feat: add gas fees endpoint for cosmos

go/coinstacks/cosmos/api/api.go

@@ -119,6 +119,7 @@ func New(httpClient *cosmos.HTTPClient, grpcClient *cosmos.GRPCClient, wsClient
 
 	v1Gas := v1.PathPrefix("/gas").Subrouter()
 	v1Gas.HandleFunc("/estimate", a.EstimateGas).Methods("POST")
+	v1Gas.HandleFunc("/fees", a.Fees).Methods("GET")
 
 	v1ValidatorsRoot := v1.PathPrefix("/validators").Subrouter()
 	v1ValidatorsRoot.HandleFunc("", a.GetValidators).Methods("GET")
@@ -206,3 +207,22 @@ func (a *API) ValidatorTxHistory(w http.ResponseWriter, r *http.Request) {
 
 	api.HandleResponse(w, http.StatusOK, txHistory)
 }
+
+// swagger:route GET /api/v1/gas/fees v1 Fees
+//
+// Get current fees.
+//
+// responses:
+//
+//	200: Fees
+//	400: BadRequestError
+//	500: InternalServerError
+func (a *API) Fees(w http.ResponseWriter, r *http.Request) {
+	fees, err := a.handler.GetFees()
+	if err != nil {
+		api.HandleError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	api.HandleResponse(w, http.StatusOK, fees)
+}

go/coinstacks/cosmos/api/handler.go

@@ -234,3 +234,31 @@ func (h *Handler) getAPRData() (*APRData, error) {
 
 	return aprData, nil
 }
+
+// Contains info about the current fees
+// swagger:model Fees
+type Fees map[string]string
+
+func (h *Handler) GetFees() (*Fees, error) {
+	globalMinGasPrices, err := h.HTTPClient.GetGlobalMinimumGasPrices()
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to get global minimum gas prices")
+	}
+
+	localMinGasPrice, err := h.HTTPClient.GetLocalMinimumGasPrices()
+	if err != nil {
+		return nil, errors.Wrap(err, "failed to get local minimum gas prices")
+	}
+
+	minGasPrices := make(Fees)
+	for k, global := range globalMinGasPrices {
+		minGasPrices[k] = global.String()
+		if local, ok := localMinGasPrice[k]; ok {
+			if local.GT(global) {
+				minGasPrices[k] = local.String()
+			}
+		}
+	}
+
+	return &minGasPrices, nil
+}

go/coinstacks/cosmos/api/swagger.json

@@ -170,6 +170,35 @@
         }
       }
     },
+    "/api/v1/gas/fees": {
+      "get": {
+        "tags": [
+          "v1"
+        ],
+        "summary": "Get current fees.",
+        "operationId": "Fees",
+        "responses": {
+          "200": {
+            "description": "Fees",
+            "schema": {
+              "$ref": "#/definitions/Fees"
+            }
+          },
+          "400": {
+            "description": "BadRequestError",
+            "schema": {
+              "$ref": "#/definitions/BadRequestError"
+            }
+          },
+          "500": {
+            "description": "InternalServerError",
+            "schema": {
+              "$ref": "#/definitions/InternalServerError"
+            }
+          }
+        }
+      }
+    },
     "/api/v1/info": {
       "get": {
         "tags": [
@@ -678,6 +707,14 @@
       },
       "x-go-package": "github.com/shapeshift/unchained/pkg/cosmos"
     },
+    "Fees": {
+      "description": "Contains info about the current fees",
+      "type": "object",
+      "additionalProperties": {
+        "type": "string"
+      },
+      "x-go-package": "github.com/shapeshift/unchained/coinstacks/cosmos/api"
+    },
     "GasAmount": {
       "type": "string",
       "x-go-package": "github.com/shapeshift/unchained/pkg/api"

go/pkg/cosmos/fees.go

@@ -0,0 +1,91 @@
+package cosmos
+
+import (
+	"encoding/json"
+	"fmt"
+
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/pkg/errors"
+)
+
+func (c *HTTPClient) GetGlobalMinimumGasPrices() (map[string]sdk.Dec, error) {
+	gasPrices := make(map[string]sdk.Dec)
+
+	var res struct {
+		Param struct {
+			Amount string `json:"subspace"`
+			Key    string `json:"key"`
+			Value  string `json:"value"`
+		} `json:"param"`
+	}
+
+	e := &ErrorResponse{}
+
+	queryParams := map[string]string{
+		"subspace": "globalfee",
+		"key":      "MinimumGasPricesParam",
+	}
+
+	r, err := c.LCD.R().SetResult(&res).SetError(e).SetQueryParams(queryParams).Get("/cosmos/params/v1beta1/params")
+	if err != nil {
+		return gasPrices, errors.Wrap(err, "failed to get globalfee params")
+	}
+
+	if r.Error() != nil {
+		return gasPrices, errors.Errorf("failed to get globalfee params: %s", e.Msg)
+	}
+
+	values := []struct {
+		Denom  string `json:"denom"`
+		Amount string `json:"amount"`
+	}{}
+
+	err = json.Unmarshal([]byte(res.Param.Value), &values)
+	if err != nil {
+		return gasPrices, errors.Wrapf(err, "failed to unmarshal value: %s", res.Param.Value)
+	}
+
+	for _, value := range values {
+		coinStr := fmt.Sprintf("%s%s", value.Amount, value.Denom)
+
+		coin, err := sdk.ParseDecCoin(coinStr)
+		if err != nil {
+			logger.Errorf("failed to parse dec coin: %s: %v", coinStr, err)
+			continue
+		}
+
+		gasPrices[coin.GetDenom()] = coin.Amount
+	}
+
+	return gasPrices, nil
+}
+
+func (c *HTTPClient) GetLocalMinimumGasPrices() (map[string]sdk.Dec, error) {
+	gasPrices := make(map[string]sdk.Dec)
+
+	var res struct {
+		MinimumGasPrice string `json:"minimum_gas_price"`
+	}
+
+	e := &ErrorResponse{}
+
+	r, err := c.LCD.R().SetResult(&res).SetError(e).Get("/cosmos/base/node/v1beta1/config")
+	if err != nil {
+		return gasPrices, errors.Wrap(err, "failed to get base node config")
+	}
+
+	if r.Error() != nil {
+		return gasPrices, errors.Errorf("failed to get base node config: %s", e.Msg)
+	}
+
+	coins, err := sdk.ParseDecCoins(res.MinimumGasPrice)
+	if err != nil {
+		return gasPrices, errors.Wrap(err, "failed to parse coins")
+	}
+
+	for _, coin := range coins {
+		gasPrices[coin.GetDenom()] = coin.Amount
+	}
+
+	return gasPrices, nil
+}