package libevm

import (
	"github.com/ethereum/go-ethereum/common"
	"github.com/holiman/uint256"
)

// PrecompiledContract is an exact copy of vm.PrecompiledContract, mirrored here
// for instances where importing that package would result in a circular
// dependency.
type PrecompiledContract interface {
	RequiredGas(input []byte) uint64
	Run(input []byte) ([]byte, error)
}

// StateReader is a subset of vm.StateDB, exposing only methods that read from
// but do not modify state. See method comments in vm.StateDB, which aren't
// copied here as they risk becoming outdated.
type StateReader interface {
	GetBalance(common.Address) *uint256.Int
	GetNonce(common.Address) uint64

	GetCodeHash(common.Address) common.Hash
	GetCode(common.Address) []byte
	GetCodeSize(common.Address) int

	GetRefund() uint64

	GetCommittedState(common.Address, common.Hash) common.Hash
	GetState(common.Address, common.Hash) common.Hash

	GetTransientState(addr common.Address, key common.Hash) common.Hash

	HasSelfDestructed(common.Address) bool

	Exist(common.Address) bool
	Empty(common.Address) bool

	AddressInAccessList(addr common.Address) bool
	SlotInAccessList(addr common.Address, slot common.Hash) (addressOk bool, slotOk bool)
}

// AddressContext carries addresses available to contexts such as calls and
// contract creation.
//
// With respect to contract creation, the Self address MAY be the predicted
// address of the contract about to be deployed, which may not exist yet.
type AddressContext struct {
	Origin common.Address // equivalent to vm.ORIGIN op code
	Caller common.Address // equivalent to vm.CALLER op code
	Self   common.Address // equivalent to vm.ADDRESS op code
}