Create remote file browser service (#448)

* code refactoring

* Add filebrowser service and tests

* change dataset reference

* Address pr comments

* add more tests

* address pr comments

* address pr comments and added more tests

* minor change

* minor fix

* Fix test break and add dataset result check

src/Microsoft.SqlTools.ServiceLayer/DisasterRecovery/DisasterRecoveryFileValidator.cs

@@ -0,0 +1,162 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+using System.Data;
+using System.Data.Common;
+using System.Data.SqlClient;
+using System.Globalization;
+using System.IO;
+using Microsoft.SqlServer.Management.Sdk.Sfc;
+using Microsoft.SqlServer.Management.Smo;
+using Microsoft.SqlTools.ServiceLayer.Connection;
+using Microsoft.SqlTools.ServiceLayer.Connection.ReliableConnection;
+using Microsoft.SqlTools.ServiceLayer.FileBrowser;
+
+namespace Microsoft.SqlTools.ServiceLayer.DisasterRecovery
+{
+    /// <summary>
+    /// Validate selected file paths for backup/restore operations
+    /// </summary>
+    public static class DisasterRecoveryFileValidator
+    {
+        internal const string LocalSqlServer = "(local)";
+        internal const string LocalMachineName = ".";
+
+        public static bool ValidatePaths(FileBrowserValidateEventArgs args, out string errorMessage)
+        {
+            errorMessage = string.Empty;
+            bool result = true;
+            SqlConnection connection = null;
+
+            if (args != null)
+            {
+                ConnectionInfo connInfo;
+                ConnectionService.Instance.TryFindConnection(args.OwnerUri, out connInfo);
+                if (connInfo != null)
+                {
+                    DbConnection dbConnection = null;
+                    connInfo.TryGetConnection(Connection.ConnectionType.Default, out dbConnection);
+                    if (dbConnection != null)
+                    {
+                        connection = ReliableConnectionHelper.GetAsSqlConnection(dbConnection);
+                    }
+                }
+
+                if (connection != null)
+                {
+                    bool isLocal = false;
+                    if (string.Compare(GetMachineName(connection.DataSource), Environment.MachineName, StringComparison.OrdinalIgnoreCase) == 0)
+                    {
+                        isLocal = true;
+                    }
+
+                    foreach (string filePath in args.FilePaths)
+                    {
+                        bool isFolder;
+                        bool existing = IsPathExisting(connection, filePath, out isFolder);
+
+                        if (existing)
+                        {
+                            if (isFolder)
+                            {
+                                errorMessage = string.Format(SR.BackupPathIsFolderError, filePath);
+                                result = false;
+                                break;
+                            }
+                        }
+                        else
+                        {
+                            // If the file path doesn't exist, check if the folder exists
+                            string folderPath = PathWrapper.GetDirectoryName(filePath);
+                            if (isLocal)
+                            {
+                                if (!string.IsNullOrEmpty(folderPath) && !Directory.Exists(folderPath))
+                                {
+                                    errorMessage = string.Format(SR.InvalidBackupPathError, folderPath);
+                                    result = false;
+                                    break;
+                                }
+                            }
+                            else
+                            {
+                                bool isFolderOnRemote;
+                                bool existsOnRemote = IsPathExisting(connection, folderPath, out isFolderOnRemote);
+                                if (!existsOnRemote)
+                                {
+                                    errorMessage = string.Format(SR.InvalidBackupPathError, folderPath);
+                                    result = false;
+                                    break;
+                                }
+                            }
+                        }
+                    }
+                }
+                else
+                {
+                    result = false;
+                }
+            }
+            else
+            {
+                result = false;
+            }
+
+            return result;
+        }
+
+        #region private methods
+
+        internal static bool IsPathExisting(SqlConnection connection, string path, out bool isFolder)
+        {
+            Request req = new Request
+            {
+                Urn = "Server/File[@FullName='" + Urn.EscapeString(path) + "']",
+                Fields = new[] { "IsFile" }
+            };
+
+            Enumerator en = new Enumerator();
+            bool isExisting = false;
+            isFolder = false;
+
+            using (DataSet ds = en.Process(connection, req))
+            {
+                if (FileBrowserBase.IsValidDataSet(ds))
+                {
+                    isFolder = !(Convert.ToBoolean(ds.Tables[0].Rows[0]["IsFile"], CultureInfo.InvariantCulture));
+                    isExisting = true;
+                }
+            }
+
+            return isExisting;
+        }
+
+        internal static string GetMachineName(string sqlServerName)
+        {
+            string machineName = string.Empty;
+            if (sqlServerName != null)
+            {
+                string serverName = sqlServerName.ToLowerInvariant().Trim();
+                if ((serverName == LocalSqlServer) || (serverName == LocalMachineName))
+                {
+                    machineName = System.Environment.MachineName;
+                }
+                else
+                {
+                    machineName = sqlServerName;
+                    if (sqlServerName.Trim().Length != 0)
+                    {
+                        // [0] = machine, [1] = instance
+                        return sqlServerName.Split('\\')[0];
+                    }
+                }
+            }
+
+            return machineName;
+        }
+
+        #endregion
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/DisasterRecovery/DisasterRecoveryService.cs

