import axios from 'axios'
import * as jwtDecode from 'jwt-decode'
import { getTokens, setTokens } from './localStorage'

interface IToken {
  readonly iat: number
  readonly exp: number
}

export interface IRefreshTokenOptions<P> {
  onSuccess?: (principal: P) => void
  onFailure?: (err: any) => void
}

export function refreshTokensNeeded(): boolean {
  const tokens = getTokens()
  if (tokens.access && tokens.refresh) {
    const { iat, exp } = jwtDecode<IToken>(tokens.access)
    // refresh tokens if access token has exceeded half of it's lifetime
    return (iat + exp) / 2 * 1000 < Date.now()
  } else {
    return false
  }
}

export async function refreshTokens(): Promise<boolean> {
  const tokens = getTokens()
  if (tokens.access && tokens.refresh) {
    try {
      const response = await axios({
        data: `grant_type=refresh_token&refresh_token=${encodeURIComponent(tokens.refresh)}`,
        headers: {
          'content-type': 'application/x-www-form-urlencoded',
        },
        method: 'post',
        url: '/api/auth/token/create',
      })

      setTokens({
        access: response.data.access_token,
        refresh: response.data.refresh_token,
      })

      return true
    } catch (err) {
      if (err.response && err.response.status === 403) {
        return false
      } else {
        throw err
      }
    }
  } else {
    return false
  }
}