P2P Network Protocol

┌─────────────────────────────────────────────────────────────┐
│                    TOS Network Layer Stack                  │
├─────────────────────────────────────────────────────────────┤
│ Application Layer │ Wallet, Mining, Smart Contracts         │
├─────────────────────────────────────────────────────────────┤
│ Protocol Layer    │ Block Sync, Transaction Relay, Mining   │
├─────────────────────────────────────────────────────────────┤
│ Network Layer     │ Peer Discovery, Message Routing         │
├─────────────────────────────────────────────────────────────┤
│ Security Layer    │ Encryption, Authentication, Privacy     │
├─────────────────────────────────────────────────────────────┤
│ Transport Layer   │ TCP/UDP, QUIC, Connection Management    │
└─────────────────────────────────────────────────────────────┘

// Network topology configuration
const networkTopology = {
  maxPeers: 50,
  targetPeers: 25,
  minPeers: 8,
 
  // Node type distribution targets
  nodeDistribution: {
    fullNodes: 0.6,      // 60% full nodes
    lightNodes: 0.3,     // 30% light nodes
    miningNodes: 0.08,   // 8% mining nodes
    validatorNodes: 0.02 // 2% validator nodes
  },
 
  // Connection preferences
  connectionPreferences: {
    diverseGeolocation: true,
    lowLatencyPriority: true,
    highUptimePriority: true,
    aiMiningCapability: true
  }
};

┌─────────────────────────────────────────────────────────────┐
│                    TOS P2P Message Format                   │
├─────────────────┬───────────────────────────────────────────┤
│ Header (32 bytes)                                           │
├─────────────────┼───────────────────────────────────────────┤
│ Magic (4 bytes) │ Protocol Version (2 bytes)                │
├─────────────────┼───────────────────────────────────────────┤
│ Message Type (2 bytes) │ Payload Length (4 bytes)          │
├─────────────────┼───────────────────────────────────────────┤
│ Checksum (8 bytes) │ Timestamp (8 bytes)                   │
├─────────────────┼───────────────────────────────────────────┤
│ Node ID (32 bytes)                                          │
├─────────────────────────────────────────────────────────────┤
│ Encrypted Payload (Variable Length)                        │
└─────────────────────────────────────────────────────────────┘

use serde::{Serialize, Deserialize};
use sha3::{Sha3_256, Digest};
 
#[derive(Serialize, Deserialize, Clone)]
pub struct P2PMessage {
    pub header: MessageHeader,
    pub payload: MessagePayload,
}
 
#[derive(Serialize, Deserialize, Clone)]
pub struct MessageHeader {
    pub magic: [u8; 4],           // Network magic bytes
    pub version: u16,             // Protocol version
    pub message_type: u16,        // Message type identifier
    pub payload_length: u32,      // Payload size in bytes
    pub checksum: u64,           // Payload checksum
    pub timestamp: u64,          // Unix timestamp
    pub node_id: [u8; 32],       // Sender node ID
}
 
#[derive(Serialize, Deserialize, Clone)]
pub enum MessagePayload {
    Ping(PingMessage),
    Pong(PongMessage),
    PeerExchange(PeerExchangeMessage),
    BlockAnnounce(BlockAnnounceMessage),
    BlockRequest(BlockRequestMessage),
    BlockResponse(BlockResponseMessage),
    TransactionAnnounce(TransactionAnnounceMessage),
    TransactionRequest(TransactionRequestMessage),
    TransactionResponse(TransactionResponseMessage),
    ConsensusVote(ConsensusVoteMessage),
    AIMiningShare(AIMiningShareMessage),
}
 
impl P2PMessage {
    pub fn new(message_type: u16, payload: MessagePayload, node_id: [u8; 32]) -> Self {
        let serialized_payload = bincode::serialize(&payload).unwrap();
        let checksum = Self::calculate_checksum(&serialized_payload);
 
        let header = MessageHeader {
            magic: [0x54, 0x4F, 0x53, 0x4E], // "TOSN"
            version: 1,
            message_type,
            payload_length: serialized_payload.len() as u32,
            checksum,
            timestamp: std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_secs(),
            node_id,
        };
 
        Self { header, payload }
    }
 
    pub fn calculate_checksum(data: &[u8]) -> u64 {
        let mut hasher = Sha3_256::new();
        hasher.update(data);
        let result = hasher.finalize();
        u64::from_be_bytes(result[0..8].try_into().unwrap())
    }
 
    pub fn verify_checksum(&self) -> bool {
        let serialized_payload = bincode::serialize(&self.payload).unwrap();
        let calculated_checksum = Self::calculate_checksum(&serialized_payload);
        calculated_checksum == self.header.checksum
    }
 
    pub fn encrypt(&mut self, peer_public_key: &[u8; 32]) {
        // Implement encryption using ChaCha20-Poly1305
        let encrypted_payload = encrypt_payload(&self.payload, peer_public_key);
        // Update payload with encrypted data
    }
 
    pub fn decrypt(&mut self, private_key: &[u8; 32]) -> Result<(), String> {
        // Implement decryption
        let decrypted_payload = decrypt_payload(&self.payload, private_key)?;
        self.payload = decrypted_payload;
        Ok(())
    }
}
 
// Specific message types
#[derive(Serialize, Deserialize, Clone)]
pub struct PingMessage {
    pub nonce: u64,
    pub user_agent: String,
    pub services: u64,
    pub timestamp: u64,
}
 
#[derive(Serialize, Deserialize, Clone)]
pub struct PongMessage {
    pub nonce: u64,
    pub timestamp: u64,
}
 
#[derive(Serialize, Deserialize, Clone)]
pub struct BlockAnnounceMessage {
    pub block_hash: [u8; 32],
    pub block_height: u64,
    pub difficulty: u64,
    pub ai_mined: bool,
    pub timestamp: u64,
}
 
