Added moved funds sweep action

pkg/tbtc/moved_funds_sweep.go

@@ -5,6 +5,9 @@ import (
 	"math/big"
 	"time"
 
+	"github.com/keep-network/keep-core/pkg/bitcoin"
+	"go.uber.org/zap"
+
 	"github.com/ipfs/go-log/v2"
 )
 
@@ -27,12 +30,37 @@ type MovedFundsSweepRequest struct {
 }
 
 const (
-	// movedFundsSweepProposalValidityBlocks determines the moving funds
+	// movedFundsSweepProposalValidityBlocks determines the moved funds sweep
 	// proposal validity time expressed in blocks. In other words, this is the
-	// worst-case time for a moving funds during which the wallet is busy and
-	// cannot take another actions. The value of 600 blocks is roughly 2 hours,
-	// assuming 12 seconds per block.
+	// worst-case time for a moved funds sweep during which the wallet is busy
+	// and cannot take another actions. The value of 600 blocks is roughly
+	// 2 hours, assuming 12 seconds per block.
 	movedFundsSweepProposalValidityBlocks = 600
+	// movedFundsSweepSigningTimeoutSafetyMarginBlocks determines the duration of
+	// the safety margin that must be preserved between the signing timeout and
+	// the timeout of the entire moved funds sweep action. This safety margin
+	// prevents against the case where signing completes late and there is not
+	// enough time to broadcast the moved funds sweep transaction properly.
+	// In such a case, wallet signatures may leak and make the wallet subject
+	// of fraud accusations. Usage of the safety margin ensures there is enough
+	// time to perform post-signing steps of the moved funds sweep action.
+	// The value of 300 blocks is roughly 1 hour, assuming 12 seconds per block.
+	movedFundsSweepSigningTimeoutSafetyMarginBlocks = 300
+	// movedFundsSweepBroadcastTimeout determines the time window for moved
+	// funds sweep transaction broadcast. It is guaranteed that at least
+	// movedFundsSweepSigningTimeoutSafetyMarginBlocks is preserved for the
+	// broadcast step. However, the happy path for the broadcast step is usually
+	// quick and few retries are needed to recover from temporary problems. That
+	// said, if the broadcast step does not succeed in a tight timeframe, there
+	// is no point to retry for the entire possible time window. Hence, the
+	// timeout for broadcast step is set as 25% of the entire time widow
+	// determined by movedFundsSweepSigningTimeoutSafetyMarginBlocks.
+	movedFundsSweepBroadcastTimeout = 15 * time.Minute
+	// movedFundsSweepBroadcastCheckDelay determines the delay that must
+	// be preserved between transaction broadcast and the check that ensures
+	// the transaction is known on the Bitcoin chain. This delay is needed
+	// as spreading the transaction over the Bitcoin network takes time.
+	movedFundsSweepBroadcastCheckDelay = 1 * time.Minute
 )
 
 // MovedFundsSweepProposal represents a moved funds sweep proposal issued by a
@@ -51,6 +79,69 @@ func (mfsp *MovedFundsSweepProposal) ValidityBlocks() uint64 {
 	return movedFundsSweepProposalValidityBlocks
 }
 
