add new settings redirect_to_flutter

routes/index.tsx

@@ -3,7 +3,10 @@ import { Handlers, PageProps } from "$fresh/server.ts";
 import GlobalContext from "../components/GlobalContext.tsx";
 import Container from "../islands/Container.tsx";
 import { get_i18nmap, i18n_handle_request } from "../server/i18ns.ts";
+import { get_task_manager } from "../server.ts";
 import { UserAgent } from "std/http/user_agent.ts";
+import { exists } from "std/fs/exists.ts";
+import { get_host } from "../server/utils.ts";
 
 type Props = {
     lang: string;
@@ -11,13 +14,28 @@ type Props = {
 };
 
 export const handler: Handlers<Props> = {
-    GET(req, ctx) {
+    async GET(req, ctx) {
         const re = i18n_handle_request(req);
+        const m = get_task_manager();
         if (typeof re === "string") {
             return ctx.render({
                 lang: re,
                 userAgent: req.headers.get("User-Agent"),
             });
+        } else if (m.cfg.redirect_to_flutter) {
+            let flutter_base = import.meta.resolve("../static/flutter").slice(
+                7,
+            );
+            if (Deno.build.os === "windows") {
+                flutter_base = flutter_base.slice(1);
+            }
+            if (m.cfg.flutter_frontend) {
+                flutter_base = m.cfg.flutter_frontend;
+            }
+            if (!await exists(flutter_base)) {
+                return re;
+            }
+            return Response.redirect(`${get_host(req)}/flutter/`);
         }
         return re;
     },