adding a new event for when definition is requested (#167)

* sending telemetry events for intellisense usage

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

@@ -0,0 +1,116 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlServer.Management.SqlParser.Parser;
+using Microsoft.SqlTools.ServiceLayer.Utility;
+using Microsoft.SqlTools.ServiceLayer.Workspace.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.LanguageServices.Completion
+{
+    /// <summary>
+    /// A class to calculate the numbers used by SQL parser using the text positions and content
+    /// </summary>
+    internal class ScriptDocumentInfo
+    {
+        /// <summary>
+        /// Create new instance
+        /// </summary>
+        public ScriptDocumentInfo(TextDocumentPosition textDocumentPosition, ScriptFile scriptFile, ScriptParseInfo scriptParseInfo)
+        {
+            StartLine = textDocumentPosition.Position.Line;
+            ParserLine = textDocumentPosition.Position.Line + 1;
+            StartColumn = TextUtilities.PositionOfPrevDelimeter(
+                                scriptFile.Contents,
+                                textDocumentPosition.Position.Line,
+                                textDocumentPosition.Position.Character);
+            EndColumn = TextUtilities.PositionOfNextDelimeter(
+                                scriptFile.Contents,
+                                textDocumentPosition.Position.Line,
+                                textDocumentPosition.Position.Character);
+            ParserColumn = textDocumentPosition.Position.Character + 1;
+            ScriptParseInfo = scriptParseInfo;
+            Contents = scriptFile.Contents;
+
+            // need to adjust line & column for base-1 parser indices
+            Token = GetToken(scriptParseInfo, ParserLine, ParserColumn);
+        }
+
+        /// <summary>
+        /// Gets a string containing the full contents of the file.
+        /// </summary>
+        public string Contents { get; private set; }
+
+        /// <summary>
+        /// Script Parse Info Instance
+        /// </summary>
+        public ScriptParseInfo ScriptParseInfo { get; private set; }
+
+        /// <summary>
+        /// Start Line
+        /// </summary>
+        public int StartLine { get; private set; }
+
+        /// <summary>
+        /// Parser Line
+        /// </summary>
+        public int ParserLine { get; private set; }
+
+        /// <summary>
+        /// Start Column
+        /// </summary>
+        public int StartColumn { get; private set; }
+
+        /// <summary>
+        /// end Column
+        /// </summary>
+        public int EndColumn { get; private set; }
+
+        /// <summary>
+        /// Parser Column
+        /// </summary>
+        public int ParserColumn { get; private set; }
+
+        /// <summary>
+        /// The token text in the file content used for completion list
+        /// </summary>
+        public string TokenText
+        {
+            get
+            {
+                return Token != null ? Token.Text : null;
+            }
+        }
+
+        /// <summary>
+        /// The token in the file content used for completion list
+        /// </summary>
+        public Token Token { get; private set; }
+
+        /// <summary>
+        /// Returns the token that will be used by SQL parser for creating the completion list
+        /// </summary>
+        internal static Token GetToken(ScriptParseInfo scriptParseInfo, int startLine, int startColumn)
+        {
+            if (scriptParseInfo != null && scriptParseInfo.ParseResult != null && scriptParseInfo.ParseResult.Script != null && scriptParseInfo.ParseResult.Script.Tokens != null)
+            {
+                var tokenIndex = scriptParseInfo.ParseResult.Script.TokenManager.FindToken(startLine, startColumn);
+                if (tokenIndex >= 0)
+                {
+                    // return the current token
+                    int currentIndex = 0;
+                    foreach (var token in scriptParseInfo.ParseResult.Script.Tokens)
+                    {
+                        if (currentIndex == tokenIndex)
+                        {
+                            return token;
+                        }
+                        ++currentIndex;
+                    }
+                }
+            }
+            return null;
+        }
+    }
+}