From 064acda30468bc0aceabd34fb49b9dd224ddb64e Mon Sep 17 00:00:00 2001
From: Nikolaj <nel@umbraco.dk>
Date: Wed, 2 Sep 2020 10:17:33 +0200
Subject: [PATCH] First shake at RoslynCompiler

---
 .../RoslynCompiler.cs                         | 52 +++++++++++++++++++
 .../Umbraco.ModelsBuilder.Embedded.csproj     |  4 ++
 2 files changed, 56 insertions(+)
 create mode 100644 src/Umbraco.ModelsBuilder.Embedded/RoslynCompiler.cs

diff --git a/src/Umbraco.ModelsBuilder.Embedded/RoslynCompiler.cs b/src/Umbraco.ModelsBuilder.Embedded/RoslynCompiler.cs
new file mode 100644
index 0000000000..43a9202c13
--- /dev/null
+++ b/src/Umbraco.ModelsBuilder.Embedded/RoslynCompiler.cs
@@ -0,0 +1,52 @@
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.Diagnostics;
+using Microsoft.CodeAnalysis.Text;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Reflection;
+using System.Text;
+
+namespace Umbraco.ModelsBuilder.Embedded
+{
+    public class RoslynCompiler
+    {
+        private OutputKind _outputKind;
+        private CSharpParseOptions _parseOptions;
+
+        public RoslynCompiler()
+        {
+            _outputKind = OutputKind.DynamicallyLinkedLibrary;
+            _parseOptions = CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.Latest);  // What languageversion should we default to?
+        }
+
+        public Assembly GetCompiledAssembly(string pathToSourceFile, IEnumerable<MetadataReference> refs)
+        {
+            // TODO: Get proper temp file location/filename
+            var outputPath = $"generated.cs.{Guid.NewGuid()}.dll";
+            var sourceCode = File.ReadAllText(pathToSourceFile);
+
+            CompileToFile(outputPath, sourceCode, "ModelsGenerated", refs);
+            return Assembly.LoadFile(outputPath);
+
+        } 
+
+        private void CompileToFile(string outputFile, string sourceCode, string assemblyName, IEnumerable<MetadataReference> references)
+        {
+            var sourceText = SourceText.From(sourceCode);
+
+            var syntaxTree = SyntaxFactory.ParseSyntaxTree(sourceText, _parseOptions);
+
+            var compilation = CSharpCompilation.Create(assemblyName,
+                new[] { syntaxTree },
+                references: references,
+                options: new CSharpCompilationOptions(_outputKind,
+                optimizationLevel: OptimizationLevel.Release,
+                // Not entirely certain that assemblyIdentityComparer is nececary? 
+                assemblyIdentityComparer: DesktopAssemblyIdentityComparer.Default));
+
+            compilation.Emit(outputFile);
+        }
+    }
+}
diff --git a/src/Umbraco.ModelsBuilder.Embedded/Umbraco.ModelsBuilder.Embedded.csproj b/src/Umbraco.ModelsBuilder.Embedded/Umbraco.ModelsBuilder.Embedded.csproj
index 0046c568f1..ff6d55d8eb 100644
--- a/src/Umbraco.ModelsBuilder.Embedded/Umbraco.ModelsBuilder.Embedded.csproj
+++ b/src/Umbraco.ModelsBuilder.Embedded/Umbraco.ModelsBuilder.Embedded.csproj
@@ -10,6 +10,10 @@
         <DocumentationFile>bin\Release\Umbraco.ModelsBuilder.Embedded.xml</DocumentationFile>
     </PropertyGroup>
 
+    <ItemGroup>
+      <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="3.7.0" />
+    </ItemGroup>
+
     <ItemGroup>
       <ProjectReference Include="..\Umbraco.Core\Umbraco.Core.csproj" />
       <ProjectReference Include="..\Umbraco.Infrastructure\Umbraco.Infrastructure.csproj" />