account

type Account struct {
	// Value is the value of the account reflected in on-chain output that
	// backs the existence of an account.
	Value btcutil.Amount

	// Expiry is the expiration block height of an account. After this
	// point, the trader is able to withdraw the funds from their account
	// without cooperation of the auctioneer.
	Expiry uint32

	// TraderKey is the base trader's key in the 2-of-2 multi-sig
	// construction of a CLM account. This key will never be included in the
	// account script, but rather it will be tweaked with the per-batch key
	// and the account secret to prevent script reuse and provide plausible
	// deniability between account outputs to third parties.
	TraderKey *keychain.KeyDescriptor

	// AuctioneerKey is the base auctioneer's key in the 2-of-2 multi-sig
	// construction of a CLM account. This key will never be included in the
	// account script, but rather it will be tweaked with the per-batch
	// trader key to prevent script reuse and provide plausible deniability
	// between account outputs to third parties.
	AuctioneerKey *btcec.PublicKey

	// BatchKey is the batch key that is used to tweak the trader key of an
	// account with, along with the secret. This will be incremented by the
	// curve's base point each time the account is modified or participates
	// in a cleared batch to prevent output script reuse for accounts
	// on-chain.
	BatchKey *btcec.PublicKey

	// Secret is a static shared secret between the trader and the
	// auctioneer that is used to tweak the trader key of an account with,
	// along with the batch key. This ensures that only the trader and
	// auctioneer are able to successfully identify every past/future output
	// of an account.
	Secret [32]byte

	// State describes the state of the account.
	State State

	// HeightHint is the earliest height in the chain at which we can find
	// the account output in a block.
	HeightHint uint32

	// OutPoint is the outpoint of the output used to fund the account. This
	// only exists once the account has reached StatePendingOpen.
	OutPoint wire.OutPoint

	// LatestTx is the latest transaction of an account.
	//
	// NOTE: This is only nil within the StateInitiated phase. There are no
	// guarantees as to whether the transaction has its witness populated.
	LatestTx *wire.MsgTx
}

type Auctioneer interface {
	// ReserveAccount reserves an account of the specified value with the
	// auctioneer. The auctioneer checks the account value against current
	// min/max values configured. If the value is valid, it returns the
	// public key we should use for them in our 2-of-2 multi-sig
	// construction. To address an edge case in the account recovery where
	// the trader crashes before confirming the account with the auctioneer,
	// we also send the trader key and expiry along with the reservation.
	ReserveAccount(context.Context, btcutil.Amount, uint32,
		*btcec.PublicKey) (*Reservation, error)

	// InitAccount initializes an account with the auctioneer such that it
	// can be used once fully confirmed.
	InitAccount(context.Context, *Account) error

	// ModifyAccount sends an intent to the auctioneer that we'd like to
	// modify the account with the associated trader key. The auctioneer's
	// signature is returned, allowing us to broadcast a transaction
	// spending from the account allowing our modifications to take place.
	// The inputs and outputs provided should exclude the account input
	// being spent and the account output potentially being recreated, since
	// the auctioneer can construct those themselves.
	ModifyAccount(context.Context, *Account, []*wire.TxIn,
		[]*wire.TxOut, []Modifier) ([]byte, error)

	// StartAccountSubscription opens a stream to the server and subscribes
	// to all updates that concern the given account, including all orders
	// that spend from that account. Only a single stream is ever open to
	// the server, so a second call to this method will send a second
	// subscription over the same stream, multiplexing all messages into the
	// same connection. A stream can be long-lived, so this can be called
	// for every account as soon as it's confirmed open. This method will
	// return as soon as the authentication was successful. Messages sent
	// from the server can then be received on the FromServerChan channel.
	StartAccountSubscription(context.Context, *keychain.KeyDescriptor) error

