package tron

import (
	"crypto/sha256"
	"math/big"
	"strings"

	"github.com/ethereum/go-ethereum/accounts/abi"
	ecommon "github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/fbsobreira/gotron-sdk/pkg/client"
	"github.com/fbsobreira/gotron-sdk/pkg/common"
	"github.com/fbsobreira/gotron-sdk/pkg/proto/core"
	"google.golang.org/grpc"
	"google.golang.org/grpc/credentials/insecure"
	"google.golang.org/protobuf/proto"
)

func (ta *TronAccount) SignTx(tx *core.Transaction) (*core.Transaction, error) {

	rawData, err := proto.Marshal(tx.GetRawData())
	if err != nil {
		return nil, err
	}
	h256h := sha256.New()
	h256h.Write(rawData)
	hash := h256h.Sum(nil)

	signature, err := crypto.Sign(hash, ta.privateKey.ToECDSA())
	if err != nil {
		return nil, err
	}
	tx.Signature = append(tx.Signature, signature)

	return tx, nil
}

type TransactionRawData = map[string]interface{}
type TransactionData struct {
	From  string
	To    string
	Value string
}

func DecodeTRC20Transfer(data []byte) (tx TransactionData, err error) {
	abi, err := abi.JSON(strings.NewReader(COMMON_ABI))
	if err != nil {
		return TransactionData{}, err
	}
	raw := make(TransactionRawData)
	if len(data) < 4 {
		return TransactionData{}, nil
	}
	methodSigData := data[:4]
	method, err := abi.MethodById(methodSigData)
	if err != nil {
		return TransactionData{}, err
	}
	inputsSigData := data[4:]
	if err := method.Inputs.UnpackIntoMap(raw, inputsSigData); err != nil {
		return TransactionData{}, err
	}
	tx = TransactionData{}
	if raw["_from"] != nil {
		tx.From = common.EncodeCheck(
			ToTronAddress(raw["_from"].(ecommon.Address).Bytes()),
		)
	}
	if raw["_to"] != nil {
		tx.To = common.EncodeCheck(
			ToTronAddress(raw["_to"].(ecommon.Address).Bytes()),
		)
	}
	if raw["_value"] != nil {
		tx.Value = raw["_value"].(*big.Int).String()
	}
	return tx, nil
}

func GetTransactionByHash(txHash string) (*core.Transaction, error) {
	conn := client.NewGrpcClient(tronNode.grpcNode)
	err := conn.Start(grpc.WithTransportCredentials(insecure.NewCredentials()))
	if err != nil {
		return nil, err
	}
	tx, err := conn.GetTransactionByID(txHash)
	if err != nil {
		return nil, err
	}
	return tx, nil
}