add internal redirect

src/lib/internalRedirect.ts

@@ -0,0 +1,48 @@
+import { cleanRedirect } from "@app/lib/cleanRedirect";
+
+export const INTERNAL_REDIRECT_KEY = "internal_redirect";
+
+/**
+ * Consumes the internal_redirect value from localStorage if present and valid
+ * (within TTL). Removes it from storage. Returns the path segment (with leading
+ * slash) to append to an orgId, or null if none/expired/invalid.
+ */
+export function consumeInternalRedirectPath(): string | null {
+    if (typeof window === "undefined") return null;
+    try {
+        const raw = window.localStorage.getItem(INTERNAL_REDIRECT_KEY);
+        if (raw == null || raw === "") return null;
+
+        window.localStorage.removeItem(INTERNAL_REDIRECT_KEY);
+
+        const { path: storedPath, expiresAt } = JSON.parse(raw) as {
+            path?: string;
+            expiresAt?: number;
+        };
+        if (
+            typeof storedPath !== "string" ||
+            storedPath === "" ||
+            typeof expiresAt !== "number" ||
+            Date.now() > expiresAt
+        ) {
+            return null;
+        }
+
+        const cleaned = cleanRedirect(storedPath, { fallback: "" });
+        if (!cleaned) return null;
+
+        return cleaned.startsWith("/") ? cleaned : `/${cleaned}`;
+    } catch {
+        return null;
+    }
+}
+
+/**
+ * Returns the full redirect target for an org: either `/${orgId}` or
+ * `/${orgId}${path}` if a valid internal_redirect was stored. Consumes the
+ * stored value.
+ */
+export function getInternalRedirectTarget(orgId: string): string {
+    const path = consumeInternalRedirectPath();
+    return path ? `/${orgId}${path}` : `/${orgId}`;
+}