@@ -9,12 +9,11 @@ using Microsoft.SqlTools.Hosting.Protocol;
 using Microsoft.SqlTools.ServiceLayer.Admin;
 using Microsoft.SqlTools.ServiceLayer.Admin.Contracts;
 using Microsoft.SqlTools.ServiceLayer.Connection;
-using Microsoft.SqlTools.ServiceLayer.DisasterRecovery.Contracts;
-using Microsoft.SqlTools.ServiceLayer.TaskServices;
-using System.Threading;
-using Microsoft.SqlTools.ServiceLayer.DisasterRecovery.RestoreOperation;
-using System.Globalization;
 using Microsoft.SqlTools.ServiceLayer.Connection.Contracts;
+using Microsoft.SqlTools.ServiceLayer.DisasterRecovery.Contracts;
+using Microsoft.SqlTools.ServiceLayer.DisasterRecovery.RestoreOperation;
+using Microsoft.SqlTools.ServiceLayer.FileBrowser;
+using Microsoft.SqlTools.ServiceLayer.TaskServices;
 
 namespace Microsoft.SqlTools.ServiceLayer.DisasterRecovery
 {
@@ -26,6 +25,7 @@ namespace Microsoft.SqlTools.ServiceLayer.DisasterRecovery
         private static readonly Lazy<DisasterRecoveryService> instance = new Lazy<DisasterRecoveryService>(() => new DisasterRecoveryService());
         private static ConnectionService connectionService = null;
         private SqlTaskManager sqlTaskManagerInstance = null;
+        private FileBrowserService fileBrowserService = null;
         private RestoreDatabaseHelper restoreDatabaseService = new RestoreDatabaseHelper();
 
         /// <summary>
@@ -78,6 +78,25 @@ namespace Microsoft.SqlTools.ServiceLayer.DisasterRecovery
             }
         }
 
+        /// <summary>
+        /// Gets or sets the current filebrowser service instance
+        /// </summary>
+        internal FileBrowserService FileBrowserServiceInstance
+        {
+            get
+            {
+                if (fileBrowserService == null)
+                {
+                    fileBrowserService = FileBrowserService.Instance;
+                }
+                return fileBrowserService;
+            }
+            set
+            {
+                fileBrowserService = value;
+            }
+        }
+
         /// <summary>
         /// Initializes the service instance
         /// </summary>
@@ -89,14 +108,18 @@ namespace Microsoft.SqlTools.ServiceLayer.DisasterRecovery
             // Create backup
             serviceHost.SetRequestHandler(BackupRequest.Type, HandleBackupRequest);
 
-            // Create respore task
+            // Create restore task
             serviceHost.SetRequestHandler(RestoreRequest.Type, HandleRestoreRequest);
 
-            // Create respore plan
+            // Create restore plan
             serviceHost.SetRequestHandler(RestorePlanRequest.Type, HandleRestorePlanRequest);
 
-            // Create respore config
+            // Create restore config
             serviceHost.SetRequestHandler(RestoreConfigInfoRequest.Type, HandleRestoreConfigInfoRequest);
+
+            // Register file path validation callbacks
+            FileBrowserServiceInstance.RegisterValidatePathsCallback(FileValidationServiceConstants.Backup, DisasterRecoveryFileValidator.ValidatePaths);
+            FileBrowserServiceInstance.RegisterValidatePathsCallback(FileValidationServiceConstants.Restore, DisasterRecoveryFileValidator.ValidatePaths);
         }
 
         /// <summary>