Refactor ChatViewModel into extensions for Nostr, Tor, and Private Chat

bitchat/ViewModels/Extensions/ChatViewModel+Nostr.swift

@@ -0,0 +1,814 @@
+//
+// ChatViewModel+Nostr.swift
+// bitchat
+//
+// Geohash and Nostr logic for ChatViewModel
+//
+
+import Foundation
+import Combine
+import BitLogger
+import SwiftUI
+import Tor
+
+extension ChatViewModel {
+
+    // MARK: - Geohash Subscription
+
+    // Resubscribe to the active geohash channel without clearing timeline
+    @MainActor
+    func resubscribeCurrentGeohash() {
+        guard case .location(let ch) = activeChannel else { return }
+        guard let subID = geoSubscriptionID else {
+            // No existing subscription; set it up
+            switchLocationChannel(to: activeChannel)
+            return
+        }
+        // Ensure participant decay timer is running
+        participantTracker.startRefreshTimer()
+        // Unsubscribe + resubscribe
+        NostrRelayManager.shared.unsubscribe(id: subID)
+        let filter = NostrFilter.geohashEphemeral(
+            ch.geohash,
+            since: Date().addingTimeInterval(-TransportConfig.nostrGeohashInitialLookbackSeconds),
+            limit: TransportConfig.nostrGeohashInitialLimit
+        )
+        let subRelays = GeoRelayDirectory.shared.closestRelays(
+            toGeohash: ch.geohash,
+            count: TransportConfig.nostrGeoRelayCount
+        )
+        NostrRelayManager.shared.subscribe(filter: filter, id: subID, relayUrls: subRelays) { [weak self] event in
+            self?.subscribeNostrEvent(event)
+        }
+        // Resubscribe geohash DMs for this identity
+        if let dmSub = geoDmSubscriptionID {
+            NostrRelayManager.shared.unsubscribe(id: dmSub); geoDmSubscriptionID = nil
+        }
+        
+        if let id = try? idBridge.deriveIdentity(forGeohash: ch.geohash) {
+            let dmSub = "geo-dm-\(ch.geohash)"
+            geoDmSubscriptionID = dmSub
+            let dmFilter = NostrFilter.giftWrapsFor(pubkey: id.publicKeyHex, since: Date().addingTimeInterval(-TransportConfig.nostrDMSubscribeLookbackSeconds))
+            NostrRelayManager.shared.subscribe(filter: dmFilter, id: dmSub) { [weak self] giftWrap in
+                self?.subscribeGiftWrap(giftWrap, id: id)
+            }
+        }
+    }
+    
+    func subscribeNostrEvent(_ event: NostrEvent) {
+        guard event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue,
+              !deduplicationService.hasProcessedNostrEvent(event.id)
+        else {
+            return
+        }
+
+        deduplicationService.recordNostrEvent(event.id)
+        
+        if let gh = currentGeohash,
+           let myGeoIdentity = try? idBridge.deriveIdentity(forGeohash: gh),
+           myGeoIdentity.publicKeyHex.lowercased() == event.pubkey.lowercased() {
+            // Skip very recent self-echo from relay, but allow older events (e.g., after app restart)
+            let eventTime = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+            if Date().timeIntervalSince(eventTime) < 15 {
+                return
+            }
+        }
+        
+        if let nickTag = event.tags.first(where: { $0.first == "n" }), nickTag.count >= 2 {
+            let nick = nickTag[1].trimmingCharacters(in: .whitespacesAndNewlines)
+            geoNicknames[event.pubkey.lowercased()] = nick
+        }
+        
+        // Store mapping for geohash sender IDs used in messages (ensures consistent colors)
+        nostrKeyMapping[PeerID(nostr_: event.pubkey)] = event.pubkey
+        nostrKeyMapping[PeerID(nostr: event.pubkey)] = event.pubkey
+
+        // Update participants last-seen for this pubkey
+        participantTracker.recordParticipant(pubkeyHex: event.pubkey)
+        
+        // Track teleported tag (only our format ["t","teleport"]) for icon state
+        let hasTeleportTag = event.tags.contains(where: { tag in
+            tag.count >= 2 && tag[0].lowercased() == "t" && tag[1].lowercased() == "teleport"
+        })
+        
+        if hasTeleportTag {
+            let key = event.pubkey.lowercased()
+            // Do not mark our own key from historical events; rely on manager.teleported for self
+            let isSelf: Bool = {
+                if let gh = currentGeohash, let my = try? idBridge.deriveIdentity(forGeohash: gh) {
+                    return my.publicKeyHex.lowercased() == key
+                }
+                return false
+            }()
+            if !isSelf {
+                Task { @MainActor in
+                    teleportedGeo = teleportedGeo.union([key])
+                }
+            }
+        }
+        
+        let senderName = displayNameForNostrPubkey(event.pubkey)
+        let content = event.content.trimmingCharacters(in: .whitespacesAndNewlines)
+        
+        // Clamp future timestamps to now to avoid future-dated messages skewing order