	// Terms returns the current dynamic auctioneer terms like max account
	// size, max order duration in blocks and the auction fee schedule.
	Terms(ctx context.Context) (*terms.AuctioneerTerms, error)
}

type FeeExpr interface {
	// CloseOutputs is the list of outputs that should be used for the
	// closing transaction of an account based on the concrete fee
	// expression implementation.
	CloseOutputs(btcutil.Amount, witnessType) ([]*wire.TxOut, error)
}

type Manager struct {
	// contains filtered or unexported fields
}

type ManagerConfig struct {
	// Store is responsible for storing and retrieving account information
	// reliably.
	Store Store

	// Auctioneer provides us with the different ways we are able to
	// communicate with our auctioneer during the process of
	// opening/closing/modifying accounts.
	Auctioneer Auctioneer

	// Wallet handles all of our on-chain transaction interaction, whether
	// that is deriving keys, creating transactions, etc.
	Wallet lndclient.WalletKitClient

	// Signer is responsible for deriving shared secrets for accounts
	// between the trader and auctioneer and signing account-related
	// transactions.
	Signer lndclient.SignerClient

	// ChainNotifier is responsible for requesting confirmation and spend
	// notifications for accounts.
	ChainNotifier lndclient.ChainNotifierClient

	// TxSource is a source that provides us with transactions previously
	// broadcast by us.
	TxSource TxSource

	// TxFeeEstimator is an estimator that can calculate the total on-chain
	// fees to send to an account output.
	TxFeeEstimator TxFeeEstimator

	// TxLabelPrefix is set, then all transactions the account manager
	// makes will use this string as a prefix for added transaction labels.
	TxLabelPrefix string
}

type Modifier func(*Account)

type OutputWithFee struct {
	// PkScript is the destination output script. Note that this may be nil,
	// in which case a wallet-derived P2WKH script should be used.
	PkScript []byte

	// FeeRate is the accompanying fee rate to use to determine the
	// transaction fee.
	FeeRate chainfee.SatPerKWeight
}

type OutputsWithImplicitFee []*wire.TxOut

type Reservation struct {
	// AuctioneerKey is the base auctioneer's key in the 2-of-2 multi-sig
	// construction of a CLM account. This key will never be included in the
	// account script, but rather it will be tweaked with the per-batch
	// trader key to prevent script reuse and provide plausible deniability
	// between account outputs to third parties.
	AuctioneerKey *btcec.PublicKey

	// InitialBatchKey is the initial batch key that is used to tweak the
	// trader key of an account.
	InitialBatchKey *btcec.PublicKey
}

type State uint8

type Store interface {
	// AddAccount adds a record for the account to the database.
	AddAccount(*Account) error

	// UpdateAccount updates an account in the database according to the
	// given modifiers.
	UpdateAccount(*Account, ...Modifier) error

	// Account retrieves the account associated with the given trader key
	// from the database.
	Account(*btcec.PublicKey) (*Account, error)

	// Accounts retrieves all existing accounts.
	Accounts() ([]*Account, error)

	// PendingBatch determines whether we currently have a pending batch.
	// If a batch doesn't exist, ErrNoPendingBatch is returned.
	PendingBatch() error

	// MarkBatchComplete marks the batch with the given ID as complete,
	// indicating that the staged account updates can be applied to disk.
	MarkBatchComplete() error

	// LockID retrieves the global lock ID we'll use to lock any outputs
	// when performing coin selection.
	LockID() (wtxmgr.LockID, error)
}

type TxFeeEstimator interface {
	// EstimateFeeToP2WSH estimates the total chain fees in satoshis to send
	// the given amount to a single P2WSH output with the given target
	// confirmation.
	EstimateFeeToP2WSH(ctx context.Context, amt btcutil.Amount,
		confTarget int32) (btcutil.Amount, error)
}

type TxSource interface {
	// ListTransactions returns all known transactions of the backing lnd
	// node. It takes a start and end block height which can be used to
	// limit the block range that we query over. These values can be left
	// as zero to include all blocks. To include unconfirmed transactions
	// in the query, endHeight must be set to -1.
	ListTransactions(ctx context.Context, startHeight,
		endHeight int32) ([]lndclient.Transaction, error)
}