[#128] innerring: Add GAS pouring mechanism for a configurable list of wallets

Signed-off-by: Artem Tataurov <a.tataurov@yadro.com>

pkg/morph/client/client.go

@@ -244,6 +244,40 @@ func (c *Client) TransferGas(receiver util.Uint160, amount fixedn.Fixed8) error
 	return nil
 }
 
+func (c *Client) BatchTransferGas(receivers []util.Uint160, amount fixedn.Fixed8) error {
+	c.switchLock.RLock()
+	defer c.switchLock.RUnlock()
+
+	if c.inactive {
+		return ErrConnectionLost
+	}
+
+	transferParams := make([]nep17.TransferParameters, len(receivers))
+	receiversLog := make([]string, len(receivers))
+
+	for i, receiver := range receivers {
+		transferParams[i] = nep17.TransferParameters{
+			From:   c.accAddr,
+			To:     receiver,
+			Amount: big.NewInt(int64(amount)),
+			Data:   nil,
+		}
+		receiversLog[i] = receiver.StringLE()
+	}
+
+	txHash, vub, err := c.gasToken.MultiTransfer(transferParams)
+	if err != nil {
+		return err
+	}
+
+	c.logger.Debug("batch gas transfer invoke",
+		zap.Strings("to", receiversLog),
+		zap.Stringer("tx_hash", txHash.Reverse()),
+		zap.Uint32("vub", vub))
+
+	return nil
+}
+
 // Wait function blocks routing execution until there
 // are `n` new blocks in the chain.
 //