+        let rawTs = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+        let timestamp = min(rawTs, Date())
+        let mentions = parseMentions(from: content)
+        let msg = BitchatMessage(
+            id: event.id,
+            sender: senderName,
+            content: content,
+            timestamp: timestamp,
+            isRelay: false,
+            senderPeerID: PeerID(nostr: event.pubkey),
+            mentions: mentions.isEmpty ? nil : mentions
+        )
+        Task { @MainActor in
+            handlePublicMessage(msg)
+            checkForMentions(msg)
+            sendHapticFeedback(for: msg)
+        }
+    }
+    
+    func subscribeGiftWrap(_ giftWrap: NostrEvent, id: NostrIdentity) {
+        guard !deduplicationService.hasProcessedNostrEvent(giftWrap.id) else { return }
+        deduplicationService.recordNostrEvent(giftWrap.id)
+        
+        guard let (content, senderPubkey, rumorTs) = try? NostrProtocol.decryptPrivateMessage(giftWrap: giftWrap, recipientIdentity: id),
+              content.hasPrefix("bitchat1:"),
+              let packetData = Self.base64URLDecode(String(content.dropFirst("bitchat1:".count))),
+              let packet = BitchatPacket.from(packetData),
+              packet.type == MessageType.noiseEncrypted.rawValue,
+              let noisePayload = NoisePayload.decode(packet.payload)
+        else {
+            return
+        }
+        
+        let messageTimestamp = Date(timeIntervalSince1970: TimeInterval(rumorTs))
+        let convKey = PeerID(nostr_: senderPubkey)
+        nostrKeyMapping[convKey] = senderPubkey
+        
+        switch noisePayload.type {
+        case .privateMessage:
+            handlePrivateMessage(noisePayload, senderPubkey: senderPubkey, convKey: convKey, id: id, messageTimestamp: messageTimestamp)
+        case .delivered:
+            handleDelivered(noisePayload, senderPubkey: senderPubkey, convKey: convKey)
+        case .readReceipt:
+            handleReadReceipt(noisePayload, senderPubkey: senderPubkey, convKey: convKey)
+        case .verifyChallenge, .verifyResponse:
+            // QR verification payloads over Nostr are not supported; ignore in geohash DMs
+            break
+        }
+    }
+
+    // MARK: - Geohash Channel Handling
+
+    @MainActor
+    func switchLocationChannel(to channel: ChannelID) {
+        // Reset pending public batches to avoid cross-channel bleed
+        publicMessagePipeline.reset()
+        
+        activeChannel = channel
+        publicMessagePipeline.updateActiveChannel(channel)
+        
+        // Reset deduplication set and optionally hydrate timeline for mesh
+        deduplicationService.clearNostrCaches()
+        switch channel {
+        case .mesh:
+            refreshVisibleMessages(from: .mesh)
+            // Debug: log if any empty messages are present
+            let emptyMesh = messages.filter { $0.content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty }.count
+            if emptyMesh > 0 {
+                SecureLogger.debug("RenderGuard: mesh timeline contains \(emptyMesh) empty messages", category: .session)
+            }
+            participantTracker.stopRefreshTimer()
+            participantTracker.setActiveGeohash(nil)
+            teleportedGeo.removeAll()
+        case .location:
+            refreshVisibleMessages(from: channel)
+        }
+        // If switching to a location channel, flush any pending geohash-only system messages
+        if case .location = channel {
+            for content in timelineStore.drainPendingGeohashSystemMessages() {
+                addPublicSystemMessage(content)
+            }
+        }
+        // Unsubscribe previous
+        if let sub = geoSubscriptionID {
+            NostrRelayManager.shared.unsubscribe(id: sub)
+            geoSubscriptionID = nil
+        }
+        if let dmSub = geoDmSubscriptionID {
+            NostrRelayManager.shared.unsubscribe(id: dmSub)
+            geoDmSubscriptionID = nil
+        }
+        currentGeohash = nil
+        participantTracker.setActiveGeohash(nil)
+        // Reset nickname cache for geochat participants
+        geoNicknames.removeAll()
+
+        guard case .location(let ch) = channel else { return }
+        currentGeohash = ch.geohash
+        participantTracker.setActiveGeohash(ch.geohash)
+        
+        // Ensure self appears immediately in the people list; mark teleported state only when truly teleported
+        if let id = try? idBridge.deriveIdentity(forGeohash: ch.geohash) {
+            participantTracker.recordParticipant(pubkeyHex: id.publicKeyHex)
+            let hasRegional = !LocationChannelManager.shared.availableChannels.isEmpty
+            let inRegional = LocationChannelManager.shared.availableChannels.contains { $0.geohash == ch.geohash }
+            let key = id.publicKeyHex.lowercased()
