ElmRouteUrlAttempt

module Main exposing (..)

import Html exposing (..)
import Html.Attributes exposing (..)
import Html.Events exposing (..)
import Navigation
import Json.Decode as Json
import RouteUrl exposing (HistoryEntry(..), UrlChange)
import UrlParser exposing (..)


main =
  RouteUrl.program
    { init = init
    , view = view
    , update = update
    , subscriptions = (\_ -> Sub.none)
    }


type alias Model =
    { currentRoute : Route }


type Route
  = DogRoute
  | CatRoute


type Msg
    = SetActiveRoute Route
    | NoOpString String
    | NoOp


init : ( Model, Cmd Msg )
init =
  let
    model = { currentRoute = DogRoute }

  in
    ( model, Cmd.none )


delta2url : Model -> Model -> Maybe UrlChange
delta2url previous current =
  case current.currentRoute of
    DogRoute ->
      Just <| UrlChange NewEntry "/dogs"

    CatRoute ->
      Just <| UrlChange NewEntry "/cats"


url2messages : Navigation.Location -> List Msg
url2messages location =
  case parser location of
    Just route ->
      [SetActiveRoute route]

    Nothing ->
      [NoOp]


matchers: Parser (Route -> a) a
matchers =
  oneOf
    [ UrlParser.map DogRoute (UrlParser.s "dogs")
    , UrlParser.map CatRoute (UrlParser.s "cats")
    ]


parser : Navigation.Location -> Maybe Route
parser location =
  parsePath matchers location


-- UPDATE

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    SetActiveRoute activeRoute ->
      ( { model | currentRoute = activeRoute }, Cmd.none )

    NoOpString _ ->
      (model, Cmd.none)

    NoOp ->
      (model, Cmd.none)


-- VIEW


view : Model -> Html Msg
view model =
  div []
    [ h1 [] [ text "Pages" ]
    , ul [] (List.map viewLink [ "cats", "dogs" ])
    ]


viewLink : String -> Html Msg
viewLink name =
  li []
    [ a
      [ href ("/" ++ name)
      , stopPropagation
      ]
      [ text name ]
    ]


stopPropagation =
  onWithOptions "click"
    { stopPropagation = False
    , preventDefault = True
    }
    (Json.map NoOpString <| Json.succeed "")