Search/node.go

package main

import (
	"bytes"
	"crypto/rand"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"sync"
	"time"

	libp2p "github.com/libp2p/go-libp2p"
	crypto "github.com/libp2p/go-libp2p-core/crypto"
	"github.com/libp2p/go-libp2p-core/peer"
)

var (
	authCode      string
	peers         []string
	authMutex     sync.Mutex
	authenticated = make(map[string]bool)
	hostID        peer.ID
)

type Message struct {
	ID      string `json:"id"`
	Type    string `json:"type"`
	Content string `json:"content"`
}

type CrawlerConfig struct {
	ID       string
	Host     string
	Port     int
	AuthCode string
}

func loadNodeConfig() {
	config := loadConfig()
	authCode = config.AuthCode
	peers = config.Peers
}

func initP2P() (peer.ID, error) {
	priv, _, err := crypto.GenerateKeyPairWithReader(crypto.Ed25519, 2048, rand.Reader)
	if err != nil {
		return "", fmt.Errorf("failed to generate key pair: %v", err)
	}

	h, err := libp2p.New(libp2p.Identity(priv))
	if err != nil {
		return "", fmt.Errorf("failed to create libp2p host: %v", err)
	}

	return h.ID(), nil
}

func sendMessage(serverAddr string, msg Message) error {
	msgBytes, err := json.Marshal(msg)
	if err != nil {
		return fmt.Errorf("failed to marshal message: %v", err)
	}

	req, err := http.NewRequest("POST", serverAddr, bytes.NewBuffer(msgBytes))
	if err != nil {
		return fmt.Errorf("failed to create request: %v", err)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", authCode)

	client := &http.Client{
		Timeout: time.Second * 10,
	}

	resp, err := client.Do(req)
	if err != nil {
		return fmt.Errorf("failed to send request: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		body, _ := ioutil.ReadAll(resp.Body)
		return fmt.Errorf("server error: %s", body)
	}

	return nil
}

func handleNodeRequest(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Invalid request method", http.StatusMethodNotAllowed)
		return
	}

	auth := r.Header.Get("Authorization")
	if auth != authCode {
		http.Error(w, "Unauthorized", http.StatusUnauthorized)
		return
	}

	var msg Message
	err := json.NewDecoder(r.Body).Decode(&msg)
	if err != nil {
		http.Error(w, "Error parsing JSON", http.StatusBadRequest)
		return
	}
	defer r.Body.Close()

	log.Printf("Received message: %+v\n", msg)
	w.Write([]byte("Message received"))

	interpretMessage(msg)
}

func startNodeClient() {
	for {
		for _, peerAddr := range peers {
			msg := Message{
				ID:      hostID.Pretty(),
				Type:    "test",
				Content: "This is a test message from the client node",
			}

			err := sendMessage(peerAddr, msg)
			if err != nil {
				log.Printf("Error sending message to %s: %v", peerAddr, err)
			} else {
				log.Println("Message sent successfully to", peerAddr)
			}
		}
		time.Sleep(10 * time.Second)
	}
}

func interpretMessage(msg Message) {
	switch msg.Type {
	case "test":
		fmt.Println("Received test message:", msg.Content)
	case "update":
		fmt.Println("Received update message:", msg.Content)
		go update()
	case "heartbeat":
		handleHeartbeat(msg.Content)
	case "election":
		handleElection(msg.Content)
	default:
		fmt.Println("Received unknown message type:", msg.Type)
	}
}