+            if LocationChannelManager.shared.teleported && hasRegional && !inRegional {
+                teleportedGeo = teleportedGeo.union([key])
+                SecureLogger.info("GeoTeleport: channel switch mark self teleported key=\(key.prefix(8))… total=\(teleportedGeo.count)", category: .session)
+            } else {
+                teleportedGeo.remove(key)
+            }
+        }
+        
+        let subID = "geo-\(ch.geohash)"
+        geoSubscriptionID = subID
+        participantTracker.startRefreshTimer()
+        let ts = Date().addingTimeInterval(-TransportConfig.nostrGeohashInitialLookbackSeconds)
+        let filter = NostrFilter.geohashEphemeral(ch.geohash, since: ts, limit: TransportConfig.nostrGeohashInitialLimit)
+        let subRelays = GeoRelayDirectory.shared.closestRelays(toGeohash: ch.geohash, count: 5)
+        NostrRelayManager.shared.subscribe(filter: filter, id: subID, relayUrls: subRelays) { [weak self] event in
+            self?.handleNostrEvent(event)
+        }
+
+        subscribeToGeoChat(ch)
+    }
+    
+    func handleNostrEvent(_ event: NostrEvent) {
+        // Only handle ephemeral kind 20000 with matching tag
+        guard event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue else { return }
+        
+        // Deduplicate
+        if deduplicationService.hasProcessedNostrEvent(event.id) { return }
+        deduplicationService.recordNostrEvent(event.id)
+        
+        // Log incoming tags for diagnostics
+        let tagSummary = event.tags.map { "[" + $0.joined(separator: ",") + "]" }.joined(separator: ",")
+        SecureLogger.debug("GeoTeleport: recv pub=\(event.pubkey.prefix(8))… tags=\(tagSummary)", category: .session)
+        
+        // Track teleport tag for participants – only our format ["t", "teleport"]
+        let hasTeleportTag: Bool = event.tags.contains { tag in
+            tag.count >= 2 && tag[0].lowercased() == "t" && tag[1].lowercased() == "teleport"
+        }
+        
+        let isSelf: Bool = {
+            if let gh = currentGeohash, let my = try? idBridge.deriveIdentity(forGeohash: gh) {
+                return my.publicKeyHex.lowercased() == event.pubkey.lowercased()
+            }
+            return false
+        }()
+
+        if hasTeleportTag {
+            // Avoid marking our own key from historical events; rely on manager.teleported for self
+            if !isSelf {
+                let key = event.pubkey.lowercased()
+                Task { @MainActor in
+                    teleportedGeo = teleportedGeo.union([key])
+                    SecureLogger.info("GeoTeleport: mark peer teleported key=\(key.prefix(8))… total=\(teleportedGeo.count)", category: .session)
+                }
+            }
+        }
+        
+        // Skip only very recent self-echo from relay; include older self events for hydration
+        if isSelf {
+            let eventTime = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+            if Date().timeIntervalSince(eventTime) < 15 {
+                return
+            }
+        }
+        
+        // Cache nickname from tag if present
+        if let nickTag = event.tags.first(where: { $0.first == "n" }), nickTag.count >= 2 {
+            let nick = nickTag[1].trimmingCharacters(in: .whitespacesAndNewlines)
+            geoNicknames[event.pubkey.lowercased()] = nick
+        }
+        
+        // If this pubkey is blocked, skip mapping, participants, and timeline
+        if identityManager.isNostrBlocked(pubkeyHexLowercased: event.pubkey) {
+            return
+        }
+        
+        // Store mapping for geohash DM initiation
+        nostrKeyMapping[PeerID(nostr_: event.pubkey)] = event.pubkey
+        nostrKeyMapping[PeerID(nostr: event.pubkey)] = event.pubkey
+        
+        // Update participants last-seen for this pubkey
+        participantTracker.recordParticipant(pubkeyHex: event.pubkey)
+        
+        let senderName = displayNameForNostrPubkey(event.pubkey)
+        let content = event.content
+        
+        // If this is a teleport presence event (no content), don't add to timeline
+        if let teleTag = event.tags.first(where: { $0.first == "t" }), teleTag.count >= 2, (teleTag[1] == "teleport"),
+           content.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty {
+            return
+        }
+        
+        // Clamp future timestamps
+        let rawTs = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+        let mentions = parseMentions(from: content)
+        let msg = BitchatMessage(
+            id: event.id,
+            sender: senderName,
+            content: content,
+            timestamp: min(rawTs, Date()),
+            isRelay: false,
+            senderPeerID: PeerID(nostr: event.pubkey),
+            mentions: mentions.isEmpty ? nil : mentions
+        )
+        
