package types

import (
	"fmt"
	"math/big"

	"github.com/cosmos/ethermint/utils"

	ethcmn "github.com/ethereum/go-ethereum/common"
)

// TxData implements the Ethereum transaction data structure. It is used
// solely as intended in Ethereum abiding by the protocol.
type TxData struct {
	AccountNonce uint64          `json:"nonce"`
	Price        *big.Int        `json:"gasPrice"`
	GasLimit     uint64          `json:"gas"`
	Recipient    *ethcmn.Address `json:"to" rlp:"nil"` // nil means contract creation
	Amount       *big.Int        `json:"value"`
	Payload      []byte          `json:"input"`

	// signature values
	V *big.Int `json:"v"`
	R *big.Int `json:"r"`
	S *big.Int `json:"s"`

	// hash is only used when marshaling to JSON
	Hash *ethcmn.Hash `json:"hash" rlp:"-"`
}

// encodableTxData implements the Ethereum transaction data structure. It is used
// solely as intended in Ethereum abiding by the protocol.
type encodableTxData struct {
	AccountNonce uint64          `json:"nonce"`
	Price        string          `json:"gasPrice"`
	GasLimit     uint64          `json:"gas"`
	Recipient    *ethcmn.Address `json:"to" rlp:"nil"` // nil means contract creation
	Amount       string          `json:"value"`
	Payload      []byte          `json:"input"`

	// signature values
	V string `json:"v"`
	R string `json:"r"`
	S string `json:"s"`

	// hash is only used when marshaling to JSON
	Hash *ethcmn.Hash `json:"hash" rlp:"-"`
}

func (td TxData) String() string {
	if td.Recipient != nil {
		return fmt.Sprintf("nonce=%d price=%s gasLimit=%d recipient=%s amount=%s data=0x%x v=%s r=%s s=%s",
			td.AccountNonce, td.Price, td.GasLimit, td.Recipient.Hex(), td.Amount, td.Payload, td.V, td.R, td.S)
	}

	return fmt.Sprintf("nonce=%d price=%s gasLimit=%d recipient=nil amount=%s data=0x%x v=%s r=%s s=%s",
		td.AccountNonce, td.Price, td.GasLimit, td.Amount, td.Payload, td.V, td.R, td.S)
}

// MarshalAmino defines custom encoding scheme for TxData
func (td TxData) MarshalAmino() ([]byte, error) {
	gasPrice, err := utils.MarshalBigInt(td.Price)
	if err != nil {
		return nil, err
	}

	amount, err := utils.MarshalBigInt(td.Amount)
	if err != nil {
		return nil, err
	}

	v, err := utils.MarshalBigInt(td.V)
	if err != nil {
		return nil, err
	}

	r, err := utils.MarshalBigInt(td.R)
	if err != nil {
		return nil, err
	}

	s, err := utils.MarshalBigInt(td.S)
	if err != nil {
		return nil, err
	}

	e := encodableTxData{
		AccountNonce: td.AccountNonce,
		Price:        gasPrice,
		GasLimit:     td.GasLimit,
		Recipient:    td.Recipient,
		Amount:       amount,
		Payload:      td.Payload,
		V:            v,
		R:            r,
		S:            s,
		Hash:         td.Hash,
	}

	return ModuleCdc.MarshalBinaryBare(e)
}

// UnmarshalAmino defines custom decoding scheme for TxData
func (td *TxData) UnmarshalAmino(data []byte) error {
	var e encodableTxData
	err := ModuleCdc.UnmarshalBinaryBare(data, &e)
	if err != nil {
		return err
	}

	td.AccountNonce = e.AccountNonce
	td.GasLimit = e.GasLimit
	td.Recipient = e.Recipient
	td.Payload = e.Payload
	td.Hash = e.Hash

	price, err := utils.UnmarshalBigInt(e.Price)
	if err != nil {
		return err
	}

	if td.Price != nil {
		td.Price.Set(price)
	} else {
		td.Price = price
	}

	amt, err := utils.UnmarshalBigInt(e.Amount)
	if err != nil {
		return err
	}

	if td.Amount != nil {
		td.Amount.Set(amt)
	} else {
		td.Amount = amt
	}

	v, err := utils.UnmarshalBigInt(e.V)
	if err != nil {
		return err
	}

	if td.V != nil {
		td.V.Set(v)
	} else {
		td.V = v
	}

	r, err := utils.UnmarshalBigInt(e.R)
	if err != nil {
		return err
	}

	if td.R != nil {
		td.R.Set(r)
	} else {
		td.R = r
	}

	s, err := utils.UnmarshalBigInt(e.S)
	if err != nil {
		return err
	}

	if td.S != nil {
		td.S.Set(s)
	} else {
		td.S = s
	}

	return nil
}

// TODO: Implement JSON marshaling/ unmarshaling for this type

// TODO: Implement YAML marshaling/ unmarshaling for this type