Update

routes/flutter/_middleware.ts

@@ -0,0 +1,25 @@
+import { MiddlewareHandlerContext } from "$fresh/server.ts";
+import { get_task_manager } from "../../server.ts";
+import { join } from "std/path/mod.ts";
+import { exists } from "std/fs/exists.ts";
+import {
+    get_file_response,
+    GetFileResponseOptions,
+} from "../../server/get_file_response.ts";
+
+export async function handler(req: Request, _ctx: MiddlewareHandlerContext) {
+    const m = get_task_manager();
+    if (!m.cfg.flutter_frontend) {
+        return new Response("Flutter frontend is not enabled", { status: 404 });
+    }
+    const u = new URL(req.url);
+    let p = join(m.cfg.flutter_frontend, u.pathname);
+    if (!(await exists(p))) {
+        p = join(m.cfg.flutter_frontend, "/index.html");
+    }
+    const opts: GetFileResponseOptions = {};
+    opts.range = req.headers.get("range");
+    opts.if_modified_since = req.headers.get("If-Modified-Since");
+    opts.if_unmodified_since = req.headers.get("If-Unmodified-Since");
+    return await get_file_response(p, opts);
+}