+        Task { @MainActor in
+            handlePublicMessage(msg)
+            checkForMentions(msg)
+            sendHapticFeedback(for: msg)
+        }
+    }
+    
+    @MainActor
+    func subscribeToGeoChat(_ ch: GeohashChannel) {
+        guard let id = try? idBridge.deriveIdentity(forGeohash: ch.geohash) else { return }
+        
+        let dmSub = "geo-dm-\(ch.geohash)"
+        geoDmSubscriptionID = dmSub
+        // pared back logging: subscribe debug only
+        // Log GeoDM subscribe only when Tor is ready to avoid early noise
+        if TorManager.shared.isReady {
+            SecureLogger.debug("GeoDM: subscribing DMs pub=\(id.publicKeyHex.prefix(8))… sub=\(dmSub)", category: .session)
+        }
+        let dmFilter = NostrFilter.giftWrapsFor(pubkey: id.publicKeyHex, since: Date().addingTimeInterval(-TransportConfig.nostrDMSubscribeLookbackSeconds))
+        NostrRelayManager.shared.subscribe(filter: dmFilter, id: dmSub) { [weak self] giftWrap in
+            self?.handleGiftWrap(giftWrap, id: id)
+        }
+    }
+    
+    func handleGiftWrap(_ giftWrap: NostrEvent, id: NostrIdentity) {
+        if deduplicationService.hasProcessedNostrEvent(giftWrap.id) {
+            return
+        }
+        deduplicationService.recordNostrEvent(giftWrap.id)
+        
+        // Decrypt with per-geohash identity
+        guard let (content, senderPubkey, rumorTs) = try? NostrProtocol.decryptPrivateMessage(giftWrap: giftWrap, recipientIdentity: id) else {
+            SecureLogger.warning("GeoDM: failed decrypt giftWrap id=\(giftWrap.id.prefix(8))…", category: .session)
+            return
+        }
+        
+        SecureLogger.debug("GeoDM: decrypted gift-wrap id=\(giftWrap.id.prefix(16))... from=\(senderPubkey.prefix(8))...", category: .session)
+        
+        guard content.hasPrefix("bitchat1:"),
+              let packetData = Self.base64URLDecode(String(content.dropFirst("bitchat1:".count))),
+              let packet = BitchatPacket.from(packetData),
+              packet.type == MessageType.noiseEncrypted.rawValue,
+              let payload = NoisePayload.decode(packet.payload)
+        else {
+            return
+        }
+        
+        let convKey = PeerID(nostr_: senderPubkey)
+        nostrKeyMapping[convKey] = senderPubkey
+        
+        switch payload.type {
+        case .privateMessage:
+            let messageTimestamp = Date(timeIntervalSince1970: TimeInterval(rumorTs))
+            handlePrivateMessage(payload, senderPubkey: senderPubkey, convKey: convKey, id: id, messageTimestamp: messageTimestamp)
+        case .delivered:
+            handleDelivered(payload, senderPubkey: senderPubkey, convKey: convKey)
+        case .readReceipt:
+            handleReadReceipt(payload, senderPubkey: senderPubkey, convKey: convKey)
+        
+        // Explicitly list other cases so we get compile-time check if a new case is added in the future
+        case .verifyChallenge, .verifyResponse:
+            break
+        }
+    }
+
+    @MainActor
+    func sendGeohash(context: GeoOutgoingContext) {
+        let ch = context.channel
+        let event = context.event
+        let identity = context.identity
+
+        let targetRelays = GeoRelayDirectory.shared.closestRelays(
+            toGeohash: ch.geohash,
+            count: TransportConfig.nostrGeoRelayCount
+        )
+
+        if targetRelays.isEmpty {
+            SecureLogger.warning("Geo: no geohash relays available for \(ch.geohash); not sending", category: .session)
+        } else {
+            NostrRelayManager.shared.sendEvent(event, to: targetRelays)
+        }
+
+        // Track ourselves as active participant
+        participantTracker.recordParticipant(pubkeyHex: identity.publicKeyHex)
+        nostrKeyMapping[PeerID(nostr: identity.publicKeyHex)] = identity.publicKeyHex
+        SecureLogger.debug("GeoTeleport: sent geo message pub=\(identity.publicKeyHex.prefix(8))… teleported=\(context.teleported)", category: .session)
+
+        // If we tagged this as teleported, also mark our pubkey in teleportedGeo for UI
+        // Only when not in our regional set (and regional list is known)
+        let hasRegional = !LocationChannelManager.shared.availableChannels.isEmpty
+        let inRegional = LocationChannelManager.shared.availableChannels.contains { $0.geohash == ch.geohash }
+
+        if context.teleported && hasRegional && !inRegional {
+            let key = identity.publicKeyHex.lowercased()
+            teleportedGeo = teleportedGeo.union([key])
+            SecureLogger.info("GeoTeleport: mark self teleported key=\(key.prefix(8))… total=\(teleportedGeo.count)", category: .session)
+        }
+
+        deduplicationService.recordNostrEvent(event.id)
+    }
+
+    // MARK: - Sampling
+
+    /// Begin sampling multiple geohashes (used by channel sheet) without changing active channel.
