// Copyright 2021 Evmos Foundation
// This file is part of Evmos' Ethermint library.
//
// The Ethermint library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The Ethermint library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the Ethermint library. If not, see https://github.com/evmos/ethermint/blob/main/LICENSE
package types

import (
	"bytes"

	errorsmod "cosmossdk.io/errors"
	errortypes "github.com/cosmos/cosmos-sdk/types/errors"
	"github.com/ethereum/go-ethereum/common"
)

// IsEmptyHash returns true if the hash corresponds to an empty ethereum hex hash.
func IsEmptyHash(hash string) bool {
	return bytes.Equal(common.HexToHash(hash).Bytes(), common.Hash{}.Bytes())
}

// IsZeroAddress returns true if the address corresponds to an empty ethereum hex address.
func IsZeroAddress(address string) bool {
	return bytes.Equal(common.HexToAddress(address).Bytes(), common.Address{}.Bytes())
}

// ValidateAddress returns an error if the provided string is either not a hex formatted string address
func ValidateAddress(address string) error {
	if !common.IsHexAddress(address) {
		return errorsmod.Wrapf(
			errortypes.ErrInvalidAddress, "address '%s' is not a valid ethereum hex address",
			address,
		)
	}
	return nil
}

// ValidateNonZeroAddress returns an error if the provided string is not a hex
// formatted string address or is equal to zero
func ValidateNonZeroAddress(address string) error {
	if IsZeroAddress(address) {
		return errorsmod.Wrapf(
			errortypes.ErrInvalidAddress, "address '%s' must not be zero",
			address,
		)
	}
	return ValidateAddress(address)
}