fix: build signin url properly

Author: joonatank

apps/ui/middleware.ts

@@ -1,25 +1,23 @@
 import { NextResponse } from "next/server";
 import type { NextRequest } from "next/server";
 import { getSignInUrl } from "@/modules/const";
+import { env } from "@/env.mjs";
 
 function redirectProtectedRoute(req: NextRequest) {
   // TODO check that the cookie is valid not just present
   const { cookies, headers } = req;
   const hasSession = cookies.has("sessionid");
-  const apiBaseUrl = process.env.NEXT_PUBLIC_API_BASE_URL ?? "";
+  const apiBaseUrl = env.TILAVARAUS_API_URL ?? "";
 
   if (!hasSession) {
     // on the server we are behind a gateway so get the forwarded headers
     // localhost has no headers
     const currentUrl = req.url;
+    const url = new URL(currentUrl);
     const protocol = headers.get("x-forwarded-proto") ?? "http";
-    const host = headers.get("x-forwarded-host");
-    const originalUrl = headers.get("x-original-url");
-    if (host && originalUrl) {
-      const origin = `${protocol}://${host}`;
-      return getSignInUrl(apiBaseUrl, originalUrl, origin);
-    }
-    return getSignInUrl(apiBaseUrl, currentUrl);
+    const host = headers.get("x-forwarded-host") ?? url.host;
+    const origin = `${protocol}://${host}`;
+    return getSignInUrl(apiBaseUrl, url.pathname, origin);
   }
   return undefined;
 }

packages/common/src/urlBuilder.ts

@@ -30,13 +30,15 @@ export function getSignInUrl(
   originOverride?: string
 ): string {
   const authUrl = buildAuthUrl(apiBaseUrl);
-  // TODO why is originOveride only used when on logout?
   if (callBackUrl.includes(`/logout`)) {
+    // TODO this is unsound if the callback url is not a full url but this at least redirects to an error page
     const baseUrl =
       originOverride != null ? originOverride : new URL(callBackUrl).origin;
     return `${authUrl}login?next=${baseUrl}`;
   }
-  return `${authUrl}login?next=${callBackUrl}`;
+  const next =
+    originOverride != null ? `${originOverride}/${callBackUrl}` : callBackUrl;
+  return `${authUrl}login?next=${next}`;
 }
 
 /// @param apiBaseUrl - base url for api (hostname typically)