/// <summary>
        /// Get the file in different search paths corresponding to current culture.
        ///
        /// The file name to search is the filename part of path parameter. (Normally path
        /// parameter should contain only the filename part).
        /// </summary>
        /// <param name="file">This is the path to the file. If it has a path, we need to search under that path first.</param>
        /// <param name="searchPaths">Additional search paths.</param>
        /// <returns></returns>
        internal static string LocateFile(string file, Collection <string> searchPaths)
        {
            MUIFileSearcher searcher = new MUIFileSearcher(file, searchPaths, SearchMode.First);

            if (searcher.Result == null || searcher.Result.Count == 0)
            {
                return(null);
            }

            return(searcher.Result[0]);
        }
        /// <summary>
        /// Load help file provided.
        /// </summary>
        /// <remarks>
        /// This will load providerHelpInfo from help file into help cache.
        /// </remarks>
        /// <param name="providerInfo">ProviderInfo for which to locate help.</param>
        private void LoadHelpFile(ProviderInfo providerInfo)
        {
            if (providerInfo == null)
            {
                throw PSTraceSource.NewArgumentNullException(nameof(providerInfo));
            }

            string helpFile = providerInfo.HelpFile;

            if (string.IsNullOrEmpty(helpFile) || _helpFiles.Contains(helpFile))
            {
                return;
            }

            string helpFileToLoad = helpFile;

            // Get the mshsnapinfo object for this cmdlet.
            PSSnapInInfo mshSnapInInfo = providerInfo.PSSnapIn;

            // Search fallback
            // 1. If PSSnapInInfo exists, then always look in the application base
            //    of the mshsnapin
            // Otherwise,
            //    Look in the default search path and cmdlet assembly path
            Collection <string> searchPaths = new Collection <string>();

            if (mshSnapInInfo != null)
            {
                Diagnostics.Assert(!string.IsNullOrEmpty(mshSnapInInfo.ApplicationBase),
                                   "Application Base is null or empty.");
                // not minishell case..
                // we have to search only in the application base for a mshsnapin...
                // if you create an absolute path for helpfile, then MUIFileSearcher
                // will look only in that path.
                helpFileToLoad = Path.Combine(mshSnapInInfo.ApplicationBase, helpFile);
            }
            else if ((providerInfo.Module != null) && (!string.IsNullOrEmpty(providerInfo.Module.Path)))
            {
                helpFileToLoad = Path.Combine(providerInfo.Module.ModuleBase, helpFile);
            }
            else
            {
                searchPaths.Add(GetDefaultShellSearchPath());
                searchPaths.Add(GetProviderAssemblyPath(providerInfo));
            }

            string location = MUIFileSearcher.LocateFile(helpFileToLoad, searchPaths);

            if (string.IsNullOrEmpty(location))
            {
                throw new FileNotFoundException(helpFile);
            }

            XmlDocument doc = InternalDeserializer.LoadUnsafeXmlDocument(
                new FileInfo(location),
                false, /* ignore whitespace, comments, etc. */
                null); /* default maxCharactersInDocument */

            // Add this file into _helpFiles hashtable to prevent it to be loaded again.
            _helpFiles[helpFile] = 0;

            XmlNode helpItemsNode = null;

            if (doc.HasChildNodes)
            {
                for (int i = 0; i < doc.ChildNodes.Count; i++)
                {
                    XmlNode node = doc.ChildNodes[i];
                    if (node.NodeType == XmlNodeType.Element && string.Equals(node.Name, "helpItems", StringComparison.OrdinalIgnoreCase))
                    {
                        helpItemsNode = node;
                        break;
                    }
                }
            }

            if (helpItemsNode == null)
            {
                return;
            }

            using (this.HelpSystem.Trace(location))
            {
                if (helpItemsNode.HasChildNodes)
                {
                    for (int i = 0; i < helpItemsNode.ChildNodes.Count; i++)
                    {
                        XmlNode node = helpItemsNode.ChildNodes[i];
                        if (node.NodeType == XmlNodeType.Element && string.Equals(node.Name, "providerHelp", StringComparison.OrdinalIgnoreCase))
                        {
                            HelpInfo helpInfo = ProviderHelpInfo.Load(node);

                            if (helpInfo != null)
                            {
                                this.HelpSystem.TraceErrors(helpInfo.Errors);
                                // Add snapin qualified type name for this command..
                                // this will enable customizations of the help object.
                                helpInfo.FullHelp.TypeNames.Insert(0, string.Format(CultureInfo.InvariantCulture,
                                                                                    "ProviderHelpInfo#{0}#{1}", providerInfo.PSSnapInName, helpInfo.Name));

                                if (!string.IsNullOrEmpty(providerInfo.PSSnapInName))
                                {
                                    helpInfo.FullHelp.Properties.Add(new PSNoteProperty("PSSnapIn", providerInfo.PSSnapIn));
                                    helpInfo.FullHelp.TypeNames.Insert(1, string.Format(CultureInfo.InvariantCulture,
                                                                                        "ProviderHelpInfo#{0}", providerInfo.PSSnapInName));
                                }

                                AddCache(providerInfo.PSSnapInName + "\\" + helpInfo.Name, helpInfo);
                            }
                        }
                    }
                }
            }
        }
        /// <summary>
        /// Search for files in specified search paths.
        /// </summary>
        /// <param name="pattern"></param>
        /// <param name="searchPaths"></param>
        /// <returns></returns>
        internal static Collection <string> SearchFiles(string pattern, Collection <string> searchPaths)
        {
            MUIFileSearcher searcher = new MUIFileSearcher(pattern, searchPaths);

            return(searcher.Result);
        }