#[derive(Serialize, Deserialize, Clone)]
pub struct TransactionAnnounceMessage {
    pub tx_hash: [u8; 32],
    pub fee: u64,
    pub priority: u8,
    pub privacy_level: u8,
    pub energy_used: u64,
}

import asyncio
import socket
import random
from typing import List, Tuple
 
class TOS_PeerDiscovery:
    def __init__(self, network_id: str = "mainnet"):
        self.network_id = network_id
        self.known_peers: List[Tuple[str, int]] = []
        self.connected_peers: List[Tuple[str, int]] = []
        self.bootstrap_nodes = self.get_bootstrap_nodes()
 
    def get_bootstrap_nodes(self) -> List[Tuple[str, int]]:
        """Get initial bootstrap nodes for network entry"""
        bootstrap_nodes = {
            "mainnet": [
                ("seed1.tos.network", 2080),
                ("seed2.tos.network", 2080),
                ("seed3.tos.network", 2080),
                ("seed4.tos.network", 2080),
                ("seed5.tos.network", 2080),
            ],
            "testnet": [
                ("testseed1.tos.network", 2080),
                ("testseed2.tos.network", 2080),
            ],
            "devnet": [
                ("127.0.0.1", 2080),
            ]
        }
        return bootstrap_nodes.get(self.network_id, [])
 
    async def discover_peers(self) -> List[Tuple[str, int]]:
        """Discover new peers using multiple methods"""
        discovered_peers = []
 
        # Method 1: DNS seeds
        dns_peers = await self.discover_via_dns()
        discovered_peers.extend(dns_peers)
 
        # Method 2: DHT (Distributed Hash Table)
        dht_peers = await self.discover_via_dht()
        discovered_peers.extend(dht_peers)
 
        # Method 3: Peer exchange
        exchange_peers = await self.discover_via_peer_exchange()
        discovered_peers.extend(exchange_peers)
 
        # Method 4: mDNS (for local network)
        mdns_peers = await self.discover_via_mdns()
        discovered_peers.extend(mdns_peers)
 
        # Remove duplicates and return
        unique_peers = list(set(discovered_peers))
        return unique_peers
 
    async def discover_via_dns(self) -> List[Tuple[str, int]]:
        """Discover peers via DNS TXT records"""
        peers = []
        dns_seeds = [
            f"peers.{self.network_id}.tos.network",
            f"nodes.{self.network_id}.tos.network",
        ]
 
        for seed in dns_seeds:
            try:
                # Query DNS TXT records for peer information
                import dns.resolver
                answers = dns.resolver.resolve(seed, 'TXT')
 
                for answer in answers:
                    # Parse TXT record: "ip:port:node_type:capabilities"
                    record = answer.to_text().strip('"')
                    parts = record.split(':')
                    if len(parts) >= 2:
                        ip, port = parts[0], int(parts[1])
                        peers.append((ip, port))
 
            except Exception as e:
                print(f"DNS discovery failed for {seed}: {e}")
 
        return peers
 
    async def discover_via_dht(self) -> List[Tuple[str, int]]:
        """Discover peers via Distributed Hash Table"""
        # Simplified DHT implementation
        dht_nodes = [
            ("dht1.tos.network", 6881),
            ("dht2.tos.network", 6881),
        ]
 
        peers = []
        for node_ip, node_port in dht_nodes:
            try:
                # Query DHT for TOS Network peers
                dht_peers = await self.query_dht_node(node_ip, node_port)
                peers.extend(dht_peers)
            except Exception as e:
                print(f"DHT discovery failed for {node_ip}: {e}")
 
        return peers
 
    async def discover_via_peer_exchange(self) -> List[Tuple[str, int]]:
        """Request peer lists from connected peers"""
        peers = []
 
        for peer_ip, peer_port in self.connected_peers:
            try:
                # Send PEER_EXCHANGE message
                peer_list = await self.request_peer_list(peer_ip, peer_port)
                peers.extend(peer_list)
            except Exception as e:
                print(f"Peer exchange failed with {peer_ip}: {e}")
 
        return peers
 
    async def discover_via_mdns(self) -> List[Tuple[str, int]]:
        """Discover local network peers via mDNS"""
        peers = []
 
        try:
            # Broadcast mDNS query for TOS Network services
            service_name = f"_tos-{self.network_id}._tcp.local"
            # Implementation would use zeroconf library
            # peers = query_mdns_service(service_name)
        except Exception as e:
            print(f"mDNS discovery failed: {e}")
 
        return peers
 
    def calculate_peer_score(self, peer_info: dict) -> float:
        """Calculate quality score for peer selection"""
        score = 100.0  # Base score
 
        # Uptime factor (0.5x to 1.5x)
        uptime_factor = min(1.5, peer_info.get('uptime', 0.8))
        score *= uptime_factor
 
        # Latency factor (0.5x to 1.2x)
        latency = peer_info.get('latency_ms', 100)
        latency_factor = max(0.5, 1.2 - (latency / 1000))
        score *= latency_factor
 
        # Bandwidth factor (0.8x to 1.3x)
        bandwidth = peer_info.get('bandwidth_mbps', 10)
        bandwidth_factor = min(1.3, 0.8 + (bandwidth / 100))
        score *= bandwidth_factor
 
        # AI mining capability bonus
        if peer_info.get('ai_mining_capable', False):
            score *= 1.1
 
        # Geographic diversity bonus
        if self.is_geographically_diverse(peer_info):
            score *= 1.05
 
        return score
 
    async def connect_to_peers(self, max_connections: int = 25):
        """Establish connections to high-quality peers"""
        discovered_peers = await self.discover_peers()
 
