Offline worst case trade fees (#274)

* Really basic getSimulated fee function everywhere

* Worst case fees for all exchanges

* Adds tests, fixes comment spacing. Adds wrapper logic. Makes test api key var name consistent. Removes some okcoin ETT tests

* Removes redundant functions

* linting issues. Fixes introduces huobi issues

* More linting

* Stops trying to hide ETT problems, uses iota

* Skips ETT tests for now

exchanges/btcc/btcc.go

@@ -104,6 +104,8 @@ func (b *BTCC) GetFee(feeBuilder *exchange.FeeBuilder) (float64, error) {
 		fee = getCryptocurrencyWithdrawalFee(feeBuilder.Pair.Base)
 	case exchange.InternationalBankWithdrawalFee:
 		fee = getInternationalBankWithdrawalFee(feeBuilder.FiatCurrency, feeBuilder.Amount)
+	case exchange.OfflineTradeFee:
+		fee = getOfflineTradeFee(feeBuilder.PurchasePrice, feeBuilder.Amount)
 	}
 	if fee < 0 {
 		fee = 0
@@ -111,6 +113,11 @@ func (b *BTCC) GetFee(feeBuilder *exchange.FeeBuilder) (float64, error) {
 	return fee, nil
 }
 
+// getOfflineTradeFee calculates the worst case-scenario trading fee
+func getOfflineTradeFee(price, amount float64) float64 {
+	return 0.001 * price * amount
+}
+
 func getCryptocurrencyWithdrawalFee(c currency.Code) float64 {
 	return WithdrawalFees[c]
 }

exchanges/btcc/btcc_test.go

@@ -84,6 +84,21 @@ func setFeeBuilder() *exchange.FeeBuilder {
 	}
 }
 
+// TestGetFeeByTypeOfflineTradeFee logic test
+func TestGetFeeByTypeOfflineTradeFee(t *testing.T) {
+	var feeBuilder = setFeeBuilder()
+	b.GetFeeByType(feeBuilder)
+	if apiKey == "" || apiSecret == "" {
+		if feeBuilder.FeeType != exchange.OfflineTradeFee {
+			t.Errorf("Expected %v, received %v", exchange.OfflineTradeFee, feeBuilder.FeeType)
+		}
+	} else {
+		if feeBuilder.FeeType != exchange.CryptocurrencyTradeFee {
+			t.Errorf("Expected %v, received %v", exchange.CryptocurrencyTradeFee, feeBuilder.FeeType)
+		}
+	}
+}
+
 func TestGetFee(t *testing.T) {
 	b.SetDefaults()
 	TestSetup(t)

exchanges/btcc/btcc_wrapper.go

@@ -158,6 +158,10 @@ func (b *BTCC) GetWebsocket() (*exchange.Websocket, error) {
 
 // GetFeeByType returns an estimate of fee based on type of transaction
 func (b *BTCC) GetFeeByType(feeBuilder *exchange.FeeBuilder) (float64, error) {
+	if (b.APIKey == "" || b.APISecret == "") && // Todo check connection status
+		feeBuilder.FeeType == exchange.CryptocurrencyTradeFee {
+		feeBuilder.FeeType = exchange.OfflineTradeFee
+	}
 	return b.GetFee(feeBuilder)
 }