Files
bitchat/bitchat/Nostr/NostrRelayManager.swift
T

605 lines
24 KiB
Swift

import Foundation
import Network
import Combine
/// Manages WebSocket connections to Nostr relays
@MainActor
class NostrRelayManager: ObservableObject {
static let shared = NostrRelayManager()
// Track gift-wraps (kind 1059) we initiated so we can log OK acks at info
private(set) static var pendingGiftWrapIDs = Set<String>()
static func registerPendingGiftWrap(id: String) {
pendingGiftWrapIDs.insert(id)
}
struct Relay: Identifiable {
let id = UUID()
let url: String
var isConnected: Bool = false
var lastError: Error?
var lastConnectedAt: Date?
var messagesSent: Int = 0
var messagesReceived: Int = 0
var reconnectAttempts: Int = 0
var lastDisconnectedAt: Date?
var nextReconnectTime: Date?
}
// Default relay list (can be customized)
private static let defaultRelays = [
"wss://relay.damus.io",
"wss://nos.lol",
"wss://relay.primal.net",
"wss://offchain.pub",
"wss://nostr21.com"
// For local testing, you can add: "ws://localhost:8080"
]
@Published private(set) var relays: [Relay] = []
@Published private(set) var isConnected = false
private var connections: [String: URLSessionWebSocketTask] = [:]
private var subscriptions: [String: Set<String>] = [:] // relay URL -> subscription IDs
private var messageHandlers: [String: (NostrEvent) -> Void] = [:]
private var cancellables = Set<AnyCancellable>()
// Message queue for reliability
private var messageQueue: [(event: NostrEvent, relayUrls: [String])] = []
private let messageQueueLock = NSLock()
// Exponential backoff configuration
private let initialBackoffInterval: TimeInterval = TransportConfig.nostrRelayInitialBackoffSeconds
private let maxBackoffInterval: TimeInterval = TransportConfig.nostrRelayMaxBackoffSeconds
private let backoffMultiplier: Double = TransportConfig.nostrRelayBackoffMultiplier
private let maxReconnectAttempts = TransportConfig.nostrRelayMaxReconnectAttempts
// Reconnection timer
private var reconnectionTimer: Timer?
init() {
// Initialize with default relays
self.relays = Self.defaultRelays.map { Relay(url: $0) }
}
/// Connect to all configured relays
func connect() {
SecureLogger.log("🌐 Connecting to \(relays.count) Nostr relays", category: SecureLogger.session, level: .debug)
for relay in relays {
connectToRelay(relay.url)
}
}
/// Disconnect from all relays
func disconnect() {
for (_, task) in connections {
task.cancel(with: .goingAway, reason: nil)
}
connections.removeAll()
updateConnectionStatus()
}
/// Ensure connections exist to the given relay URLs (idempotent).
func ensureConnections(to relayUrls: [String]) {
let existing = Set(relays.map { $0.url })
for url in Set(relayUrls) {
if !existing.contains(url) {
relays.append(Relay(url: url))
}
if connections[url] == nil {
connectToRelay(url)
}
}
}
/// Send an event to specified relays (or all if none specified)
func sendEvent(_ event: NostrEvent, to relayUrls: [String]? = nil) {
let targetRelays = relayUrls ?? Self.defaultRelays
ensureConnections(to: targetRelays)
// Add to queue for reliability
messageQueueLock.lock()
messageQueue.append((event, targetRelays))
messageQueueLock.unlock()
// Attempt immediate send
for relayUrl in targetRelays {
if let connection = connections[relayUrl] {
sendToRelay(event: event, connection: connection, relayUrl: relayUrl)
}
}
}
/// Subscribe to events matching a filter. If `relayUrls` provided, targets only those relays.
func subscribe(
filter: NostrFilter,
id: String = UUID().uuidString,
relayUrls: [String]? = nil,
handler: @escaping (NostrEvent) -> Void
) {
messageHandlers[id] = handler
SecureLogger.log("📡 Subscribing to Nostr filter id=\(id) kinds=\(filter.kinds ?? []) since=\(filter.since ?? 0)",
category: SecureLogger.session, level: .debug)
let req = NostrRequest.subscribe(id: id, filters: [filter])
do {
let encoder = JSONEncoder()
encoder.outputFormatting = .sortedKeys // For consistent output
let message = try encoder.encode(req)
guard let messageString = String(data: message, encoding: .utf8) else {
SecureLogger.log("❌ Failed to encode subscription request", category: SecureLogger.session, level: .error)
return
}
// SecureLogger.log("📋 Subscription filter JSON: \(messageString.prefix(200))...",
// category: SecureLogger.session, level: .debug)
// Target specific relays if provided; else all connections
let urls = relayUrls ?? Self.defaultRelays
ensureConnections(to: urls)
let targets: [(String, URLSessionWebSocketTask)] = urls.compactMap { url in
connections[url].map { (url, $0) }
}
for (relayUrl, connection) in targets {
connection.send(.string(messageString)) { error in
if let error = error {
SecureLogger.log("❌ Failed to send subscription to \(relayUrl): \(error)",
category: SecureLogger.session, level: .error)
} else {
// SecureLogger.log("✅ Subscription '\(id)' sent to relay: \(relayUrl)",
// category: SecureLogger.session, level: .debug)
// Subscription sent successfully
Task { @MainActor in
var subs = self.subscriptions[relayUrl] ?? Set<String>()
subs.insert(id)
self.subscriptions[relayUrl] = subs
}
}
}
}
if connections.isEmpty {
SecureLogger.log("⚠️ No relay connections available for subscription",
category: SecureLogger.session, level: .warning)
}
} catch {
SecureLogger.log("❌ Failed to encode subscription request: \(error)",
category: SecureLogger.session, level: .error)
}
}
/// Unsubscribe from a subscription
func unsubscribe(id: String) {
messageHandlers.removeValue(forKey: id)
let req = NostrRequest.close(id: id)
let message = try? JSONEncoder().encode(req)
guard let messageData = message,
let messageString = String(data: messageData, encoding: .utf8) else { return }
// Send unsubscribe to all relays
for (relayUrl, connection) in connections {
if subscriptions[relayUrl]?.contains(id) == true {
connection.send(.string(messageString)) { _ in
Task { @MainActor in
self.subscriptions[relayUrl]?.remove(id)
}
}
}
}
}
// MARK: - Private Methods
private func connectToRelay(_ urlString: String) {
guard let url = URL(string: urlString) else {
SecureLogger.log("Invalid relay URL: \(urlString)", category: SecureLogger.session, level: .warning)
return
}
// Skip if we already have a connection object
if connections[urlString] != nil {
return
}
// Attempting to connect to Nostr relay
let session = URLSession(configuration: .default)
let task = session.webSocketTask(with: url)
connections[urlString] = task
task.resume()
// Start receiving messages
receiveMessage(from: task, relayUrl: urlString)
// Send initial ping to verify connection
task.sendPing { [weak self] error in
DispatchQueue.main.async {
if error == nil {
SecureLogger.log("✅ Connected to Nostr relay: \(urlString)",
category: SecureLogger.session, level: .debug)
self?.updateRelayStatus(urlString, isConnected: true)
} else {
SecureLogger.log("❌ Failed to connect to Nostr relay \(urlString): \(error?.localizedDescription ?? "Unknown error")",
category: SecureLogger.session, level: .error)
self?.updateRelayStatus(urlString, isConnected: false, error: error)
// Trigger disconnection handler for proper backoff
self?.handleDisconnection(relayUrl: urlString, error: error ?? NSError(domain: "NostrRelay", code: -1, userInfo: nil))
}
}
}
}
private func receiveMessage(from task: URLSessionWebSocketTask, relayUrl: String) {
task.receive { [weak self] result in
guard let self = self else { return }
switch result {
case .success(let message):
switch message {
case .string(let text):
Task { @MainActor in
self.handleMessage(text, from: relayUrl)
}
case .data(let data):
if let text = String(data: data, encoding: .utf8) {
Task { @MainActor in
self.handleMessage(text, from: relayUrl)
}
}
@unknown default:
break
}
// Continue receiving
Task { @MainActor in
self.receiveMessage(from: task, relayUrl: relayUrl)
}
case .failure(let error):
DispatchQueue.main.async {
self.handleDisconnection(relayUrl: relayUrl, error: error)
}
}
}
}
private func handleMessage(_ message: String, from relayUrl: String) {
guard let data = message.data(using: .utf8) else { return }
do {
// Try to decode as an array first
