Initial implementation for autocomplete.

src/ServiceHost/Connection/ConnectionMessages.cs

@@ -0,0 +1,63 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.EditorServices.Protocol.MessageProtocol;
+
+namespace Microsoft.SqlTools.EditorServices.Connection
+{
+    /// <summary>
+    /// Message format for the initial connection request
+    /// </summary>
+    public class ConnectionDetails
+    {
+        /// <summary>
+        /// Gets or sets the connection server name
+        /// </summary>
+        public string ServerName { get; set; }
+
+        /// <summary>
+        /// Gets or sets the connection database name
+        /// </summary>
+        public string DatabaseName { get; set; }
+
+        /// <summary>
+        /// Gets or sets the connection user name
+        /// </summary>
+        public string UserName { get; set; }
+
+        /// <summary>
+        /// Gets or sets the connection password
+        /// </summary>
+        /// <returns></returns>
+        public string Password { get; set; }
+    }
+
+    /// <summary>
+    /// Message format for the connection result response
+    /// </summary>
+    public class ConnectionResult
+    {
+        /// <summary>
+        /// Gets or sets the connection id
+        /// </summary>
+        public int ConnectionId { get; set; }
+
+        /// <summary>
+        /// Gets or sets any connection error messages
+        /// </summary>
+        public string Messages { get; set; }
+    }
+
+    /// <summary>
+    /// Connect request mapping entry 
+    /// </summary>
+    public class ConnectionRequest
+    {
+        public static readonly
+            RequestType<ConnectionDetails, ConnectionResult> Type =
+            RequestType<ConnectionDetails, ConnectionResult>.Create("connection/connect");
+    }
+
+}

src/ServiceHost/Connection/ConnectionService.cs

@@ -0,0 +1,160 @@
+//
+// 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.Collections.Generic;
+using System.Data.SqlClient;
+using System.Threading.Tasks;
+
+namespace Microsoft.SqlTools.EditorServices.Connection
+{
+    /// <summary>
+    /// Main class for the Connection Management services
+    /// </summary>
+    public class ConnectionService
+    {
+        /// <summary>
+        /// Singleton service instance
+        /// </summary>
+        private static Lazy<ConnectionService> instance 
+            = new Lazy<ConnectionService>(() => new ConnectionService());
+
+        /// <summary>
+        /// The SQL connection factory object
+        /// </summary>
+        private ISqlConnectionFactory connectionFactory;
+
+        /// <summary>
+        /// The current connection id that was previously used
+        /// </summary>
+        private int maxConnectionId = 0;
+
+        /// <summary>
+        /// Active connections lazy dictionary instance
+        /// </summary>
+        private Lazy<Dictionary<int, ISqlConnection>> activeConnections
+            = new Lazy<Dictionary<int, ISqlConnection>>(() 
+                => new Dictionary<int, ISqlConnection>());
+          
+        /// <summary>
+        /// Callback for onconnection handler
+        /// </summary>
+        /// <param name="sqlConnection"></param>
+        public delegate Task OnConnectionHandler(ISqlConnection sqlConnection); 
+
+        /// <summary>
+        /// List of onconnection handlers
+        /// </summary>
+        private readonly List<OnConnectionHandler> onConnectionActivities = new List<OnConnectionHandler>(); 
+
+        /// <summary>
+        /// Gets the active connection map
+        /// </summary>
+        public Dictionary<int, ISqlConnection> ActiveConnections
+        {
+            get
+            {
+                return activeConnections.Value;
+            }
+        }
+
+        /// <summary>
+        /// Gets the singleton service instance
+        /// </summary>
+        public static ConnectionService Instance 
+        {
+            get
+            {
+                return instance.Value;
+            }
+        }
+
+        /// <summary>
+        /// Gets the SQL connection factory instance
+        /// </summary>
+        public ISqlConnectionFactory ConnectionFactory
+        {
+            get
+            {
+                if (this.connectionFactory == null)
+                {
+                    this.connectionFactory = new SqlConnectionFactory();
+                }
+                return this.connectionFactory;
+            }
+        }
+
+        /// <summary>
+        /// Default constructor is private since it's a singleton class
+        /// </summary>
+        private ConnectionService()
+        {
+        }
+
+        /// <summary>
+        /// Test constructor that injects dependency interfaces
+        /// </summary>
+        /// <param name="testFactory"></param>
+        public ConnectionService(ISqlConnectionFactory testFactory)
+        {
+            this.connectionFactory = testFactory;
+        }
+
+        /// <summary>
+        /// Open a connection with the specified connection details
+        /// </summary>
+        /// <param name="connectionDetails"></param>
+        public ConnectionResult Connect(ConnectionDetails connectionDetails)
+        {
+            // build the connection string from the input parameters
+            string connectionString = BuildConnectionString(connectionDetails);
+
+            // create a sql connection instance
+            ISqlConnection connection = this.ConnectionFactory.CreateSqlConnection();
+
+            // open the database
+            connection.OpenDatabaseConnection(connectionString);
+
+            // map the connection id to the connection object for future lookups
+            this.ActiveConnections.Add(++maxConnectionId, connection);
+
+            // invoke callback notifications
+            foreach (var activity in this.onConnectionActivities)
+            {
+                activity(connection);
+            }
+
+            // return the connection result
+            return new ConnectionResult()
+            {
+                ConnectionId = maxConnectionId
+            };
+        }
+
+        /// <summary> 
+        /// Add a new method to be called when the onconnection request is submitted 
+        /// </summary> 
+        /// <param name="activity"></param> 
+        public void RegisterOnConnectionTask(OnConnectionHandler activity) 
+        { 
+            onConnectionActivities.Add(activity); 
+        } 
+
+        /// <summary>
+        /// Build a connection string from a connection details instance
+        /// </summary>
+        /// <param name="connectionDetails"></param>
+        private string BuildConnectionString(ConnectionDetails connectionDetails)
+        {
+            SqlConnectionStringBuilder connectionBuilder = new SqlConnectionStringBuilder();
+            connectionBuilder["Data Source"] = connectionDetails.ServerName;
+            connectionBuilder["Integrated Security"] = false;
+            connectionBuilder["User Id"] = connectionDetails.UserName;
+            connectionBuilder["Password"] = connectionDetails.Password;
+            connectionBuilder["Initial Catalog"] = connectionDetails.DatabaseName;
+            return connectionBuilder.ToString();
+        }
+    }
+}

