support exchange rate

pkg/api/exchange_rates.go

@@ -0,0 +1,54 @@
+package api
+
+import (
+	"encoding/xml"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/mayswind/lab/pkg/core"
+	"github.com/mayswind/lab/pkg/errs"
+	"github.com/mayswind/lab/pkg/log"
+	"github.com/mayswind/lab/pkg/models"
+)
+
+const EuroCentralBankExchangeRateUrl = "https://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml"
+
+type ExchangeRatesApi struct {}
+
+var (
+	ExchangeRates = &ExchangeRatesApi{}
+)
+
+func (a *ExchangeRatesApi) LatestExchangeRateHandler(c *core.Context) (interface{}, *errs.Error) {
+	uid := c.GetCurrentUid()
+	resp, err := http.Get(EuroCentralBankExchangeRateUrl)
+
+	if err != nil {
+		log.ErrorfWithRequestId(c, "[exchange_rates.LatestExchangeRateHandler] failed to request latest exchange rate data for user \"uid:%d\", because %s", uid, err.Error())
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	if resp.StatusCode != 200 {
+		log.ErrorfWithRequestId(c, "[exchange_rates.LatestExchangeRateHandler] failed to get latest exchange rate data response for user \"uid:%d\", because response code is not 200", uid)
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	euroCentralBankData := &models.EuroCentralBankExchangeRateData{}
+	err = xml.Unmarshal(body, euroCentralBankData)
+
+	if err != nil {
+		log.ErrorfWithRequestId(c, "[exchange_rates.LatestExchangeRateHandler] failed to parse xml data for user \"uid:%d\", response is %s, because %s", uid, string(body), err.Error())
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	latestExchangeRateResponse := euroCentralBankData.ToLatestExchangeRateResponse()
+
+	if latestExchangeRateResponse == nil {
+		log.ErrorfWithRequestId(c, "[exchange_rates.LatestExchangeRateHandler] failed to parse latest exchange rate data for user \"uid:%d\", response is %s,", uid, string(body))
+		return nil, errs.ErrFailedToRequestRemoteApi
+	}
+
+	return latestExchangeRateResponse, nil
+}