1package node
  2
  3import (
  4	"crypto/ecdsa"
  5	"time"
  6
  7	"github.com/arnaucube/slowlorisdb/core"
  8)
  9
 10type Node struct {
 11	PrivK      *ecdsa.PrivateKey
 12	Addr       core.Address
 13	Bc         *core.Blockchain
 14	Miner      bool // indicates if the node is running as a miner
 15	PendingTxs []core.Tx
 16}
 17
 18func NewNode(privK *ecdsa.PrivateKey, bc *core.Blockchain, isMiner bool) (*Node, error) {
 19	addr := core.AddressFromPrivK(privK)
 20
 21	node := &Node{
 22		PrivK:      privK,
 23		Addr:       addr,
 24		Bc:         bc,
 25		Miner:      isMiner,
 26		PendingTxs: []core.Tx{},
 27	}
 28	return node, nil
 29}
 30
 31func (node *Node) Sign(m []byte) (*core.Signature, error) {
 32	return core.Sign(node.PrivK, m)
 33}
 34
 35func (node *Node) SignBlock(block *core.Block) error {
 36	block.CalculateHash()
 37	sig, err := core.Sign(node.PrivK, block.Hash[:])
 38	if err != nil {
 39		return err
 40	}
 41	block.Signature = sig.Bytes()
 42	return nil
 43}
 44
 45func (node *Node) AddToPendingTxs(tx core.Tx) {
 46	node.PendingTxs = append(node.PendingTxs, tx)
 47}
 48
 49func (node *Node) BlockFromPendingTxs() (*core.Block, error) {
 50	block, err := node.NewBlock(node.PendingTxs)
 51	if err != nil {
 52		return nil, err
 53	}
 54	block.PrevHash = node.Bc.LastBlock.Hash
 55	err = block.CalculatePoW(node.Bc.Difficulty)
 56	if err != nil {
 57		return nil, err
 58	}
 59	err = node.SignBlock(block)
 60	if err != nil {
 61		return nil, err
 62	}
 63	block.CalculateHash()
 64
 65	return block, nil
 66}
 67
 68func (node *Node) NewBlock(txs []core.Tx) (*core.Block, error) {
 69	block := &core.Block{
 70		Height:    node.Bc.GetHeight() + 1,
 71		PrevHash:  node.Bc.LastBlock.Hash,
 72		Txs:       txs,
 73		Miner:     core.Address{},
 74		MinerPubK: &node.PrivK.PublicKey,
 75		Timestamp: time.Now(),
 76		Nonce:     0,
 77		Hash:      core.Hash{},
 78		Signature: []byte{},
 79	}
 80	block.CalculateHash()
 81	err := node.SignBlock(block)
 82	if err != nil {
 83		return nil, err
 84	}
 85	return block, nil
 86}
 87
 88func (node *Node) CreateGenesis() (*core.Block, error) {
 89	block := &core.Block{
 90		Height:    node.Bc.LastBlock.Height + 1,
 91		PrevHash:  node.Bc.LastBlock.Hash,
 92		Txs:       []core.Tx{},
 93		Miner:     node.Addr,
 94		MinerPubK: &node.PrivK.PublicKey,
 95		Timestamp: time.Now(),
 96		Nonce:     uint64(0),
 97		Hash:      core.Hash{},
 98		Signature: []byte{},
 99	}
100
101	block.CalculateHash()
102	err := node.SignBlock(block)
103	if err != nil {
104		return nil, err
105	}
106	return block, nil
107}