const CryptoJS = require('crypto')

module.exports = class BinanceKit {
  // 创建签名
  static createSignature(secretKey, data) {
    const hmac = CryptoJS.createHmac('sha256', secretKey)
    hmac.update(BinanceKit.toQueryString(data))
    return hmac.digest('hex')
  }

  // 将map转换为queryString
  static toQueryString(data) {
    let queryString = ''
    for (let key in data) {
      queryString = queryString + `${key}=${data[key]}&`
    }
    return queryString.substring(0, queryString.length - 1)
  }

  // 获取最终QueryURL
  static toFinalQueryURL(url, data, signature) {
    return `${url}?${BinanceKit.toQueryString(data)}&signature=${signature}`
  }

  static buildExchangeInfoSymbols(symbols) {
    let buffer = ''
    let isFirst = true

    for (const symbol of symbols) {
      if (isFirst) {
        isFirst = false
        buffer = `["${symbol}"`
      } else {
        buffer = `${buffer},"${symbol}"`
      }
    }

    return `${buffer}]`
  }

  static parseLotSizeFilterMap(pairInfoList) {
    if (pairInfoList === undefined) throw new Error('exchange info symbols is undefined!')

    const filterMap = {}

    pairInfoList.forEach(function (pairInfo) {
      const lotSizeFilter = pairInfo.filters.filter(filterObj => filterObj.filterType === 'LOT_SIZE')[0]

      filterMap[pairInfo.symbol] = Math.log10(1 / parseFloat(lotSizeFilter.stepSize))
    })

    return filterMap
  }
}