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package monitor
import (
"context"
"fmt"
"log"
"math/big"
"strings"
"time"
ethereum "github.com/ethereum/go-ethereum"
"github.com/ethereum/go-ethereum/accounts/abi"
"github.com/ethereum/go-ethereum/accounts/abi/bind"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/ethclient"
)
type backendIntf interface {
FetchFinedNodes(chan node)
NodeSet() []node
BalanceFromAddress(*ethclient.Client, common.Address) *big.Int
}
// BlockchainBackend is the blockchain backend object for fetching blockchain info.
type BlockchainBackend struct {
networkID int
}
// NodeSet returns the registered nodes.
func (b *BlockchainBackend) NodeSet() []node {
nc := NetworkConfigMap[int64(b.networkID)]
conn, err := ethclient.Dial(nc.HTTPEndpoint)
if err != nil {
log.Println("EthClient Dial failed: ", err)
return []node{}
}
g, err := NewGovernance(GovAddress, conn)
if err != nil {
panic(err)
}
txOps := &bind.CallOpts{}
nodeLen, err := g.NodesLength(txOps)
if err != nil {
panic(err)
}
minStake, err := g.MinStake(txOps)
if err != nil {
panic(err)
}
nodes := []node{}
for i := uint64(0); i < nodeLen.Uint64(); i++ {
n, err := g.Nodes(txOps, big.NewInt(int64(i)))
if n.Staked.Cmp(minStake) < 0 {
continue
}
if err != nil {
panic(err)
}
publicKey, err := crypto.UnmarshalPubkey(n.PublicKey)
if err != nil {
log.Println("Unmarshal publicKey fail: ", err)
continue
}
address := crypto.PubkeyToAddress(*publicKey)
nodes = append(nodes, node{
owner: n.Owner,
email: n.Email,
fined: n.Fined,
name: n.Name,
publicKey: n.PublicKey,
nodeKeyAddress: address,
})
}
return nodes
}
// BalanceFromAddress return address's balance.
func (b *BlockchainBackend) BalanceFromAddress(conn *ethclient.Client,
address common.Address) *big.Int {
balance, err := conn.BalanceAt(context.Background(),
address, nil)
if err != nil {
log.Println("Get balance fail: ", err)
return big.NewInt(0)
}
return balance
}
func (b *BlockchainBackend) subscribe(
logs chan types.Log,
headers chan *types.Header,
) (ethereum.Subscription, *ethclient.Client, error) {
nc := NetworkConfigMap[int64(b.networkID)]
conn, err := ethclient.Dial(nc.WSEndpoint)
if err != nil {
log.Println("EthClient Dial failed: ", err)
return nil, conn, err
}
abiObject, err := abi.JSON(strings.NewReader(GovernanceABI))
query := ethereum.FilterQuery{
Addresses: []common.Address{GovAddress},
Topics: [][]common.Hash{
[]common.Hash{
abiObject.Events["Fined"].Id(),
},
},
}
sub, err := conn.SubscribeFilterLogs(context.Background(), query, logs)
if err != nil {
log.Println("Subscribe logs failed: ", err)
return nil, conn, err
}
// Subscribe chain head to keep ws from timeout
_, err = conn.SubscribeNewHead(context.Background(), headers)
if err != nil {
log.Println("Subscribe chain head failed: ", err)
}
return sub, conn, nil
}
// FetchFinedNodes fetches nodes' information from blockchain.
func (b *BlockchainBackend) FetchFinedNodes(nodeChan chan node) {
logs := make(chan types.Log)
headers := make(chan *types.Header)
sub, conn, err := b.subscribe(logs, headers)
if err != nil {
panic(err)
}
for {
select {
case err := <-sub.Err():
log.Println("sub.Err()", err)
// retry
for err != nil {
sub, conn, err = b.subscribe(logs, headers)
time.Sleep(30000)
}
case vLog := <-logs:
nodeAddress := common.BytesToAddress(vLog.Topics[1].Bytes())
log.Println("Notify node: ", nodeAddress.Hex())
nodeChan <- b.getNodeByAddress(nodeAddress, conn)
}
}
}
func (b *BlockchainBackend) getNodeByAddress(
nodeAddress common.Address, conn *ethclient.Client) node {
g, err := NewGovernance(GovAddress, conn)
if err != nil {
panic(err)
}
txOps := &bind.CallOpts{}
offset, err := g.NodesOffsetByAddress(txOps, nodeAddress)
if err != nil {
panic(err)
}
n, err := g.Nodes(txOps, offset)
if err != nil {
panic(err)
}
return node{
owner: n.Owner,
email: n.Email,
fined: n.Fined,
name: n.Name,
}
}
func printNodes(nodes []node) {
for i := range nodes {
fmt.Println("Owner", nodes[i].owner.Hex())
fmt.Println("Email", nodes[i].email)
fmt.Println("Fined", nodes[i].fined.Uint64())
}
}
// NewBlockchainBackend is the blockchain backend constructor.
func NewBlockchainBackend(networkID int) *BlockchainBackend {
return &BlockchainBackend{networkID: networkID}
}
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