From 92797c4ea51bce9fc7d2f50b8f6156f2d5204497 Mon Sep 17 00:00:00 2001
From: Mohammed Sohail <sohailsameja@gmail.com>
Date: Tue, 14 Dec 2021 17:50:07 +0300
Subject: [PATCH] add: batch rpc calls

---
 internal/server/handlers.go | 63 ++++++++++++++++++-------------------
 internal/server/router.go   | 28 +++++++++++++++++
 pkg/rpc/client.go           | 16 ++++++++--
 3 files changed, 73 insertions(+), 34 deletions(-)

diff --git a/internal/server/handlers.go b/internal/server/handlers.go
index 82a57a9..7193618 100644
--- a/internal/server/handlers.go
+++ b/internal/server/handlers.go
@@ -1,52 +1,51 @@
 package server
 
 import (
-	"net/http"
-
-	"github.com/gin-gonic/gin"
-	"github.com/rs/zerolog/log"
-
 	"git.grassecon.org/grassrootseconomics/openethereum-node-status/pkg/rpc"
-)
-
-type (
-	R struct {
-		Result string `json:"result"`
-	}
-
-	P map[string]interface{}
+	"github.com/rs/zerolog/log"
+	"github.com/ybbus/jsonrpc/v2"
 )
 
 var (
 	RpcClient rpc.RpcClient
 )
 
-func metricsHandler(c *gin.Context) {
-	// pllholder rpc call
-	rpcResponse, err := RpcClient.EthRpcCall("eth_gasPrice")
+type BatchResponse struct {
+	SyncComplete bool
+	ChainName    string
+}
+
+func batchCall() (bool, BatchResponse) {
+	var batchResponse BatchResponse
+
+	rpcResponses, err := RpcClient.EthBatchRpcCall(jsonrpc.RPCRequests{
+		jsonrpc.NewRequest("eth_syncing"),
+		jsonrpc.NewRequest("parity_chain"),
+	})
+
 	if err != nil {
 		log.Error().
 			Err(err).
 			Str("module", "server").
-			Msg("rpc call failed")
+			Msg("error in batch responses")
+		return false, batchResponse
 	}
 
-	value, err := rpcResponse.GetString()
-	if err != nil {
-		log.Error().
-			Err(err).
-			Str("module", "server").
-			Msg("rpc response to string conversion failed")
+	if syncStatus, ok := rpcResponses[0]; ok {
+		val, err := syncStatus.GetBool()
+		if err != nil {
+			return false, batchResponse
+		}
+		batchResponse.SyncComplete = !val
 	}
 
-	c.JSON(http.StatusOK, gin.H{
-		"ok":   true,
-		"data": value,
-	})
-}
+	if chainName, ok := rpcResponses[1]; ok {
+		val, err := chainName.GetString()
+		if err != nil {
+			return false, batchResponse
+		}
+		batchResponse.ChainName = val
+	}
 
-func healthHandler(c *gin.Context) {
-	c.JSON(http.StatusOK, gin.H{
-		"ok": true,
-	})
+	return true, batchResponse
 }
diff --git a/internal/server/router.go b/internal/server/router.go
index 82c9469..e547b49 100644
--- a/internal/server/router.go
+++ b/internal/server/router.go
@@ -1,6 +1,9 @@
 package server
 
 import (
+	"fmt"
+	"net/http"
+
 	"github.com/gin-gonic/gin"
 )
 
@@ -15,3 +18,28 @@ func Start(port string, ginMode string) error {
 
 	return router.Run(port)
 }
+
+func healthHandler(c *gin.Context) {
+	allOk, data := batchCall()
+
+	fmt.Println(data.SyncComplete)
+	if !allOk {
+		c.JSON(http.StatusExpectationFailed, gin.H{
+			"ok":      false,
+			"message": "could not get node health status",
+		})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"ok":           true,
+		"syncComplete": data.SyncComplete,
+		"chainName":    data.ChainName,
+	})
+}
+
+func metricsHandler(c *gin.Context) {
+	c.JSON(http.StatusOK, gin.H{
+		"ok": true,
+	})
+}
diff --git a/pkg/rpc/client.go b/pkg/rpc/client.go
index 1fc7712..29b113e 100644
--- a/pkg/rpc/client.go
+++ b/pkg/rpc/client.go
@@ -19,12 +19,24 @@ func NewRpcClient(endpoint string) RpcClient {
 func (r *RpcClient) EthRpcCall(method string) (*jsonrpc.RPCResponse, error) {
 	response, err := r.ethClient.Call(method)
 	if err != nil {
-		return response, err
+		return nil, err
 	}
 
 	if response.Error != nil {
-		return response, fmt.Errorf("rpc client error: (code %d) %s", response.Error.Code, response.Error.Message)
+		return nil, fmt.Errorf("rpc client error: (code %d) %s", response.Error.Code, response.Error.Message)
 	}
 
 	return response, nil
 }
+
+func (r *RpcClient) EthBatchRpcCall(batchedMethods jsonrpc.RPCRequests) (map[int]*jsonrpc.RPCResponse, error) {
+	response, _ := r.ethClient.CallBatch(batchedMethods)
+
+	if response.HasError() {
+		return nil, fmt.Errorf("batch rpc request failed")
+	}
+
+	results := response.AsMap()
+
+	return results, nil
+}