engine

type BridgeStore interface {
	// CreateTransfer inserts a new transfer record. Returns true if the record was newly
	// inserted, false if it already existed (idempotent via ON CONFLICT DO NOTHING).
	CreateTransfer(ctx context.Context, transfer *relayer.Transfer) (bool, error)
	GetTransfer(ctx context.Context, id string) (*relayer.Transfer, error)
	// UpdateTransferStatus updates status, destination tx hash, and optionally error message.
	UpdateTransferStatus(ctx context.Context, id string, status relayer.TransferStatus, destTxHash *string, errMsg *string) error
	// IncrementRetryCount atomically increments the retry_count for a transfer.
	IncrementRetryCount(ctx context.Context, id string) error
	GetChainState(ctx context.Context, chainID string) (*relayer.ChainState, error)
	SetChainState(ctx context.Context, chainID string, blockNumber uint64, offset string) error
	GetPendingTransfers(ctx context.Context, direction relayer.TransferDirection) ([]*relayer.Transfer, error)
	ListTransfers(ctx context.Context, limit int) ([]*relayer.Transfer, error)
}

type CantonBridgeClient interface {
	canton.Bridge
}

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

type Destination interface {
	SubmitTransfer(ctx context.Context, event *relayer.Event) (destTxHash string, skipped bool, err error)
	GetChainID() string
}

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

type ErrorCategory string

type EthereumBridgeClient interface {
	GetLatestBlockNumber(ctx context.Context) (uint64, error)
	WithdrawFromCanton(
		ctx context.Context,
		token common.Address,
		recipient common.Address,
		amount *big.Int,
		nonce *big.Int,
		cantonTxHash [32]byte,
	) (common.Hash, error)
	WatchDepositEvents(ctx context.Context, fromBlock uint64, handler func(*ethereum.DepositEvent) error) error
	IsWithdrawalProcessed(ctx context.Context, cantonTxHash [32]byte) (bool, error)
	GetLastScannedBlock() uint64
}

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

type EventType string

type Metrics struct {

	// TransfersTotal counts completed/failed transfers by direction and status.
	TransfersTotal *prometheus.CounterVec

	// TransferDuration tracks transfer processing time by direction.
	TransferDuration *prometheus.HistogramVec

	// TransferAmount observes token amounts per transfer.
	TransferAmount *prometheus.HistogramVec

	// TransactionsSent counts transactions sent to each chain by status.
	TransactionsSent *prometheus.CounterVec

	// EventsDetected counts events detected on each chain by event type.
	EventsDetected *prometheus.CounterVec

	// LastProcessedBlock tracks the last processed block number per chain.
	LastProcessedBlock *prometheus.GaugeVec

	// ProcessorRestarts counts processor restart events by chain and reason.
	ProcessorRestarts *prometheus.CounterVec

	// EventProcessingErrors counts errors at each processing stage.
	EventProcessingErrors *prometheus.CounterVec

	// ErrorsTotal counts errors by component and error type.
	ErrorsTotal *prometheus.CounterVec

	// PendingTransfers tracks number of pending transfers by direction (gauge).
	PendingTransfers *prometheus.GaugeVec

	// ReconciliationDuration tracks how long each reconciliation run takes.
	ReconciliationDuration prometheus.Histogram

	// ReconciliationRuns counts reconciliation runs by result.
	ReconciliationRuns *prometheus.CounterVec

	// TransferRetries counts transfer retry attempts by direction and outcome.
	TransferRetries *prometheus.CounterVec

	// TransferAge tracks the full lifecycle duration of a transfer (created → completed).
	// TODO: Use source chain block timestamp instead of event detection time for true
	// on-chain age. Requires adding SourceTimestamp to relayer.Event, fetching block
	// headers in ethereumSource, and extracting RecordTime in cantonSource.
	TransferAge *prometheus.HistogramVec

	// ChainHeadPosition tracks the remote chain head for each chain
	// (block number for Ethereum, ledger offset for Canton).
	ChainHeadPosition *prometheus.GaugeVec

	// Ready indicates whether the relayer engine is fully synced (1=yes, 0=no).
	Ready prometheus.Gauge
}

type OffsetUpdateFunc func(ctx context.Context, chainID string, offset string) error

type PostSubmitHook func(ctx context.Context, event *relayer.Event, destTxHash string) error

type ProcessingStage string

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

type ReconciliationResult string

type RestartReason string

type RetryOutcome string

type Source interface {
	StreamEvents(ctx context.Context, offset string) (<-chan *relayer.Event, <-chan error)
	GetChainID() string
	// ExtractOffset returns the offset string to persist after processing event.
	// Returns "" when no offset should be saved for this event.
	ExtractOffset(event *relayer.Event) string
}

type TransferResult string

type TxStatus string