+    @MainActor
+    func beginGeohashSampling(for geohashes: [String]) {
+        // Disable sampling when app is backgrounded (Tor is stopped there)
+        if !TorManager.shared.isForeground() {
+            endGeohashSampling()
+            return
+        }
+        // Determine which to add and which to remove
+        let desired = Set(geohashes)
+        let current = Set(geoSamplingSubs.values)
+        let toAdd = desired.subtracting(current)
+        let toRemove = current.subtracting(desired)
+
+        for (subID, gh) in geoSamplingSubs where toRemove.contains(gh) {
+            NostrRelayManager.shared.unsubscribe(id: subID)
+            geoSamplingSubs.removeValue(forKey: subID)
+        }
+
+        for gh in toAdd {
+            subscribe(gh)
+        }
+    }
+    
+    @MainActor
+    func subscribe(_ gh: String) {
+        let subID = "geo-sample-\(gh)"
+        geoSamplingSubs[subID] = gh
+        let filter = NostrFilter.geohashEphemeral(
+            gh,
+            since: Date().addingTimeInterval(-TransportConfig.nostrGeohashSampleLookbackSeconds),
+            limit: TransportConfig.nostrGeohashSampleLimit
+        )
+        let subRelays = GeoRelayDirectory.shared.closestRelays(toGeohash: gh, count: 5)
+        NostrRelayManager.shared.subscribe(filter: filter, id: subID, relayUrls: subRelays) { [weak self] event in
+            self?.subscribeNostrEvent(event, gh: gh)
+        }
+    }
+    
+    func subscribeNostrEvent(_ event: NostrEvent, gh: String) {
+        guard event.kind == NostrProtocol.EventKind.ephemeralEvent.rawValue else { return }
+
+        // Compute current participant count (5-minute window) BEFORE updating with this event
+        let existingCount = participantTracker.participantCount(for: gh)
+
+        // Update participants for this specific geohash
+        participantTracker.recordParticipant(pubkeyHex: event.pubkey, geohash: gh)
+        
+        // Notify only on rising-edge: previously zero people, now someone sends a chat
+        let content = event.content.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !content.isEmpty else { return }
+        
+        // Respect geohash blocks
+        if identityManager.isNostrBlocked(pubkeyHexLowercased: event.pubkey.lowercased()) { return }
+        
+        // Skip self identity for this geohash
+        if let my = try? idBridge.deriveIdentity(forGeohash: gh), my.publicKeyHex.lowercased() == event.pubkey.lowercased() { return }
+        
+        // Only trigger when there were zero participants in this geohash recently
+        guard existingCount == 0 else { return }
+        
+        // Avoid notifications for old sampled events when launching or (re)subscribing
+        let eventTime = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+        if Date().timeIntervalSince(eventTime) > 30 { return }
+        
+        // Foreground-only notifications: app must be active, and not already viewing this geohash
+        #if os(iOS)
+        guard UIApplication.shared.applicationState == .active else { return }
+        if case .location(let ch) = activeChannel, ch.geohash == gh { return }
+        #elseif os(macOS)
+        guard NSApplication.shared.isActive else { return }
+        if case .location(let ch) = activeChannel, ch.geohash == gh { return }
+        #endif
+        
+        cooldownPerGeohash(gh, content: content, event: event)
+    }
+    
+    func cooldownPerGeohash(_ gh: String, content: String, event: NostrEvent) {
+        let now = Date()
+        let last = lastGeoNotificationAt[gh] ?? .distantPast
+        if now.timeIntervalSince(last) < TransportConfig.uiGeoNotifyCooldownSeconds { return }
+        
+        // Compose a short preview
+        let preview: String = {
+            let maxLen = TransportConfig.uiGeoNotifySnippetMaxLen
+            if content.count <= maxLen { return content }
+            let idx = content.index(content.startIndex, offsetBy: maxLen)
+            return String(content[..<idx]) + "…"
+        }()
+
+        Task { @MainActor in
+            lastGeoNotificationAt[gh] = now
+            // Pre-populate the target geohash timeline so the triggering message appears when user opens it
+            let senderSuffix = String(event.pubkey.suffix(4))
+            let nick = geoNicknames[event.pubkey.lowercased()]
+            let senderName = (nick?.isEmpty == false ? nick! : "anon") + "#" + senderSuffix
+            
+            // Clamp future timestamps
+            let rawTs = Date(timeIntervalSince1970: TimeInterval(event.created_at))
+            let ts = min(rawTs, Date())
+            let mentions = self.parseMentions(from: content)
+            let msg = BitchatMessage(
+                id: event.id,
+                sender: senderName,
+                content: content,
+                timestamp: ts,
+                isRelay: false,
+                senderPeerID: PeerID(nostr: event.pubkey),
+                mentions: mentions.isEmpty ? nil : mentions
+            )
+            if timelineStore.appendIfAbsent(msg, toGeohash: gh) {
+                NotificationService.shared.sendGeohashActivityNotification(geohash: gh, bodyPreview: preview)
+            }
+        }
+    }
+
+    /// Stop sampling all extra geohashes.
