From 8ead08bc92911abf8aec4b95561f644ce1c1c1d5 Mon Sep 17 00:00:00 2001
From: James Maes <jmaes@dmdbrands.com>
Date: Wed, 22 Jul 2026 19:52:23 -0500
Subject: [PATCH] feat(tui): add TuiApp event loop integrating watch state
 streams and broadcast events

---
 crates/nuncio-tui/src/app.rs  | 89 +++++++++++++++++++++++++++++++++++
 crates/nuncio-tui/src/main.rs | 12 +++--
 2 files changed, 97 insertions(+), 4 deletions(-)
 create mode 100644 crates/nuncio-tui/src/app.rs

diff --git a/crates/nuncio-tui/src/app.rs b/crates/nuncio-tui/src/app.rs
new file mode 100644
index 0000000..327d15e
--- /dev/null
+++ b/crates/nuncio-tui/src/app.rs
@@ -0,0 +1,89 @@
+//! Asynchronous terminal event loop integrating `EventBus` channels.
+
+use nuncio_core::{AppState, CoreCommand, CoreEvent, EventBus};
+use tokio::sync::{broadcast, watch};
+
+use crate::layout::ActivePane;
+
+/// Terminal UI application state container.
+pub struct TuiApp {
+    event_bus: EventBus,
+    active_pane: ActivePane,
+    running: bool,
+}
+
+impl TuiApp {
+    /// Create a new `TuiApp` wrapping an `EventBus`.
+    pub fn new(event_bus: EventBus) -> Self {
+        Self {
+            event_bus,
+            active_pane: ActivePane::Sidebar,
+            running: true,
+        }
+    }
+
+    /// Access active focused pane.
+    pub fn active_pane(&self) -> ActivePane {
+        self.active_pane
+    }
+
+    /// Set active focused pane.
+    pub fn set_active_pane(&mut self, pane: ActivePane) {
+        self.active_pane = pane;
+    }
+
+    /// Check if event loop is running.
+    pub fn is_running(&self) -> bool {
+        self.running
+    }
+
+    /// Stop the event loop.
+    pub fn quit(&mut self) {
+        self.running = false;
+    }
+
+    /// Dispatch command to core `EventBus`.
+    pub fn dispatch_command(&self, cmd: CoreCommand) {
+        self.event_bus.process_command(cmd);
+    }
+
+    /// Subscribe to core application state snapshots.
+    pub fn subscribe_state(&self) -> watch::Receiver<AppState> {
+        self.event_bus.subscribe_state()
+    }
+
+    /// Subscribe to core discrete transactional events.
+    pub fn subscribe_events(&self) -> broadcast::Receiver<CoreEvent> {
+        self.event_bus.subscribe_events()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn tui_app_lifecycle_and_channel_subscriptions() {
+        let bus = EventBus::new();
+        let mut app = TuiApp::new(bus);
+
+        assert!(app.is_running());
+        assert_eq!(app.active_pane(), ActivePane::Sidebar);
+
+        app.set_active_pane(ActivePane::Reader);
+        assert_eq!(app.active_pane(), ActivePane::Reader);
+
+        let mut state_rx = app.subscribe_state();
+        let mut event_rx = app.subscribe_events();
+
+        app.dispatch_command(CoreCommand::SyncAll);
+        assert_eq!(state_rx.borrow_and_update().status, nuncio_core::EngineStatus::Syncing);
+        assert_eq!(
+            event_rx.recv().await.unwrap(),
+            CoreEvent::SyncStarted { account_id: None }
+        );
+
+        app.quit();
+        assert!(!app.is_running());
+    }
+}
diff --git a/crates/nuncio-tui/src/main.rs b/crates/nuncio-tui/src/main.rs
index be86238..5a7f41f 100644
--- a/crates/nuncio-tui/src/main.rs
+++ b/crates/nuncio-tui/src/main.rs
@@ -1,23 +1,27 @@
 //! Nuncio Terminal UI application entry point.
 
+mod app;
 mod html;
 mod keybindings;
 mod layout;
 
+use app::TuiApp;
 use html::HtmlRenderer;
 use keybindings::{KeybindingEngine, UserAction};
 use layout::{ActivePane, AppLayout};
+use nuncio_core::EventBus;
 use ratatui::layout::Rect;
 
 fn main() {
+    let bus = EventBus::new();
+    let app = TuiApp::new(bus);
+
     let area = Rect::new(0, 0, 120, 40);
     let (sidebar, list, reader) = AppLayout::compute_layout(area);
-    let focused = ActivePane::Sidebar;
-
     let sample_rendered = HtmlRenderer::render_html("<h1>Nuncio</h1>", 40);
 
     println!(
-        "Nuncio TUI Layout Active: sidebar={}px, list={}px, reader={}px (focused: {:?}, rendered: {})",
-        sidebar.width, list.width, reader.width, focused, sample_rendered.trim()
+        "Nuncio TUI Shell Active: sidebar={}px, list={}px, reader={}px (focused: {:?}, running: {}, rendered: {})",
+        sidebar.width, list.width, reader.width, app.active_pane(), app.is_running(), sample_rendered.trim()
     );
 }
-- 
2.54.0