        # Score and sort peers
        peer_scores = []
        for peer in discovered_peers:
            peer_info = await self.get_peer_info(peer)
            score = self.calculate_peer_score(peer_info)
            peer_scores.append((peer, score))
 
        # Sort by score (highest first)
        peer_scores.sort(key=lambda x: x[1], reverse=True)
 
        # Connect to top peers
        connection_tasks = []
        for i, (peer, score) in enumerate(peer_scores[:max_connections]):
            if len(self.connected_peers) >= max_connections:
                break
 
            task = asyncio.create_task(self.connect_to_peer(peer))
            connection_tasks.append(task)
 
        # Wait for connections to complete
        await asyncio.gather(*connection_tasks, return_exceptions=True)

use chacha20poly1305::{ChaCha20Poly1305, Key, Nonce, aead::Aead};
use x25519_dalek::{PublicKey, StaticSecret};
use rand::rngs::OsRng;
 
pub struct SecureChannel {
    local_private_key: StaticSecret,
    local_public_key: PublicKey,
    remote_public_key: Option<PublicKey>,
    shared_secret: Option<[u8; 32]>,
    cipher: Option<ChaCha20Poly1305>,
}
 
impl SecureChannel {
    pub fn new() -> Self {
        let private_key = StaticSecret::new(OsRng);
        let public_key = PublicKey::from(&private_key);
 
        Self {
            local_private_key: private_key,
            local_public_key: public_key,
            remote_public_key: None,
            shared_secret: None,
            cipher: None,
        }
    }
 
    pub fn establish_channel(&mut self, remote_public_key: PublicKey) {
        let shared_secret = self.local_private_key.diffie_hellman(&remote_public_key);
        let shared_secret_bytes = shared_secret.as_bytes();
 
        self.remote_public_key = Some(remote_public_key);
        self.shared_secret = Some(*shared_secret_bytes);
 
        // Derive encryption key from shared secret
        let key = Key::from_slice(shared_secret_bytes);
        self.cipher = Some(ChaCha20Poly1305::new(key));
    }
 
    pub fn encrypt_message(&self, plaintext: &[u8]) -> Result<Vec<u8>, String> {
        let cipher = self.cipher.as_ref().ok_or("Channel not established")?;
 
        // Generate random nonce
        let mut nonce_bytes = [0u8; 12];
        use rand::RngCore;
        OsRng.fill_bytes(&mut nonce_bytes);
        let nonce = Nonce::from_slice(&nonce_bytes);
 
        // Encrypt message
        let ciphertext = cipher.encrypt(nonce, plaintext)
            .map_err(|e| format!("Encryption failed: {:?}", e))?;
 
        // Prepend nonce to ciphertext
        let mut result = nonce_bytes.to_vec();
        result.extend_from_slice(&ciphertext);
 
        Ok(result)
    }
 
    pub fn decrypt_message(&self, encrypted_data: &[u8]) -> Result<Vec<u8>, String> {
        if encrypted_data.len() < 12 {
            return Err("Invalid encrypted data length".to_string());
        }
 
        let cipher = self.cipher.as_ref().ok_or("Channel not established")?;
 
        // Extract nonce and ciphertext
        let nonce = Nonce::from_slice(&encrypted_data[0..12]);
        let ciphertext = &encrypted_data[12..];
 
        // Decrypt message
        let plaintext = cipher.decrypt(nonce, ciphertext)
            .map_err(|e| format!("Decryption failed: {:?}", e))?;
 
        Ok(plaintext)
    }
 
    pub fn get_public_key(&self) -> PublicKey {
        self.local_public_key
    }
}
 
// Digital signatures for message authentication
use ed25519_dalek::{Signature, Signer, SigningKey, Verifier, VerifyingKey};
 
pub struct MessageSigner {
    signing_key: SigningKey,
    verifying_key: VerifyingKey,
}
 
impl MessageSigner {
    pub fn new() -> Self {
        let signing_key = SigningKey::generate(&mut OsRng);
        let verifying_key = signing_key.verifying_key();
 
        Self {
            signing_key,
            verifying_key,
        }
    }
 
    pub fn sign_message(&self, message: &[u8]) -> Signature {
        self.signing_key.sign(message)
    }
 
    pub fn verify_signature(&self, message: &[u8], signature: &Signature, public_key: &VerifyingKey) -> bool {
        public_key.verify(message, signature).is_ok()
    }
 
    pub fn get_public_key(&self) -> VerifyingKey {
        self.verifying_key
    }
}

import time
import collections
from typing import Dict, Set
from dataclasses import dataclass
 
@dataclass
class ConnectionInfo:
    ip_address: str
    connection_time: float
    message_count: int
    bandwidth_used: int
    reputation_score: float
    is_blacklisted: bool = False
 
class DDoSProtection:
    def __init__(self):
        self.connections: Dict[str, ConnectionInfo] = {}
        self.message_rate_limit = 100  # messages per minute
        self.bandwidth_limit = 1048576  # 1MB per minute
        self.connection_limit_per_ip = 3
        self.reputation_threshold = 0.3
 
        # Rate limiting windows
        self.message_windows: Dict[str, collections.deque] = {}
        self.bandwidth_windows: Dict[str, collections.deque] = {}
 
        # Blacklist and whitelist
        self.blacklisted_ips: Set[str] = set()
        self.whitelisted_ips: Set[str] = set()
 
    def should_accept_connection(self, ip_address: str) -> bool:
        """Determine if a new connection should be accepted"""
 
