feat: finalizations for M0-M2

crates/bds-ui/src/state/mod.rs

@@ -1,5 +1,7 @@
 pub mod navigation;
 pub mod tabs;
+pub mod toast;
 
 pub use navigation::{SidebarView, PanelTab, TaskSnapshot, OutputEntry};
 pub use tabs::{Tab, TabType};
+pub use toast::{Toast, ToastLevel};

crates/bds-ui/src/state/toast.rs

@@ -0,0 +1,80 @@
+/// Toast notification state.
+///
+/// Toasts are ephemeral, auto-dismissing messages shown at the top of
+/// the workspace.  Each toast has a severity level, a message, and a
+/// monotonically increasing id used for targeted dismissal.
+
+use std::sync::atomic::{AtomicU64, Ordering};
+
+static NEXT_TOAST_ID: AtomicU64 = AtomicU64::new(1);
+
+/// Severity determines the visual style.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ToastLevel {
+    Info,
+    Success,
+    Warning,
+    Error,
+}
+
+/// A single toast notification.
+#[derive(Debug, Clone)]
+pub struct Toast {
+    pub id: u64,
+    pub level: ToastLevel,
+    pub message: String,
+    /// Unix-millis when this toast was created.
+    pub created_at: u64,
+}
+
+impl Toast {
+    /// Default display duration in milliseconds.
+    pub const DEFAULT_DURATION_MS: u64 = 4000;
+
+    pub fn new(level: ToastLevel, message: String) -> Self {
+        let now = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_millis() as u64;
+        Self {
+            id: NEXT_TOAST_ID.fetch_add(1, Ordering::Relaxed),
+            level,
+            message,
+            created_at: now,
+        }
+    }
+
+    /// Whether this toast has exceeded its display duration.
+    pub fn is_expired(&self) -> bool {
+        let now = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap_or_default()
+            .as_millis() as u64;
+        now.saturating_sub(self.created_at) >= Self::DEFAULT_DURATION_MS
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn toast_ids_are_unique() {
+        let a = Toast::new(ToastLevel::Info, "a".into());
+        let b = Toast::new(ToastLevel::Info, "b".into());
+        assert_ne!(a.id, b.id);
+    }
+
+    #[test]
+    fn toast_levels() {
+        let t = Toast::new(ToastLevel::Error, "oops".into());
+        assert_eq!(t.level, ToastLevel::Error);
+        assert!(!t.message.is_empty());
+    }
+
+    #[test]
+    fn fresh_toast_not_expired() {
+        let t = Toast::new(ToastLevel::Info, "test".into());
+        assert!(!t.is_expired());
+    }
+}