add the currency service

currency/handler/currency.go

@@ -0,0 +1,105 @@
+package handler
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/micro/v3/service/logger"
+	pb "github.com/micro/services/currency/proto"
+)
+
+type Currency struct {
+	Api string
+}
+
+func (c *Currency) Rates(ctx context.Context, req *pb.RatesRequest, rsp *pb.RatesResponse) error {
+	if len(req.Code) == 0 {
+		return errors.BadRequest("currency.rates", "missing code")
+	}
+	if len(req.Code) != 3 {
+		return errors.BadRequest("currency.rates", "code is invalid")
+	}
+
+	resp, err := http.Get(c.Api + "/latest/" + req.Code)
+	if err != nil {
+		logger.Errorf("Failed to get rates: %v\n", err)
+		return errors.InternalServerError("currency.rates", "failed to get rates")
+	}
+	defer resp.Body.Close()
+
+	b, _ := ioutil.ReadAll(resp.Body)
+
+	if resp.StatusCode != 200 {
+		logger.Errorf("Failed to get rates (non 200): %d %v\n", resp.StatusCode, string(b))
+		return errors.InternalServerError("currency.rates", "failed to get rates")
+	}
+
+	var respBody map[string]interface{}
+
+	if err := json.Unmarshal(b, &respBody); err != nil {
+		logger.Errorf("Failed to unmarshal rates: %v\n", err)
+		return errors.InternalServerError("currency.rates", "failed to get rates")
+	}
+
+	rates, ok := respBody["conversion_rates"].(map[string]interface{})
+	if !ok {
+		logger.Errorf("Failed to convert rates to map[string]interface{}: %v\n", ok)
+		return errors.InternalServerError("currency.rates", "failed to get rates")
+	}
+
+	rsp.Code = req.Code
+	rsp.Rates = make(map[string]float64)
+
+	for code, rate := range rates {
+		rsp.Rates[code], _ = rate.(float64)
+	}
+
+	return nil
+}
+
+func (c *Currency) Convert(ctx context.Context, req *pb.ConvertRequest, rsp *pb.ConvertResponse) error {
+	if len(req.From) != 3 {
+		return errors.BadRequest("currency.convert", "invalid from code")
+	}
+	if len(req.To) != 3 {
+		return errors.BadRequest("currency.convert", "invalid to code")
+	}
+
+	uri := fmt.Sprintf("%s/pair/%s/%s", c.Api, req.From, req.To)
+
+	if req.Amount > 0.0 {
+		uri = fmt.Sprintf("%s/%v", uri, req.Amount)
+	}
+
+	resp, err := http.Get(uri)
+	if err != nil {
+		logger.Errorf("Failed to convert: %v\n", err)
+		return errors.InternalServerError("currency.convert", "failed to convert")
+	}
+	defer resp.Body.Close()
+
+	b, _ := ioutil.ReadAll(resp.Body)
+
+	if resp.StatusCode != 200 {
+		logger.Errorf("Failed to get convert (non 200): %d %v\n", resp.StatusCode, string(b))
+		return errors.InternalServerError("currency.convert", "failed to convert")
+	}
+
+	var respBody map[string]interface{}
+
+	if err := json.Unmarshal(b, &respBody); err != nil {
+		logger.Errorf("Failed to unmarshal conversion: %v\n", err)
+		return errors.InternalServerError("currency.convet", "failed to convert")
+	}
+
+	rsp.From = req.From
+	rsp.To = req.To
+	rsp.Rate, _ = respBody["conversion_rate"].(float64)
+	rsp.Amount, _ = respBody["conversion_result"].(float64)
+
+	return nil
+}