Kelp UI: Move options metadata to the backend and expand options (#208)

addresses part of issue #67

* 1 - flux the optionsMetadata structure in preparation to move to backend

* 2 - move v0.1 impl of optionsMetadata to backend

* 3 - builder pattern to create optionsMetadata along with preloading logic when making APIServer

* 4 - add support for fiat via currencylayer API

* 5 - dynamically include whitelisted ccxt markets

* 6 - refactor asset converters, adding custom Display assetConverter and using for CCXT

* 7 - inclide all CCXT exchanges

* 8 - don't log the optionsMetadata json response since it's too verbose

* 9 - blacklist some ccxt exchanges that are not loading for me so startup is faster

* 10 - add all fiat currencies available via currencylayer

* 11 - list all coinmarketcap tokens via their API

* 12 - remove commented out optionsMetadata struct

api/exchange.go

@@ -96,7 +96,7 @@ type OrderbookFetcher interface {
 
 // TradeAPI is the interface we use as a generic API for trading on any crypto exchange
 type TradeAPI interface {
-	GetAssetConverter() *model.AssetConverter
+	GetAssetConverter() model.AssetConverterInterface
 
 	Constrainable
 

gui/backend/api_server.go

@@ -17,17 +17,18 @@ import (
 
 // APIServer is an instance of the API service
 type APIServer struct {
-	dirPath           string
-	binPath           string
-	configsDir        string
-	logsDir           string
-	kos               *kelpos.KelpOS
-	horizonTestnetURI string
-	horizonPubnetURI  string
-	apiTestNet        *horizonclient.Client
-	apiPubNet         *horizonclient.Client
-	apiTestNetOld     *horizon.Client
-	apiPubNetOld      *horizon.Client
+	dirPath               string
+	binPath               string
+	configsDir            string
+	logsDir               string
+	kos                   *kelpos.KelpOS
+	horizonTestnetURI     string
+	horizonPubnetURI      string
+	apiTestNet            *horizonclient.Client
+	apiPubNet             *horizonclient.Client
+	apiTestNetOld         *horizon.Client
+	apiPubNetOld          *horizon.Client
+	cachedOptionsMetadata metadata
 }
 
 // MakeAPIServer is a factory method
@@ -62,18 +63,24 @@ func MakeAPIServer(kos *kelpos.KelpOS, horizonTestnetURI string, horizonPubnetUR
 		HTTP: http.DefaultClient,
 	}
 
+	optionsMetadata, e := loadOptionsMetadata()
+	if e != nil {
+		return nil, fmt.Errorf("error while loading options metadata when making APIServer: %s", e)
+	}
+
 	return &APIServer{
-		dirPath:           dirPath,
-		binPath:           binPath,
-		configsDir:        configsDir,
-		logsDir:           logsDir,
-		kos:               kos,
-		horizonTestnetURI: horizonTestnetURI,
-		horizonPubnetURI:  horizonPubnetURI,
-		apiTestNet:        apiTestNet,
-		apiPubNet:         apiPubNet,
-		apiTestNetOld:     apiTestNetOld,
-		apiPubNetOld:      apiPubNetOld,
+		dirPath:               dirPath,
+		binPath:               binPath,
+		configsDir:            configsDir,
+		logsDir:               logsDir,
+		kos:                   kos,
+		horizonTestnetURI:     horizonTestnetURI,
+		horizonPubnetURI:      horizonPubnetURI,
+		apiTestNet:            apiTestNet,
+		apiPubNet:             apiPubNet,
+		apiTestNetOld:         apiTestNetOld,
+		apiPubNetOld:          apiPubNetOld,
+		cachedOptionsMetadata: optionsMetadata,
 	}, nil
 }
 
@@ -110,13 +117,19 @@ func (s *APIServer) writeErrorJson(w http.ResponseWriter, message string) {
 }
 
 func (s *APIServer) writeJson(w http.ResponseWriter, v interface{}) {
+	s.writeJsonWithLog(w, v, true)
+}
+
+func (s *APIServer) writeJsonWithLog(w http.ResponseWriter, v interface{}, doLog bool) {
 	marshalledJson, e := json.MarshalIndent(v, "", "    ")
 	if e != nil {
 		s.writeErrorJson(w, fmt.Sprintf("unable to marshal json with indentation: %s", e))
 		return
 	}
 
-	log.Printf("responseJson: %s\n", string(marshalledJson))
+	if doLog {
+		log.Printf("responseJson: %s\n", string(marshalledJson))
+	}
 	w.WriteHeader(http.StatusOK)
 	w.Write(marshalledJson)
 }