1  //! Tor transport stub.
  2  //!
  3  //! This module provides a placeholder implementation for Tor-based messaging.
  4  //! Actual Tor support will be implemented in a future phase using the Arti
  5  //! (Tor in Rust) library.
  6  //!
  7  //! # Planned Features
  8  //!
  9  //! - Onion service hosting for receiving messages
 10  //! - Anonymous outbound connections
 11  //! - Circuit management for connection reuse
 12  //! - Optional guard node configuration
 13  //!
 14  //! # Architecture (Planned)
 15  //!
 16  //! ```text
 17  //! ┌─────────────────────────────────────────────────────────┐
 18  //! │                    TorTransport                         │
 19  //! │  - Manages Arti TorClient                               │
 20  //! │  - Hosts onion service                                  │
 21  //! │  - Routes messages through Tor network                  │
 22  //! └─────────────────────────────────────────────────────────┘
 23  //!                          │
 24  //!                          ▼
 25  //! ┌─────────────────────────────────────────────────────────┐
 26  //! │                   Arti TorClient                        │
 27  //! │  - Tor protocol implementation                          │
 28  //! │  - Circuit building                                     │
 29  //! │  - Onion service support                                │
 30  //! └─────────────────────────────────────────────────────────┘
 31  //! ```
 32  
 33  use async_trait::async_trait;
 34  
 35  use super::{Transport, TransportAddress, TransportError, TransportResult, TransportType};
 36  
 37  /// Tor transport stub implementation.
 38  ///
 39  /// This is a placeholder that returns `NotAvailable` for all operations.
 40  /// Full implementation will come in Phase 2 with Arti integration.
 41  pub struct TorTransport {
 42      /// Placeholder for future Tor client.
 43      _initialized: bool,
 44  }
 45  
 46  impl TorTransport {
 47      /// Create a new Tor transport stub.
 48      pub fn new() -> Self {
 49          Self {
 50              _initialized: false,
 51          }
 52      }
 53  }
 54  
 55  impl Default for TorTransport {
 56      fn default() -> Self {
 57          Self::new()
 58      }
 59  }
 60  
 61  impl std::fmt::Debug for TorTransport {
 62      fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 63          f.debug_struct("TorTransport")
 64              .field("status", &"stub - not implemented")
 65              .finish()
 66      }
 67  }
 68  
 69  #[async_trait]
 70  impl Transport for TorTransport {
 71      async fn initialize(&mut self) -> TransportResult<()> {
 72          Err(TransportError::NotAvailable(
 73              "Tor transport not yet implemented. Coming in Phase 2.".to_string()
 74          ))
 75      }
 76  
 77      async fn shutdown(&mut self) -> TransportResult<()> {
 78          // Nothing to shut down in stub
 79          Ok(())
 80      }
 81  
 82      async fn send(&self, _recipient: &TransportAddress, _message: &[u8]) -> TransportResult<()> {
 83          Err(TransportError::NotAvailable(
 84              "Tor transport not yet implemented".to_string()
 85          ))
 86      }
 87  
 88      async fn receive(&self) -> TransportResult<(TransportAddress, Vec<u8>)> {
 89          Err(TransportError::NotAvailable(
 90              "Tor transport not yet implemented".to_string()
 91          ))
 92      }
 93  
 94      fn is_available(&self) -> bool {
 95          false
 96      }
 97  
 98      fn priority(&self) -> u8 {
 99          // Tor is lower priority than BLE (10 vs 0)
100          10
101      }
102  
103      fn transport_type(&self) -> TransportType {
104          TransportType::Tor
105      }
106  
107      fn name(&self) -> &str {
108          "Tor (stub)"
109      }
110  
111      fn local_address(&self) -> Option<TransportAddress> {
112          // Would return onion address when implemented
113          None
114      }
115  }
116  
117  #[cfg(test)]
118  mod tests {
119      use super::*;
120  
121      #[test]
122      fn test_tor_transport_new() {
123          let transport = TorTransport::new();
124          assert!(!transport.is_available());
125      }
126  
127      #[tokio::test]
128      async fn test_tor_transport_initialize() {
129          let mut transport = TorTransport::new();
130          let result = transport.initialize().await;
131          assert!(matches!(result, Err(TransportError::NotAvailable(_))));
132      }
133  
134      #[tokio::test]
135      async fn test_tor_transport_send() {
136          let transport = TorTransport::new();
137          let addr = TransportAddress::tor(&"a".repeat(56));
138          let result = transport.send(&addr, b"test").await;
139          assert!(matches!(result, Err(TransportError::NotAvailable(_))));
140      }
141  
142      #[tokio::test]
143      async fn test_tor_transport_receive() {
144          let transport = TorTransport::new();
145          let result = transport.receive().await;
146          assert!(matches!(result, Err(TransportError::NotAvailable(_))));
147      }
148  
149      #[test]
150      fn test_tor_transport_properties() {
151          let transport = TorTransport::new();
152          assert_eq!(transport.transport_type(), TransportType::Tor);
153          assert_eq!(transport.priority(), 10);
154          assert!(transport.name().contains("Tor"));
155          assert!(transport.local_address().is_none());
156      }
157  }