Fix drill-down logic and structure in dashboard

backend/app/services/dashboard_service.py

@@ -176,14 +176,17 @@ async def inventory_drilldown(
     brand_id=None,
     specs_hash=None,
 ) -> dict:
-    """Stock quantity as a three-level tree; each aggregate keyed by unit code
-    so incompatible units never merge into one number."""
+    """Stock quantity as a three-level tree: Material -> Project -> Warehouse."""
     stmt = (
         select(
-            Project.id,
-            Project.name,
-            Warehouse.id,
-            Warehouse.name,
+            Material.id.label("mid"),
+            Material.name.label("mname"),
+            Brand.name.label("bname"),
+            InventoryItem.specs,
+            Project.id.label("pid"),
+            Project.name.label("pname"),
+            Warehouse.id.label("wid"),
+            Warehouse.name.label("wname"),
             Unit.code,
             Unit.name_fa,
             func.sum(InventoryItem.quantity).label("qty"),
@@ -194,9 +197,8 @@ async def inventory_drilldown(
         .join(Project, Project.id == Warehouse.project_id)
         .join(Material, Material.id == InventoryItem.material_id)
         .join(Unit, Unit.id == InventoryItem.unit_id)
-        .where(InventoryItem.quantity > 0)
-        .group_by(Project.id, Project.name, Warehouse.id, Warehouse.name, Unit.code, Unit.name_fa)
-        .order_by(Project.name, Warehouse.name)
+        .outerjoin(Brand, Brand.id == InventoryItem.brand_id)
+        .group_by(Material.id, Material.name, Brand.name, InventoryItem.specs, Project.id, Project.name, Warehouse.id, Warehouse.name, Unit.code, Unit.name_fa)
     )
     stmt = _stock_filters(
         stmt, category_id=category_id, material_id=material_id, brand_id=brand_id, specs_hash=specs_hash
@@ -207,33 +209,59 @@ async def inventory_drilldown(
     units_legend: dict[str, str] = {}
     total_by_unit: dict[str, float] = {}
     total_rows = 0
-    projects_tree: dict[uuid.UUID, dict] = {}
-    for pid, pname, wid, wname, ucode, uname_fa, qty, row_count in rows:
+
+    materials_tree: dict[str, dict] = {}
+    
+    for mid, mname, bname, specs, pid, pname, wid, wname, ucode, uname_fa, qty, row_count in rows:
         q = _qty(qty)
         units_legend[ucode] = uname_fa
         total_by_unit[ucode] = round(total_by_unit.get(ucode, 0.0) + q, 4)
         total_rows += row_count
-        proj = projects_tree.setdefault(
+        
+        # Build full material name
+        parts = [mname]
+        if bname:
+            parts.append(bname)
+        if specs:
+            parts.extend(str(v) for v in specs.values() if v)
+        full_name = " ".join(parts)
+        # Use full_name + unit as unique key for material level, or just full_name
+        mat_key = f"{mid}_{full_name}"
+        
+        mat = materials_tree.setdefault(
+            mat_key,
+            {"id": mat_key, "name": full_name, "qty_by_unit": {}, "rows": 0, "_projects": {}},
+        )
+        mat["qty_by_unit"][ucode] = round(mat["qty_by_unit"].get(ucode, 0.0) + q, 4)
+        mat["rows"] += row_count
+        
+        proj = mat["_projects"].setdefault(
             pid,
             {"id": str(pid), "name": pname, "qty_by_unit": {}, "rows": 0, "_warehouses": {}},
         )
         proj["qty_by_unit"][ucode] = round(proj["qty_by_unit"].get(ucode, 0.0) + q, 4)
         proj["rows"] += row_count
+
         wh = proj["_warehouses"].setdefault(wid, {"id": str(wid), "name": wname, "qty_by_unit": {}, "rows": 0})
         wh["qty_by_unit"][ucode] = round(wh["qty_by_unit"].get(ucode, 0.0) + q, 4)
         wh["rows"] += row_count
 
-    projects = []
-    for proj in projects_tree.values():
-        warehouses = sorted(proj.pop("_warehouses").values(), key=lambda w: w["name"])
-        projects.append({**proj, "warehouses": warehouses})
-    projects.sort(key=lambda p: p["name"])
+    materials = []
+    for mat in materials_tree.values():
+        projects_list = []
+        for proj in mat.pop("_projects").values():
+            warehouses = sorted(proj.pop("_warehouses").values(), key=lambda w: w["name"])
+            projects_list.append({**proj, "warehouses": warehouses})
+        projects_list.sort(key=lambda p: p["name"])
+        materials.append({**mat, "projects": projects_list})
+    
+    materials.sort(key=lambda m: m["name"])
 
     return {
         "data": {
             "units": units_legend,
             "total": {"qty_by_unit": total_by_unit, "rows": total_rows},
-            "projects": projects,
+            "materials": materials,
         }
     }