Main.elm

module Main exposing (main)

import Browser
import Html exposing (..)
import Html.Attributes exposing (style)
import Html.Events exposing (..)
import Http
import Json.Decode exposing (Decoder, field, string, map3)
import Debug


-- MAIN


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



-- MODEL


type Model
  = Failure
  | Loading
  | Success Page


type alias Page =
  { title : String
  , story : String
  , journal : String
  }


init : () -> (Model, Cmd Msg)
init _ =
  (Loading, getWikiPageJson)



-- UPDATE


type Msg
  = DoIt
  | GotPage (Result Http.Error Page)


update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
  case msg of
    DoIt ->
      (Loading, getWikiPageJson)

    GotPage result ->
      case result of
        Ok page ->
          (Success page, Cmd.none)

        Err err ->
          let
            errorMsg =
              case err of
                Http.Timeout ->
                  "Timeout"

                Http.NetworkError ->
                  "Network Error"

                Http.BadStatus status ->
                  "Bad Status: " ++ String.fromInt status

                Http.BadBody body ->
                  let
                    _ = Debug.log "GotPage JSON:" body -- Log the JSON content in case of Failure
                  in
                  "Bad Body: " ++ body

                Http.BadUrl _ ->
                  Debug.todo "Handle BadUrl case" -- Placeholder for handling BadUrl case
          in
          (Failure, Cmd.none)



-- SUBSCRIPTIONS


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



-- VIEW


view : Model -> Html Msg
view model =
  div []
    [ h2 [] [ text "Wiki Page JSON" ]
    , viewPage model
    ]


viewPage : Model -> Html Msg
viewPage model =
  case model of
    Failure ->
      div []
        [ text "I could not load the Wiki Page JSON for some reason. "
        , button [ onClick DoIt ] [ text "Try Again!" ]
        ]

    Loading ->
      text "Loading..."

    Success page ->
      div []
        [ button [ onClick DoIt, style "display" "block" ] [ text "Do it" ]
        , blockquote [] [ text page.title ]
        ]



-- HTTP


getWikiPageJson : Cmd Msg
getWikiPageJson =
  Http.get
    { url = "https://wiki.ralfbarkow.ch/2023-05-31.json"
    , expect = Http.expectJson GotPage pageDecoder
    }


pageDecoder : Decoder Page
pageDecoder =
  map3 Page
    (field "title" string)
    (field "story" storyDecoder)
    (field "journal" journalDecoder)


storyDecoder : Decoder String
storyDecoder =
  field "story" string |> Debug.log "Decoding story:"


journalDecoder : Decoder String
journalDecoder =
  field "journal" string |> Debug.log "Decoding journal:"