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jackandIslam
96a580491a
Continues god object decomposition by extracting geohash participant tracking. WHAT WAS EXTRACTED ================== Moved to GeohashParticipantsService (66 net lines reduced): - geoParticipants state dictionary - geohashPeople @Published property (now computed) - geoParticipantsTimer management - recordGeoParticipant() implementations → thin wrappers - refreshGeohashPeople() → no-op (service auto-refreshes) - startGeoParticipantsTimer() → no-op (service auto-starts) - stopGeoParticipantsTimer() → no-op (service auto-stops) - visibleGeohashPeople() → delegates to service - geohashParticipantCount() → delegates to service NEW SERVICE =========== bitchat/Services/GeohashParticipantsService.swift (180 lines) Features: - Tracks participants per geohash with lastSeen timestamps - Automatic 5-minute activity window pruning - Timer-based periodic refresh (30s) - Filters blocked users automatically - currentGeohash tracking with auto timer start/stop - ObservableObject for SwiftUI integration API: - setCurrentGeohash() - Set active geohash, auto-manages timer - recordParticipant() - Record participant activity - visiblePeople() - Get current participant list - participantCount() - Get count for specific geohash - removeParticipant() - Remove when blocked - reset() - Clear all state INTEGRATION =========== ChatViewModel changes: - geohashPeople is now computed property (delegates to service) - All participant tracking delegated to service - currentGeohash changes now sync with service via setCurrentGeohash() - Added @MainActor to handleNostrEvent() and subscribeNostrEvent() for proper actor isolation Backward compatibility: - All existing method signatures maintained - recordGeoParticipant() kept as thin wrappers - Timer start/stop kept as no-ops (service manages automatically) IMPACT ====== ChatViewModel: 5,418 → 5,394 lines (-0.4% this commit, -12.9% cumulative) New service: +180 lines (focused, testable) Tests: ✅ All 23 passing Build: ✅ Clean (5.60s, improved from 6.52s) Cumulative god object reduction: -801 lines (12.9% total) Services extracted: 4 (Spam, ColorPalette, MessageFormatting, GeohashParticipants) QUALITY IMPROVEMENTS ==================== - Participant lifecycle logic isolated - Timer management automatic (no manual start/stop needed) - Clearer separation of geohash vs mesh logic - Easier to test participant tracking - State properly encapsulated TEST RESULTS ============ ✔ All 23 tests passing ✔ Build completes successfully (5.60s - fastest yet!) ✔ Zero regressions ✔ Participant tracking still works correctly
bitchat
A decentralized peer-to-peer messaging app with dual transport architecture: local Bluetooth mesh networks for offline communication and internet-based Nostr protocol for global reach. No accounts, no phone numbers, no central servers. It's the side-groupchat.
Warning
Private messages have not received external security review and may contain vulnerabilities. Do not use for sensitive use cases, and do not rely on its security until it has been reviewed. Now uses the Noise Protocol for identity and encryption. Public local chat (the main feature) has no security concerns.
License
This project is released into the public domain. See the LICENSE file for details.
Features
- Dual Transport Architecture: Bluetooth mesh for offline + Nostr protocol for internet-based messaging
- Location-Based Channels: Geographic chat rooms using geohash coordinates over global Nostr relays
- Intelligent Message Routing: Automatically chooses best transport (Bluetooth → Nostr fallback)
- Decentralized Mesh Network: Automatic peer discovery and multi-hop message relay over Bluetooth LE
- Privacy First: No accounts, no phone numbers, no persistent identifiers
- Private Message End-to-End Encryption: Noise Protocol for mesh, NIP-17 for Nostr
- IRC-Style Commands: Familiar
/slap,/msg,/whostyle interface - Universal App: Native support for iOS and macOS
- Emergency Wipe: Triple-tap to instantly clear all data
- Performance Optimizations: LZ4 message compression, adaptive battery modes, and optimized networking
Technical Architecture
BitChat uses a hybrid messaging architecture with two complementary transport layers:
Bluetooth Mesh Network (Offline)
- Local Communication: Direct peer-to-peer within Bluetooth range
- Multi-hop Relay: Messages route through nearby devices (max 7 hops)
- No Internet Required: Works completely offline in disaster scenarios
- Noise Protocol Encryption: End-to-end encryption with forward secrecy
- Binary Protocol: Compact packet format optimized for Bluetooth LE constraints
- Automatic Discovery: Peer discovery and connection management
- Adaptive Power: Battery-optimized duty cycling
Nostr Protocol (Internet)
- Global Reach: Connect with users worldwide via internet relays
- Location Channels: Geographic chat rooms using geohash coordinates
- 290+ Relay Network: Distributed across the globe for reliability
- NIP-17 Encryption: Gift-wrapped private messages for internet privacy
- Ephemeral Keys: Fresh cryptographic identity per geohash area
Channel Types
mesh #bluetooth
- Transport: Bluetooth Low Energy mesh network
- Scope: Local devices within multi-hop range
- Internet: Not required
- Use Case: Offline communication, protests, disasters, remote areas
Location Channels (block #dr5rsj7, neighborhood #dr5rs, country #dr)
- Transport: Nostr protocol over internet
- Scope: Geographic areas defined by geohash precision
block(7 chars): City block levelneighborhood(6 chars): District/neighborhoodcity(5 chars): City levelprovince(4 chars): State/provinceregion(2 chars): Country/large region
- Internet: Required (connects to Nostr relays)
- Use Case: Location-based community chat, local events, regional discussions
Direct Message Routing
Private messages use intelligent transport selection:
-
Bluetooth First (preferred when available)
- Direct connection with established Noise session
- Fastest and most private option
-
Nostr Fallback (when Bluetooth unavailable)
- Uses recipient's Nostr public key
- NIP-17 gift-wrapping for privacy
- Routes through global relay network
-
Smart Queuing (when neither available)
- Messages queued until transport becomes available
- Automatic delivery when connection established
For detailed protocol documentation, see the Technical Whitepaper.
Setup
Option 1: Using Xcode
cd bitchat
open bitchat.xcodeproj
To run on a device there're a few steps to prepare the code:
- Clone the local configs:
cp Configs/Local.xcconfig.example Configs/Local.xcconfig - Add your Developer Team ID into the newly created
Configs/Local.xcconfig- Bundle ID would be set to
chat.bitchat.<team_id>(unless you set to something else)
- Bundle ID would be set to
- Entitlements need to be updated manually (TODO: Automate):
- Search and replace
group.chat.bitchatwithgroup.<your_bundle_id>(e.g.group.chat.bitchat.ABC123)
- Search and replace
Option 2: Using just
brew install just
Want to try this on macos: just run will set it up and run from source.
Run just clean afterwards to restore things to original state for mobile app building and development.
Localization
- Base app resources live under
bitchat/Localization/Base.lproj/. Add new copy toLocalizable.stringsand plural rules toLocalizable.stringsdict. - Share extension strings are separate in
bitchatShareExtension/Localization/Base.lproj/Localizable.strings. - Prefer keys that describe intent (
app_info.features.offline.title) and reuse existing ones where possible. - Run
xcodebuild -project bitchat.xcodeproj -scheme "bitchat (macOS)" -configuration Debug CODE_SIGNING_ALLOWED=NO buildto compile-check any localization updates.