import { atom } from 'jotai';

export type BackendUser = {
  id: string;
  email: string | null;
  isGuest: boolean;
  profileComplete: boolean;
};

export type GuestSession = {
  id: string;
  isGuest: true;
  createdAt: string;
};

export const GUEST_SESSION_STORAGE_KEY = 'guest-session';

const readGuestSession = (): GuestSession | null => {
  if (typeof window === 'undefined') return null;
  const raw = localStorage.getItem(GUEST_SESSION_STORAGE_KEY);
  if (!raw) return null;
  try {
    const parsed = JSON.parse(raw) as GuestSession;
    if (!parsed?.id || parsed?.isGuest !== true) return null;
    return parsed;
  } catch {
    return null;
  }
};

export const backendUserAtom = atom<BackendUser | null>(null);

export const isAuthenticatedAtom = atom<boolean>((get) => {
  return !!get(backendUserAtom);
});

export const guestSessionAtom = atom<GuestSession | null>(readGuestSession());
export const guestSessionHydratedAtom = atom(false);
export const isGuestAtom = atom<boolean>((get) => !!get(guestSessionAtom));

export const effectiveUserIdAtom = atom<string | null>((get) => {
  const user = get(backendUserAtom);
  if (user?.id) return user.id;
  const guest = get(guestSessionAtom);
  return guest?.id ?? null;
});

export const authInitialCheckDoneAtom = atom(false);