package statedb

import "github.com/ethereum/go-ethereum/common"

// TxConfig encapulates the readonly information of current tx for `StateDB`.
type TxConfig struct {
	BlockHash common.Hash // hash of current block
	TxHash    common.Hash // hash of current tx
	TxIndex   uint        // the index of current transaction
	LogIndex  uint        // the index of next log within current block
}

// NewTxConfig returns a TxConfig
func NewTxConfig(bhash, thash common.Hash, txIndex, logIndex uint) TxConfig {
	return TxConfig{
		BlockHash: bhash,
		TxHash:    thash,
		TxIndex:   txIndex,
		LogIndex:  logIndex,
	}
}

// NewEmptyTxConfig construct an empty TxConfig,
// used in context where there's no transaction, e.g. `eth_call`/`eth_estimateGas`.
func NewEmptyTxConfig(bhash common.Hash) TxConfig {
	return TxConfig{
		BlockHash: bhash,
		TxHash:    common.Hash{},
		TxIndex:   0,
		LogIndex:  0,
	}
}