Subcommands (#62)

Gitea.Declarative/OutputSchema.fs

@@ -0,0 +1,47 @@
+namespace Gitea.Declarative
+
+open System.IO
+open Argu
+
+type OutputSchemaArgsFragment =
+    | Output of string
+
+    interface IArgParserTemplate with
+        member s.Usage =
+            match s with
+            | Output _ -> "path to the file to be written (or overwritten, if it already exists), instead of stdout"
+
+type OutputSchemaArgs =
+    {
+        Output : FileInfo option
+    }
+
+    static member OfParse
+        (parsed : ParseResults<OutputSchemaArgsFragment>)
+        : Result<OutputSchemaArgs, ArguParseException>
+        =
+        try
+            {
+                Output = parsed.TryGetResult OutputSchemaArgsFragment.Output |> Option.map FileInfo
+            }
+            |> Ok
+        with :? ArguParseException as e ->
+            Error e
+
+[<RequireQualifiedAccess>]
+module OutputSchema =
+
+    let run (args : OutputSchemaArgs) : Async<int> =
+        async {
+            use stream = GiteaConfig.getSchema ()
+
+            match args.Output with
+            | None ->
+                let reader = new StreamReader (stream)
+                System.Console.WriteLine (reader.ReadToEnd ())
+            | Some output ->
+                use output = output.OpenWrite ()
+                stream.CopyTo output
+
+            return 0
+        }