+type movedFundsSweepAction struct {
+	logger   *zap.SugaredLogger
+	chain    Chain
+	btcChain bitcoin.Chain
+
+	movedFundsSweepWallet wallet
+	transactionExecutor   *walletTransactionExecutor
+
+	proposal                     *MovedFundsSweepProposal
+	proposalProcessingStartBlock uint64
+	proposalExpiryBlock          uint64
+
+	signingTimeoutSafetyMarginBlocks uint64
+	broadcastTimeout                 time.Duration
+	broadcastCheckDelay              time.Duration
+}
+
+func newMovedFundsSweepAction(
+	logger *zap.SugaredLogger,
+	chain Chain,
+	btcChain bitcoin.Chain,
+	movedFundsSweepWallet wallet,
+	signingExecutor walletSigningExecutor,
+	proposal *MovedFundsSweepProposal,
+	proposalProcessingStartBlock uint64,
+	proposalExpiryBlock uint64,
+	waitForBlockFn waitForBlockFn,
+) *movedFundsSweepAction {
+	transactionExecutor := newWalletTransactionExecutor(
+		btcChain,
+		movedFundsSweepWallet,
+		signingExecutor,
+		waitForBlockFn,
+	)
+
+	return &movedFundsSweepAction{
+		logger:                           logger,
+		chain:                            chain,
+		btcChain:                         btcChain,
+		movedFundsSweepWallet:            movedFundsSweepWallet,
+		transactionExecutor:              transactionExecutor,
+		proposal:                         proposal,
+		proposalProcessingStartBlock:     proposalProcessingStartBlock,
+		proposalExpiryBlock:              proposalExpiryBlock,
+		signingTimeoutSafetyMarginBlocks: movedFundsSweepSigningTimeoutSafetyMarginBlocks,
+		broadcastTimeout:                 movedFundsSweepBroadcastTimeout,
+		broadcastCheckDelay:              movedFundsSweepBroadcastCheckDelay,
+	}
+}
+
+func (mfsa *movedFundsSweepAction) execute() error {
+	// TODO: Implement
+	return nil
+}
+
+func (mfsa *movedFundsSweepAction) wallet() wallet {
+	return mfsa.movedFundsSweepWallet
+}
+
+func (mfsa *movedFundsSweepAction) actionType() WalletActionType {
+	return ActionMovedFundsSweep
+}
+
 // ValidateMovedFundsSweepProposal checks the moved funds sweep proposal with
 // on-chain validation rules.
 func ValidateMovedFundsSweepProposal(

pkg/tbtc/node.go

@@ -684,7 +684,64 @@ func (n *node) handleMovedFundsSweepProposal(
 	startBlock uint64,
 	expiryBlock uint64,
 ) {
-	// TODO: Implement
+	walletPublicKeyBytes, err := marshalPublicKey(wallet.publicKey)
+	if err != nil {
+		logger.Errorf("cannot marshal wallet public key: [%v]", err)
+		return
+	}
+
+	signingExecutor, ok, err := n.getSigningExecutor(wallet.publicKey)
+	if err != nil {
+		logger.Errorf("cannot get signing executor: [%v]", err)
+		return
+	}
+	// This check is actually redundant. We know the node controls some
+	// wallet signers as we just got the wallet from the registry using their
+	// public key hash. However, we are doing it just in case. The API
+	// contract of getSigningExecutor may change one day.
+	if !ok {
+		logger.Infof(
+			"node does not control signers of wallet PKH [0x%x]; "+
+				"ignoring the received moved funds sweep proposal",
+			walletPublicKeyBytes,
+		)
+		return
+	}
+
+	logger.Infof(
+		"starting orchestration of the moved funds sweep action for wallet "+
+			"[0x%x]; 20-byte public key hash of that wallet is [0x%x]",
+		walletPublicKeyBytes,
+		bitcoin.PublicKeyHash(wallet.publicKey),
+	)
+
+	walletActionLogger := logger.With(
+		zap.String("wallet", fmt.Sprintf("0x%x", walletPublicKeyBytes)),
+		zap.String("action", ActionMovedFundsSweep.String()),
+		zap.Uint64("startBlock", startBlock),
+		zap.Uint64("expiryBlock", expiryBlock),
+	)
+	walletActionLogger.Infof("dispatching wallet action")
+
+	action := newMovedFundsSweepAction(
+		walletActionLogger,
+		n.chain,
+		n.btcChain,
+		wallet,
+		signingExecutor,
+		proposal,
+		startBlock,
+		expiryBlock,
+		n.waitForBlockHeight,
+	)
+
+	err = n.walletDispatcher.dispatch(action)
+	if err != nil {
+		walletActionLogger.Errorf("cannot dispatch wallet action: [%v]", err)
+		return
+	}
+
+	walletActionLogger.Infof("wallet action dispatched successfully")
 }
 
 // coordinationLayerSettings represents settings for the coordination layer.