const mem = require('mem')
const configManager = require('./new-config-manager')
const ph = require('./plugin-helper')
const logger = require('./logger')
const axios = require('axios')

const lastRate = {}

const FETCH_INTERVAL = 60000

function _getRates (settings, fiatCode, cryptoCode) {
  return Promise.resolve()
    .then(() => {
      const config = settings.config
      const plugin = configManager.getWalletSettings(cryptoCode, config).ticker

      const account = settings.accounts[plugin]
      const ticker = ph.load(ph.TICKER, plugin)

      const market = [cryptoCode, fiatCode].join('-')

      return ticker.ticker(account, fiatCode, cryptoCode)
        .then(r => ({
          rates: r.rates,
          timestamp: Date.now()
        }))
        .then(r => {
          lastRate[market] = r
          return r
        })
        .catch(err => {
          logger.error(err)
          return lastRate[market]
        })
    })
}

const getRates = mem(_getRates, {
  maxAge: FETCH_INTERVAL,
  cacheKey: (settings, fiatCode, cryptoCode) => JSON.stringify([fiatCode, cryptoCode])
})

const getBtcRates = (to = null, from = 'USD') => {
  // if to !== null, then we return only the rates with from (default USD) and to (so an array with 2 items)
  return axios.get('https://bitpay.com/api/rates').then(response => {
    const fxRates = response.data
    if (to === null) {
      return fxRates
    }
    const toRate = fxRates.find(o => o.code === to)
    const fromRate = fxRates.find(o => o.code === from)

    let res = []
    if (toRate && to !== from) {
      res = [...res, toRate]
    }
    if (fromRate) {
      res = [...res, fromRate]
    }

    return res
  })
}

module.exports = { getBtcRates, getRates }