using System.Numerics;
using Nethereum.Hex.HexConvertors.Extensions;
using Nethereum.RLP;

namespace Nethereum.Util
{
    public static class ContractUtils
    {
        public static string CalculateContractAddress(string address, BigInteger nonce)
        {
            if (string.IsNullOrEmpty(address))
            {
                throw new System.ArgumentException($"'{nameof(address)}' cannot be null or empty.", nameof(address));
            }

            var sha3 = new Sha3Keccack();
            return
                sha3.CalculateHash(RLP.RLP.EncodeList(RLP.RLP.EncodeElement(address.HexToByteArray()),
                        RLP.RLP.EncodeElement(nonce.ToBytesForRLPEncoding()))).ToHex().Substring(24)
                    .ConvertToEthereumChecksumAddress();
        }

        public static string CalcualteCreate2AddressMinimalProxy(string address, string saltHex,
            string deploymentAddress)
        {
            if (string.IsNullOrEmpty(deploymentAddress))
            {
                throw new System.ArgumentException($"'{nameof(deploymentAddress)}' cannot be null or empty.",
                    nameof(deploymentAddress));
            }

            var bytecode = "363d3d373d3d3d363d73" + deploymentAddress.RemoveHexPrefix() +
                           "5af43d82803e903d91602b57fd5bf3";
            return CalculateCreate2Address(address, saltHex, bytecode);
        }

        public static string CalculateCreate2Address(string address, string saltHex, string byteCodeHex)
        {
            if (string.IsNullOrEmpty(address))
            {
                throw new System.ArgumentException($"'{nameof(address)}' cannot be null or empty.", nameof(address));
            }

            if (string.IsNullOrEmpty(saltHex))
            {
                throw new System.ArgumentException($"'{nameof(saltHex)}' cannot be null or empty.", nameof(saltHex));
            }

            if (saltHex.EnsureHexPrefix().Length != 66)
            {
                throw new System.ArgumentException($"'{nameof(saltHex)}' needs to be 32 bytes", nameof(saltHex));
            }

            var sha3 = new Sha3Keccack();
            return sha3.CalculateHashFromHex("0xff", address, saltHex, sha3.CalculateHashFromHex(byteCodeHex))
                .Substring(24).ConvertToEthereumChecksumAddress();
        }
    }
}