From d98fbfe2bf6a22850d817b7dd1520843d5be784a Mon Sep 17 00:00:00 2001
From: Dillon Kearns <dillon@incrementalelm.com>
Date: Thu, 15 Sep 2022 10:59:33 -0700
Subject: [PATCH] Add starting point for wiring up elm-codegen for Main.elm.

---
 codegen/Generate.elm                          | 12 +++-
 codegen/GenerateMain.elm                      | 63 +++++++++++++++++++
 .../src/generate-template-module-connector.js |  8 ++-
 3 files changed, 80 insertions(+), 3 deletions(-)

diff --git a/codegen/Generate.elm b/codegen/Generate.elm
index 7cf4996b..9dd65741 100644
--- a/codegen/Generate.elm
+++ b/codegen/Generate.elm
@@ -18,6 +18,7 @@ import Gen.Path
 import Gen.Server.Response
 import Gen.String
 import Gen.Tuple
+import GenerateMain
 import Pages.Internal.RoutePattern as RoutePattern exposing (RoutePattern)
 import Pretty
 import Regex exposing (Regex)
@@ -34,8 +35,17 @@ main =
     Platform.worker
         { init =
             \{ templates, basePath } ->
+                let
+                    routes : List RoutePattern.RoutePattern
+                    routes =
+                        templates
+                            |> List.filterMap RoutePattern.fromModuleName
+                in
                 ( ()
-                , onSuccessSend [ file templates basePath ]
+                , onSuccessSend
+                    [ file templates basePath
+                    , GenerateMain.otherFile routes
+                    ]
                 )
         , update =
             \_ model ->
diff --git a/codegen/GenerateMain.elm b/codegen/GenerateMain.elm
index e69de29b..dd5dbae6 100644
--- a/codegen/GenerateMain.elm
+++ b/codegen/GenerateMain.elm
@@ -0,0 +1,63 @@
+module GenerateMain exposing (..)
+
+import Elm exposing (File)
+import Elm.Annotation as Type
+import Elm.Case
+import Elm.CodeGen
+import Elm.Declare
+import Elm.Op
+import Elm.Pretty
+import Gen.Basics
+import Gen.CodeGen.Generate exposing (Error)
+import Gen.Html
+import Gen.Html.Attributes
+import Gen.List
+import Gen.Path
+import Gen.Server.Response
+import Gen.String
+import Gen.Tuple
+import Pages.Internal.RoutePattern as RoutePattern exposing (RoutePattern)
+import Pretty
+import Regex exposing (Regex)
+
+
+otherFile : List RoutePattern.RoutePattern -> File
+otherFile routes =
+    Elm.file [ "Main" ]
+        [ Elm.alias "Model"
+            (Type.record
+                [ ( "global", Type.named [ "Shared" ] "Model" )
+                , ( "page", Type.named [] "PageModel" )
+                , ( "current"
+                  , Type.maybe
+                        (Type.record
+                            [ ( "path", Type.named [ "Path" ] "Path" )
+                            , ( "query", Type.named [ "Path" ] "Path" |> Type.maybe )
+                            , ( "fragment", Type.string |> Type.maybe )
+                            ]
+                        )
+                  )
+                ]
+            )
+        , Elm.customType "PageModel"
+            ((routes
+                |> List.map
+                    (\route ->
+                        Elm.variantWith
+                            ("Model"
+                                ++ (RoutePattern.toModuleName route |> String.join "__")
+                            )
+                            [ Type.named
+                                ("Route"
+                                    :: RoutePattern.toModuleName route
+                                )
+                                "Model"
+                            ]
+                    )
+             )
+                ++ [ Elm.variantWith "ModelErrorPage____"
+                        [ Type.named [ "ErrorPage" ] "Model" ]
+                   , Elm.variant "NotFound"
+                   ]
+            )
+        ]
diff --git a/generator/src/generate-template-module-connector.js b/generator/src/generate-template-module-connector.js
index 29fae10b..1c0fc81b 100644
--- a/generator/src/generate-template-module-connector.js
+++ b/generator/src/generate-template-module-connector.js
@@ -38,12 +38,15 @@ async function generateTemplateModuleConnector(basePath, phase) {
       ],
     };
   }
-  const routesModule = await runElmCodegenCli(
+  const elmCodegenFiles = await runElmCodegenCli(
     sortTemplates(templates),
     basePath
   );
+  const routesModule = elmCodegenFiles[0].contents;
+  const newMain = elmCodegenFiles[1].contents;
 
   return {
+    // mainModule: newMain,
     mainModule: `port module Main exposing (..)
 
 import Api
@@ -1044,8 +1047,9 @@ async function runElmCodegenCli(templates, basePath) {
     }
   });
   const filesToGenerate = await promise;
+  console.dir(filesToGenerate.map((file) => file.path));
 
-  return filesToGenerate[0].contents;
+  return filesToGenerate;
 }
 
 function emptyRouteParams(name) {