quotes

-- Press a button to send a GET request for random quotes.
--
-- Read how it works:
--   https://guide.elm-lang.org/effects/json.html
--

import Browser
import Html exposing (..)
import Html.Attributes exposing (style)
import Html.Events exposing (..)
import Http
import Json.Decode exposing (Decoder, map4, field, int, string)

-- MAIN

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

-- MODEL

type Model
  = Failure
  | Loading
  | Success Quote

type alias Quote =
  { quote : String
  , source : String
  , author : String
  , year : Int
  }

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

-- UPDATE

type Msg
  = MorePlease
  | GotQuote (Result Http.Error Quote)

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

GotQuote result ->
      case result of
        Ok quote ->
          (Success quote, Cmd.none)

Err _ ->
          (Failure, Cmd.none)

-- SUBSCRIPTIONS

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

-- VIEW

view : Model -> Html Msg
view model =
  div []
    [ h2 [] [ text "Random Quotes" ]
    , viewQuote model
    ]

viewQuote : Model -> Html Msg
viewQuote model =
  case model of
    Failure ->
      div []
        [ text "I could not load a random quote for some reason. "
        , button [ onClick MorePlease ] [ text "Try Again!" ]
        ]

Loading ->
      text "Loading..."

Success quote ->
      div []
        [ button [ onClick MorePlease, style "display" "block" ] [ text "More Please!" ]
        , blockquote [] [ text quote.quote ]
        , p [ style "text-align" "right" ]
            [ text "— "
            , cite [] [ text quote.source ]
            , text (" by " ++ quote.author ++ " (" ++ String.fromInt quote.year ++ ")")
            ]
        ]

-- HTTP

getRandomQuote : Cmd Msg
getRandomQuote =
  Http.get
    { url = "https://elm-lang.org/api/random-quotes"
    , expect = Http.expectJson GotQuote quoteDecoder
    }

quoteDecoder : Decoder Quote
quoteDecoder =
  map4 Quote
    (field "quote" string)
    (field "source" string)
    (field "author" string)
    (field "year" int)