*
        /// <summary>
        /// Converts an array of COM HRESULTs structures to .NET ResultID objects.
        /// </summary>
        internal static ResultID[] GetResultIDs(ref IntPtr pInput, int count, bool deallocate)
        {
            ResultID[] output = null;
			
            if (pInput != IntPtr.Zero && count > 0)
            {
                output = new ResultID[count];

                int[] errors = OpcCom.Interop.GetInt32s(ref pInput, count, deallocate);

                for (int ii = 0; ii < count; ii++)
                {
                    output[ii] = OpcCom.Interop.GetResultID(errors[ii]);
                }
            }

            return output;
        }		
		
        /// <summary>
        /// Converts an array of COM SourceServer structures to .NET SourceServer objects.
        /// </summary>
        internal static SourceServer[] GetSourceServers(ref IntPtr pInput, int count, bool deallocate)
        {
            SourceServer[] output = null;
			
            if (pInput != IntPtr.Zero && count > 0)
            {
                output = new SourceServer[count];

                IntPtr pos = pInput;

                for (int ii = 0; ii < count; ii++)
                {
                    OpcRcw.Dx.SourceServer server = (OpcRcw.Dx.SourceServer)Marshal.PtrToStructure(pos, typeof(OpcRcw.Dx.SourceServer));

                    output[ii] = new SourceServer();

                    output[ii].ItemName         = server.szItemName;
                    output[ii].ItemPath         = server.szItemPath;
                    output[ii].Version          = server.szVersion;
                    output[ii].Name             = server.szName;
                    output[ii].Description      = server.szDescription;
                    output[ii].ServerType       = server.szServerType;
                    output[ii].ServerURL        = server.szServerURL;
                    output[ii].DefaultConnected = server.bDefaultSourceServerConnected != 0;

                    pos = (IntPtr)(pos.ToInt64() + Marshal.SizeOf(typeof(OpcRcw.Dx.SourceServer)));
                }

                if (deallocate)
                {
                    Marshal.FreeCoTaskMem(pInput);
                    pInput = IntPtr.Zero;
                }
            }

            return output;
        }		

        /// <summary>
        /// Converts an array of .NET SourceServer objects to COM SourceServer structures.
        /// </summary>
        internal static OpcRcw.Dx.SourceServer[] GetSourceServers(SourceServer[] input)
        {
            OpcRcw.Dx.SourceServer[] output = null;
			
            if (input != null && input.Length > 0)
            {
                output = new OpcRcw.Dx.SourceServer[input.Length];

                for (int ii = 0; ii < input.Length; ii++)
                {
                    output[ii] =  new OpcRcw.Dx.SourceServer();

                    output[ii].dwMask                        = (uint)OpcRcw.Dx.Mask.All;
                    output[ii].szItemName                    = input[ii].ItemName;
                    output[ii].szItemPath                    = input[ii].ItemPath;
                    output[ii].szVersion                     = input[ii].Version;
                    output[ii].szName                        = input[ii].Name;
                    output[ii].szDescription                 = input[ii].Description;
                    output[ii].szServerType                  = input[ii].ServerType;
                    output[ii].szServerURL                   = input[ii].ServerURL;
                    output[ii].bDefaultSourceServerConnected = (input[ii].DefaultConnected)?1:0;					
                }
            }

            return output;
        }		

        /// <summary>
        /// Converts an array of COM DXGeneralResponse structure to a .NET GeneralResponse object.
        /// </summary>
        internal static GeneralResponse GetGeneralResponse(OpcRcw.Dx.DXGeneralResponse input, bool deallocate)
        {		
            Opc.Dx.IdentifiedResult[] results = Interop.GetIdentifiedResults(ref input.pIdentifiedResults, input.dwCount, deallocate);

            return  new GeneralResponse(input.szConfigurationVersion, results);
        }	

        /// <summary>
        /// Converts an array of COM IdentifiedResult structures to .NET IdentifiedResult objects.
        /// </summary>
        internal static Opc.Dx.IdentifiedResult[] GetIdentifiedResults(ref IntPtr pInput, int count, bool deallocate)
        {
            Opc.Dx.IdentifiedResult[] output = null;
			
            if (pInput != IntPtr.Zero && count > 0)
            {
                output = new Opc.Dx.IdentifiedResult[count];

