// session.ts — 会话存储
// access token：仅内存(防 XSS 持久化窃取)；refresh token：localStorage(header token 方案)。
// 取舍：doc/05 §2 给「HttpOnly+Secure cookie 或 header token」两选;纯静态导出无服务端
// 设置 cookie 的能力,故取 header token + localStorage,并配合静默续期与登出失效收敛风险。
import type { Session } from './types';

const REFRESH_KEY = 'pg_uc_refresh';

let accessToken: string | null = null;
let accessExpiresAt = 0;

export function getAccessToken(): string | null {
  return accessToken;
}

export function accessValid(skewMs = 15_000): boolean {
  return !!accessToken && Date.now() < accessExpiresAt - skewMs;
}

export function getRefreshToken(): string | null {
  if (typeof window === 'undefined') return null;
  try {
    return window.localStorage.getItem(REFRESH_KEY);
  } catch {
    return null;
  }
}

export function setSession(s: Session): void {
  accessToken = s.accessToken;
  accessExpiresAt = s.accessExpiresAt;
  if (typeof window !== 'undefined') {
    try {
      window.localStorage.setItem(REFRESH_KEY, s.refreshToken);
    } catch {
      /* ignore quota / privacy mode */
    }
  }
}

export function clearSession(): void {
  accessToken = null;
  accessExpiresAt = 0;
  if (typeof window !== 'undefined') {
    try {
      window.localStorage.removeItem(REFRESH_KEY);
    } catch {
      /* ignore */
    }
  }
}

export function hasRefresh(): boolean {
  return !!getRefreshToken();
}