package ethapi

import (
	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/common/hexutil"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/log"
	"github.com/ethereum/go-ethereum/params"
	"github.com/ethereum/go-ethereum/portalnetwork/history"
)

func rpcMarshalBlock(block *types.Block, fullTx bool, chainId *big.Int) (map[string]interface{}, error) {
	fields := RPCMarshalHeader(block.Header())
	fields["size"] = hexutil.Uint64(block.Size())

	formatTx := func(idx int, tx *types.Transaction) interface{} {
		return tx.Hash()
	}
	if fullTx {
		formatTx = func(idx int, tx *types.Transaction) interface{} {
			return newRPCTransactionFromBlockIndex(block, uint64(idx), chainId)
		}
	}
	txs := block.Transactions()
	transactions := make([]interface{}, len(txs))
	for i, tx := range txs {
		transactions[i] = formatTx(i, tx)
	}
	fields["transactions"] = transactions

	uncles := block.Uncles()
	uncleHashes := make([]common.Hash, len(uncles))
	for i, uncle := range uncles {
		uncleHashes[i] = uncle.Hash()
	}
	fields["uncles"] = uncleHashes
	if block.Header().WithdrawalsHash != nil {
		fields["withdrawals"] = block.Withdrawals()
	}
	return fields, nil
}

func RPCMarshalHeader(head *types.Header) map[string]interface{} {
	result := map[string]interface{}{
		"number":           (*hexutil.Big)(head.Number),
		"hash":             head.Hash(),
		"parentHash":       head.ParentHash,
		"nonce":            head.Nonce,
		"mixHash":          head.MixDigest,
		"sha3Uncles":       head.UncleHash,
		"logsBloom":        head.Bloom,
		"stateRoot":        head.Root,
		"miner":            head.Coinbase,
		"difficulty":       (*hexutil.Big)(head.Difficulty),
		"extraData":        hexutil.Bytes(head.Extra),
		"gasLimit":         hexutil.Uint64(head.GasLimit),
		"gasUsed":          hexutil.Uint64(head.GasUsed),
		"timestamp":        hexutil.Uint64(head.Time),
		"transactionsRoot": head.TxHash,
		"receiptsRoot":     head.ReceiptHash,
	}
	if head.BaseFee != nil {
		result["baseFeePerGas"] = (*hexutil.Big)(head.BaseFee)
	}
	if head.WithdrawalsHash != nil {
		result["withdrawalsRoot"] = head.WithdrawalsHash
	}
	if head.BlobGasUsed != nil {
		result["blobGasUsed"] = hexutil.Uint64(*head.BlobGasUsed)
	}
	if head.ExcessBlobGas != nil {
		result["excessBlobGas"] = hexutil.Uint64(*head.ExcessBlobGas)
	}
	if head.ParentBeaconRoot != nil {
		result["parentBeaconBlockRoot"] = head.ParentBeaconRoot
	}
	return result
}

func newRPCTransactionFromBlockIndex(b *types.Block, index uint64, chainId *big.Int) *RPCTransaction {
	txs := b.Transactions()
	if index >= uint64(len(txs)) {
		return nil
	}
	return newRPCTransaction(txs[index], b.Hash(), b.NumberU64(), b.Time(), index, b.BaseFee(), chainId)
}

func newRPCTransaction(tx *types.Transaction, blockHash common.Hash, blockNumber uint64, blockTime uint64, index uint64, baseFee *big.Int, chainId *big.Int) *RPCTransaction {
	config := &params.ChainConfig{
		ChainID: chainId,
	}

	signer := types.MakeSigner(config, new(big.Int).SetUint64(blockNumber), blockTime)
	from, _ := types.Sender(signer, tx)
	v, r, s := tx.RawSignatureValues()
	result := &RPCTransaction{
		Type:     hexutil.Uint64(tx.Type()),
		From:     from,
		Gas:      hexutil.Uint64(tx.Gas()),
		GasPrice: (*hexutil.Big)(tx.GasPrice()),
		Hash:     tx.Hash(),
		Input:    hexutil.Bytes(tx.Data()),
		Nonce:    hexutil.Uint64(tx.Nonce()),
		To:       tx.To(),
		Value:    (*hexutil.Big)(tx.Value()),
		V:        (*hexutil.Big)(v),
		R:        (*hexutil.Big)(r),
		S:        (*hexutil.Big)(s),
	}
	if blockHash != (common.Hash{}) {
		result.BlockHash = &blockHash
		result.BlockNumber = (*hexutil.Big)(new(big.Int).SetUint64(blockNumber))
		result.TransactionIndex = (*hexutil.Uint64)(&index)
	}

