Create flow: session UI + sign out

app/create/hooks/useCreateFlowExit.ts

@@ -0,0 +1,62 @@
+"use client";
+
+import { useCallback } from "react";
+import type { CreateFlowState, CreateFlowStep } from "../types";
+import { saveDraftToServer } from "../../../lib/create/api";
+import messages from "../../../messages/en/index";
+
+const SYNC_ENABLED = process.env.NEXT_PUBLIC_ENABLE_BACKEND_SYNC === "true";
+
+export type CreateFlowExitClearState = () => void;
+
+type AppRouterLike = { push: (_href: string) => void };
+
+/**
+ * Leave the create flow for a **signed-in** user. Caller must not invoke for anonymous users.
+ */
+export function useCreateFlowExit({
+  state,
+  currentStep,
+  clearState,
+  router,
+  user,
+}: {
+  state: CreateFlowState;
+  currentStep: CreateFlowStep | null;
+  clearState: CreateFlowExitClearState;
+  router: AppRouterLike;
+  user: { id: string; email: string } | null;
+}): (options?: { saveDraft?: boolean }) => Promise<void> {
+  return useCallback(
+    async (options?: { saveDraft?: boolean }) => {
+      if (!user) return;
+
+      const saveDraft = options?.saveDraft ?? false;
+
+      if (!saveDraft && typeof window !== "undefined") {
+        const confirmed = window.confirm(
+          messages.create.topNav.leaveConfirmLoss,
+        );
+        if (!confirmed) return;
+      }
+
+      if (saveDraft && SYNC_ENABLED) {
+        const payload: CreateFlowState = {
+          ...state,
+          ...(currentStep ? { currentStep } : {}),
+        };
+        const ok = await saveDraftToServer(payload);
+        if (!ok && typeof window !== "undefined") {
+          const leave = window.confirm(
+            messages.create.topNav.leaveConfirmSaveFailed,
+          );
+          if (!leave) return;
+        }
+      }
+
+      clearState();
+      router.push("/");
+    },
+    [state, currentStep, clearState, router, user],
+  );
+}