module Cart exposing (..) import Browser import Browser.Navigation as Nav import Html exposing (..) import Html.Attributes exposing (..) import Html.Events exposing (..) import Http import Json.Decode as D import Json.Encode as Encode import Url import Url.Parser as P exposing ((), Parser, int, oneOf, s, string) type alias Product = { id : Int , name : String , kind : Maybe String , price : Float , description : Maybe String } type alias CartListing = { productItem : Product , quantity : Int } type alias Model = { pageStatus : Status , products : List CartListing } type Status = Loading | Loaded | NotLoaded type Msg = CartLoaded (Result Http.Error (List CartListing)) | FetchCartItems | RemoveFromCart Int | CartItemRemoved (Result Http.Error ()) | AddToCartSuccess (Result Http.Error ()) | AddToCartPressed Int init : Model init = Model NotLoaded [] update : Msg -> Model -> ( Model, Cmd Msg ) update msg model = case msg of CartLoaded res -> case res of Ok s -> ( { model | products = s, pageStatus = Loaded }, Cmd.none ) Err e -> let _ = Debug.log "error" e in ( { model | pageStatus = NotLoaded }, Cmd.none ) RemoveFromCart id -> ( model, removeProduct id ) CartItemRemoved _ -> ( { model | pageStatus = Loading }, fetchCartItems ) FetchCartItems -> ( { model | pageStatus = Loading }, fetchCartItems ) AddToCartPressed id -> ( model, addToCart id ) AddToCartSuccess _ -> ( { model | pageStatus = Loading }, fetchCartItems ) decodeProduct : D.Decoder Product decodeProduct = D.map5 Product (D.field "id" D.int) (D.field "name" D.string) (D.field "kind" (D.nullable D.string)) (D.field "price" D.float) (D.field "description" (D.nullable D.string)) decodeResponse : D.Decoder (List CartListing) decodeResponse = D.list (D.map2 CartListing (D.field "product_item" decodeProduct) (D.field "quantity" D.int) ) removeProduct : Int -> Cmd Msg removeProduct id = let _ = Debug.log "cart" "fetching cart items" in Http.riskyRequest { method = "POST" , headers = [] , url = "http://127.0.0.1:7878/cart/remove" , body = Http.stringBody "application/json" <| String.fromInt id , expect = Http.expectWhatever CartItemRemoved , timeout = Nothing , tracker = Nothing } fetchCartItems : Cmd Msg fetchCartItems = let _ = Debug.log "cart" "fetching cart items" in Http.riskyRequest { method = "GET" , headers = [] , url = "http://127.0.0.1:7878/cart/items" , body = Http.emptyBody , expect = Http.expectJson CartLoaded decodeResponse , timeout = Nothing , tracker = Nothing } viewStatus : Status -> String viewStatus s = case s of Loading -> "Loading" Loaded -> "Ready!" NotLoaded -> "Not loaded ..." addToCart : Int -> Cmd Msg addToCart id = let _ = Debug.log "err" <| "adding to cart: " ++ String.fromInt id in Http.riskyRequest { method = "POST" , headers = [] , url = "http://127.0.0.1:7878/cart/add" , body = Http.stringBody "applcation/json" <| String.fromInt <| id , expect = Http.expectWhatever AddToCartSuccess , timeout = Nothing , tracker = Nothing } calculateTotal : Model -> Float calculateTotal model = let items = model.products in items |> List.map (\i -> toFloat i.quantity * i.productItem.price) |> List.foldl (+) 0 viewCartItemListing : CartListing -> Html Msg viewCartItemListing listing = div [] [ text listing.productItem.name , div [] [ text <| Maybe.withDefault "" listing.productItem.kind ] , div [] [ text <| Maybe.withDefault "" listing.productItem.description ] , div [] [ text <| String.fromFloat listing.productItem.price ] , div [] [ text <| String.fromInt listing.quantity ] , div [] [ button [ onClick (AddToCartPressed listing.productItem.id) ] [ text "Add" ] ] , div [] [ button [ onClick (RemoveFromCart listing.productItem.id) ] [ text "Remove" ] ] , div [] [ a [ href ("/product/" ++ String.fromInt listing.productItem.id) ] [ text "View Product" ] ] ] view : Model -> Html Msg view model = case model.pageStatus of Loading -> div [] [ text <| viewStatus Loading ] _ -> div [] [ let cart = List.map viewCartItemListing model.products in if List.isEmpty cart then text "No items in cart" else ul [] cart , calculateTotal model |> String.fromFloat |> text , a [ href "/checkout" ] [ text "Checkout" ] ]