Initial metadata and scripting services (#280)

* Initial metadata service and scripting service files

* Simple metadata lookup with SMO objects

* Add metadata type class

* Remove SMO from metadata service.

* Cleanup metadata service SQL

* Initial MetadataService test

* Add scripting commands

* Add metadata test case

* Remove sleep used for testing

* Use random table name in metadata test

* Add scripting tests

src/Microsoft.SqlTools.ServiceLayer/Scripting/Contracts/ScriptingSelectRequest.cs

@@ -0,0 +1,54 @@
+//
+// 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.Hosting.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Metadata.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.Scripting.Contracts
+{
+    /// <summary>
+    /// The type of scripting operation requested
+    /// </summary>
+    public enum ScriptOperation
+    {
+        Select = 0,
+        Create = 1,
+        Insert = 2,
+        Update = 3,
+        Delete = 4
+    }
+
+    /// <summary>
+    /// Script as request parameter type
+    /// </summary>
+    public class ScriptingScriptAsParams 
+    {
+        public string OwnerUri { get; set; }
+
+        public ScriptOperation Operation { get; set; }
+
+        public ObjectMetadata Metadata { get; set; }
+    }
+
+    /// <summary>
+    /// Script as request result type
+    /// </summary>
+    public class ScriptingScriptAsResult
+    {
+        public string OwnerUri { get; set; }
+
+        public string Script { get; set; }
+    }
+
+    /// <summary>
+    /// Script as request message type
+    /// </summary>
+    public class ScriptingScriptAsRequest
+    {
+        public static readonly
+            RequestType<ScriptingScriptAsParams, ScriptingScriptAsResult> Type =
+                RequestType<ScriptingScriptAsParams, ScriptingScriptAsResult>.Create("scripting/scriptas");
+    }
+}

src/Microsoft.SqlTools.ServiceLayer/Scripting/ScriptingService.cs

@@ -0,0 +1,82 @@
+//
+// 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.Threading.Tasks;
+using Microsoft.SqlTools.Hosting.Protocol;
+using Microsoft.SqlTools.ServiceLayer.Hosting;
+using Microsoft.SqlTools.ServiceLayer.Scripting.Contracts;
+
+namespace Microsoft.SqlTools.ServiceLayer.Scripting
+{
+    /// <summary>
+    /// Main class for Scripting Service functionality
+    /// </summary>
+    public sealed class ScriptingService
+    {
+        private static readonly Lazy<ScriptingService> LazyInstance = new Lazy<ScriptingService>(() => new ScriptingService());
+
+        public static ScriptingService Instance => LazyInstance.Value;
+
+        /// <summary>
+        /// Initializes the Scripting Service instance
+        /// </summary>
+        /// <param name="serviceHost"></param>
+        /// <param name="context"></param>
+        public void InitializeService(ServiceHost serviceHost)
+        {
+            serviceHost.SetRequestHandler(ScriptingScriptAsRequest.Type, HandleScriptingScriptAsRequest);
+        }
+
+        /// <summary>
+        /// Handles script as request messages
+        /// </summary>
+        /// <param name="scriptingParams"></param>
+        /// <param name="requestContext"></param>
+        internal static async Task HandleScriptingScriptAsRequest(
+            ScriptingScriptAsParams scriptingParams,
+            RequestContext<ScriptingScriptAsResult> requestContext)
+        {
+            string script = string.Empty;
+            if (scriptingParams.Operation == ScriptOperation.Select)
+            {
+                script = string.Format(
+@"SELECT *
+FROM {0}.{1}",
+                scriptingParams.Metadata.Schema, scriptingParams.Metadata.Name);
+            }
+            else if (scriptingParams.Operation == ScriptOperation.Create)
+            {
+                script = string.Format(
+@"CREATE {0}.{1}",
+                scriptingParams.Metadata.Schema, scriptingParams.Metadata.Name);
+            }
+            else if (scriptingParams.Operation == ScriptOperation.Update)
+            {
+                script = string.Format(
+@"UPDATE {0}.{1}",
+                scriptingParams.Metadata.Schema, scriptingParams.Metadata.Name);
+            }
+            else if (scriptingParams.Operation == ScriptOperation.Insert)
+            {
+                script = string.Format(
+@"INSERT {0}.{1}",
+                scriptingParams.Metadata.Schema, scriptingParams.Metadata.Name);
+            }
+            else if (scriptingParams.Operation == ScriptOperation.Delete)
+            {
+                script = string.Format(
+@"DELETE {0}.{1}",
+                scriptingParams.Metadata.Schema, scriptingParams.Metadata.Name);
+            }
+
+            await requestContext.SendResult(new ScriptingScriptAsResult()
+            {
+                OwnerUri = scriptingParams.OwnerUri,
+                Script = script
+            });
+        }
+    }
+}