src/ServiceHost/Connection/ISqlConnection.cs

@@ -0,0 +1,34 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Collections.Generic;
+
+namespace Microsoft.SqlTools.EditorServices.Connection
+{
+    /// <summary>
+    /// Interface for the SQL Connection factory
+    /// </summary>
+    public interface ISqlConnectionFactory
+    {
+        /// <summary>
+        /// Create a new SQL Connection object
+        /// </summary>
+        ISqlConnection CreateSqlConnection();
+    }
+
+    /// <summary>
+    /// Interface for the SQL Connection wrapper
+    /// </summary>
+    public interface ISqlConnection
+    {
+        /// <summary>
+        /// Open a connection to the provided connection string
+        /// </summary>
+        /// <param name="connectionString"></param>
+        void OpenDatabaseConnection(string connectionString);
+
+        IEnumerable<string> GetServerObjects();
+    }
+}

src/ServiceHost/Connection/SqlConnection.cs

@@ -0,0 +1,70 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Collections.Generic;
+using System.Data;
+using System.Data.SqlClient;
+
+namespace Microsoft.SqlTools.EditorServices.Connection
+{
+    /// <summary>
+    /// Factory class to create SqlClientConnections
+    /// The purpose of the factory is to make it easier to mock out the database
+    /// in 'offline' unit test scenarios.
+    /// </summary>
+    public class SqlConnectionFactory : ISqlConnectionFactory
+    {
+        /// <summary>
+        /// Creates a new SqlClientConnection object
+        /// </summary>
+        public ISqlConnection CreateSqlConnection()
+        {
+            return new SqlClientConnection();
+        }
+    }
+
+    /// <summary>
+    /// Wrapper class that implements ISqlConnection and hosts a SqlConnection.
+    /// This wrapper exists primarily for decoupling to support unit testing.
+    /// </summary>
+    public class SqlClientConnection : ISqlConnection
+    {
+        /// <summary>
+        /// the underlying SQL connection
+        /// </summary>
+        private SqlConnection connection;
+
+        /// <summary>
+        /// Opens a SqlConnection using provided connection string
+        /// </summary>
+        /// <param name="connectionString"></param>
+        public void OpenDatabaseConnection(string connectionString)
+        {
+            this.connection = new SqlConnection(connectionString);
+            this.connection.Open();
+        }
+
+        /// <summary>
+        /// Gets a list of database server schema objects
+        /// </summary>
+        /// <returns></returns>
+        public IEnumerable<string> GetServerObjects()
+        {
+            SqlCommand command = connection.CreateCommand();
+            command.CommandText = "SELECT name FROM sys.objects";
+            command.CommandTimeout = 15;
+            command.CommandType = CommandType.Text;
+            var reader = command.ExecuteReader();
+
+            List<string> results = new List<string>();
+            while (reader.Read())
+            {
+                results.Add(reader[0].ToString());
+            }
+
+            return results;
+        }
+    }
+}

src/ServiceHost/LanguageSupport/AutoCompleteService.cs

@@ -0,0 +1,49 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.EditorServices.Connection;
+using System;
+using System.Collections.Generic;
+
+namespace Microsoft.SqlTools.LanguageSupport
+{
+    /// <summary>
+    /// Main class for Autocomplete functionality
+    /// </summary>
+    public class AutoCompleteService
+    {
+        /// <summary>
+        /// Singleton service instance
+        /// </summary>
+        private static Lazy<AutoCompleteService> instance 
+            = new Lazy<AutoCompleteService>(() => new AutoCompleteService());
+
+        private IEnumerable<string> autoCompleteList;
+
+        public IEnumerable<string> AutoCompleteList
+        {
+            get
+            {
+                return this.autoCompleteList;
+            }
+        }
+
+        /// <summary>
+        /// Gets the singleton service instance
+        /// </summary>
+        public static AutoCompleteService Instance 
+        {
+            get
+            {
+                return instance.Value;
+            }
+        }
+
+        public void UpdateAutoCompleteCache(ISqlConnection connection)
+        {
+            this.autoCompleteList = connection.GetServerObjects();
+        }
+    }
+}