        # Check whitelist first
        if ip_address in self.whitelisted_ips:
            return True
 
        # Check blacklist
        if ip_address in self.blacklisted_ips:
            return False
 
        # Check connection count from this IP
        ip_connections = sum(1 for conn in self.connections.values()
                           if conn.ip_address == ip_address)
 
        if ip_connections >= self.connection_limit_per_ip:
            return False
 
        return True
 
    def should_accept_message(self, ip_address: str, message_size: int) -> bool:
        """Determine if a message should be processed"""
 
        if ip_address in self.whitelisted_ips:
            return True
 
        if ip_address in self.blacklisted_ips:
            return False
 
        current_time = time.time()
 
        # Check message rate limit
        if not self._check_message_rate(ip_address, current_time):
            self._penalize_peer(ip_address, "message_rate_exceeded")
            return False
 
        # Check bandwidth limit
        if not self._check_bandwidth_limit(ip_address, message_size, current_time):
            self._penalize_peer(ip_address, "bandwidth_exceeded")
            return False
 
        # Update counters
        self._update_message_counter(ip_address, message_size, current_time)
 
        return True
 
    def _check_message_rate(self, ip_address: str, current_time: float) -> bool:
        """Check if peer is within message rate limits"""
        if ip_address not in self.message_windows:
            self.message_windows[ip_address] = collections.deque()
 
        window = self.message_windows[ip_address]
 
        # Remove old messages (older than 1 minute)
        while window and current_time - window[0] > 60:
            window.popleft()
 
        return len(window) < self.message_rate_limit
 
    def _check_bandwidth_limit(self, ip_address: str, message_size: int, current_time: float) -> bool:
        """Check if peer is within bandwidth limits"""
        if ip_address not in self.bandwidth_windows:
            self.bandwidth_windows[ip_address] = collections.deque()
 
        window = self.bandwidth_windows[ip_address]
 
        # Remove old entries (older than 1 minute)
        while window and current_time - window[0][0] > 60:
            window.popleft()
 
        # Calculate current bandwidth usage
        current_bandwidth = sum(size for _, size in window)
 
        return current_bandwidth + message_size <= self.bandwidth_limit
 
    def _update_message_counter(self, ip_address: str, message_size: int, current_time: float):
        """Update message and bandwidth counters"""
        # Update message window
        if ip_address not in self.message_windows:
            self.message_windows[ip_address] = collections.deque()
        self.message_windows[ip_address].append(current_time)
 
        # Update bandwidth window
        if ip_address not in self.bandwidth_windows:
            self.bandwidth_windows[ip_address] = collections.deque()
        self.bandwidth_windows[ip_address].append((current_time, message_size))
 
        # Update connection info
        if ip_address in self.connections:
            self.connections[ip_address].message_count += 1
            self.connections[ip_address].bandwidth_used += message_size
 
    def _penalize_peer(self, ip_address: str, reason: str):
        """Apply penalty to misbehaving peer"""
        if ip_address in self.connections:
            conn = self.connections[ip_address]
 
            # Reduce reputation score
            penalty_map = {
                "message_rate_exceeded": 0.1,
                "bandwidth_exceeded": 0.15,
                "invalid_message": 0.2,
                "consensus_violation": 0.3,
            }
 
            penalty = penalty_map.get(reason, 0.1)
            conn.reputation_score = max(0, conn.reputation_score - penalty)
 
            # Blacklist if reputation is too low
            if conn.reputation_score < self.reputation_threshold:
                self.blacklisted_ips.add(ip_address)
                conn.is_blacklisted = True
                print(f"Blacklisted peer {ip_address} due to low reputation: {conn.reputation_score}")
 
    def update_reputation(self, ip_address: str, behavior: str):
        """Update peer reputation based on behavior"""
        if ip_address not in self.connections:
            return
 
        conn = self.connections[ip_address]
 
        reputation_changes = {
            "valid_block": +0.05,
            "valid_transaction": +0.02,
            "helpful_peer_info": +0.01,
            "fast_response": +0.01,
            "invalid_block": -0.2,
            "invalid_transaction": -0.1,
            "slow_response": -0.01,
            "connection_drop": -0.05,
        }
 
        change = reputation_changes.get(behavior, 0)
        conn.reputation_score = max(0, min(1, conn.reputation_score + change))
 
        # Remove from blacklist if reputation improves
        if conn.reputation_score > self.reputation_threshold and ip_address in self.blacklisted_ips:
            self.blacklisted_ips.remove(ip_address)
            conn.is_blacklisted = False
            print(f"Removed {ip_address} from blacklist due to improved reputation")
 
    def get_peer_stats(self, ip_address: str) -> Dict:
        """Get statistics for a peer"""
        if ip_address not in self.connections:
            return {}
 
        conn = self.connections[ip_address]
        current_time = time.time()
 
        # Calculate recent message rate
        if ip_address in self.message_windows:
            recent_messages = len([t for t in self.message_windows[ip_address]
                                 if current_time - t < 60])
        else:
            recent_messages = 0
 
        # Calculate recent bandwidth usage
        if ip_address in self.bandwidth_windows:
            recent_bandwidth = sum(size for time, size in self.bandwidth_windows[ip_address]
                                 if current_time - time < 60)
        else:
            recent_bandwidth = 0
 
        return {
            "ip_address": ip_address,
            "connected_duration": current_time - conn.connection_time,
            "total_messages": conn.message_count,
            "total_bandwidth": conn.bandwidth_used,
            "recent_message_rate": recent_messages,
            "recent_bandwidth_usage": recent_bandwidth,
            "reputation_score": conn.reputation_score,
            "is_blacklisted": conn.is_blacklisted,
        }

package consensus
 
import (
    "crypto/sha256"
    "encoding/hex"
    "fmt"
    "sync"
    "time"
)
 
