handle errors better

app.py

@@ -282,6 +282,12 @@ class SessionMoverApp(App):
         color: $text;
     }
 
+    #current-selection.error {
+        background: $error;
+        color: $text;
+        text-style: bold;
+    }
+
     #selection-count {
         height: auto;
         padding: 1;
@@ -385,10 +391,13 @@ class SessionMoverApp(App):
             self.db.connect()
             self.db.load_reference_data()
         except FileNotFoundError as e:
-            self.notify(str(e), severity="error", timeout=10)
-            self.set_timer(1, self.exit)
+            widget = self.query_one("#current-selection", Static)
+            widget.add_class("error")
+            widget.update(f"Error: {e}\n\nPress q to quit.")
+            self._db_error = True
             return
 
+        self._db_error = False
         self._project_ids: List[str] = []
         self.refresh_project_list()
 
@@ -398,15 +407,14 @@ class SessionMoverApp(App):
         self.query_one("#archived-toggle", Button).can_focus = False
 
         # Setup sessions table (but don't load data yet)
-        table = self.query_one("#sessions-table")
+        table = self.query_one("#sessions-table", DataTable)
         table.zebra_stripes = True
         table.cursor_type = "row"
         table.show_cursor = False
         table.add_columns(" ", "ID", "Title", "Project", "Workspace", "Msgs", "Created")
-        
+
         # Don't load sessions until a project is selected
-        status = self.query_one("#current-selection")
-        status.update("Select a project from the left")
+        self.query_one("#current-selection", Static).update("Select a project from the left")
 
     def on_input_changed(self, event: Input.Changed) -> None:
         if event.input.id == "filter-input":
@@ -655,6 +663,11 @@ class SessionMoverApp(App):
         self.refresh_sessions()
         self.notify("Data refreshed", severity="information")
 
+    async def action_quit(self) -> None:
+        """Exit the app, with a non-zero return code if there was a DB error."""
+        return_code = 1 if getattr(self, "_db_error", False) else 0
+        self.exit(return_code)
+
     def on_unmount(self) -> None:
         """Cleanup on exit."""
         self.db.close()

database.py

@@ -74,7 +74,8 @@ class Database:
 
     def load_reference_data(self):
         """Load projects and workspaces into memory for fast lookups."""
-        assert self.conn is not None
+        if self.conn is None:
+            raise RuntimeError("Database is not connected. Call connect() first.")
         cursor = self.conn.cursor()
 
         # Load projects
@@ -125,7 +126,8 @@ class Database:
         Returns:
             List of Session objects with computed counts
         """
-        assert self.conn is not None, "Database not connected"
+        if self.conn is None:
+            raise RuntimeError("Database is not connected. Call connect() first.")
         cursor = self.conn.cursor()
 
         query = """
@@ -205,7 +207,8 @@ class Database:
 
     def get_session_counts_by_project(self) -> dict:
         """Return a dict of project_id -> active session count."""
-        assert self.conn is not None
+        if self.conn is None:
+            raise RuntimeError("Database is not connected. Call connect() first.")
         cursor = self.conn.cursor()
         cursor.execute(
             "SELECT project_id, COUNT(*) FROM session WHERE time_archived IS NULL GROUP BY project_id"
@@ -228,7 +231,8 @@ class Database:
         Returns:
             (success, list of SQL statements executed)
         """
-        assert self.conn is not None, "Database not connected"
+        if self.conn is None:
+            raise RuntimeError("Database is not connected. Call connect() first.")
         cursor = self.conn.cursor()
 
         # Verify target project exists
@@ -265,7 +269,8 @@ class Database:
         Returns:
             (success, list of SQL statements, list of new session IDs)
         """
-        assert self.conn is not None, "Database not connected"
+        if self.conn is None:
+            raise RuntimeError("Database is not connected. Call connect() first.")
         import uuid
 
         cursor = self.conn.cursor()
@@ -355,7 +360,8 @@ class Database:
         Returns:
             (success, error_message)
         """
-        assert self.conn is not None, "Database not connected"
+        if self.conn is None:
+            raise RuntimeError("Database is not connected. Call connect() first.")
         cursor = self.conn.cursor()
 
         try: