attempt to use rosyln compiler for trigger completion but it's too much

BtcTransmuter/BtcTransmuter.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk.Web">
+<Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
     <TargetFramework>netcoreapp2.2</TargetFramework>
@@ -18,6 +18,11 @@
     <PackageReference Include="ExtCore.WebApplication" Version="4.0.0" />
     <PackageReference Include="Microsoft.AspNetCore.App" />
     <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.2.0" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Features" Version="3.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Scripting" Version="3.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="3.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Features" Version="3.0.0" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.2.2" />
     <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="2.2.0" />
     <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.2.2" PrivateAssets="All" />

BtcTransmuter/Controllers/TestController.cs

@@ -0,0 +1,94 @@
+using System;
+using System.Collections.Generic;
+using System.Composition.Hosting;
+using System.Linq;
+using System.Reflection;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.Completion;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Host.Mef;
+using Microsoft.CodeAnalysis.Text;
+
+namespace BtcTransmuter.Controllers
+{
+    [Route("[controller]")]
+    public class TestController: Controller
+    {
+        [AllowAnonymous]
+        [HttpPost("")]
+        public async Task<IActionResult> Test([FromBody]GetAutoCompleteRequest request)
+        {
+            var assemblies = new[]
+            {
+                typeof(string).Assembly,
+                typeof(IList<string>).Assembly,
+                Assembly.Load("Microsoft.CodeAnalysis"),
+                Assembly.Load("Microsoft.CodeAnalysis.CSharp"),
+                Assembly.Load("Microsoft.CodeAnalysis.Features"),
+                Assembly.Load("Microsoft.CodeAnalysis.CSharp.Features"),
+            };
+
+            var partTypes = MefHostServices.DefaultAssemblies.Concat(assemblies)
+                .Distinct()
+                .SelectMany(x => x.GetTypes())
+                .ToArray();
+
+            var compositionContext = new ContainerConfiguration()
+                .WithParts(partTypes)
+                .CreateContainer();
+
+            MefHostServices host = MefHostServices.Create(compositionContext);
+            var workspace = new AdhocWorkspace(host);
+
+//            var variableCode = "";
+//            foreach (var variable in request.Variables)
+//            {
+//                variableCode = $"{variable.Value} {variable.Key};";
+//            }
+
+//            var scriptCode = $"{variableCode} var x={request.Command}";
+            var pos = request.Pos.GetValueOrDefault(request.Command.Length );
+//            pos = (scriptCode.Length - request.Command.Length) + pos;
+            var scriptCode = request.Command;
+            var compilationOptions = new CSharpCompilationOptions(
+                OutputKind.DynamicallyLinkedLibrary,
+                usings: new[] { "System" });
+
+            var scriptProjectInfo = ProjectInfo.Create(ProjectId.CreateNewId(), VersionStamp.Create(), "Script",
+                    "Script", LanguageNames.CSharp, isSubmission: true)
+                .WithMetadataReferences(new[]
+                {
+                    MetadataReference.CreateFromFile(typeof(object).Assembly.Location)
+                })
+                .WithCompilationOptions(compilationOptions);
+
+            var scriptProject = workspace.AddProject(scriptProjectInfo);
+            var scriptDocumentInfo = DocumentInfo.Create(
+                DocumentId.CreateNewId(scriptProject.Id), "Script",
+                sourceCodeKind: SourceCodeKind.Script,
+                loader: TextLoader.From(TextAndVersion.Create(SourceText.From(scriptCode), VersionStamp.Create())));
+            var scriptDocument = workspace.AddDocument(scriptDocumentInfo);
+
+            var completionService = CompletionService.GetService(scriptDocument);
+            var results = await completionService.GetCompletionsAsync(scriptDocument, pos);
+
+            return Json(results.Items.Where(item => item.Tags.Contains("Public")).Select(item => new
+            {
+                Text = item.DisplayText,
+                Props = item.Properties.Select(pair => $"{pair.Key}:{pair.Value}"),
+                Tags = item.Tags
+            }));
+        }
+    }
+
+    public class GetAutoCompleteRequest
+    {
+        public string Command { get; set; }
+
+        public Dictionary<string, string>  Variables{ get; set; }
+        public int? Pos { get; set; } 
+    }
+}