import Taro from '@tarojs/taro'

const TOKEN_KEY = 'token'
const TOKEN_TYPE_KEY = 'token_type'
const USER_ID_KEY = 'user_id'
const EXPIRES_IN_KEY = 'expires_in'
const TOKEN_EXPIRES_AT_KEY = 'token_expires_at'
const LOGIN_PAGE_URL = '/pages/login/index'

let redirectingToLogin = false

export interface StoredLoginSession {
  access_token: string
  token_type: string
  expires_in: number
  user_id: number
}

export function saveLoginSession(session: StoredLoginSession): void {
  const expiresAt = Date.now() + Math.max(session.expires_in, 0) * 1000
  Taro.setStorageSync(TOKEN_KEY, session.access_token)
  Taro.setStorageSync(TOKEN_TYPE_KEY, session.token_type)
  Taro.setStorageSync(USER_ID_KEY, session.user_id)
  Taro.setStorageSync(EXPIRES_IN_KEY, session.expires_in)
  Taro.setStorageSync(TOKEN_EXPIRES_AT_KEY, expiresAt)
}

export function clearLoginSession(): void {
  Taro.removeStorageSync(TOKEN_KEY)
  Taro.removeStorageSync(TOKEN_TYPE_KEY)
  Taro.removeStorageSync(USER_ID_KEY)
  Taro.removeStorageSync(EXPIRES_IN_KEY)
  Taro.removeStorageSync(TOKEN_EXPIRES_AT_KEY)
}

function getTokenExpiresAt(): number {
  const rawValue = Number(Taro.getStorageSync(TOKEN_EXPIRES_AT_KEY) || 0)
  return Number.isFinite(rawValue) ? rawValue : 0
}

export function getToken(): string {
  const token = Taro.getStorageSync(TOKEN_KEY) || ''
  if (!token) return ''

  const expiresAt = getTokenExpiresAt()
  if (expiresAt > 0 && Date.now() >= expiresAt) {
    clearLoginSession()
    return ''
  }

  return token
}

export function getCurrentUserId(): number {
  if (!getToken()) return 0
  return Number(Taro.getStorageSync(USER_ID_KEY) || 0)
}

export function handleUnauthorized(options: { redirect?: boolean } = {}): void {
  const { redirect = true } = options
  clearLoginSession()

  if (!redirect || redirectingToLogin) return

  redirectingToLogin = true
  setTimeout(() => {
    Taro.reLaunch({ url: LOGIN_PAGE_URL })
    setTimeout(() => {
      redirectingToLogin = false
    }, 600)
  }, 120)
}