🧪 feat: add middleware for authentication and parsing requests

Implements a new middleware function in the web app for handling authentication and parsing incoming requests.

- Adds a new file `apps/web/middleware.ts` for the middleware implementation.
- Uses Next.js middleware API for handling requests and responses, and NextAuth's `getToken` for obtaining user session data.
- Parses the request to extract the domain, path, and other information.
- Redirects unauthenticated users to the sign-in page if they try to access protected routes.
- Exports a `parse` function for parsing incoming requests and extracting relevant information.

Author: mangledbottles

apps/web/middleware.ts

@@ -0,0 +1,54 @@
+import { NextFetchEvent, NextRequest, NextResponse } from "next/server";
+import { getToken } from "next-auth/jwt";
+
+export default async function middleware(req: NextRequest, ev: NextFetchEvent) {
+    const { path, fullPath } = parse(req);
+
+    // Use regex to match {domain}/app/* paths
+    const appPathRegex = /^\/app\/.*/;
+    if (!appPathRegex.test(path)) {
+        return;
+    }
+
+    const session = (await getToken({
+        req,
+        secret: process.env.NEXTAUTH_SECRET,
+    })) as {
+        uid?: string;
+    };
+
+    const authIssue = !session || !session?.uid;
+
+    if (authIssue && (path !== "/signin" &&
+        path !== "/signup" &&
+        path !== "/api/auth/signin" &&
+        path !== "/api/auth/signup" && path !== "/api/auth/providers")) {
+        return NextResponse.redirect(
+            new URL(
+                `/signin${path === "/" ? "" : `?redirect=${encodeURIComponent(fullPath)}`}`,
+                req.url,
+            ),
+        );
+    }
+
+    return;
+}
+
+export const parse = (req: NextRequest) => {
+    let domain = req.headers.get("host") as string;
+    domain = domain.replace("www.", ""); // remove www. from domain
+
+    // path is the path of the URL (e.g. screenlink.io/view/id -> /view/id)
+    let path = req.nextUrl.pathname;
+
+    // fullPath is the full URL path (along with search params)
+    const searchParams = req.nextUrl.searchParams.toString();
+    const fullPath = `${path}${searchParams.length > 0 ? `?${searchParams}` : ""
+        }`;
+
+    // Here, we are using decodeURIComponent to handle foreign languages like Hebrew
+    const key = decodeURIComponent(path.split("/")[1]); // key is the first part of the path (e.g. screenlink.io/view/id -> view)
+    const fullKey = decodeURIComponent(path.slice(1)); // fullKey is the full path without the first slash (to account for multi-level subpaths, e.g. screenlink.io/view/id -> view/id)
+
+    return { domain, path, fullPath, key, fullKey };
+};