.elm

module Main exposing (Flags, Model, Msg(..), init, main, subscriptions, update, view)

import Browser
import Browser.Navigation as Nav exposing (Key)
import Html exposing (Html, a, button, div, h1, img, li, text, ul)
import Html.Attributes as Attr
import Html.Events as Events
import Time
import Url exposing (Url)



-- MODEL


type alias Model =
    { key : Nav.Key
    , title : String
    , counter : Int
    }


type alias Flags =
    {}


init : Flags -> Url -> Key -> ( Model, Cmd Msg )
init flags url key =
    ( { key = key
      , title = "hello"
      , counter = 1
      }
    , Cmd.none
    )



-- UPDATE


type Msg
    = NoOp
    | ClickedLink Browser.UrlRequest
    | Tick Time.Posix
    | Increment


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        NoOp ->
            ( model, Cmd.none )

        Increment ->
            ( { model | counter = model.counter + 1 }, Cmd.none )

        Tick posix ->
            let
                newTitle =
                    if model.title == "hello" then
                        "bye"

                    else
                        "hello"
            in
            ( { model | title = newTitle }
            , Cmd.none
            )

        ClickedLink req ->
            case req of
                Browser.Internal url ->
                    ( model, Nav.pushUrl model.key (Url.toString url) )

                Browser.External string ->
                    ( model, Nav.load string )



-- VIEW


view : Model -> Browser.Document Msg
view model =
    { title = model.title
    , body =
        [ ul
            []
            [ li [] [ a [ Attr.href "/a" ] [ text "a" ] ]
            , li [] [ a [ Attr.href "/b" ] [ text "b" ] ]
            , li [] [ a [ Attr.href "/c" ] [ text "c" ] ]
            , li [] [ a [ Attr.href "https://google.com" ] [ text "google.com" ] ]
            ]
        , button
            [ Events.onClick Increment ]
            [ text ("Increment " ++ String.fromInt model.counter) ]
        ]
    }



-- SUBSCRIPTIONS


subscriptions : Model -> Sub Msg
subscriptions model =
    Time.every 1000 Tick


main : Program Flags Model Msg
main =
    Browser.application
        { init = init
        , update = update
        , view = view
        , subscriptions = subscriptions
        , onUrlChange =
            \url ->
                let
                    _ =
                        Debug.log "onUrlChange" url
                in
                NoOp
        , onUrlRequest =
            \req ->
                let
                    _ =
                        Debug.log "onUrlRequest" req
                in
                ClickedLink req
        }