export const ACCESS_TOKEN_KEY = 'cc-client-access-token'
export const REFRESH_TOKEN_KEY = 'cc-client-refresh-token'
export const OVERSEAS_ACCESS_TOKEN_KEY = 'cc-client-overseas-access-token'
export const OVERSEAS_EXPIRES_AT_KEY = 'cc-client-overseas-expires-at'

export interface TokenPair {
  tokenType: string
  accessToken: string
  expiresIn: number
  refreshToken: string
  refreshExpiresIn: number
  overseasAccessToken?: string | null
  overseasExpiresIn?: number
}

function activeStorage() {
  if (localStorage.getItem(ACCESS_TOKEN_KEY)) return localStorage
  return sessionStorage
}

export function getAccessToken() {
  return localStorage.getItem(ACCESS_TOKEN_KEY) || sessionStorage.getItem(ACCESS_TOKEN_KEY) || ''
}

export function getRefreshToken() {
  return localStorage.getItem(REFRESH_TOKEN_KEY) || sessionStorage.getItem(REFRESH_TOKEN_KEY) || ''
}

export function getOverseasAccessToken() {
  const storage = activeStorage()
  const expiresAt = Number(storage.getItem(OVERSEAS_EXPIRES_AT_KEY) || 0)
  if (expiresAt <= Date.now() + 30_000) return ''
  return storage.getItem(OVERSEAS_ACCESS_TOKEN_KEY) || ''
}

export function persistTokenPair(tokens: TokenPair, remember?: boolean) {
  const storage = remember === undefined ? activeStorage() : remember ? localStorage : sessionStorage
  clearSessionTokens()
  storage.setItem(ACCESS_TOKEN_KEY, tokens.accessToken)
  storage.setItem(REFRESH_TOKEN_KEY, tokens.refreshToken)
  if (tokens.overseasAccessToken && Number(tokens.overseasExpiresIn) > 0) {
    storage.setItem(OVERSEAS_ACCESS_TOKEN_KEY, tokens.overseasAccessToken)
    storage.setItem(OVERSEAS_EXPIRES_AT_KEY, String(Date.now() + Number(tokens.overseasExpiresIn) * 1000))
  }
}

export function persistTemporaryAccessToken(accessToken: string) {
  clearSessionTokens()
  sessionStorage.setItem(ACCESS_TOKEN_KEY, accessToken)
}

export function clearSessionTokens() {
  for (const storage of [localStorage, sessionStorage]) {
    storage.removeItem(ACCESS_TOKEN_KEY)
    storage.removeItem(REFRESH_TOKEN_KEY)
    storage.removeItem(OVERSEAS_ACCESS_TOKEN_KEY)
    storage.removeItem(OVERSEAS_EXPIRES_AT_KEY)
    storage.removeItem('cc-client-token')
  }
}