noredink-ui/src/ClickableAttributes.elm

module ClickableAttributes exposing
    ( ClickableAttributes
    , href
    , init
    , linkExternal
    , linkExternalWithTracking
    , linkSpa
    , linkWithMethod
    , linkWithTracking
    , onClick
    , toButtonAttributes
    , toLinkAttributes
    )

{-| -}

import EventExtras
import Html.Styled exposing (Attribute)
import Html.Styled.Attributes as Attributes
import Html.Styled.Events as Events
import Json.Decode
import Nri.Ui.Html.Attributes.V2 exposing (targetBlank)


{-| -}
type alias ClickableAttributes route msg =
    { linkType : Link
    , url : Maybe route
    , urlString : Maybe String
    , onClick : Maybe msg
    }


type Link
    = Default
    | WithTracking
    | SinglePageApp
    | WithMethod String
    | External
    | ExternalWithTracking


{-| -}
init : ClickableAttributes route msg
init =
    { linkType = Default
    , url = Nothing
    , urlString = Nothing
    , onClick = Nothing
    }


{-| -}
onClick : msg -> ClickableAttributes route msg -> ClickableAttributes route msg
onClick msg clickableAttributes =
    { clickableAttributes | onClick = Just msg }


{-| -}
href : route -> ClickableAttributes route msg -> ClickableAttributes route msg
href url clickableAttributes =
    { clickableAttributes | url = Just url }


{-| -}
linkSpa : route -> ClickableAttributes route msg -> ClickableAttributes route msg
linkSpa url clickableAttributes =
    { clickableAttributes | linkType = SinglePageApp, url = Just url }


{-| -}
linkWithMethod : { method : String, url : route } -> ClickableAttributes route msg -> ClickableAttributes route msg
linkWithMethod { method, url } clickableAttributes =
    { clickableAttributes | linkType = WithMethod method, url = Just url }


{-| -}
linkWithTracking : { track : msg, url : route } -> ClickableAttributes route msg -> ClickableAttributes route msg
linkWithTracking { track, url } clickableAttributes =
    { clickableAttributes
        | linkType = WithTracking
        , url = Just url
        , onClick = Just track
    }


{-| -}
linkExternal : String -> ClickableAttributes route msg -> ClickableAttributes route msg
linkExternal url clickableAttributes =
    { clickableAttributes | linkType = External, urlString = Just url }


{-| -}
linkExternalWithTracking : { track : msg, url : String } -> ClickableAttributes route msg -> ClickableAttributes route msg
linkExternalWithTracking { track, url } clickableAttributes =
    { clickableAttributes
        | linkType = ExternalWithTracking
        , urlString = Just url
        , onClick = Just track
    }


{-| -}
toButtonAttributes : ClickableAttributes route msg -> List (Attribute msg)
toButtonAttributes clickableAttributes =
    case clickableAttributes.onClick of
        Just handler ->
            [ Events.onClick handler ]

        Nothing ->
            []


{-| -}
toLinkAttributes : (route -> String) -> ClickableAttributes route msg -> ( String, List (Attribute msg) )
toLinkAttributes routeToString clickableAttributes =
    let
        stringUrl =
            case ( clickableAttributes.urlString, clickableAttributes.url ) of
                ( Just url, _ ) ->
                    url

                ( _, Just route ) ->
                    routeToString route

                ( Nothing, Nothing ) ->
                    "#"
    in
    case clickableAttributes.linkType of
        Default ->
            ( "link"
            , [ Attributes.href stringUrl
              , Attributes.target "_self"
              ]
            )

        SinglePageApp ->
            ( "linkSpa"
            , case clickableAttributes.onClick of
                Just handler ->
                    [ Attributes.href stringUrl
                    , EventExtras.onClickPreventDefaultForLinkWithHref handler
                    ]

                Nothing ->
                    [ Attributes.href stringUrl ]
            )

        WithMethod method ->
            ( "linkWithMethod"
            , [ Attributes.href stringUrl
              , Attributes.attribute "data-method" method
              ]
            )

        WithTracking ->
            ( "linkWithTracking"
            , case clickableAttributes.onClick of
                Just track ->
                    [ Attributes.href stringUrl
                    , Events.preventDefaultOn "click"
                        (Json.Decode.succeed ( track, True ))
                    ]

                Nothing ->
                    [ Attributes.href stringUrl ]
            )

        External ->
            ( "linkExternal"
            , Attributes.href stringUrl
                :: targetBlank
            )

        ExternalWithTracking ->
            ( "linkExternalWithTracking"
            , case clickableAttributes.onClick of
                Just handler ->
                    [ Attributes.href stringUrl
                    , Events.onClick handler
                    , Events.on "auxclick" (Json.Decode.succeed handler)
                    ]
                        ++ targetBlank

                Nothing ->
                    Attributes.href stringUrl
                        :: targetBlank
            )