feat: add drawer callbacks for drug selection, fragment matching, and clear (Task 4.2)

dash_app/callbacks/drawer.py

@@ -0,0 +1,72 @@
+"""Callbacks for the drug browser drawer: open/close, drug selection, fragment matching, clear."""
+from dash import Input, Output, State, ctx, no_update, ALL
+
+
+def register_drawer_callbacks(app):
+    """Register drawer-related callbacks."""
+
+    @app.callback(
+        Output("drug-drawer", "opened"),
+        Input("sidebar-drug-selection", "n_clicks"),
+        Input("sidebar-indications", "n_clicks"),
+        prevent_initial_call=True,
+    )
+    def open_drawer(_drug_clicks, _indication_clicks):
+        """Open the drawer when sidebar Drug Selection or Indications is clicked."""
+        return True
+
+    @app.callback(
+        Output("all-drugs-chips", "value"),
+        Input({"type": "drug-fragment", "index": ALL}, "n_clicks"),
+        Input("clear-drug-filters", "n_clicks"),
+        State("all-drugs-chips", "value"),
+        State("reference-data", "data"),
+        prevent_initial_call=True,
+    )
+    def handle_fragment_or_clear(fragment_clicks, _clear_clicks, current_chips, ref_data):
+        """Handle drug fragment badge click (substring match) or clear all filters.
+
+        Fragment click: find all full drug names containing the fragment substring,
+        toggle them in the chip selection.
+        Clear click: reset chip selection to empty.
+        """
+        triggered = ctx.triggered_id
+
+        # Clear button
+        if triggered == "clear-drug-filters":
+            return []
+
+        # Fragment badge click — triggered_id is a dict like {"type": "drug-fragment", "index": "DIR|FRAG"}
+        if isinstance(triggered, dict) and triggered.get("type") == "drug-fragment":
+            # Check if any fragment was actually clicked (not just initial render)
+            if not any(n for n in (fragment_clicks or []) if n):
+                return no_update
+
+            fragment_key = triggered["index"]  # e.g. "CARDIOLOGY|ABCIXIMAB"
+            fragment = fragment_key.split("|", 1)[-1] if "|" in fragment_key else fragment_key
+
+            # Get all available drugs from reference data
+            all_drugs = (ref_data or {}).get("available_drugs", [])
+
+            # Find drugs whose names contain this fragment (case-insensitive substring)
+            matching_drugs = [
+                drug for drug in all_drugs
+                if fragment.upper() in drug.upper()
+            ]
+
+            if not matching_drugs:
+                return no_update
+
+            # Toggle: if all matching drugs are already selected, deselect them;
+            # otherwise, add them to selection
+            current = set(current_chips or [])
+            all_selected = all(d in current for d in matching_drugs)
+
+            if all_selected:
+                updated = current - set(matching_drugs)
+            else:
+                updated = current | set(matching_drugs)
+
+            return sorted(updated)
+
+        return no_update