if let array = try JSONSerialization.jsonObject(with: data) as? [Any],
array.count >= 2,
let type = array[0] as? String {
// Received message from relay
switch type {
case "EVENT":
if array.count >= 3,
let subId = array[1] as? String,
let eventDict = array[2] as? [String: Any] {
let event = try NostrEvent(from: eventDict)
// Only log non-gift-wrap events to reduce noise
if event.kind != 1059 {
SecureLogger.log("📥 Event kind=\(event.kind) id=\(event.id.prefix(16))… relay=\(relayUrl)",
category: SecureLogger.session, level: .debug)
}
DispatchQueue.main.async {
// Update relay stats
if let index = self.relays.firstIndex(where: { $0.url == relayUrl }) {
self.relays[index].messagesReceived += 1
}
// Call handler
if let handler = self.messageHandlers[subId] {
handler(event)
} else {
SecureLogger.log("⚠️ No handler for subscription \(subId)",
category: SecureLogger.session, level: .warning)
}
}
}
case "EOSE":
if array.count >= 2 {
// End of stored events
}
case "OK":
if array.count >= 3,
let eventId = array[1] as? String,
let success = array[2] as? Bool {
let reason = array.count >= 4 ? (array[3] as? String ?? "no reason given") : "no reason given"
if success {
_ = Self.pendingGiftWrapIDs.remove(eventId)
SecureLogger.log("✅ Accepted id=\(eventId.prefix(16))… relay=\(relayUrl)",
category: SecureLogger.session, level: .debug)
} else {
let isGiftWrap = Self.pendingGiftWrapIDs.remove(eventId) != nil
SecureLogger.log("📮 Rejected id=\(eventId.prefix(16))… reason=\(reason)",
category: SecureLogger.session, level: isGiftWrap ? .warning : .error)
}
}
case "NOTICE":
if array.count >= 2 {
// Server notice received
}
default:
break // Unknown message type
}
}
} catch {
SecureLogger.log("Failed to parse Nostr message: \(error)", category: SecureLogger.session, level: .error)
}
}
private func sendToRelay(event: NostrEvent, connection: URLSessionWebSocketTask, relayUrl: String) {
let req = NostrRequest.event(event)
do {
let encoder = JSONEncoder()
encoder.outputFormatting = .sortedKeys
let data = try encoder.encode(req)
let message = String(data: data, encoding: .utf8) ?? ""
SecureLogger.log("📤 Send kind=\(event.kind) id=\(event.id.prefix(16))… relay=\(relayUrl)",
category: SecureLogger.session, level: .debug)
connection.send(.string(message)) { [weak self] error in
DispatchQueue.main.async {
if let error = error {
SecureLogger.log("❌ Failed to send event to \(relayUrl): \(error)",
category: SecureLogger.session, level: .error)
} else {
// SecureLogger.log("✅ Event sent to relay: \(relayUrl)",
// category: SecureLogger.session, level: .debug)
// Update relay stats
if let index = self?.relays.firstIndex(where: { $0.url == relayUrl }) {
self?.relays[index].messagesSent += 1
}
}
}
}
} catch {
SecureLogger.log("Failed to encode event: \(error)", category: SecureLogger.session, level: .error)
}
}
private func updateRelayStatus(_ url: String, isConnected: Bool, error: Error? = nil) {
if let index = relays.firstIndex(where: { $0.url == url }) {
relays[index].isConnected = isConnected
relays[index].lastError = error
if isConnected {
relays[index].lastConnectedAt = Date()
relays[index].reconnectAttempts = 0 // Reset on successful connection
relays[index].nextReconnectTime = nil
} else {
relays[index].lastDisconnectedAt = Date()
}
}
updateConnectionStatus()
}
private func updateConnectionStatus() {
isConnected = relays.contains { $0.isConnected }
}
private func handleDisconnection(relayUrl: String, error: Error) {
connections.removeValue(forKey: relayUrl)
subscriptions.removeValue(forKey: relayUrl)
updateRelayStatus(relayUrl, isConnected: false, error: error)
// Check if this is a DNS error
let errorDescription = error.localizedDescription.lowercased()
if errorDescription.contains("hostname could not be found") ||
errorDescription.contains("dns") {
// Only log once for DNS failures
if relays.first(where: { $0.url == relayUrl })?.lastError == nil {
SecureLogger.log("Nostr relay DNS failure for \(relayUrl) - not retrying", category: SecureLogger.session, level: .warning)
}
// Mark relay as permanently failed
if let index = relays.firstIndex(where: { $0.url == relayUrl }) {
relays[index].lastError = error
}
return
}
// Implement exponential backoff for non-DNS errors
guard let index = relays.firstIndex(where: { $0.url == relayUrl }) else { return }
relays[index].reconnectAttempts += 1
// Stop attempting after max attempts
if relays[index].reconnectAttempts >= maxReconnectAttempts {
SecureLogger.log("Max reconnection attempts (\(maxReconnectAttempts)) reached for \(relayUrl)",
category: SecureLogger.session, level: .warning)
return
}
// Calculate backoff interval
