import Browser
import Browser.Navigation as Nav
import Html exposing (..)
import Html.Attributes exposing (..)
import Url

main =
  Browser.application
  { init = init
  , view = view
  , update = update
  , subscriptions = subscriptions
  , onUrlChange = UrlChanged
  , onUrlRequest = LinkClicked }

type alias Model =
  { key : Nav.Key
  , url : Url.Url
  }

init : () -> Url.Url -> Nav.Key -> ( Model, Cmd Msg )
init _ url key =
  ( Model key url, Cmd.none )

type Msg
  = LinkClicked Browser.UrlRequest
  | UrlChanged Url.Url

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    LinkClicked urlRequest ->
      case urlRequest of
        Browser.Internal url ->
          ( model, Nav.pushUrl model.key (Url.toString url) )
        Browser.External href ->
          ( model, Nav.load href )
    UrlChanged url ->
      ( { model | url = url}
      , Cmd.none )

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

view : Model -> Browser.Document Msg
view model =
  { title = "URL Interceptor"
  , body =
    [ text "The current URL is: "
    , b [] [ text (Url.toString model.url)
    , ul []
      [ viewLink "/home"
      , viewLink "/profile"
      , viewLink "/reviews/the-century-of-the-self"
      , viewLink "/reviews/public-opinion"
      , viewLink "/reviews/shah-of-shahs" ] ] ] }

viewLink : String -> Html msg
viewLink path =
  li [] [ a [ href path ] [ text path ] ]