package chain

import (
	"bytes"
	"crypto"
	"crypto/rand"
	"crypto/rsa"
	"crypto/sha256"
	"encoding/gob"
	"time"
)

type transaction struct {
	Src       string
	Dst       string
	Amount    int
	Timestamp int64
}

func NewTransaction(source string, dst string, amount int) transaction {
	return transaction{Src: source, Dst: dst, Amount: amount, Timestamp: time.Now().Unix()}
}

func (ta transaction) SignTransaction(privKey *rsa.PrivateKey, d int) ([]byte, error) {

	return rsa.SignPKCS1v15(rand.Reader, privKey, crypto.SHA256, ta.HashTransaction())
}

func (ta transaction) HashTransaction() []byte {
	var buf bytes.Buffer
	gob.NewEncoder(&buf).Encode(ta)
	hash := sha256.New().Sum(buf.Bytes())
	return hash
}

func (ta transaction) ToBytes() []byte {
	bytes := []byte(ta.Src)
	bytes = append(bytes, []byte(ta.Dst)...)
	bytes = append(bytes, byte(ta.Amount))
	//bytes = append(bytes, []byte(ta.Timestamp))
	return bytes
}

func (ta transaction) ToBytesSerialize() []byte {
	var buf bytes.Buffer
	gob.NewEncoder(&buf).Encode(ta)
	return buf.Bytes()
}