KakaDudu.elm

module KakaDudu exposing (..)

import Browser
import Dict
import Html exposing (..)
import Task
import Time
import TimeZone


main =
    Browser.element
        { init = init
        , view = view
        , update = update
        , subscriptions = subscriptions
        }


type alias Model =
    ( String, Time.Zone )


deprecatedTimeZones : String -> String
deprecatedTimeZones oldName =
    case oldName of
        "Europe/Copenhagen" ->
            "Europe/Berlin"

        _ ->
            oldName


requestBrowserTimeZone : Cmd Msg
requestBrowserTimeZone =
    Task.attempt ReceiveTimeZone Time.getZoneName


initialTime =
    ( "UTC", Time.utc )


init : () -> ( Model, Cmd Msg )
init _ =
    ( initialTime
    , requestBrowserTimeZone
    )


type Msg
    = ReceiveTimeZone (Result String Time.ZoneName)


update : Msg -> Model -> ( Model, Cmd Msg )
update msg ( modelZoneName, modelZone ) =
    case msg of
        ReceiveTimeZone result ->
            case result of
                Ok zoneName ->
                    case zoneName of
                        Time.Name newZoneName ->
                            let
                                betterZoneName =
                                    deprecatedTimeZones newZoneName
                            in
                            case Dict.get betterZoneName TimeZone.zones of
                                Just zone ->
                                    ( ( newZoneName, zone () ), Cmd.none )

                                Nothing ->
                                    ( initialTime, Cmd.none )

                        Time.Offset _ ->
                            ( initialTime, Cmd.none )

                Err _ ->
                    ( initialTime, Cmd.none )


subscriptions : Model -> Sub Msg
subscriptions _ =
    Sub.none


view : Model -> Html Msg
view ( zoneName, zone ) =
    h1 [] [ text zoneName ]