type BlockDAGVote struct {
    BlockHash     [32]byte  `json:"block_hash"`
    VoterID       [32]byte  `json:"voter_id"`
    VoteType      VoteType  `json:"vote_type"`
    Timestamp     int64     `json:"timestamp"`
    Signature     [64]byte  `json:"signature"`
    ParentVotes   [][32]byte `json:"parent_votes"`
}
 
type VoteType int
 
const (
    VoteAccept VoteType = iota
    VoteReject
    VoteAbstain
)
 
type ConsensusNetwork struct {
    peers           map[string]*Peer
    votes           map[[32]byte]*BlockDAGVote
    voteCache       *VoteCache
    propagationMux  sync.RWMutex
    maxVoteAge      time.Duration
}
 
type VoteCache struct {
    cache map[[32]byte]CacheEntry
    mutex sync.RWMutex
}
 
type CacheEntry struct {
    vote      *BlockDAGVote
    timestamp time.Time
    propagated bool
}
 
func NewConsensusNetwork() *ConsensusNetwork {
    return &ConsensusNetwork{
        peers:       make(map[string]*Peer),
        votes:       make(map[[32]byte]*BlockDAGVote),
        voteCache:   &VoteCache{cache: make(map[[32]byte]CacheEntry)},
        maxVoteAge:  30 * time.Minute,
    }
}
 
func (cn *ConsensusNetwork) PropagateVote(vote *BlockDAGVote) error {
    // Validate vote first
    if !cn.validateVote(vote) {
        return fmt.Errorf("invalid vote")
    }
 
    // Check if already propagated
    voteHash := cn.calculateVoteHash(vote)
    if cn.voteCache.isAlreadyPropagated(voteHash) {
        return nil // Already propagated
    }
 
    // Add to cache
    cn.voteCache.addVote(voteHash, vote)
 
    // Propagate to peers
    cn.propagationMux.RLock()
    defer cn.propagationMux.RUnlock()
 
    var wg sync.WaitGroup
    for peerID, peer := range cn.peers {
        if peer.SupportsConsensus() {
            wg.Add(1)
            go func(p *Peer, id string) {
                defer wg.Done()
                if err := p.SendVote(vote); err != nil {
                    fmt.Printf("Failed to send vote to peer %s: %v\n", id, err)
                }
            }(peer, peerID)
        }
    }
 
    wg.Wait()
    return nil
}
 
func (cn *ConsensusNetwork) HandleIncomingVote(vote *BlockDAGVote, fromPeer string) error {
    // Validate vote
    if !cn.validateVote(vote) {
        return fmt.Errorf("invalid vote from peer %s", fromPeer)
    }
 
    // Check vote age
    voteAge := time.Since(time.Unix(vote.Timestamp, 0))
    if voteAge > cn.maxVoteAge {
        return fmt.Errorf("vote too old: %v", voteAge)
    }
 
    // Add to local vote storage
    voteHash := cn.calculateVoteHash(vote)
    cn.votes[voteHash] = vote
 
    // Propagate to other peers (excluding sender)
    return cn.propagateToOthers(vote, fromPeer)
}
 
func (cn *ConsensusNetwork) validateVote(vote *BlockDAGVote) bool {
    // Basic validation
    if vote.Timestamp == 0 {
        return false
    }
 
    // Verify signature
    if !cn.verifyVoteSignature(vote) {
        return false
    }
 
    // Check voter authorization
    if !cn.isAuthorizedVoter(vote.VoterID) {
        return false
    }
 
    // Validate parent votes exist
    for _, parentHash := range vote.ParentVotes {
        if _, exists := cn.votes[parentHash]; !exists {
            // Request missing parent vote
            cn.requestVote(parentHash)
        }
    }
 
    return true
}
 
func (cn *ConsensusNetwork) calculateVoteHash(vote *BlockDAGVote) [32]byte {
    data := fmt.Sprintf("%x%x%d%d", vote.BlockHash, vote.VoterID,
                       vote.VoteType, vote.Timestamp)
    return sha256.Sum256([]byte(data))
}
 
func (cn *ConsensusNetwork) verifyVoteSignature(vote *BlockDAGVote) bool {
    // Implement Ed25519 signature verification
    // This is a simplified placeholder
    return true
}
 
func (cn *ConsensusNetwork) isAuthorizedVoter(voterID [32]byte) bool {
    // Check if voter has sufficient stake or authority
    // Implement stake verification logic
    return true
}
 
func (cn *ConsensusNetwork) propagateToOthers(vote *BlockDAGVote, excludePeer string) error {
    cn.propagationMux.RLock()
    defer cn.propagationMux.RUnlock()
 
    for peerID, peer := range cn.peers {
        if peerID != excludePeer && peer.SupportsConsensus() {
            go func(p *Peer, id string) {
                if err := p.SendVote(vote); err != nil {
                    fmt.Printf("Failed to propagate vote to peer %s: %v\n", id, err)
                }
            }(peer, peerID)
        }
    }
 
    return nil
}
 
func (vc *VoteCache) isAlreadyPropagated(voteHash [32]byte) bool {
    vc.mutex.RLock()
    defer vc.mutex.RUnlock()
 
    entry, exists := vc.cache[voteHash]
    return exists && entry.propagated
}
 
func (vc *VoteCache) addVote(voteHash [32]byte, vote *BlockDAGVote) {
    vc.mutex.Lock()
    defer vc.mutex.Unlock()
 
    vc.cache[voteHash] = CacheEntry{
        vote:       vote,
        timestamp:  time.Now(),
        propagated: true,
    }
}
 
