Merge branch 'dev' into feature/queryExecutionV1

Also adding a fancy new mocked out reader for mocking db calls.

src/Microsoft.SqlTools.ServiceLayer/LanguageServices/AutoCompleteService.cs

@@ -0,0 +1,139 @@
+//
+// 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;
+using System.Data.SqlClient;
+using System.Threading.Tasks;
+using Microsoft.SqlTools.ServiceLayer.ConnectionServices;
+using Microsoft.SqlTools.ServiceLayer.ConnectionServices.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Hosting;
+using Microsoft.SqlTools.ServiceLayer.LanguageServices.Contracts;
+using Microsoft.SqlTools.ServiceLayer.WorkspaceServices.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.LanguageServices
+{
+    /// <summary>
+    /// Main class for Autocomplete functionality
+    /// </summary>
+    public class AutoCompleteService
+    {
+        #region Singleton Instance Implementation
+
+        /// <summary>
+        /// Singleton service instance
+        /// </summary>
+        private static Lazy<AutoCompleteService> instance 
+            = new Lazy<AutoCompleteService>(() => new AutoCompleteService());
+
+        /// <summary>
+        /// Gets the singleton service instance
+        /// </summary>
+        public static AutoCompleteService Instance 
+        {
+            get
+            {
+                return instance.Value;
+            }
+        }
+
+        /// <summary>
+        /// Default, parameterless constructor.
+        /// TODO: Figure out how to make this truely singleton even with dependency injection for tests
+        /// </summary>
+        public AutoCompleteService()
+        { 
+        }
+
+        #endregion
+
+        /// <summary>
+        /// Gets the current autocomplete candidate list
+        /// </summary>
+        public IEnumerable<string> AutoCompleteList { get; private set; }
+
+        public void InitializeService(ServiceHost serviceHost)
+        {
+            // Register a callback for when a connection is created
+            ConnectionService.Instance.RegisterOnConnectionTask(UpdateAutoCompleteCache);
+        }
+
+        /// <summary>
+        /// Update the cached autocomplete candidate list when the user connects to a database
+        /// TODO: Update with refactoring/async
+        /// </summary>
+        /// <param name="connection"></param>
+        public async Task UpdateAutoCompleteCache(ISqlConnection connection)
+        {
+            IDbCommand command = connection.CreateCommand();
+            command.CommandText = "SELECT name FROM sys.tables";
+            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());
+            }
+
+            AutoCompleteList = results;
+            await Task.FromResult(0);
+        }
+
+        /// <summary>
+        /// Return the completion item list for the current text position
+        /// </summary>
+        /// <param name="textDocumentPosition"></param>
+        public CompletionItem[] GetCompletionItems(TextDocumentPosition textDocumentPosition)
+        {
+            var completions = new List<CompletionItem>();
+
+            int i = 0;
+
+            // the completion list will be null is user not connected to server
+            if (this.AutoCompleteList != null)
+            {
+                foreach (var autoCompleteItem in this.AutoCompleteList)
+                {
+                    // convert the completion item candidates into CompletionItems
+                    completions.Add(new CompletionItem()
+                    {
+                        Label = autoCompleteItem,
+                        Kind = CompletionItemKind.Keyword,
+                        Detail = autoCompleteItem + " details",
+                        Documentation = autoCompleteItem + " documentation",
+                        TextEdit = new TextEdit
+                        {
+                            NewText = autoCompleteItem,
+                            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;
+                    }
+                }
+            }
+            return completions.ToArray();
+        }
+        
+    }
+}