Added generation options

Author: MIchaelMainer

src/Typewriter/Options.cs

@@ -10,6 +10,25 @@ public enum VerbosityLevel
         Trace
     }
 
+    /// <summary>
+    /// Specifies how Typewriter will processes the input metadata and what type of outputs it produces.
+    /// </summary>
+    public enum GenerationMode
+    {
+        /// <summary>
+        /// (default) Produces the output code files by cleaning the input metadata, parsing the docs, and adding annotations before generating the output files.
+        /// </summary>
+        Full,
+        /// <summary>
+        /// Produces an output metadata file by cleaning metadata, documentation parsing, and adding doc annotations.
+        /// </summary>
+        Metadata,
+        /// <summary>
+        /// Uses the input metadata and only generates code files for the target platform. It bypasses the cleaning, doc parsing, and adding doc annotations.
+        /// </summary>
+        Files
+    }
+
     class Options
     {
         [Option('l', "language", Default = "CSharp", HelpText = "The target language for the generated code files. The values can be: Android, Java, ObjC, CSharp, PHP, Python, TypeScript, or GraphEndpointList")]
@@ -26,5 +45,11 @@ class Options
 
         [Option('d', "docs", Default = ".", HelpText = "Path to the root of the documentation repo folder")]
         public string DocsRoot { get; set; }
+
+        [Option('g', "generationmode", Default = GenerationMode.Full, HelpText = "Specifies the generation mode. The values can be: Full, Metadata, or Files. Full generation mode produces " +
+            "the output code files by cleaning the input metadata, parsing the documentation, and adding annotations before generating the output files. Metadata generation mode" +
+            "produces an output metadata file by cleaning metadata, documentation parsing, and adding documentation annotations. Files generation mode produces code files from" +
+            "an input metadata and bypasses the cleaning, documentation parsing, and adding documentation annotations.")]
+        public GenerationMode GenerateMode { get; set; }
     }
 }

src/Typewriter/Program.cs

@@ -31,16 +31,40 @@ private static void GenerateSDK(Options options)
 
             string csdlContents = MetadataResolver.GetMetadata(options.Metadata);
 
+            // Generate the files from the input metadata and do not preprocess.
+            if (options.GenerateMode == GenerationMode.Files)
+            {
+                var files = MetadataToClientSource(csdlContents, options.Language);
+                FileWriter.WriteAsync(files, options.Output);
+
+                stopwatch.Stop();
+                Logger.Info($"Generation time: {stopwatch.Elapsed } seconds.");
+
+                return;
+            }
+
             // Clean up EDMX to work with the generators assumptions.
             string processedCsdlContents = MetadataPreprocessor.CleanMetadata(csdlContents);
 
             // Inject documentation annotations into the CSDL using ApiDoctor.
             string csdlWithDocAnnotations = AnnotationHelper.ApplyAnnotationsToCsdl(processedCsdlContents, options).Result;
+
+            // Output the clean and annotated metadata. 
+            if (options.GenerateMode == GenerationMode.Metadata)
+            {
+                // TODO: Write the metadata to the output directory using csdlWithDocAnnotations.
+
+                stopwatch.Stop();
+                Logger.Info($"Generation time: {stopwatch.Elapsed } seconds.");
+
+                return;
+            }
 
+            // Default GenerationMode.Full.
             // Create code files from the CSDL with annotations for the target platform and write those files to disk.
             var files = MetadataToClientSource(csdlWithDocAnnotations, options.Language);
             FileWriter.WriteAsync(files, options.Output);
-
+            
             stopwatch.Stop();
             Logger.Info($"Generation time: {stopwatch.Elapsed } seconds.");
         }