add National Bank of Georgia exchange rates data source

pkg/exchangerates/national_bank_of_georgia_datasource.go

@@ -0,0 +1,142 @@
+package exchangerates
+
+import (
+	"encoding/json"
+	"math"
+	"time"
+
+	"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 nationalBankOfGeorgiaExchangeRateUrl = "https://nbg.gov.ge/gw/api/ct/monetarypolicy/currencies/en/json"
+const nationalBankOfGeorgiaExchangeRateReferenceUrl = "https://nbg.gov.ge/en/monetary-policy/currency"
+const nationalBankOfGeorgiaDataSource = "National Bank of Georgia"
+const nationalBankOfGeorgiaBaseCurrency = "GEL"
+
+const nationalBankOfGeorgiaUpdateDateFormat = "2006-01-02T15:04:05.999Z"
+
+// NationalBankOfGeorgiaDataSource defines the structure of exchange rates data source of national bank of Georgia
+type NationalBankOfGeorgiaDataSource struct {
+	ExchangeRatesDataSource
+}
+
+// NationalBankOfGeorgiaExchangeRates represents the exchange rates data from national bank of Georgia
+type NationalBankOfGeorgiaExchangeRates struct {
+	Date          string                               `json:"date"`
+	ExchangeRates []*NationalBankOfGeorgiaExchangeRate `json:"currencies"`
+}
+
+// NationalBankOfGeorgiaExchangeRate represents the exchange rate data from national bank of Georgia
+type NationalBankOfGeorgiaExchangeRate struct {
+	Currency string  `json:"code"`
+	Quantity float64 `json:"quantity"`
+	Rate     float64 `json:"rate"`
+	Date     string  `json:"date"`
+}
+
+// ToLatestExchangeRateResponse returns a view-object according to original data from national bank of Georgia
+func (e *NationalBankOfGeorgiaExchangeRates) ToLatestExchangeRateResponse(c core.Context) *models.LatestExchangeRateResponse {
+	if len(e.ExchangeRates) < 1 {
+		log.Errorf(c, "[national_bank_of_georgia_datasource.ToLatestExchangeRateResponse] exchange rates is empty")
+		return nil
+	}
+
+	exchangeRates := make(models.LatestExchangeRateSlice, 0, len(e.ExchangeRates))
+	latestUpdateTime := int64(0)
+
+	for i := 0; i < len(e.ExchangeRates); i++ {
+		exchangeRate := e.ExchangeRates[i]
+
+		if _, exists := validators.AllCurrencyNames[exchangeRate.Currency]; !exists {
+			continue
+		}
+
+		updateTime, err := time.Parse(nationalBankOfGeorgiaUpdateDateFormat, exchangeRate.Date)
+
+		if err != nil {
+			log.Errorf(c, "[national_bank_of_georgia_datasource.ToLatestExchangeRateResponse] failed to parse update date, datetime is %s", exchangeRate.Date)
+			return nil
+		}
+
+		if updateTime.Unix() > latestUpdateTime {
+			latestUpdateTime = updateTime.Unix()
+		}
+
+		finalExchangeRate := exchangeRate.ToLatestExchangeRate(c)
+
+		if finalExchangeRate == nil {
+			continue
+		}
+
+		exchangeRates = append(exchangeRates, finalExchangeRate)
+	}
+
+	latestExchangeRateResp := &models.LatestExchangeRateResponse{
+		DataSource:    nationalBankOfGeorgiaDataSource,
+		ReferenceUrl:  nationalBankOfGeorgiaExchangeRateReferenceUrl,
+		UpdateTime:    latestUpdateTime,
+		BaseCurrency:  nationalBankOfGeorgiaBaseCurrency,
+		ExchangeRates: exchangeRates,
+	}
+
+	return latestExchangeRateResp
+}
+
+// ToLatestExchangeRate returns a data pair according to original data from national bank of Georgia
+func (e *NationalBankOfGeorgiaExchangeRate) ToLatestExchangeRate(c core.Context) *models.LatestExchangeRate {
+	if e.Rate <= 0 {
+		log.Warnf(c, "[national_bank_of_georgia_datasource.ToLatestExchangeRate] rate is invalid, currency is %s, rate is %f", e.Currency, e.Rate)
+		return nil
+	}
+
+	if e.Quantity <= 0 {
+		log.Warnf(c, "[national_bank_of_georgia_datasource.ToLatestExchangeRate] quantity is invalid, currency is %s, quantity is %f", e.Currency, e.Quantity)
+		return nil
+	}
+
+	finalRate := e.Quantity / e.Rate
+
+	if math.IsInf(finalRate, 0) {
+		return nil
+	}
+
+	return &models.LatestExchangeRate{
+		Currency: e.Currency,
+		Rate:     utils.Float64ToString(finalRate),
+	}
+}
+
+// GetRequestUrls returns the national bank of Georgia data source urls
+func (e *NationalBankOfGeorgiaDataSource) GetRequestUrls() []string {
+	return []string{nationalBankOfGeorgiaExchangeRateUrl}
+}
+
+// Parse returns the common response entity according to the national bank of Georgia data source raw response
+func (e *NationalBankOfGeorgiaDataSource) Parse(c core.Context, content []byte) (*models.LatestExchangeRateResponse, error) {
+	nationalBankOfGeorgiaData := &[]*NationalBankOfGeorgiaExchangeRates{}
+	err := json.Unmarshal(content, nationalBankOfGeorgiaData)
+
+	if err != nil {
+		log.Errorf(c, "[national_bank_of_georgia_datasource.Parse] failed to parse xml data, content is %s, because %s", string(content), err.Error())
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	if nationalBankOfGeorgiaData == nil || len(*nationalBankOfGeorgiaData) < 1 {
+		log.Errorf(c, "[national_bank_of_georgia_datasource.ToLatestExchangeRateResponse] all exchange rates is empty")
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	latestExchangeRateResponse := (*nationalBankOfGeorgiaData)[0].ToLatestExchangeRateResponse(c)
+
+	if latestExchangeRateResponse == nil {
+		log.Errorf(c, "[national_bank_of_georgia_datasource.Parse] failed to parse latest exchange rate data, content is %s", string(content))
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	return latestExchangeRateResponse, nil
+}