support exchange rate

pkg/models/exchange_rate.go

@@ -0,0 +1,67 @@
+package models
+
+import "encoding/xml"
+
+const EuroCentralBankDataSource = "European Central Bank"
+const EuroCentralBankBaseCurrency = "EUR"
+
+type LatestExchangeRateResponse struct {
+	DataSource    string                `json:"dataSource"`
+	Date          string                `json:"date"`
+	BaseCurrency  string                `json:"baseCurrency"`
+	ExchangeRates []*LatestExchangeRate `json:"exchangeRates"`
+}
+
+type LatestExchangeRate struct {
+	Currency string `json:"currency"`
+	Rate     string `json:"rate"`
+}
+
+type EuroCentralBankExchangeRateData struct {
+	XMLName          xml.Name                        `xml:"Envelope"`
+	AllExchangeRates []*EuroCentralBankExchangeRates `xml:"Cube>Cube"`
+}
+
+type EuroCentralBankExchangeRates struct {
+	Date          string                         `xml:"time,attr"`
+	ExchangeRates []*EuroCentralBankExchangeRate `xml:"Cube"`
+}
+
+type EuroCentralBankExchangeRate struct {
+	Currency string `xml:"currency,attr"`
+	Rate     string `xml:"rate,attr"`
+}
+
+func (e EuroCentralBankExchangeRateData) ToLatestExchangeRateResponse() *LatestExchangeRateResponse {
+	if len(e.AllExchangeRates) < 1 {
+		return nil
+	}
+
+	latestEuroCentralBankExchangeRate := e.AllExchangeRates[0]
+
+	if len(latestEuroCentralBankExchangeRate.ExchangeRates) < 1 {
+		return nil
+	}
+
+	exchangeRates := make([]*LatestExchangeRate, len(latestEuroCentralBankExchangeRate.ExchangeRates))
+
+	for i := 0; i < len(latestEuroCentralBankExchangeRate.ExchangeRates); i++ {
+		exchangeRates[i] = latestEuroCentralBankExchangeRate.ExchangeRates[i].ToLatestExchangeRate()
+	}
+
+	latestExchangeRateResp := &LatestExchangeRateResponse{
+		DataSource:    EuroCentralBankDataSource,
+		Date:          latestEuroCentralBankExchangeRate.Date,
+		BaseCurrency:  EuroCentralBankBaseCurrency,
+		ExchangeRates: exchangeRates,
+	}
+
+	return latestExchangeRateResp
+}
+
+func (e EuroCentralBankExchangeRate) ToLatestExchangeRate() *LatestExchangeRate {
+	return &LatestExchangeRate{
+		Currency: e.Currency,
+		Rate:     e.Rate,
+	}
+}