// Clean up old votes periodically
func (cn *ConsensusNetwork) CleanupOldVotes() {
    ticker := time.NewTicker(5 * time.Minute)
    defer ticker.Stop()
 
    for range ticker.C {
        cn.voteCache.mutex.Lock()
        now := time.Now()
        for hash, entry := range cn.voteCache.cache {
            if now.Sub(entry.timestamp) > cn.maxVoteAge {
                delete(cn.voteCache.cache, hash)
            }
        }
        cn.voteCache.mutex.Unlock()
    }
}

import numpy as np
import networkx as nx
from typing import Dict, List, Tuple, Set
import machine_learning as ml
 
class AIRoutingEngine:
    def __init__(self):
        self.network_graph = nx.Graph()
        self.peer_metrics = {}
        self.routing_model = self.load_routing_model()
        self.message_priority_weights = {
            'block_announce': 1.0,
            'transaction': 0.8,
            'consensus_vote': 0.9,
            'peer_exchange': 0.3,
            'ping': 0.1
        }
 
    def load_routing_model(self):
        """Load pre-trained ML model for routing decisions"""
        # This would load a trained neural network model
        # For now, we'll use a simple heuristic-based approach
        return None
 
    def update_network_topology(self, peers: Dict[str, Dict]):
        """Update network graph with current peer information"""
        # Clear existing graph
        self.network_graph.clear()
 
        # Add nodes for each peer
        for peer_id, peer_info in peers.items():
            self.network_graph.add_node(peer_id, **peer_info)
 
        # Add edges based on peer connections
        for peer_id, peer_info in peers.items():
            connected_peers = peer_info.get('connected_peers', [])
            for connected_peer in connected_peers:
                if connected_peer in peers:
                    # Weight edge by connection quality
                    weight = self.calculate_connection_weight(
                        peer_info, peers[connected_peer]
                    )
                    self.network_graph.add_edge(peer_id, connected_peer, weight=weight)
 
    def calculate_connection_weight(self, peer1_info: Dict, peer2_info: Dict) -> float:
        """Calculate connection quality weight between two peers"""
        # Factors affecting connection quality
        latency1 = peer1_info.get('latency_ms', 100)
        latency2 = peer2_info.get('latency_ms', 100)
        avg_latency = (latency1 + latency2) / 2
 
        bandwidth1 = peer1_info.get('bandwidth_mbps', 10)
        bandwidth2 = peer2_info.get('bandwidth_mbps', 10)
        min_bandwidth = min(bandwidth1, bandwidth2)
 
        uptime1 = peer1_info.get('uptime', 0.9)
        uptime2 = peer2_info.get('uptime', 0.9)
        avg_uptime = (uptime1 + uptime2) / 2
 
        # Calculate composite weight (lower is better)
        weight = (avg_latency / 1000) / (min_bandwidth * avg_uptime)
        return weight
 
    def find_optimal_routes(self, source: str, targets: List[str],
                           message_type: str) -> Dict[str, List[str]]:
        """Find optimal routing paths for message propagation"""
        routes = {}
        message_priority = self.message_priority_weights.get(message_type, 0.5)
 
        for target in targets:
            if target == source:
                continue
 
            try:
                # Use Dijkstra's algorithm with AI-enhanced weights
                path = nx.shortest_path(
                    self.network_graph,
                    source,
                    target,
                    weight='weight'
                )
                routes[target] = path
 
            except nx.NetworkXNoPath:
                # No direct path found, use flood routing
                routes[target] = self.find_flood_route(source, target)
 
        return routes
 
    def find_flood_route(self, source: str, target: str) -> List[str]:
        """Find route using controlled flooding"""
        # BFS to find any available path
        visited = set([source])
        queue = [(source, [source])]
 
        while queue:
            current, path = queue.pop(0)
 
            if current == target:
                return path
 
            for neighbor in self.network_graph.neighbors(current):
                if neighbor not in visited:
                    visited.add(neighbor)
                    queue.append((neighbor, path + [neighbor]))
 
        return []  # No path found
 
    def optimize_propagation_strategy(self, message_type: str,
                                    urgency: float) -> Dict[str, float]:
        """AI-optimized message propagation strategy"""
 
        # Feature vector for ML model
        features = np.array([
            urgency,
            self.message_priority_weights.get(message_type, 0.5),
            len(self.network_graph.nodes()),  # Network size
            nx.density(self.network_graph),   # Network density
            self.calculate_network_congestion(),
        ])
 
        # If ML model is available, use it for optimization
        if self.routing_model:
            strategy_params = self.routing_model.predict([features])[0]
        else:
            # Fallback to heuristic-based optimization
            strategy_params = self.heuristic_optimization(features)
 
        return {
            'redundancy_factor': strategy_params[0],  # How many paths to use
            'timeout_multiplier': strategy_params[1], # Timeout adjustment
            'retry_attempts': int(strategy_params[2]), # Number of retries
            'batching_factor': strategy_params[3],    # Message batching
        }
 
    def heuristic_optimization(self, features: np.ndarray) -> List[float]:
        """Heuristic-based optimization when ML model is not available"""
        urgency, priority, network_size, density, congestion = features
 
        # Redundancy factor (1.0 to 3.0)
        redundancy = 1.0 + (urgency * priority * 2.0)
        redundancy = min(3.0, redundancy)
 
        # Timeout multiplier (0.5 to 2.0)
        timeout_mult = 1.0 + (congestion * 1.0) - (density * 0.5)
        timeout_mult = max(0.5, min(2.0, timeout_mult))
 
        # Retry attempts (1 to 5)
        retries = max(1, int(urgency * priority * 5))
        retries = min(5, retries)
 
        # Batching factor (0.1 to 1.0)
        batching = max(0.1, 1.0 - urgency)
 
        return [redundancy, timeout_mult, retries, batching]
 
    def calculate_network_congestion(self) -> float:
        """Calculate current network congestion level"""
        if not self.network_graph.nodes():
            return 0.0
 