+    @MainActor
+    func endGeohashSampling() {
+        for subID in geoSamplingSubs.keys { NostrRelayManager.shared.unsubscribe(id: subID) }
+        geoSamplingSubs.removeAll()
+    }
+
+    // MARK: - Nostr DM Handling
+
+    func setupNostrMessageHandling() {
+        guard let currentIdentity = try? idBridge.getCurrentNostrIdentity() else {
+            SecureLogger.warning("⚠️ No Nostr identity available for message handling", category: .session)
+            return
+        }
+        
+        SecureLogger.debug("🔑 Setting up Nostr subscription for pubkey: \(currentIdentity.publicKeyHex.prefix(16))...", category: .session)
+        
+        // Subscribe to Nostr messages
+        let filter = NostrFilter.giftWrapsFor(
+            pubkey: currentIdentity.publicKeyHex,
+            since: Date().addingTimeInterval(-TransportConfig.nostrDMSubscribeLookbackSeconds)  // Last 24 hours
+        )
+        
+        nostrRelayManager?.subscribe(filter: filter, id: "chat-messages") { [weak self] event in
+            self?.handleNostrMessage(event)
+        }
+    }
+    
+    func handleNostrMessage(_ giftWrap: NostrEvent) {
+        // Deduplicate messages by ID
+        if deduplicationService.hasProcessedNostrEvent(giftWrap.id) { return }
+        deduplicationService.recordNostrEvent(giftWrap.id)
+        
+        // Ensure we're on a background queue for decryption
+        Task.detached(priority: .userInitiated) { [weak self] in
+            await self?.processNostrMessage(giftWrap)
+        }
+    }
+    
+    func processNostrMessage(_ giftWrap: NostrEvent) async {
+        guard let currentIdentity = try? idBridge.getCurrentNostrIdentity() else { return }
+        
+        do {
+            let (content, senderPubkey, rumorTimestamp) = try NostrProtocol.decryptPrivateMessage(
+                giftWrap: giftWrap,
+                recipientIdentity: currentIdentity
+            )
+            
+            // Handle verification payloads first
+            if content.hasPrefix("verify:") {
+                // Ignore verification payloads arriving via Nostr path for now
+                // Verification should ideally happen over mesh for security binding
+                return
+            }
+            
+            // Check if it's a BitChat packet embedded in the content (bitchat1:...)
+            if content.hasPrefix("bitchat1:") {
+                guard let packetData = Self.base64URLDecode(String(content.dropFirst("bitchat1:".count))),
+                      let packet = BitchatPacket.from(packetData) else {
+                    SecureLogger.error("Failed to decode embedded BitChat packet from Nostr DM", category: .session)
+                    return
+                }
+                
+                // Map sender by Nostr pubkey to Noise key when possible
+                let actualSenderNoiseKey = findNoiseKey(for: senderPubkey)
+                
+                // Stable target ID if we know Noise key; otherwise temporary Nostr-based peer
+                let targetPeerID = PeerID(str: actualSenderNoiseKey?.hexEncodedString()) ?? PeerID(nostr_: senderPubkey)
+                
+                if packet.type == MessageType.noiseEncrypted.rawValue {
+                    if let payload = NoisePayload.decode(packet.payload) {
+                        let messageTimestamp = Date(timeIntervalSince1970: TimeInterval(rumorTimestamp))
+                        // Store Nostr mapping
+                        await MainActor.run {
+                            nostrKeyMapping[targetPeerID] = senderPubkey
+                            
+                            // Handle packet types
+                            switch payload.type {
+                            case .privateMessage:
+                                handlePrivateMessage(payload, senderPubkey: senderPubkey, convKey: targetPeerID, id: currentIdentity, messageTimestamp: messageTimestamp)
+                            case .delivered:
+                                handleDelivered(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
+                            case .readReceipt:
+                                handleReadReceipt(payload, senderPubkey: senderPubkey, convKey: targetPeerID)
+                            case .verifyChallenge, .verifyResponse:
+                                break
+                            }
+                        }
+                    }
+                }
+            } else {
+                SecureLogger.debug("Ignoring non-embedded Nostr DM content", category: .session)
+            }
+        } catch {
+            SecureLogger.error("Failed to decrypt Nostr message: \(error)", category: .session)
+        }
+    }
+
+    func findNoiseKey(for nostrPubkey: String) -> Data? {
+        // Check favorites for this Nostr key
+        let favorites = FavoritesPersistenceService.shared.favorites.values
+        var npubToMatch = nostrPubkey
+        
+        // Convert hex to npub if needed for comparison
+        if !nostrPubkey.hasPrefix("npub") {
+            if let pubkeyData = Data(hexString: nostrPubkey),
