predicate

predicate.elm

type Predicate
    = And (List Predicate)
    | Or (List Predicate)
    | Not Predicate
    | Condition String Op String


type Op
    = Contains
    | Equals
    | GreaterThan
    | LessThan
    | EqualsOrGreaterThan
    | EqualsOrLessThan


type Msg
    = SetType String


empty : Predicate
empty =
    And []


editor : Predicate -> Html Msg
editor model =
    div [] [ predicate model ]


update : Msg -> Predicate -> ( Predicate, Cmd Msg )
update msg predicate =
    case msg of
        SetType newType ->
            predicate => Cmd.none


predicate : Predicate -> Html Msg
predicate model =
    let
        subs =
            case model of
                And els ->
                    List.map predicate els

                Or els ->
                    List.map predicate els

                _ ->
                    []
    in
        div []
            [ select [ onInput SetType ]
                [ typeOption (Not empty) model "Inverse"
                , typeOption (And []) model "Toutes les"
                , typeOption (Or []) model "Au moins une"
                , typeOption (Condition "" Contains "") model "Contient"
                ]
            , div [] subs
            ]


typeOption val currentValue lbl =
    let
        valueName =
            typeToString val

        currentValueName =
            typeToString currentValue

        sel =
            valueName == currentValueName
    in
        option [ value valueName, selected sel ] [ text lbl ]


typeToString predicate =
    case predicate of
        And _ ->
            "and"

        Or _ ->
            "or"

        Not _ ->
            "not"

        Condition _ Contains _ ->
            "contains"

        Condition _ Equals _ ->
            "equals"

        Condition _ GreaterThan _ ->
            "gt"

        Condition _ LessThan _ ->
            "lt"

        Condition _ EqualsOrGreaterThan _ ->
            "gte"

        Condition _ EqualsOrLessThan _ ->
            "lte"