        # Simple congestion metric based on average degree and load
        total_load = 0
        total_capacity = 0
 
        for node in self.network_graph.nodes():
            node_data = self.network_graph.nodes[node]
            load = node_data.get('message_queue_size', 0)
            capacity = node_data.get('max_message_queue', 1000)
 
            total_load += load
            total_capacity += capacity
 
        if total_capacity == 0:
            return 0.0
 
        return total_load / total_capacity
 
    def adaptive_routing_decision(self, message_type: str, target_peers: List[str],
                                current_network_state: Dict) -> Dict[str, List[str]]:
        """Make adaptive routing decisions based on current network state"""
 
        # Update network state
        self.update_network_topology(current_network_state.get('peers', {}))
 
        # Calculate message urgency
        urgency = self.calculate_message_urgency(message_type, current_network_state)
 
        # Get optimization strategy
        strategy = self.optimize_propagation_strategy(message_type, urgency)
 
        # Find routes with redundancy
        routes = {}
        redundancy_factor = strategy['redundancy_factor']
 
        for target in target_peers:
            primary_route = self.find_optimal_routes('self', [target], message_type)
            routes[target] = primary_route.get(target, [])
 
            # Add backup routes if redundancy is needed
            if redundancy_factor > 1.0:
                backup_routes = self.find_backup_routes('self', target,
                                                      int(redundancy_factor) - 1)
                routes[f"{target}_backup"] = backup_routes
 
        return routes
 
    def calculate_message_urgency(self, message_type: str,
                                network_state: Dict) -> float:
        """Calculate urgency score for message type"""
        base_urgency = {
            'block_announce': 0.9,
            'consensus_vote': 0.95,
            'transaction': 0.7,
            'ai_mining_share': 0.8,
            'peer_exchange': 0.2,
            'ping': 0.1
        }.get(message_type, 0.5)
 
        # Adjust based on network conditions
        network_load = network_state.get('congestion_level', 0.5)
        block_height = network_state.get('current_block_height', 0)
        last_block_time = network_state.get('last_block_time', 0)
 
        # Increase urgency if network is behind
        if last_block_time > 0:
            time_since_last_block = time.time() - last_block_time
            if time_since_last_block > 30:  # 30 seconds threshold
                base_urgency *= 1.2
 
        # Decrease urgency if network is congested
        if network_load > 0.8:
            base_urgency *= 0.8
 
        return min(1.0, base_urgency)
 
    def find_backup_routes(self, source: str, target: str,
                          num_backups: int) -> List[List[str]]:
        """Find backup routing paths"""
        backup_routes = []
 
        try:
            # Find k-shortest paths
            paths = list(nx.shortest_simple_paths(
                self.network_graph, source, target, weight='weight'
            ))
 
            # Take the requested number of backup paths
            backup_routes = paths[1:num_backups+1]  # Skip primary path
 
        except (nx.NetworkXNoPath, nx.NetworkXError):
            pass
 
        return backup_routes

class TOSNetworkMonitor {
  constructor() {
    this.metrics = {
      totalPeers: 0,
      activePeers: 0,
      networkLatency: 0,
      messageRate: 0,
      blockPropagationTime: 0,
      consensusParticipation: 0,
      networkHealthScore: 0
    };
 
    this.peerMetrics = new Map();
    this.messageStats = {
      sent: 0,
      received: 0,
      dropped: 0,
      duplicate: 0
    };
 
    this.monitoringInterval = 30000; // 30 seconds
    this.startMonitoring();
  }
 
  startMonitoring() {
    setInterval(() => {
      this.collectMetrics();
      this.updateNetworkHealth();
      this.reportMetrics();
    }, this.monitoringInterval);
  }
 
  collectMetrics() {
    // Collect peer metrics
    this.metrics.totalPeers = this.peerMetrics.size;
    this.metrics.activePeers = Array.from(this.peerMetrics.values())
      .filter(peer => peer.lastSeen > Date.now() - 300000).length; // 5 min
 
    // Calculate average latency
    const latencies = Array.from(this.peerMetrics.values())
      .map(peer => peer.latency)
      .filter(latency => latency > 0);
 
    this.metrics.networkLatency = latencies.length > 0
      ? latencies.reduce((sum, lat) => sum + lat, 0) / latencies.length
      : 0;
 
    // Calculate message rate (messages per second)
    const timeWindow = 60000; // 1 minute
    const currentTime = Date.now();
    const recentMessages = Array.from(this.peerMetrics.values())
      .reduce((total, peer) => {
        const recentCount = peer.messageHistory
          .filter(timestamp => currentTime - timestamp < timeWindow).length;
        return total + recentCount;
      }, 0);
 
    this.metrics.messageRate = recentMessages / 60; // per second
 
    // Calculate consensus participation
    const votingPeers = Array.from(this.peerMetrics.values())
      .filter(peer => peer.supportsConsensus && peer.isActive).length;
 
    this.metrics.consensusParticipation = this.metrics.activePeers > 0
      ? votingPeers / this.metrics.activePeers
      : 0;
  }
 
  updateNetworkHealth() {
    let healthScore = 100;
 
    // Penalty for low peer count
    if (this.metrics.activePeers < 10) {
      healthScore -= (10 - this.metrics.activePeers) * 5;
    }
 
    // Penalty for high latency
    if (this.metrics.networkLatency > 1000) { // 1 second
      healthScore -= Math.min(30, (this.metrics.networkLatency - 1000) / 100);
    }
 
    // Penalty for low consensus participation
    if (this.metrics.consensusParticipation < 0.5) {
      healthScore -= (0.5 - this.metrics.consensusParticipation) * 40;
    }
 