let backoffInterval = min(
initialBackoffInterval * pow(backoffMultiplier, Double(relays[index].reconnectAttempts - 1)),
maxBackoffInterval
)
let nextReconnectTime = Date().addingTimeInterval(backoffInterval)
relays[index].nextReconnectTime = nextReconnectTime
// Schedule reconnection with exponential backoff
DispatchQueue.main.asyncAfter(deadline: .now() + backoffInterval) { [weak self] in
guard let self = self else { return }
// Check if we should still reconnect (relay might have been removed)
if self.relays.contains(where: { $0.url == relayUrl }) {
self.connectToRelay(relayUrl)
}
}
}
// MARK: - Public Utility Methods
/// Manually retry connection to a specific relay
func retryConnection(to relayUrl: String) {
guard let index = relays.firstIndex(where: { $0.url == relayUrl }) else { return }
// Reset reconnection attempts
relays[index].reconnectAttempts = 0
relays[index].nextReconnectTime = nil
// Disconnect if connected
if let connection = connections[relayUrl] {
connection.cancel(with: .goingAway, reason: nil)
connections.removeValue(forKey: relayUrl)
}
// Attempt immediate reconnection
connectToRelay(relayUrl)
}
/// Get detailed status for all relays
func getRelayStatuses() -> [(url: String, isConnected: Bool, reconnectAttempts: Int, nextReconnectTime: Date?)] {
return relays.map { relay in
(url: relay.url,
isConnected: relay.isConnected,
reconnectAttempts: relay.reconnectAttempts,
nextReconnectTime: relay.nextReconnectTime)
}
}
/// Reset all relay connections
func resetAllConnections() {
disconnect()
// Reset all relay states
for index in relays.indices {
relays[index].reconnectAttempts = 0
relays[index].nextReconnectTime = nil
relays[index].lastError = nil
}
// Reconnect
connect()
}
}
// MARK: - Nostr Protocol Types
enum NostrRequest: Encodable {
case event(NostrEvent)
case subscribe(id: String, filters: [NostrFilter])
case close(id: String)
func encode(to encoder: Encoder) throws {
var container = encoder.unkeyedContainer()
switch self {
case .event(let event):
try container.encode("EVENT")
try container.encode(event)
case .subscribe(let id, let filters):
try container.encode("REQ")
try container.encode(id)
for filter in filters {
try container.encode(filter)
}
case .close(let id):
try container.encode("CLOSE")
try container.encode(id)
}
}
}
struct NostrFilter: Encodable {
var ids: [String]?
var authors: [String]?
var kinds: [Int]?
var since: Int?
var until: Int?
var limit: Int?
// Tag filters - stored internally but encoded specially
fileprivate var tagFilters: [String: [String]]?
init() {
// Default initializer
}
// Custom encoding to handle tag filters properly
enum CodingKeys: String, CodingKey {
case ids, authors, kinds, since, until, limit
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: DynamicCodingKey.self)
// Encode standard fields
if let ids = ids { try container.encode(ids, forKey: DynamicCodingKey(stringValue: "ids")) }
if let authors = authors { try container.encode(authors, forKey: DynamicCodingKey(stringValue: "authors")) }
if let kinds = kinds { try container.encode(kinds, forKey: DynamicCodingKey(stringValue: "kinds")) }
if let since = since { try container.encode(since, forKey: DynamicCodingKey(stringValue: "since")) }
if let until = until { try container.encode(until, forKey: DynamicCodingKey(stringValue: "until")) }
if let limit = limit { try container.encode(limit, forKey: DynamicCodingKey(stringValue: "limit")) }
// Encode tag filters with # prefix
if let tagFilters = tagFilters {
for (tag, values) in tagFilters {
try container.encode(values, forKey: DynamicCodingKey(stringValue: "#\(tag)"))
}
}
}
// For NIP-17 gift wraps
static func giftWrapsFor(pubkey: String, since: Date? = nil) -> NostrFilter {
var filter = NostrFilter()
filter.kinds = [1059] // Gift wrap kind
filter.since = since?.timeIntervalSince1970.toInt()
filter.tagFilters = ["p": [pubkey]]
filter.limit = TransportConfig.nostrRelayDefaultFetchLimit // reasonable limit
return filter
}
// For location channels: geohash-scoped ephemeral events (kind 20000)
static func geohashEphemeral(_ geohash: String, since: Date? = nil, limit: Int = 200) -> NostrFilter {
var filter = NostrFilter()
filter.kinds = [20000]
filter.since = since?.timeIntervalSince1970.toInt()
filter.tagFilters = ["g": [geohash]]
filter.limit = limit
return filter
}
}
// Dynamic coding key for tag filters
private struct DynamicCodingKey: CodingKey {
var stringValue: String
var intValue: Int? { nil }
init(stringValue: String) {
self.stringValue = stringValue
}
init?(intValue: Int) {
return nil
}
}
private extension TimeInterval {
func toInt() -> Int {
return Int(self)
}
}