storj/satellite/payments/coinpayments/conversionrates.go

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// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.
package coinpayments
import (
"context"
"encoding/json"
"math/big"
"net/url"
"strconv"
"time"
)
// cmdRates is API command for retrieving currency rate infos.
const cmdRates = "rates"
// ExchangeStatus defines if currency is exchangeable.
type ExchangeStatus string
const (
// ExchangeStatusOnline defines exchangeable currency.
ExchangeStatusOnline ExchangeStatus = "online"
// ExchangeStatusOffline defines currency that can not be convertible at the moment.
ExchangeStatusOffline ExchangeStatus = "offline"
)
// CurrencyRateInfo holds currency conversion info.
type CurrencyRateInfo struct {
IsFiat bool
RateBTC big.Float
TXFee big.Float
Status ExchangeStatus
LastUpdate time.Time
}
// UnmarshalJSON converts JSON string to currency rate info.
func (rateInfo *CurrencyRateInfo) UnmarshalJSON(b []byte) error {
var rateRaw struct {
IsFiat int `json:"is_fiat"`
RateBTC string `json:"rate_btc"`
TXFee string `json:"tx_fee"`
Status string `json:"status"`
LastUpdate string `json:"last_update"`
}
if err := json.Unmarshal(b, &rateRaw); err != nil {
return err
}
parseBigFloat := func(s string) (*big.Float, error) {
f, _, err := big.ParseFloat(s, 10, 256, big.ToNearestEven)
return f, err
}
rateBTC, err := parseBigFloat(rateRaw.RateBTC)
if err != nil {
return err
}
txFee, err := parseBigFloat(rateRaw.TXFee)
if err != nil {
return err
}
lastUpdate, err := strconv.ParseInt(rateRaw.LastUpdate, 10, 64)
if err != nil {
return err
}
*rateInfo = CurrencyRateInfo{
IsFiat: rateRaw.IsFiat > 0,
RateBTC: *rateBTC,
TXFee: *txFee,
Status: ExchangeStatus(rateRaw.Status),
LastUpdate: time.Unix(lastUpdate, 0),
}
return nil
}
// CurrencyRateInfos maps currency to currency rate info.
type CurrencyRateInfos map[Currency]CurrencyRateInfo
// ConversionRates collection of API methods for retrieving currency
// conversion rates.
type ConversionRates struct {
client *Client
}
// Get returns USD rate for specified currency.
func (rates ConversionRates) Get(ctx context.Context) (CurrencyRateInfos, error) {
values := make(url.Values)
values.Set("short", "1")
rateInfos := make(CurrencyRateInfos)
res, err := rates.client.do(ctx, cmdRates, values)
if err != nil {
return nil, Error.Wrap(err)
}
if err = json.Unmarshal(res, &rateInfos); err != nil {
return nil, Error.Wrap(err)
}
return rateInfos, nil
}