saorsa-webrtc-core 0.3.4

//! Example implementation of SignalingTransport for gossip-based networks
//!
//! This shows how your gossip network can integrate with saorsa-webrtc
//! without any ties to DHT or other network topologies.

use crate::signaling::{SignalingTransport, SignalingMessage};
use async_trait::async_trait;
use std::net::SocketAddr;

/// Your gossip network's peer identity type
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct GossipPeerId {
    pub id: String, // Your gossip node's unique identifier
}

impl std::fmt::Display for GossipPeerId {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.id)
    }
}

impl std::str::FromStr for GossipPeerId {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Ok(GossipPeerId { id: s.to_string() })
    }
}

/// Error type for your gossip network
#[derive(Debug, thiserror::Error)]
pub enum GossipError {
    #[error("Network error: {0}")]
    NetworkError(String),
    #[error("Serialization error: {0}")]
    SerializationError(#[from] serde_json::Error),
}

/// Your gossip network transport implementation
pub struct GossipSignalingTransport {
    // Reference to your gossip network instance
    gossip_network: std::sync::Arc<YourGossipNetwork>,
    // Channel for receiving signaling messages
    message_receiver: tokio::sync::mpsc::Receiver<(GossipPeerId, SignalingMessage)>,
}

impl GossipSignalingTransport {
    pub fn new(gossip_network: std::sync::Arc<YourGossipNetwork>) -> Self {
        let (tx, rx) = tokio::sync::mpsc::channel(100);

        // Set up callback for when gossip network receives signaling messages
        gossip_network.set_signaling_callback(move |from_peer, data| {
            match serde_json::from_slice::<SignalingMessage>(&data) {
                Ok(message) => {
                    let peer_id = GossipPeerId { id: from_peer };
                    let _ = tx.try_send((peer_id, message));
                }
                Err(e) => {
                    tracing::warn!("Failed to deserialize signaling message: {}", e);
                }
            }
        });

        Self {
            gossip_network,
            message_receiver: rx,
        }
    }
}

#[async_trait]
impl SignalingTransport for GossipSignalingTransport {
    type PeerId = GossipPeerId;
    type Error = GossipError;

    async fn send_message(
        &self,
        peer: &GossipPeerId,
        message: SignalingMessage,
    ) -> Result<(), GossipError> {
        // Serialize the signaling message
        let data = serde_json::to_vec(&message)
            .map_err(GossipError::SerializationError)?;

        // Send through your gossip network
        self.gossip_network
            .send_to_peer(&peer.id, b"WEBRTC_SIGNALING", &data)
            .await
            .map_err(|e| GossipError::NetworkError(e.to_string()))?;

        Ok(())
    }

    async fn receive_message(&self) -> Result<(GossipPeerId, SignalingMessage), GossipError> {
        // Receive from the channel populated by the gossip network callback
        self.message_receiver
            .recv()
            .await
            .ok_or_else(|| GossipError::NetworkError("Channel closed".to_string()))
    }

    async fn discover_peer_endpoint(
        &self,
        peer: &GossipPeerId,
    ) -> Result<Option<SocketAddr>, GossipError> {
        // Your gossip network may or may not provide endpoint discovery
        // If it does, return the endpoint. If not, return None.
        // WebRTC will handle connectivity establishment via QUIC NAT traversal.

        match self.gossip_network.get_peer_endpoint(&peer.id) {
            Some(endpoint) => Ok(Some(endpoint)),
            None => Ok(None), // QUIC will handle direct connection
        }
    }
}

// Placeholder for your gossip network type
// Replace this with your actual gossip network interface
pub struct YourGossipNetwork {
    // Your gossip network state
}

impl YourGossipNetwork {
    pub fn set_signaling_callback<F>(&self, _callback: F)
    where
        F: Fn(String, Vec<u8>) + Send + Sync + 'static,
    {
        // Set up callback in your gossip network to forward signaling messages
        // This is called when your gossip network receives data with topic "WEBRTC_SIGNALING"
    }

    pub async fn send_to_peer(
        &self,
        _peer_id: &str,
        _topic: &[u8],
        _data: &[u8],
    ) -> Result<(), Box<dyn std::error::Error>> {
        // Send data through your gossip network
        // Use a specific topic like "WEBRTC_SIGNALING" to distinguish from other messages
        Ok(())
    }

    pub fn get_peer_endpoint(&self, _peer_id: &str) -> Option<SocketAddr> {
        // Return peer endpoint if your gossip network tracks this
        // Return None if your gossip network doesn't provide endpoint discovery
        None
    }
}

// Example usage in your application
pub async fn create_webrtc_with_gossip() -> anyhow::Result<()> {
    use crate::prelude::*;
    use crate::identity::PeerIdentityString;

    // Your gossip network instance
    let gossip_network = std::sync::Arc::new(YourGossipNetwork { /* ... */ });

    // Create gossip-based signaling transport
    let gossip_transport = GossipSignalingTransport::new(gossip_network);

    // Create WebRTC service with gossip signaling
    let service = WebRtcService::<PeerIdentityString, GossipSignalingTransport>::builder()
        .with_identity("alice-bob-charlie-david")
        .build()
        .await?;

    service.start().await?;

    // Now you can make calls that use your gossip network for signaling!
    let call_id = service.initiate_call(
        "eve-frank-grace-henry",
        MediaConstraints::video_call()
    ).await?;

    Ok(())
}