    // Penalty for message drops
    const dropRate = this.messageStats.dropped /
      (this.messageStats.sent + this.messageStats.received);
    if (dropRate > 0.05) { // 5% drop rate
      healthScore -= Math.min(25, (dropRate - 0.05) * 500);
    }
 
    this.metrics.networkHealthScore = Math.max(0, Math.min(100, healthScore));
  }
 
  updatePeerMetrics(peerId, metrics) {
    if (!this.peerMetrics.has(peerId)) {
      this.peerMetrics.set(peerId, {
        peerId: peerId,
        latency: 0,
        messageHistory: [],
        lastSeen: Date.now(),
        supportsConsensus: false,
        isActive: true,
        reputation: 1.0,
        connectionQuality: 1.0
      });
    }
 
    const peer = this.peerMetrics.get(peerId);
    Object.assign(peer, metrics);
    peer.lastSeen = Date.now();
  }
 
  recordMessage(type, direction, peerId) {
    this.messageStats[direction]++;
 
    if (this.peerMetrics.has(peerId)) {
      const peer = this.peerMetrics.get(peerId);
      peer.messageHistory.push(Date.now());
 
      // Keep only recent message history
      const cutoff = Date.now() - 3600000; // 1 hour
      peer.messageHistory = peer.messageHistory.filter(time => time > cutoff);
    }
  }
 
  recordBlockPropagation(blockHash, propagationTime) {
    // Update block propagation metrics
    if (this.blockPropagationTimes) {
      this.blockPropagationTimes.push(propagationTime);
 
      // Keep only recent measurements
      if (this.blockPropagationTimes.length > 100) {
        this.blockPropagationTimes.shift();
      }
 
      // Calculate average
      this.metrics.blockPropagationTime =
        this.blockPropagationTimes.reduce((sum, time) => sum + time, 0) /
        this.blockPropagationTimes.length;
    } else {
      this.blockPropagationTimes = [propagationTime];
      this.metrics.blockPropagationTime = propagationTime;
    }
  }
 
  getNetworkTopology() {
    const topology = {
      nodes: [],
      edges: []
    };
 
    // Add nodes
    for (const [peerId, peer] of this.peerMetrics) {
      topology.nodes.push({
        id: peerId,
        type: peer.nodeType || 'full',
        latency: peer.latency,
        reputation: peer.reputation,
        connectionQuality: peer.connectionQuality,
        isActive: peer.isActive,
        supportsAIMining: peer.supportsAIMining || false,
        location: peer.location || null
      });
    }
 
    // Add edges (connections between peers)
    for (const [peerId, peer] of this.peerMetrics) {
      if (peer.connectedPeers) {
        for (const connectedPeer of peer.connectedPeers) {
          if (this.peerMetrics.has(connectedPeer)) {
            topology.edges.push({
              source: peerId,
              target: connectedPeer,
              weight: peer.connectionQuality || 1.0
            });
          }
        }
      }
    }
 
    return topology;
  }
 
  generateNetworkReport() {
    return {
      timestamp: Date.now(),
      metrics: { ...this.metrics },
      topology: this.getNetworkTopology(),
      messageStats: { ...this.messageStats },
      peerDistribution: this.calculatePeerDistribution(),
      performanceIndicators: this.calculatePerformanceIndicators()
    };
  }
 
  calculatePeerDistribution() {
    const distribution = {
      byType: {},
      byLocation: {},
      byCapability: {}
    };
 
    for (const peer of this.peerMetrics.values()) {
      // By node type
      const type = peer.nodeType || 'unknown';
      distribution.byType[type] = (distribution.byType[type] || 0) + 1;
 
      // By location
      const location = peer.location || 'unknown';
      distribution.byLocation[location] = (distribution.byLocation[location] || 0) + 1;
 
      // By capability
      if (peer.supportsAIMining) {
        distribution.byCapability.aiMining = (distribution.byCapability.aiMining || 0) + 1;
      }
      if (peer.supportsConsensus) {
        distribution.byCapability.consensus = (distribution.byCapability.consensus || 0) + 1;
      }
    }
 
    return distribution;
  }
 
  calculatePerformanceIndicators() {
    const indicators = {};
 
    // Network efficiency
    indicators.networkEfficiency = this.metrics.activePeers > 0
      ? this.metrics.messageRate / this.metrics.activePeers
      : 0;
 
    // Consensus health
    indicators.consensusHealth = this.metrics.consensusParticipation;
 
    // Connection stability
    const stablePeers = Array.from(this.peerMetrics.values())
      .filter(peer => peer.connectionQuality > 0.8).length;
    indicators.connectionStability = this.metrics.activePeers > 0
      ? stablePeers / this.metrics.activePeers
      : 0;
 
    // Message success rate
    const totalMessages = this.messageStats.sent + this.messageStats.received;
    indicators.messageSuccessRate = totalMessages > 0
      ? 1 - (this.messageStats.dropped / totalMessages)
      : 1;
 
    return indicators;
  }
 
  reportMetrics() {
    const report = this.generateNetworkReport();
 
    console.log('TOS Network Metrics Report:');
    console.log(`Active Peers: ${report.metrics.activePeers}`);
    console.log(`Network Latency: ${report.metrics.networkLatency.toFixed(2)}ms`);
    console.log(`Message Rate: ${report.metrics.messageRate.toFixed(2)}/s`);
    console.log(`Network Health: ${report.metrics.networkHealthScore.toFixed(1)}%`);
    console.log(`Consensus Participation: ${(report.metrics.consensusParticipation * 100).toFixed(1)}%`);
 
    // Send to monitoring system
    this.sendToMonitoringSystem(report);
  }
 
  sendToMonitoringSystem(report) {
    // Implementation would send metrics to external monitoring
    // This could be Prometheus, Grafana, or custom monitoring solution
  }
}