add Bank of Russia exchange rates data source

2026-05-22 02:34:26 +08:00 · 2024-11-17 01:29:52 +08:00
parent e019f557ff
commit 69498003d8
6 changed files with 309 additions and 0 deletions
@@ -0,0 +1,149 @@
+package exchangerates
+
+import (
+	"bytes"
+	"encoding/xml"
+	"math"
+	"strings"
+	"time"
+
+	"golang.org/x/net/html/charset"
+
+	"github.com/mayswind/ezbookkeeping/pkg/core"
+	"github.com/mayswind/ezbookkeeping/pkg/errs"
+	"github.com/mayswind/ezbookkeeping/pkg/log"
+	"github.com/mayswind/ezbookkeeping/pkg/models"
+	"github.com/mayswind/ezbookkeeping/pkg/utils"
+	"github.com/mayswind/ezbookkeeping/pkg/validators"
+)
+
+const bankOfRussiaExchangeRateUrl = "https://cbr.ru/scripts/XML_daily_eng.asp"
+const bankOfRussiaExchangeRateReferenceUrl = "https://www.cbr.ru/eng/currency_base/daily/"
+const bankOfRussiaDataSource = "Bank of Russia"
+const bankOfRussiaBaseCurrency = "RUB"
+
+const bankOfRussiaUpdateDateFormat = "02.01.2006 15:04"
+const bankOfRussiaUpdateDateTimezone = "Europe/Moscow"
+
+// BankOfRussiaDataSource defines the structure of exchange rates data source of bank of Russia
+type BankOfRussiaDataSource struct {
+	ExchangeRatesDataSource
+}
+
+// BankOfRussiaExchangeRateData represents the whole data from bank of Russia
+type BankOfRussiaExchangeRateData struct {
+	XMLName       xml.Name                    `xml:"ValCurs"`
+	Date          string                      `xml:"Date,attr"`
+	ExchangeRates []*BankOfRussiaExchangeRate `xml:"Valute"`
+}
+
+// BankOfRussiaExchangeRate represents the exchange rate data from bank of Russia
+type BankOfRussiaExchangeRate struct {
+	Currency string `xml:"CharCode"`
+	Rate     string `xml:"VunitRate"`
+}
+
+// ToLatestExchangeRateResponse returns a view-object according to original data from bank of Russia
+func (e *BankOfRussiaExchangeRateData) ToLatestExchangeRateResponse(c core.Context) *models.LatestExchangeRateResponse {
+	if len(e.ExchangeRates) < 1 {
+		log.Errorf(c, "[bank_of_russia_datasource.ToLatestExchangeRateResponse] all exchange rates is empty")
+		return nil
+	}
+
+	exchangeRates := make(models.LatestExchangeRateSlice, 0, len(e.ExchangeRates))
+
+	for i := 0; i < len(e.ExchangeRates); i++ {
+		exchangeRate := e.ExchangeRates[i]
+
+		if _, exists := validators.AllCurrencyNames[exchangeRate.Currency]; !exists {
+			continue
+		}
+
+		finalExchangeRate := exchangeRate.ToLatestExchangeRate(c)
+
+		if finalExchangeRate == nil {
+			continue
+		}
+
+		exchangeRates = append(exchangeRates, finalExchangeRate)
+	}
+
+	timezone, err := time.LoadLocation(bankOfRussiaUpdateDateTimezone)
+
+	if err != nil {
+		log.Errorf(c, "[bank_of_russia_datasource.ToLatestExchangeRateResponse] failed to get timezone, timezone name is %s", bankOfRussiaUpdateDateTimezone)
+		return nil
+	}
+
+	updateDateTime := e.Date + " 15:30" // the Bank of Russia switches to setting official exchange rates of foreign currencies against the ruble as of 15:30 Moscow time.
+	updateTime, err := time.ParseInLocation(bankOfRussiaUpdateDateFormat, updateDateTime, timezone)
+
+	if err != nil {
+		log.Errorf(c, "[bank_of_russia_datasource.ToLatestExchangeRateResponse] failed to parse update date, datetime is %s", updateDateTime)
+		return nil
+	}
+
+	latestExchangeRateResp := &models.LatestExchangeRateResponse{
+		DataSource:    bankOfRussiaDataSource,
+		ReferenceUrl:  bankOfRussiaExchangeRateReferenceUrl,
+		UpdateTime:    updateTime.Unix(),
+		BaseCurrency:  bankOfRussiaBaseCurrency,
+		ExchangeRates: exchangeRates,
+	}
+
+	return latestExchangeRateResp
+}
+
+// ToLatestExchangeRate returns a data pair according to original data from bank of Russia
+func (e *BankOfRussiaExchangeRate) ToLatestExchangeRate(c core.Context) *models.LatestExchangeRate {
+	rate, err := utils.StringToFloat64(strings.ReplaceAll(e.Rate, ",", "."))
+
+	if err != nil {
+		log.Warnf(c, "[bank_of_russia_datasource.ToLatestExchangeRate] failed to parse rate, currency is %s, rate is %s", e.Currency, e.Rate)
+		return nil
+	}
+
+	if rate <= 0 {
+		log.Warnf(c, "[bank_of_russia_datasource.ToLatestExchangeRate] rate is invalid, currency is %s, rate is %s", e.Currency, e.Rate)
+		return nil
+	}
+
+	finalRate := 1 / rate
+
+	if math.IsInf(finalRate, 0) {
+		return nil
+	}
+
+	return &models.LatestExchangeRate{
+		Currency: e.Currency,
+		Rate:     utils.Float64ToString(finalRate),
+	}
+}
+
+// GetRequestUrls returns the bank of Russia data source urls
+func (e *BankOfRussiaDataSource) GetRequestUrls() []string {
+	return []string{bankOfRussiaExchangeRateUrl}
+}
+
+// Parse returns the common response entity according to the bank of Russia data source raw response
+func (e *BankOfRussiaDataSource) Parse(c core.Context, content []byte) (*models.LatestExchangeRateResponse, error) {
+	xmlDecoder := xml.NewDecoder(bytes.NewReader(content))
+	xmlDecoder.CharsetReader = charset.NewReaderLabel
+
+	bankOfRussiaData := &BankOfRussiaExchangeRateData{}
+	err := xmlDecoder.Decode(bankOfRussiaData)
+
+	if err != nil {
+		log.Errorf(c, "[bank_of_russia_datasource.Parse] failed to parse xml data, content is %s, because %s", string(content), err.Error())
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	latestExchangeRateResponse := bankOfRussiaData.ToLatestExchangeRateResponse(c)
+
+	if latestExchangeRateResponse == nil {
+		log.Errorf(c, "[bank_of_russia_datasource.Parse] failed to parse latest exchange rate data, content is %s", string(content))
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	return latestExchangeRateResponse, nil
+}