feat: Add connection infrastructure and documentation

- Implement action service for connection handling
- Add error types for connection operations
- Create todo.md for project tracking

2 files changed, 143 insertions, 0 deletions

diff --git a/crates/vcs_actions/src/connection/action_service.rs b/crates/vcs_actions/src/connection/action_service.rs
new file mode 100644
index 0000000..8d3a03d
--- /dev/null
+++ b/crates/vcs_actions/src/connection/action_service.rs
@@ -0,0 +1,129 @@
+use std::{net::SocketAddr, path::PathBuf, sync::Arc};
+
+use action_system::action_pool::ActionPool;
+use cfg_file::config::ConfigFile;
+use tcp_connection::{error::TcpTargetError, instance::ConnectionInstance};
+use tokio::{
+    net::{TcpListener, TcpStream},
+    select, signal, spawn,
+    sync::mpsc,
+};
+use vcs_data::data::vault::{Vault, config::VaultConfig};
+
+use crate::registry::server_registry::server_action_pool;
+
+// Start the server with a Vault using the specified directory
+pub async fn server_entry(path: impl Into<PathBuf>) -> Result<(), TcpTargetError> {
+    // Read the vault cfg
+    let vault_cfg = VaultConfig::read().await?;
+
+    // Create TCPListener
+    let listener = create_tcp_listener(&vault_cfg).await?;
+
+    // Initialize the vault
+    let vault: Arc<Vault> = init_vault(vault_cfg, path.into()).await?;
+
+    // Create ActionPool
+    let action_pool: Arc<ActionPool> = Arc::new(server_action_pool());
+
+    // Start the server
+    let (_shutdown_rx, future) = build_server_future(vault.clone(), action_pool.clone(), listener);
+    let _ = future.await?; // Start and block until shutdown
+
+    Ok(())
+}
+
+async fn create_tcp_listener(cfg: &VaultConfig) -> Result<TcpListener, TcpTargetError> {
+    let local_bind_addr = cfg.server_config().local_bind();
+    let bind_port = cfg.server_config().port();
+    let sock_addr = SocketAddr::new(local_bind_addr.clone(), bind_port);
+    let listener = TcpListener::bind(sock_addr).await?;
+
+    Ok(listener)
+}
+
+async fn init_vault(cfg: VaultConfig, path: PathBuf) -> Result<Arc<Vault>, TcpTargetError> {
+    // Init and create the vault
+    let Some(vault) = Vault::init(cfg, path) else {
+        return Err(TcpTargetError::NotFound("Vault not found".to_string()));
+    };
+    let vault: Arc<Vault> = Arc::new(vault);
+
+    Ok(vault)
+}
+
+fn build_server_future(
+    vault: Arc<Vault>,
+    action_pool: Arc<ActionPool>,
+    listener: TcpListener,
+) -> (
+    mpsc::Sender<()>,
+    impl std::future::Future<Output = Result<(), TcpTargetError>>,
+) {
+    let (tx, mut rx) = mpsc::channel::<i32>(100);
+    let (shutdown_tx, mut shutdown_rx) = mpsc::channel::<()>(1);
+    let mut active_connections = 0;
+    let mut shutdown_requested = false;
+
+    // Spawn task to handle Ctrl+C
+    let shutdown_tx_clone = shutdown_tx.clone();
+    spawn(async move {
+        if let Ok(()) = signal::ctrl_c().await {
+            let _ = shutdown_tx_clone.send(()).await;
+        }
+    });
+
+    let future = async move {
+        loop {
+            select! {
+                // Accept new connections
+                accept_result = listener.accept(), if !shutdown_requested => {
+                    match accept_result {
+                        Ok((stream, _addr)) => {
+                            active_connections += 1;
+                            let _ = tx.send(1).await;
+
+                            let vault_clone = vault.clone();
+                            let action_pool_clone = action_pool.clone();
+                            let tx_clone = tx.clone();
+                            spawn(async move {
+                                process_connection(stream, vault_clone, action_pool_clone).await;
+                                let _ = tx_clone.send(-1).await;
+                            });
+                        }
+                        Err(_) => {
+                            continue;
+                        }
+                    }
+                }
+
+                // Handle connection count updates
+                Some(count_change) = rx.recv() => {
+                    active_connections = (active_connections as i32 + count_change) as usize;
+
+                    // Check if we should shutdown after all connections are done
+                    if shutdown_requested && active_connections == 0 {
+                        break;
+                    }
+                }
+
+                // Handle shutdown signal
+                _ = shutdown_rx.recv() => {
+                    shutdown_requested = true;
+                    // If no active connections, break immediately
+                    if active_connections == 0 {
+                        break;
+                    }
+                }
+            }
+        }
+
+        Ok(())
+    };
+
+    (shutdown_tx, future)
+}
+
+async fn process_connection(stream: TcpStream, vault: Arc<Vault>, action_pool: Arc<ActionPool>) {
+    let instance = ConnectionInstance::from(stream);
+}
diff --git a/crates/vcs_actions/src/connection/error.rs b/crates/vcs_actions/src/connection/error.rs
new file mode 100644
index 0000000..241c16e
--- /dev/null
+++ b/crates/vcs_actions/src/connection/error.rs
@@ -0,0 +1,14 @@
+use std::io;
+use thiserror::Error;
+
+#[derive(Error, Debug, Clone)]
+pub enum ConnectionError {
+    #[error("I/O error: {0}")]
+    Io(String),
+}
+
+impl From<io::Error> for ConnectionError {
+    fn from(error: io::Error) -> Self {
+        ConnectionError::Io(error.to_string())
+    }
+}