feat: Add ETH Balance Check on RP Matching (#298)

* feat: Add WeiToEther method on utils.go

* feat: Add GetBalance method on sdk.go

* feat: Check resource provider's ETH balance before adding resource offer

* chore: Update comment to be more accurate

* feat: Use InstructionPrice for balance comparison

---------

Co-authored-by: Alvin Reyes <me@areyes.onl>

pkg/data/types.go

@@ -132,7 +132,7 @@ type ResourceOffer struct {
 	ID string `json:"id"`
 	// this is basically a nonce so we don't have one ID pointing at multiple offers
 	CreatedAt int `json:"created_at"`
-	// the address of the job creator
+	// the address of the resource provider
 	ResourceProvider string `json:"resource_provider"`
 	// allows a resource provider to manage multiple offers
 	// that are essentially the same

pkg/solver/controller.go

@@ -321,6 +321,18 @@ func (controller *SolverController) addResourceOffer(resourceOffer data.Resource
 	}
 	resourceOffer.ID = id
 
+	// Check the resource provider's ETH balance
+	balance, err := controller.web3SDK.GetBalance(resourceOffer.ResourceProvider)
+	if err != nil {
+		return nil, fmt.Errorf("failed to retrieve ETH balance for resource provider: %v", err)
+	}
+	// Convert InstructionPrice from ETH to Wei
+	requiredBalanceWei := web3.EtherToWei(float64(resourceOffer.DefaultPricing.InstructionPrice))
+	// If the balance is less than the required balance, don't add the resource offer
+	if balance.Cmp(requiredBalanceWei) < 0 {
+		return nil, err
+	}
+
 	controller.log.Info("add resource offer", resourceOffer)
 
 	metricsDashboard.TrackNodeInfo(resourceOffer)

pkg/web3/sdk.go

@@ -246,3 +246,16 @@ func (sdk *Web3SDK) WaitTx(ctx context.Context, tx *types.Transaction) (*types.R
 func (sdk *Web3SDK) GetAddress() common.Address {
 	return crypto.PubkeyToAddress(GetPublicKey(sdk.PrivateKey))
 }
+
+func (sdk *Web3SDK) GetBalance(address string) (*big.Int, error) {
+	// Convert the string address to common.Address
+	ethAddress := common.HexToAddress(address)
+
+	// Get the balance using the converted address
+	balance, err := sdk.Client.BalanceAt(context.Background(), ethAddress, nil)
+	if err != nil {
+		log.Error().Msgf("error for GetBalance: %s", err.Error())
+		return nil, err
+	}
+	return balance, nil
+}

pkg/web3/utils.go

@@ -54,6 +54,10 @@ func EtherToWeiUint64(etherAmount float64) uint64 {
 	wei := EtherToWei(etherAmount)
 	return wei.Uint64()
 }
+func WeiToEther(wei *big.Int) *big.Float {
+	ethValue := new(big.Float).Quo(new(big.Float).SetInt(wei), big.NewFloat(1e18))
+	return ethValue
+}
 
 func ConvertStringToBigInt(st string) big.Int {
 	bigInt, _ := big.NewInt(0).SetString(st, 10)