                IntPtr pos = pInput;

                for (int ii = 0; ii < count; ii++)
                {
                    OpcRcw.Dx.IdentifiedResult result = (OpcRcw.Dx.IdentifiedResult)Marshal.PtrToStructure(pos, typeof(OpcRcw.Dx.IdentifiedResult));

                    output[ii] = new Opc.Dx.IdentifiedResult();
 
                    output[ii].ItemName = result.szItemName;
                    output[ii].ItemPath = result.szItemPath;
                    output[ii].Version  = result.szVersion;
                    output[ii].ResultID = OpcCom.Interop.GetResultID(result.hResultCode);
					
                    if (deallocate)
                    {
                        Marshal.DestroyStructure(pos, typeof(OpcRcw.Dx.IdentifiedResult));
                    }

                    pos = (IntPtr)(pos.ToInt64() + Marshal.SizeOf(typeof(OpcRcw.Dx.IdentifiedResult)));
                }

                if (deallocate)
                {
                    Marshal.FreeCoTaskMem(pInput);
                    pInput = IntPtr.Zero;
                }
            }

            return output;
        }		

        /// <summary>
        /// Converts an array of COM DXConnection structures to .NET DXConnection objects.
        /// </summary>
        internal static DXConnection[] GetDXConnections(ref IntPtr pInput, int count, bool deallocate)
        {
            DXConnection[] output = null;
			
            if (pInput != IntPtr.Zero && count > 0)
            {
                output = new DXConnection[count];

                IntPtr pos = pInput;

                for (int ii = 0; ii < count; ii++)
                {
                    OpcRcw.Dx.DXConnection connection = (OpcRcw.Dx.DXConnection)Marshal.PtrToStructure(pos, typeof(OpcRcw.Dx.DXConnection));

                    output[ii] = GetDXConnection(connection, deallocate);
					
                    if (deallocate)
                    {
                        Marshal.DestroyStructure(pos, typeof(OpcRcw.Dx.DXConnection));
                    }

                    pos = (IntPtr)(pos.ToInt64() + Marshal.SizeOf(typeof(OpcRcw.Dx.DXConnection)));
                }

                if (deallocate)
                {
                    Marshal.FreeCoTaskMem(pInput);
                    pInput = IntPtr.Zero;
                }
            }

            return output;
        }		

        /// <summary>
        /// Converts an array of .NET DXConnection objects to COM DXConnection structures.
        /// </summary>
        internal static OpcRcw.Dx.DXConnection[] GetDXConnections(DXConnection[] input)
        {
            OpcRcw.Dx.DXConnection[] output = null;
			
            if (input != null && input.Length > 0)
            {
                output = new OpcRcw.Dx.DXConnection[input.Length];

                for (int ii = 0; ii < input.Length; ii++)
                {
                    output[ii] = GetDXConnection(input[ii]);
                }
            }

            return output;
        }	
	
        /// <summary>
        /// Converts a .NET DXConnection object to COM DXConnection structure.
        /// </summary>
        internal static OpcRcw.Dx.DXConnection GetDXConnection(DXConnection input)
        {			
            OpcRcw.Dx.DXConnection output = new OpcRcw.Dx.DXConnection();

            // set output default values.
            output.dwMask = 0;
            output.szItemPath = null;
            output.szItemName = null;
            output.szVersion = null;
            output.dwBrowsePathCount = 0;
            output.pszBrowsePaths = IntPtr.Zero;
            output.szName = null;
            output.szDescription = null;
            output.szKeyword = null;
            output.bDefaultSourceItemConnected = 0;
            output.bDefaultTargetItemConnected = 0;
            output.bDefaultOverridden = 0;
            output.vDefaultOverrideValue = null;
            output.vSubstituteValue = null;
            output.bEnableSubstituteValue = 0;
            output.szTargetItemPath = null;
            output.szTargetItemName = null;
            output.szSourceServerName = null;
            output.szSourceItemPath = null;
            output.szSourceItemName = null;
            output.dwSourceItemQueueSize = 0;
            output.dwUpdateRate = 0;
            output.fltDeadBand = 0;
            output.szVendorData = null;

            // item name
            if (input.ItemName != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.ItemName;
                output.szItemName = input.ItemName;
            }

            // item path
            if (input.ItemPath != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.ItemPath;
                output.szItemPath = input.ItemPath;
            }

            // version
            if (input.Version != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.Version;
                output.szVersion = input.Version;
            }