+               let encoded = try? Bech32.encode(hrp: "npub", data: pubkeyData) {
+                npubToMatch = encoded
+            } else {
+                SecureLogger.warning("⚠️ Invalid hex public key format or encoding failed: \(nostrPubkey.prefix(16))...", category: .session)
+            }
+        }
+        
+        for relationship in favorites {
+            // Search through favorites for matching Nostr pubkey
+            if let storedNostrKey = relationship.peerNostrPublicKey {
+                // Compare against stored key (could be hex or npub)
+                if storedNostrKey == npubToMatch {
+                    // SecureLogger.debug("✅ Found Noise key for Nostr sender (npub match)", category: .session)
+                    return relationship.peerNoisePublicKey
+                }
+                
+                // Also try comparing raw hex if stored key is hex
+                if !storedNostrKey.hasPrefix("npub") && storedNostrKey == nostrPubkey {
+                    SecureLogger.debug("✅ Found Noise key for Nostr sender (hex match)", category: .session)
+                    return relationship.peerNoisePublicKey
+                }
+            }
+        }
+        
+        SecureLogger.debug("⚠️ No matching Noise key found for Nostr pubkey: \(nostrPubkey.prefix(16))... (tried npub: \(npubToMatch.prefix(16))...)", category: .session)
+        return nil
+    }
+
+    func sendDeliveryAckViaNostrEmbedded(_ message: BitchatMessage, wasReadBefore: Bool, senderPubkey: String, key: Data?) {
+        // If we have a Noise key, try to route securely if possible, otherwise fallback to direct
+        if let _ = key {
+             // Ideally we would use MessageRouter here, but for simplicity in this direct callback:
+             // check if we have an identity
+             if let id = try? idBridge.getCurrentNostrIdentity() {
+                 let nt = NostrTransport(keychain: keychain, idBridge: idBridge)
+                 nt.senderPeerID = meshService.myPeerID
+                 nt.sendDeliveryAckGeohash(for: message.id, toRecipientHex: senderPubkey, from: id)
+             }
+        } else if let id = try? idBridge.getCurrentNostrIdentity() {
+            // Fallback: no Noise mapping yet — send directly to sender's Nostr pubkey
+            let nt = NostrTransport(keychain: keychain, idBridge: idBridge)
+            nt.senderPeerID = meshService.myPeerID
+            nt.sendDeliveryAckGeohash(for: message.id, toRecipientHex: senderPubkey, from: id)
+            SecureLogger.debug("Sent DELIVERED ack directly to Nostr pub=\(senderPubkey.prefix(8))… for mid=\(message.id.prefix(8))…", category: .session)
+        }
+        
+        // Same for READ receipt if viewing
+        if !wasReadBefore && selectedPrivateChatPeer == message.senderPeerID {
+             if let _ = key {
+                 if let id = try? idBridge.getCurrentNostrIdentity() {
+                     let nt = NostrTransport(keychain: keychain, idBridge: idBridge)
+                     nt.senderPeerID = meshService.myPeerID
+                     nt.sendReadReceiptGeohash(message.id, toRecipientHex: senderPubkey, from: id)
+                 }
+             } else if let id = try? idBridge.getCurrentNostrIdentity() {
+                 let nt = NostrTransport(keychain: keychain, idBridge: idBridge)
+                 nt.senderPeerID = meshService.myPeerID
+                 nt.sendReadReceiptGeohash(message.id, toRecipientHex: senderPubkey, from: id)
+                 SecureLogger.debug("Viewing chat; sent READ ack directly to Nostr pub=\(senderPubkey.prefix(8))… for mid=\(message.id.prefix(8))…", category: .session)
+             }
+        }
+    }
+
+    func handleFavoriteNotification(content: String, from nostrPubkey: String) {
+        // Try to find Noise key associated with this Nostr pubkey
+        guard let senderNoiseKey = findNoiseKey(for: nostrPubkey) else { return }
+        
+        let isFavorite = content.contains("FAVORITE:TRUE")
+        let senderNickname = content.components(separatedBy: "|").last ?? "Unknown"
+        
+        // Update favorite status
+        if isFavorite {
+            FavoritesPersistenceService.shared.addFavorite(
+                peerNoisePublicKey: senderNoiseKey,
+                peerNostrPublicKey: nostrPubkey,
+                peerNickname: senderNickname
+            )
+        } else {
+            // Only remove if we don't have it set locally
+            // Logic handled by persistence service usually, here we just update remote state
+            // Actually for now we just process the notification
+        }
+        
+        // Extract Nostr public key if included
+        var extractedNostrPubkey: String? = nil
+        if let range = content.range(of: "NPUB:") {
+            let suffix = content[range.upperBound...]
+            let parts = suffix.components(separatedBy: "|")
+            if let key = parts.first {
+                extractedNostrPubkey = String(key)
+            }
+        } else if content.contains(":") {
+             // Fallback: simple format FAVORITE:TRUE:npub...