	switch tx.Type() {
	case types.LegacyTxType:
		// if a legacy transaction has an EIP-155 chain id, include it explicitly
		if id := tx.ChainId(); id.Sign() != 0 {
			result.ChainID = (*hexutil.Big)(id)
		}

	case types.AccessListTxType:
		al := tx.AccessList()
		yparity := hexutil.Uint64(v.Sign())
		result.Accesses = &al
		result.ChainID = (*hexutil.Big)(tx.ChainId())
		result.YParity = &yparity

	case types.DynamicFeeTxType:
		al := tx.AccessList()
		yparity := hexutil.Uint64(v.Sign())
		result.Accesses = &al
		result.ChainID = (*hexutil.Big)(tx.ChainId())
		result.YParity = &yparity
		result.GasFeeCap = (*hexutil.Big)(tx.GasFeeCap())
		result.GasTipCap = (*hexutil.Big)(tx.GasTipCap())
		// if the transaction has been mined, compute the effective gas price
		if baseFee != nil && blockHash != (common.Hash{}) {
			// price = min(gasTipCap + baseFee, gasFeeCap)
			result.GasPrice = (*hexutil.Big)(effectiveGasPrice(tx, baseFee))
		} else {
			result.GasPrice = (*hexutil.Big)(tx.GasFeeCap())
		}

	case types.BlobTxType:
		al := tx.AccessList()
		yparity := hexutil.Uint64(v.Sign())
		result.Accesses = &al
		result.ChainID = (*hexutil.Big)(tx.ChainId())
		result.YParity = &yparity
		result.GasFeeCap = (*hexutil.Big)(tx.GasFeeCap())
		result.GasTipCap = (*hexutil.Big)(tx.GasTipCap())
		// if the transaction has been mined, compute the effective gas price
		if baseFee != nil && blockHash != (common.Hash{}) {
			result.GasPrice = (*hexutil.Big)(effectiveGasPrice(tx, baseFee))
		} else {
			result.GasPrice = (*hexutil.Big)(tx.GasFeeCap())
		}
		result.MaxFeePerBlobGas = (*hexutil.Big)(tx.BlobGasFeeCap())
		result.BlobVersionedHashes = tx.BlobHashes()
	}
	return result
}

type RPCTransaction struct {
	BlockHash           *common.Hash      `json:"blockHash"`
	BlockNumber         *hexutil.Big      `json:"blockNumber"`
	From                common.Address    `json:"from"`
	Gas                 hexutil.Uint64    `json:"gas"`
	GasPrice            *hexutil.Big      `json:"gasPrice"`
	GasFeeCap           *hexutil.Big      `json:"maxFeePerGas,omitempty"`
	GasTipCap           *hexutil.Big      `json:"maxPriorityFeePerGas,omitempty"`
	MaxFeePerBlobGas    *hexutil.Big      `json:"maxFeePerBlobGas,omitempty"`
	Hash                common.Hash       `json:"hash"`
	Input               hexutil.Bytes     `json:"input"`
	Nonce               hexutil.Uint64    `json:"nonce"`
	To                  *common.Address   `json:"to"`
	TransactionIndex    *hexutil.Uint64   `json:"transactionIndex"`
	Value               *hexutil.Big      `json:"value"`
	Type                hexutil.Uint64    `json:"type"`
	Accesses            *types.AccessList `json:"accessList,omitempty"`
	ChainID             *hexutil.Big      `json:"chainId,omitempty"`
	BlobVersionedHashes []common.Hash     `json:"blobVersionedHashes,omitempty"`
	V                   *hexutil.Big      `json:"v"`
	R                   *hexutil.Big      `json:"r"`
	S                   *hexutil.Big      `json:"s"`
	YParity             *hexutil.Uint64   `json:"yParity,omitempty"`
}

func effectiveGasPrice(tx *types.Transaction, baseFee *big.Int) *big.Int {
	fee := tx.GasTipCap()
	fee = fee.Add(fee, baseFee)
	if tx.GasFeeCapIntCmp(fee) < 0 {
		return tx.GasFeeCap()
	}
	return fee
}

type API struct {
	History *history.HistoryNetwork
	ChainID *big.Int
}

func (p *API) ChainId() hexutil.Uint64 {
	return (hexutil.Uint64)(p.ChainID.Uint64())
}

func (p *API) GetBlockByHash(hash *common.Hash, fullTransactions bool) (map[string]interface{}, error) {
	blockHeader, err := p.History.GetBlockHeader(hash.Bytes())
	if err != nil {
		log.Error(err.Error())
		return nil, err
	}

	blockBody, err := p.History.GetBlockBody(hash.Bytes())
	if err != nil {
		log.Error(err.Error())
		return nil, err
	}

	block := types.NewBlockWithHeader(blockHeader).WithBody(*blockBody)
	return rpcMarshalBlock(block, fullTransactions, p.ChainID)
}