src/ServiceHost/Server/LanguageServer.cs

@@ -13,6 +13,8 @@ using System.Text;
 using System.Threading;
 using System.Linq;
 using System;
+using Microsoft.SqlTools.EditorServices.Connection;
+using Microsoft.SqlTools.LanguageSupport;
 
 namespace Microsoft.SqlTools.EditorServices.Protocol.Server
 {
@@ -57,7 +59,22 @@ namespace Microsoft.SqlTools.EditorServices.Protocol.Server
             this.SetRequestHandler(DocumentHighlightRequest.Type, this.HandleDocumentHighlightRequest);
             this.SetRequestHandler(HoverRequest.Type, this.HandleHoverRequest);
             this.SetRequestHandler(DocumentSymbolRequest.Type, this.HandleDocumentSymbolRequest);
-            this.SetRequestHandler(WorkspaceSymbolRequest.Type, this.HandleWorkspaceSymbolRequest);               
+            this.SetRequestHandler(WorkspaceSymbolRequest.Type, this.HandleWorkspaceSymbolRequest);   
+
+            this.SetRequestHandler(ConnectionRequest.Type, this.HandleConnectRequest);  
+
+            // register an OnConnection callback
+            ConnectionService.Instance.RegisterOnConnectionTask(OnConnection);          
+        }
+
+        /// <summary>
+        /// Callback for when a user connection is done processing
+        /// </summary>
+        /// <param name="sqlConnection"></param>
+        public Task OnConnection(ISqlConnection sqlConnection)
+        {
+            AutoCompleteService.Instance.UpdateAutoCompleteCache(sqlConnection);
+            return Task.FromResult(true);
         }
 
         /// <summary>
@@ -245,7 +262,57 @@ namespace Microsoft.SqlTools.EditorServices.Protocol.Server
             RequestContext<CompletionItem[]> requestContext)
         {
             Logger.Write(LogLevel.Verbose, "HandleCompletionRequest");
-            await Task.FromResult(true);
+
+            var connectionService = ConnectionService.Instance;
+            if (connectionService.ActiveConnections.Count > 0)
+            {
+                AutoCompleteService.Instance.UpdateAutoCompleteCache(
+                    connectionService.ActiveConnections.First().Value);
+            }
+
+            var autoCompleteList = AutoCompleteService.Instance.AutoCompleteList;
+            var completions = new List<CompletionItem>();
+
+            int i = 0;
+            if (autoCompleteList != null)
+            {
+                foreach (var autoCompleteItem in autoCompleteList)
+                {
+                    completions.Add(new CompletionItem()
+                    {
+                        Label = autoCompleteItem,
+                        Kind = CompletionItemKind.Keyword,
+                        Detail = autoCompleteItem + " details",
+                        Documentation = autoCompleteItem + " documentation",
+                        //SortText = "SortText",
+                        TextEdit = new TextEdit
+                        {
+                            NewText = "New Text",
+                            Range = new Range
+                            {
+                                Start = new Position
+                                {
+                                    Line = textDocumentPosition.Position.Line,
+                                    Character = textDocumentPosition.Position.Character
+                                },
+                                End = new Position
+                                {
+                                    Line = textDocumentPosition.Position.Line,
+                                    Character = textDocumentPosition.Position.Character + 5
+                                }
+                            }
+                        }
+                    });
+
+                    // only show 50 items
+                    if (++i == 50)
+                    {
+                        break;
+                    }
+                }
+            }
+
+            await requestContext.SendResult(completions.ToArray());
         }
 
         protected async Task HandleCompletionResolveRequest(
@@ -296,6 +363,24 @@ namespace Microsoft.SqlTools.EditorServices.Protocol.Server
             await Task.FromResult(true);
         }
 
+        /// <summary>
+        /// Handle new connection requests
+        /// </summary>
+        /// <param name="connectionDetails"></param>
+        /// <param name="requestContext"></param>
+        /// <returns></returns>
+        protected async Task HandleConnectRequest(
+            ConnectionDetails connectionDetails,
+            RequestContext<ConnectionResult> requestContext)
+        {
+            Logger.Write(LogLevel.Verbose, "HandleConnectRequest");
+
+            // open connection base on request details
+            ConnectionResult result = ConnectionService.Instance.Connect(connectionDetails);
+
+            await requestContext.SendResult(result);     
+        }
+
         /// <summary>
         /// Runs script diagnostics on changed files
         /// </summary>

src/ServiceHost/project.json

@@ -6,7 +6,9 @@
   },
   "dependencies": {
     "Newtonsoft.Json": "9.0.1",
-    "Microsoft.SqlServer.SqlParser": "140.1.3"
+    "Microsoft.SqlServer.SqlParser": "140.1.3",
+    "System.Data.Common": "4.1.0",
+    "System.Data.SqlClient": "4.1.0"
   },
   "frameworks": {
     "netcoreapp1.0": {