import * as SecureStore from "expo-secure-store";
import { create } from "zustand";

const AUTH_TOKEN_KEY = "auth_token";

interface SessionState {
  token: string | null;
  /**
   * False until SecureStore returns the persisted token (or confirms absence).
   * The API client should treat requests as unauthenticated until this flips —
   * see `useSessionStore.subscribe` in App.tsx for the bootstrap.
   */
  hydrated: boolean;
  setToken: (token: string) => Promise<void>;
  clearToken: () => Promise<void>;
}

export const useSessionStore = create<SessionState>((set) => ({
  token: null,
  hydrated: false,

  setToken: async (token: string) => {
    await SecureStore.setItemAsync(AUTH_TOKEN_KEY, token);
    set({ token });
  },

  clearToken: async () => {
    await SecureStore.deleteItemAsync(AUTH_TOKEN_KEY);
    set({ token: null });
  },
}));

/**
 * Bootstrap the session by reading SecureStore once. Call from App.tsx before
 * mounting the navigator. Resolves after the store reflects whatever was in
 * persistent storage.
 */
export async function hydrateSession(): Promise<void> {
  try {
    const token = await SecureStore.getItemAsync(AUTH_TOKEN_KEY);
    useSessionStore.setState({ token: token ?? null, hydrated: true });
  } catch {
    // SecureStore failures are non-fatal — proceed unauthenticated.
    useSessionStore.setState({ token: null, hydrated: true });
  }
}