update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        SetUsername username ->
            { model | username = username } ! []

        SetPassword password ->
            { model | password = password } ! []

        SetDb db ->
            { model | db = db } ! []

        Authenticate ->
            let
                e =
                    Debug.log "authenticate" model.username
            in
                { model | msg = "" } ! [ authenticate model ]

        Authenticated (Ok jwt) ->
            let
                e =
                    Debug.log "authenticated" model.username
            in
                { model | jwt = jwt } ! []

        Authenticated (Err error) ->
            let
                e =
                    Debug.log "error" error
            in
                { model | msg = "Authentication problem" } ! []

        Logout ->
            { model | jwt = "" } ! []

=====================================

view : Model -> Html Msg
view model =
    Card.view []
        [ Card.title []
            [ Card.head [] [ text "Login" ] ]
        , Card.text []
            [ Textfield.render Mdl
                [ 1 ]
                model.mdl
                [ Options.onInput SetUsername
                , Textfield.label "username"
                , Textfield.value model.username
                ]
                []
            ]
        , Card.text []
            [ Textfield.render Mdl
                [ 2 ]
                model.mdl
                [ Options.onInput SetPassword
                , Textfield.password
                , Textfield.label "password"
                , Textfield.value model.password
                ]
                []
            ]
        , Card.actions []
            [ Button.render Mdl
                [ 3 ]
                model.mdl
                [ Options.onClick Authenticate ]
                [ text "Login" ]
            ]
        , Card.text []
            [ text model.msg ]
        ]