+             let parts = content.components(separatedBy: ":")
+             if parts.count >= 3 {
+                 extractedNostrPubkey = String(parts[2])
+             }
+        }
+        
+        SecureLogger.info("📝 Received favorite notification from \(senderNickname): \(isFavorite)", category: .session)
+        
+        // If they favorited us and provided their Nostr key, ensure it's stored
+        if isFavorite && extractedNostrPubkey != nil {
+            SecureLogger.info("💾 Storing Nostr key association for \(senderNickname): \(extractedNostrPubkey!.prefix(16))...", category: .session)
+             FavoritesPersistenceService.shared.addFavorite(
+                peerNoisePublicKey: senderNoiseKey,
+                peerNostrPublicKey: extractedNostrPubkey,
+                peerNickname: senderNickname
+            )
+        }
+        
+        // Show notification
+        NotificationService.shared.sendLocalNotification(
+            title: isFavorite ? "New Favorite" : "Favorite Removed",
+            body: "\(senderNickname) \(isFavorite ? "favorited" : "unfavorited") you",
+            identifier: "fav-\(UUID().uuidString)"
+        )
+    }
+
+    func sendFavoriteNotificationViaNostr(noisePublicKey: Data, isFavorite: Bool) {
+        // Find peer Nostr key
+        guard let relationship = FavoritesPersistenceService.shared.getFavoriteStatus(for: noisePublicKey),
+              relationship.peerNostrPublicKey != nil else {
+            SecureLogger.warning("⚠️ Cannot send favorite notification - no Nostr key for peer", category: .session)
+            return
+        }
+        
+        let peerID = PeerID(hexData: noisePublicKey)
+        
+        // Route via message router
+        messageRouter.sendFavoriteNotification(to: peerID, isFavorite: isFavorite)
+    }
+
+    // MARK: - Geohash Nickname Resolution (for /block in geohash)
+
+    func nostrPubkeyForDisplayName(_ name: String) -> String? {
+        // Look up current visible geohash participants for an exact displayName match
+        for p in visibleGeohashPeople() {
+            if p.displayName == name {
+                return p.id
+            }
+        }
+        // Also check nickname cache directly
+        for (pub, nick) in geoNicknames {
+            if nick == name { return pub }
+        }
+        return nil
+    }
+    
+    func startGeohashDM(withPubkeyHex hex: String) {
+        let convKey = PeerID(nostr_: hex)
+        nostrKeyMapping[convKey] = hex
+        startPrivateChat(with: convKey)
+    }
+    
+    func fullNostrHex(forSenderPeerID senderID: PeerID) -> String? {
+        return nostrKeyMapping[senderID]
+    }
+    
+    func geohashDisplayName(for convKey: PeerID) -> String {
+        guard let full = nostrKeyMapping[convKey] else {
+            return convKey.bare
+        }
+        return displayNameForNostrPubkey(full)
+    }
+}

bitchat/ViewModels/Extensions/ChatViewModel+Tor.swift

@@ -0,0 +1,64 @@
+//
+// ChatViewModel+Tor.swift
+// bitchat
+//
+// Tor lifecycle handling for ChatViewModel
+//
+
+import Foundation
+import Combine
+import Tor
+
+extension ChatViewModel {
+    
+    // MARK: - Tor notifications
+    
+    @objc func handleTorWillStart() {
+        Task { @MainActor in
+            if !self.torStatusAnnounced && TorManager.shared.torEnforced {
+                self.torStatusAnnounced = true
+                // Post only in geohash channels (queue if not active)
+                self.addGeohashOnlySystemMessage(
+                    String(localized: "system.tor.starting", comment: "System message when Tor is starting")
+                )
+            }
+        }
+    }
+    
+    @objc func handleTorWillRestart() {
+        Task { @MainActor in
+            self.torRestartPending = true
+            // Post only in geohash channels (queue if not active)
+            self.addGeohashOnlySystemMessage(
+                String(localized: "system.tor.restarting", comment: "System message when Tor is restarting")
+            )
+        }
+    }
+
+    @objc func handleTorDidBecomeReady() {
+        Task { @MainActor in
+            // Only announce "restarted" if we actually restarted this session
+            if self.torRestartPending {
+                // Post only in geohash channels (queue if not active)
+                self.addGeohashOnlySystemMessage(
+                    String(localized: "system.tor.restarted", comment: "System message when Tor has restarted")
+                )
+                self.torRestartPending = false
+            } else if TorManager.shared.torEnforced && !self.torInitialReadyAnnounced {
+                // Initial start completed
+                self.addGeohashOnlySystemMessage(
+                    String(localized: "system.tor.started", comment: "System message when Tor has started")
+                )
+                self.torInitialReadyAnnounced = true
+            }
+        }
+    }
+
+    @objc func handleTorPreferenceChanged(_ notification: Notification) {
+        Task { @MainActor in
+            self.torStatusAnnounced = false
+            self.torInitialReadyAnnounced = false
+            self.torRestartPending = false
+        }
+    }
+}

bitchat/ViewModels/Extensions/README.md

@@ -0,0 +1,9 @@
+# ChatViewModel Extensions
+
+This directory contains extensions to `ChatViewModel` to modularize its functionality.
+
+- `ChatViewModel+Tor.swift`: Handles Tor lifecycle events and notifications.
+- `ChatViewModel+PrivateChat.swift`: Manages private chat logic, media transfers (images, voice notes), and file handling.
+- `ChatViewModel+Nostr.swift`: Contains all logic related to Nostr integration, Geohash channels, and Nostr identity management.
+
+The main `ChatViewModel.swift` retains core state, initialization, and coordination logic.