Add get balance api

api/service/restclientsupport/service.go

@@ -34,6 +34,7 @@ type Service struct {
 	CreateTransactionForPickWinner  func() error
 	messageChan                     chan *msg_pb.Message
 	CallFaucetContract              func(common.Address) common.Hash
+	GetAccountBalance               func(common.Address) (*big.Int, error)
 }
 
 // New returns new client support service.
@@ -41,12 +42,13 @@ func New(
 	CreateTransactionForEnterMethod func(int64, string) error,
 	GetResult func(string) ([]string, []*big.Int),
 	CreateTransactionForPickWinner func() error,
-	CallFaucetContract func(common.Address) common.Hash) *Service {
+	CallFaucetContract func(common.Address) common.Hash, GetAccountBalance func(common.Address) (*big.Int, error)) *Service {
 	return &Service{
 		CreateTransactionForEnterMethod: CreateTransactionForEnterMethod,
 		GetResult:                       GetResult,
 		CreateTransactionForPickWinner:  CreateTransactionForPickWinner,
 		CallFaucetContract:              CallFaucetContract,
+		GetAccountBalance:               GetAccountBalance,
 	}
 }
 
@@ -108,12 +110,25 @@ type Response struct {
 // GetBalance implements the GetFreeToken interface to request free token.
 func (s *Service) GetBalance(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
-	key := r.FormValue("key")
+	addressHex := r.FormValue("key")
+	fmt.Println("fundMe: address", addressHex)
+
 	res := &Response{Success: false}
-	res.Players = append(res.Players, key)
+	if s.GetAccountBalance == nil {
-	// res.Balances = append(res.Players, GETMYBALANCE) // implements this
 		json.NewEncoder(w).Encode(res)
+		return
+	}
+	res.Players = append(res.Players, addressHex)
 
+	address := common.HexToAddress(addressHex)
+	balance, err := s.GetAccountBalance(address)
+	if err != nil {
+		json.NewEncoder(w).Encode(res)
+		return
+	}
+	res.Balances = append(res.Players, balance.String())
+	res.Success = true
+	json.NewEncoder(w).Encode(res)
 }
 
 // FundMe implements the GetFreeToken interface to request free token.
@@ -123,7 +138,7 @@ func (s *Service) FundMe(w http.ResponseWriter, r *http.Request) {
 	fmt.Println("fundMe: address", addressHex)
 
 	res := &Response{Success: false}
-	if s.CreateTransactionForEnterMethod == nil {
+	if s.CallFaucetContract == nil {
 		json.NewEncoder(w).Encode(res)
 		return
 	}

cmd/restclientsupport/main.go

@@ -7,7 +7,7 @@ import (
 )
 
 func main() {
-	s := restclientsupport.New(nil, nil, nil)
+	s := restclientsupport.New(nil, nil, nil, nil, nil)
 	s.StartService()
 	fmt.Println("Server started")
 	select {}

node/contract.go

@@ -139,13 +139,13 @@ func (node *Node) GetNonceOfAddress(address common.Address) uint64 {
 }
 
 // GetBalanceOfAddress returns balance of an address.
-func (node *Node) GetBalanceOfAddress(address common.Address) *big.Int {
+func (node *Node) GetBalanceOfAddress(address common.Address) (*big.Int, error) {
 	state, err := node.blockchain.State()
 	if err != nil {
 		log.Error("Failed to get chain state", "Error", err)
-		return nil
+		return nil, err
 	}
-	return state.GetBalance(address)
+	return state.GetBalance(address), nil
 }
 
 // AddFaucetContractToPendingTransactions adds the faucet contract the genesis block.

node/demo_contract.go

@@ -101,7 +101,8 @@ func (node *Node) GetResultDirectly(priKey string) (players []string, balances [
 			utils.GetLogInstance().Error("Error when HexToECDSA")
 		}
 		address := crypto.PubkeyToAddress(key.PublicKey)
-		balances = append(balances, node.GetBalanceOfAddress(address))
+		balance, err := node.GetBalanceOfAddress(address)
+		balances = append(balances, balance)
 	}
 	return players, balances
 }
@@ -110,7 +111,8 @@ func (node *Node) GetResultDirectly(priKey string) (players []string, balances [
 func (node *Node) GenerateResultDirectly(addresses []common.Address) (players []string, balances []*big.Int) {
 	for _, address := range addresses {
 		players = append(players, address.String())
-		balances = append(balances, node.GetBalanceOfAddress(address))
+		balance, _ := node.GetBalanceOfAddress(address)
+		balances = append(balances, balance)
 	}
 	fmt.Println("generate result", players, balances)
 	return players, balances

node/service_setup.go

@@ -64,7 +64,7 @@ func (node *Node) setupForBeaconLeader() {
 	// Register client new support service.
 	// TODO(minhdoan): Also consider provide clientsupport/restclientsupport for other shards in the future.
 	node.serviceManager.RegisterService(service.RestClientSupport, restclientsupport.New(
-		node.CreateTransactionForEnterMethod, node.GetResult, node.CreateTransactionForPickWinner, node.CallFaucetContract))
+		node.CreateTransactionForEnterMethod, node.GetResult, node.CreateTransactionForPickWinner, node.CallFaucetContract, node.GetBalanceOfAddress))
 	// Register randomness service
 	node.serviceManager.RegisterService(service.Randomness, randomness.New(node.DRand))
 	// Register explorer service.