import { storageGetSync, storageRemove, storageSetSync } from './storage/index.js';

export type UserRole = 'ADMIN' | 'USER';

export interface AuthSession {
  userId: number;
  username: string;
  displayName: string;
  role: UserRole;
}

const USER_ID_KEY = 'gc_user_id';
const USERNAME_KEY = 'gc_username';
const DISPLAY_NAME_KEY = 'gc_display_name';
const ROLE_KEY = 'gc_user_role';

function normalizeRole(role: string): UserRole {
  return role === 'ADMIN' ? 'ADMIN' : 'USER';
}

export function getAuthSession(): AuthSession | null {
  const id = storageGetSync(USER_ID_KEY);
  if (!id) return null;
  const userId = Number(id);
  if (!Number.isFinite(userId) || userId <= 0) return null;
  const username = storageGetSync(USERNAME_KEY) ?? '';
  const displayName = storageGetSync(DISPLAY_NAME_KEY) ?? username;
  const storedRole = storageGetSync(ROLE_KEY);
  const role = normalizeRole(storedRole ?? 'USER');
  return { userId, username, displayName, role };
}

export function setAuthSession(session: AuthSession): void {
  storageSetSync(USER_ID_KEY, String(session.userId));
  storageSetSync(USERNAME_KEY, session.username);
  storageSetSync(DISPLAY_NAME_KEY, session.displayName);
  storageSetSync(ROLE_KEY, session.role);
}

export async function clearAuthSession(): Promise<void> {
  await storageRemove(USER_ID_KEY);
  await storageRemove(USERNAME_KEY);
  await storageRemove(DISPLAY_NAME_KEY);
  await storageRemove(ROLE_KEY);
}

export function isLoggedIn(): boolean {
  return getAuthSession() !== null;
}