delete function

public function update(Request $request, $id) {
        ItemDetails::destroy($id);
        $existingInventory = Inventories::find($request->ItemId);
        InventoryHistories::create($request->all());

        switch($request->Source) {
            case 'Bundle':
                $existingInventory->Quantity100 = $existingInventory->Quantity100 + ($request->BundleQuantity * ($request->Quantity100));
                $existingInventory->Quantity90 = $existingInventory->Quantity90 + ($request->BundleQuantity * ($request->Quantity90));
                $existingInventory->Quantity60 = $existingInventory->Quantity60 + ($request->BundleQuantity * ($request->Quantity60));
                $existingInventory->Quantity30 = $existingInventory->Quantity30 + ($request->BundleQuantity * ($request->Quantity30));
                $existingInventory->save();
                break;
            case 'Central Procurement':
                if($request->IsAssembly == 1) {
                    Assemblies::create($request->all());
                } else {
                    $existingInventory->Quantity100 = $existingInventory->Quantity100 - $request->Quantity100;
                    $existingInventory->Quantity90 = $existingInventory->Quantity90 - $request->Quantity90;
                    $existingInventory->Quantity60 = $existingInventory->Quantity60 - $request->Quantity60;
                    $existingInventory->Quantity30 = $existingInventory->Quantity30 - $request->Quantity30;
                    $existingInventory->save();
                }
                break;
            case 'Deposit':
                if($request->IsAssembly == 1) {
                    Assemblies::create($request->all());
                } else {
                    $existingInventory->Quantity100 = $existingInventory->Quantity100 - $request->Quantity100;
                    $existingInventory->Quantity90 = $existingInventory->Quantity90 - $request->Quantity90;
                    $existingInventory->Quantity60 = $existingInventory->Quantity60 - $request->Quantity60;
                    $existingInventory->Quantity30 = $existingInventory->Quantity30 - $request->Quantity30;
                    $existingInventory->save();
                }
                break;
            case 'Return':
                if($request->IsAssembly == 1) {
                    Assemblies::create($request->all());
                } else {
                    $existingInventory->Quantity100 = $existingInventory->Quantity100 - $request->Quantity100;
                    $existingInventory->Quantity90 = $existingInventory->Quantity90 - $request->Quantity90;
                    $existingInventory->Quantity60 = $existingInventory->Quantity60 - $request->Quantity60;
                    $existingInventory->Quantity30 = $existingInventory->Quantity30 - $request->Quantity30;
                    $existingInventory->save();
                }
                break;
            case 'Transaction Warehouse':
                $existingInventory->Quantity100 = $existingInventory->Quantity100 + $request->Quantity100;
                $existingInventory->Quantity90 = $existingInventory->Quantity90 + $request->Quantity90;
                $existingInventory->Quantity60 = $existingInventory->Quantity60 + $request->Quantity60;
                $existingInventory->Quantity30 = $existingInventory->Quantity30 + $request->Quantity30;
                $existingInventory->save();
                break;
            case 'Transaction Warehouse - Customer':
                $existingInventory->Quantity100 = $existingInventory->Quantity100 + $request->Quantity100;
                $existingInventory->Quantity90 = $existingInventory->Quantity90 + $request->Quantity90;
                $existingInventory->Quantity60 = $existingInventory->Quantity60 + $request->Quantity60;
                $existingInventory->Quantity30 = $existingInventory->Quantity30 + $request->Quantity30;
                $existingInventory->save();
                break;
            case 'Shipping':
                $existingInventory->Quantity100 = $existingInventory->Quantity100 + $request->Quantity100;
                $existingInventory->Quantity90 = $existingInventory->Quantity90 + $request->Quantity90;
                $existingInventory->Quantity60 = $existingInventory->Quantity60 + $request->Quantity60;
                $existingInventory->Quantity30 = $existingInventory->Quantity30 + $request->Quantity30;
                $existingInventory->save();
                break;
            case 'Defect':
                $existingInventory->Quantity100 = $existingInventory->Quantity100 + $request->Quantity100;
                $existingInventory->Quantity90 = $existingInventory->Quantity90 + $request->Quantity90;
                $existingInventory->Quantity60 = $existingInventory->Quantity60 + $request->Quantity60;
                $existingInventory->Quantity30 = $existingInventory->Quantity30 + $request->Quantity30;
                $existingInventory->save();
                break;
            case 'Retur Supplier':
                $existingInventory->Quantity100 = $existingInventory->Quantity100 + $request->Quantity100;
                $existingInventory->Quantity90 = $existingInventory->Quantity90 + $request->Quantity90;
                $existingInventory->Quantity60 = $existingInventory->Quantity60 + $request->Quantity60;
                $existingInventory->Quantity30 = $existingInventory->Quantity30 + $request->Quantity30;
                $existingInventory->save();
                break;
            default:
                break;
        }

        return response()->json([ 'message' => 'Successfull update']);
    }