            // browse paths
            if (input.BrowsePaths.Count > 0)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.BrowsePaths;
                output.dwBrowsePathCount = input.BrowsePaths.Count;
                output.pszBrowsePaths    = OpcCom.Interop.GetUnicodeStrings(input.BrowsePaths.ToArray());
            }

            // name
            if (input.Name != null)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.Name;
                output.szName = input.Name;
            }

            // description
            if (input.Description != null)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.Description;
                output.szDescription = input.Description;
            }

            // keyword
            if (input.Keyword != null)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.Keyword;
                output.szKeyword = input.Keyword;
            }

            // default source item connected
            if (input.DefaultSourceItemConnectedSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.DefaultSourceItemConnected;
                output.bDefaultSourceItemConnected = (input.DefaultSourceItemConnected)?1:0;
            }

            // default target item connected
            if (input.DefaultTargetItemConnectedSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.DefaultTargetItemConnected;
                output.bDefaultTargetItemConnected = (input.DefaultTargetItemConnected)?1:0;
            }

            // default overridden
            if (input.DefaultOverriddenSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.DefaultOverridden;
                output.bDefaultOverridden = (input.DefaultOverridden)?1:0;
            }

            // default override value
            if (input.DefaultOverrideValue != null)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.DefaultOverrideValue;
                output.vDefaultOverrideValue = input.DefaultOverrideValue;
            }

            // substitute value
            if (input.SubstituteValue != null)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.SubstituteValue;
                output.vSubstituteValue = input.SubstituteValue;
            }

            // enable substitute value
            if (input.EnableSubstituteValueSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.EnableSubstituteValue;
                output.bEnableSubstituteValue = (input.EnableSubstituteValue)?1:0;
            }

            // target item name
            if (input.TargetItemName != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.TargetItemName;
                output.szTargetItemName = input.TargetItemName;
            }

            // target item path
            if (input.TargetItemPath != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.TargetItemPath;
                output.szTargetItemPath = input.TargetItemPath;
            }

            // source server name
            if (input.SourceServerName != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.SourceServerName;
                output.szSourceServerName = input.SourceServerName;
            }

            // source item name
            if (input.SourceItemName != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.SourceItemName;
                output.szSourceItemName = input.SourceItemName;
            }

            // source item path
            if (input.SourceItemPath != null) 
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.SourceItemPath;
                output.szSourceItemPath = input.SourceItemPath;
            }

            // source item queue size
            if (input.SourceItemQueueSizeSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.SourceItemQueueSize;
                output.dwSourceItemQueueSize = input.SourceItemQueueSize;
            }

            // update rate
            if (input.UpdateRateSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.UpdateRate;
                output.dwUpdateRate = input.UpdateRate;
            }

            // deadband
            if (input.DeadbandSpecified)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.DeadBand;
                output.fltDeadBand = input.Deadband;
            }

            // vendor data
            if (input.VendorData != null)
            {
                output.dwMask |= (uint)OpcRcw.Dx.Mask.VendorData;
                output.szVendorData = input.VendorData;
            }	

            return output;
        }	

        /// <summary>
        /// Converts a COM DXConnection structure to a .NET DXConnection object.
        /// </summary>
        internal static DXConnection GetDXConnection(OpcRcw.Dx.DXConnection input, bool deallocate)
        {			
            DXConnection output = new DXConnection();

            // set output default values.
            output.ItemPath = null;
            output.ItemName = null;
            output.Version = null;
            output.BrowsePaths.Clear();
            output.Name = null;
            output.Description = null;
            output.Keyword = null;
            output.DefaultSourceItemConnected = false;
            output.DefaultSourceItemConnectedSpecified = false;
            output.DefaultTargetItemConnected = false;
            output.DefaultTargetItemConnectedSpecified = false;
            output.DefaultOverridden = false;
            output.DefaultOverriddenSpecified = false;
            output.DefaultOverrideValue = null;
            output.SubstituteValue = null;
            output.EnableSubstituteValue = false;
            output.EnableSubstituteValueSpecified = false;
            output.TargetItemPath = null;
            output.TargetItemName = null;
            output.SourceServerName = null;
            output.SourceItemPath = null;
            output.SourceItemName = null;
            output.SourceItemQueueSize = 0;
            output.SourceItemQueueSizeSpecified = false;
            output.UpdateRate = 0;
            output.UpdateRateSpecified = false;
            output.Deadband = 0;
            output.DeadbandSpecified = false;
            output.VendorData = null;

