type alias Notebook =
    Zipper String


type alias Visual =
    { highlighted : Bool
    , text : String
    }


display : Notebook -> Element msg
display notebook =
    notebook
        |> Zipper.map (Visual False)
        |> Zipper.mapLabel (\visual -> { visual | highlighted = True })
        |> Zipper.toTree
        |> Tree.restructure identity displayItem


displayItem : Visual -> List (Element msg) -> Element msg
displayItem item children =
    Element.column
        [ Border.width 1
        , Element.padding 10
        , Element.spacing 5
        , Background.color
            (if item.highlighted then
                Element.rgb 1 1 0.6

             else
                Element.rgb 1 1 1
            )
        ]
        [ Element.text item.text
        , Element.column [ Element.spacing 5 ] children
        ]