1 files changed, 74 insertions, 0 deletions
diff --git a/src/transport.rs b/src/transport.rs
new file mode 100644
index 0000000..95d3046
--- /dev/null
+++ b/src/transport.rs
@@ -0,0 +1,74 @@
+use anyhow::Result;
+use async_trait::async_trait;
+use automerge::sync::Message;
+use std::boxed::Box;
+use std::future::Future;
+use std::pin::Pin;
+
+pub type HeadsDigest = [u8; 32];
+
+#[derive(Debug, Clone)]
+pub struct Keepalive {
+    pub heads_digest: HeadsDigest,
+}
+
+#[derive(Debug)]
+pub enum ParsedMessage {
+    Hello(HelloRequest),
+    HelloReply(HelloReply),
+    Sync(SyncEnvelope),
+    Ping(Keepalive),
+    Pong(Keepalive),
+}
+
+#[derive(Debug)]
+pub struct HelloRequest {}
+
+#[derive(Debug, Clone)]
+pub struct HelloReply {
+    pub cluster_id: String,
+    pub peers: Vec<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct SyncEnvelope {
+    pub cluster_id: String,
+    pub message: Message,
+}
+
+/// A message serialized for the wire. Cloning is cheap (shared buffer).
+#[derive(Clone, Debug)]
+pub struct EncodedMessage {
+    pub peer: String,
+    pub body: bytes::Bytes,
+}
+
+pub type HandlerFn = dyn Fn(String, ParsedMessage) -> Pin<Box<dyn Future<Output = Result<()>> + Send>>
+    + Send
+    + Sync
+    + 'static;
+pub type MessageHandler = Box<HandlerFn>;
+
+#[async_trait]
+pub trait Transport: Send + Sync {
+    /// This node's identity on the transport (for Mycelium: its public key).
+    fn local_id(&self) -> &str;
+
+    /// Resolves a user-supplied peer hint (e.g. a seed) to a peer identity.
+    async fn resolve_peer(&self, hint: &str) -> Result<String>;
+
+    fn encode(&self, peer: &str, message: &ParsedMessage) -> Result<EncodedMessage>;
+    async fn send_encoded(&self, message: &EncodedMessage) -> Result<()>;
+
+    /// Sends an outbound message payload to a targeted peer on a specific topic.
+    async fn send_message(&self, peer: &str, message: &ParsedMessage) -> Result<()> {
+        let encoded = self.encode(peer, message)?;
+        self.send_encoded(&encoded).await
+    }
+
+    /// Starts the long-polling inbound event loops, driving messages to the provided handler closure.
+    async fn start_consumer(&self, handler: MessageHandler) -> Result<()>;
+
+    /// Asynchronously monitors for fatal network client or sub-process failures.
+    async fn wait_for_exit(&self) -> std::io::Result<std::process::ExitStatus>;
+}