            // item name
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.ItemName) != 0) 
            {
                output.ItemName = input.szItemName;
            }

            // item path
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.ItemPath) != 0) 
            {
                output.ItemPath = input.szItemPath;
            }

            // version
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.Version) != 0) 
            {
                output.Version = input.szVersion;
            }

            // browse paths
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.BrowsePaths) != 0) 
            {
                string[] browsePaths =  OpcCom.Interop.GetUnicodeStrings(ref input.pszBrowsePaths, input.dwBrowsePathCount, deallocate);
				
                if (browsePaths != null)
                {
                    output.BrowsePaths.AddRange(browsePaths);
                }
            }

            // name
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.Name) != 0) 
            {
                output.Name = input.szName;
            }

            // description
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.Description) != 0) 
            {
                output.Description = input.szDescription;
            }

            // keyword
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.Keyword) != 0) 
            {
                output.Keyword = input.szKeyword;
            }

            // default source item connected
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.DefaultSourceItemConnected) != 0) 
            {
                output.DefaultSourceItemConnected = input.bDefaultSourceItemConnected != 0;
                output.DefaultSourceItemConnectedSpecified = true;
            }

            // default target item connected
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.DefaultTargetItemConnected) != 0) 
            {
                output.DefaultTargetItemConnected = input.bDefaultTargetItemConnected != 0;
                output.DefaultTargetItemConnectedSpecified = true;
            }

            // default overridden
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.DefaultOverridden) != 0) 
            {
                output.DefaultOverridden = input.bDefaultOverridden != 0;
                output.DefaultOverriddenSpecified = true;
            }

            // default override value
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.DefaultOverrideValue) != 0) 
            {
                output.DefaultOverrideValue = input.vDefaultOverrideValue;
            }

            // substitute value
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.SubstituteValue) != 0) 
            {
                output.SubstituteValue = input.vSubstituteValue;
            }

            // enable substitute value
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.EnableSubstituteValue) != 0) 
            {
                output.EnableSubstituteValue = input.bEnableSubstituteValue != 0;
                output.EnableSubstituteValueSpecified = true;
            }

            // target item name
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.TargetItemName) != 0) 
            {
                output.TargetItemName = input.szTargetItemName;
            }

            // target item path
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.TargetItemPath) != 0)
            {
                output.TargetItemPath = input.szTargetItemPath;
            }

            // source server name
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.SourceServerName) != 0)
            {
                output.SourceServerName = input.szSourceServerName;
            }

            // source item name
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.SourceItemName) != 0)
            {
                output.SourceItemName = input.szSourceItemName;
            }

            // source item path
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.SourceItemPath) != 0)
            {
                output.SourceItemPath = input.szSourceItemPath;
            }

            // source item queue size
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.SourceItemQueueSize) != 0)
            {
                output.SourceItemQueueSize = input.dwSourceItemQueueSize;
                output.SourceItemQueueSizeSpecified = true;
            }

            // update rate
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.UpdateRate) != 0)
            {
                output.UpdateRate = input.dwUpdateRate;
                output.UpdateRateSpecified = true;
            }

            // deadband
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.DeadBand) != 0)
            {
                output.Deadband = input.fltDeadBand;
                output.DeadbandSpecified = true;
            }

            // vendor data
            if ((input.dwMask & (uint)OpcRcw.Dx.Mask.VendorData) != 0)
            {
                output.VendorData = input.szVendorData;
            }	

            return output;
        }	

        /// <summary>
        /// Converts an array of .NET ItemIdentifier objects to COM ItemIdentifier structures.
        /// </summary>
        internal static OpcRcw.Dx.ItemIdentifier[] GetItemIdentifiers(Opc.Dx.ItemIdentifier[] input)
        {
            OpcRcw.Dx.ItemIdentifier[] output = null;
			
            if (input != null && input.Length > 0)
            {
                output = new OpcRcw.Dx.ItemIdentifier[input.Length];

                for (int ii = 0; ii < input.Length; ii++)
                {
                    output[ii] = new OpcRcw.Dx.ItemIdentifier();

                    output[ii].szItemName = input[ii].ItemName;
                    output[ii].szItemPath = input[ii].ItemPath;
                    output[ii].szVersion  = input[ii].Version;
                }
            }

            return output;
        }	
        */
    }
}