package eth1

import (
	"encoding/binary"
	"fmt"
	"math/big"

	"github.com/holiman/uint256"
	libcommon "github.com/ledgerwatch/erigon-lib/common"
	"github.com/ledgerwatch/erigon-lib/gointerfaces"
	"github.com/ledgerwatch/erigon-lib/gointerfaces/execution"
	types2 "github.com/ledgerwatch/erigon-lib/gointerfaces/types"
	"github.com/ledgerwatch/erigon/core/types"
)

func HeaderToHeaderRPC(header *types.Header) *execution.Header {
	difficulty := new(uint256.Int)
	difficulty.SetFromBig(header.Difficulty)

	var baseFeeReply *types2.H256
	if header.BaseFee != nil {
		var baseFee uint256.Int
		baseFee.SetFromBig(header.BaseFee)
		baseFeeReply = gointerfaces.ConvertUint256IntToH256(&baseFee)
	}
	var withdrawalHashReply *types2.H256
	if header.WithdrawalsHash != nil {
		withdrawalHashReply = gointerfaces.ConvertHashToH256(*header.WithdrawalsHash)
	}
	return &execution.Header{
		ParentHash:      gointerfaces.ConvertHashToH256(header.ParentHash),
		Coinbase:        gointerfaces.ConvertAddressToH160(header.Coinbase),
		StateRoot:       gointerfaces.ConvertHashToH256(header.Root),
		TransactionHash: gointerfaces.ConvertHashToH256(header.TxHash),
		LogsBloom:       gointerfaces.ConvertBytesToH2048(header.Bloom[:]),
		ReceiptRoot:     gointerfaces.ConvertHashToH256(header.ReceiptHash),
		PrevRandao:      gointerfaces.ConvertHashToH256(header.MixDigest),
		BlockNumber:     header.Number.Uint64(),
		Nonce:           header.Nonce.Uint64(),
		GasLimit:        header.GasLimit,
		GasUsed:         header.GasUsed,
		Timestamp:       header.Time,
		ExtraData:       header.Extra,
		Difficulty:      gointerfaces.ConvertUint256IntToH256(difficulty),
		BlockHash:       gointerfaces.ConvertHashToH256(header.Hash()),
		OmmerHash:       gointerfaces.ConvertHashToH256(header.UncleHash),
		BaseFeePerGas:   baseFeeReply,
		WithdrawalHash:  withdrawalHashReply,
		ExcessDataGas:   header.ExcessDataGas,
		DataGasUsed:     header.DataGasUsed,
	}

}

func HeaderRpcToHeader(header *execution.Header) (*types.Header, error) {
	var blockNonce types.BlockNonce
	binary.BigEndian.PutUint64(blockNonce[:], header.Nonce)
	h := &types.Header{
		ParentHash:    gointerfaces.ConvertH256ToHash(header.ParentHash),
		UncleHash:     gointerfaces.ConvertH256ToHash(header.OmmerHash),
		Coinbase:      gointerfaces.ConvertH160toAddress(header.Coinbase),
		Root:          gointerfaces.ConvertH256ToHash(header.StateRoot),
		TxHash:        gointerfaces.ConvertH256ToHash(header.TransactionHash),
		ReceiptHash:   gointerfaces.ConvertH256ToHash(header.ReceiptRoot),
		Bloom:         gointerfaces.ConvertH2048ToBloom(header.LogsBloom),
		Difficulty:    gointerfaces.ConvertH256ToUint256Int(header.Difficulty).ToBig(),
		Number:        big.NewInt(int64(header.BlockNumber)),
		GasLimit:      header.GasLimit,
		GasUsed:       header.GasUsed,
		Time:          header.Timestamp,
		Extra:         header.ExtraData,
		MixDigest:     gointerfaces.ConvertH256ToHash(header.PrevRandao),
		Nonce:         blockNonce,
		DataGasUsed:   header.DataGasUsed,
		ExcessDataGas: header.ExcessDataGas,
	}
	if header.BaseFeePerGas != nil {
		h.BaseFee = gointerfaces.ConvertH256ToUint256Int(header.BaseFeePerGas).ToBig()
	}
	if header.WithdrawalHash != nil {
		h.WithdrawalsHash = new(libcommon.Hash)
		*h.WithdrawalsHash = gointerfaces.ConvertH256ToHash(header.WithdrawalHash)
	}
	blockHash := gointerfaces.ConvertH256ToHash(header.BlockHash)
	if blockHash != h.Hash() {
		return nil, fmt.Errorf("block %d, %x has invalid hash. expected: %x", header.BlockNumber, h.Hash(), blockHash)
	}
	return h, nil
}

func ConvertWithdrawalsFromRpc(in []*types2.Withdrawal) []*types.Withdrawal {
	if in == nil {
		return nil
	}
	out := make([]*types.Withdrawal, 0, len(in))
	for _, w := range in {
		out = append(out, &types.Withdrawal{
			Index:     w.Index,
			Validator: w.ValidatorIndex,
			Address:   gointerfaces.ConvertH160toAddress(w.Address),
			Amount:    w.Amount,
		})
	}
	return out
}

func ConvertWithdrawalsToRpc(in []*types.Withdrawal) []*types2.Withdrawal {
	if in == nil {
		return nil
	}
	out := make([]*types2.Withdrawal, 0, len(in))
	for _, w := range in {
		out = append(out, &types2.Withdrawal{
			Index:          w.Index,
			ValidatorIndex: w.Validator,
			Address:        gointerfaces.ConvertAddressToH160(w.Address),
			Amount:         w.Amount,
		})
	}
	return out
}

func ConvertRawBlockBodyToRpc(in *types.RawBody, blockNumber uint64, blockHash libcommon.Hash) *execution.BlockBody {
	if in == nil {
		return nil
	}
	return &execution.BlockBody{
		BlockNumber:  blockNumber,
		BlockHash:    gointerfaces.ConvertHashToH256(blockHash),
		Transactions: in.Transactions,
		Withdrawals:  ConvertWithdrawalsToRpc(in.Withdrawals),
	}
}

func ConvertRawBlockBodyFromRpc(in *execution.BlockBody) *types.RawBody {
	if in == nil {
		return nil
	}
	return &types.RawBody{
		Transactions: in.Transactions,
		Withdrawals:  ConvertWithdrawalsFromRpc(in.Withdrawals),
	}
}