port module Client exposing (main)

import Array exposing (Array)
import Browser
import Html.Attributes
import Html.Events
import Html exposing (Html)
import Json.Decode
import Json.Encode
import Messages exposing (BlackCard, WhiteCard, GameView)
import Url exposing (Url)

port webSocketIn : (String -> msg) -> Sub msg
port webSocketOut : String -> Cmd msg

type Msg
    = Ignore
    | Send
    | WebSocketIn String
    -- Name changes
    | ChangeMyName String
    | SubmitMyName
    -- Card selection
    | SelectWhiteCard WhiteCard
    | ProposeWhiteCards

type alias Cards = {black : Array String, white : Array String}

type alias GameState =
    { cards : Cards
    , view : GameView
    , changeMyName : String
    , selectedWhiteCard : Maybe WhiteCard
    }

type Model
    = Error String
    | Connecting
        { roomId : String
        }
    | Game GameState

parseRoomId : Url -> Result String String
parseRoomId url = case String.split "/" url.path of
    _ :: "rooms" :: roomId :: _ -> Ok roomId
    _ -> Err <| "Invalid path: " ++ url.path

viewOpponent : Messages.Opponent -> Html msg
viewOpponent opponent = Html.div [] <|
    [ Html.text opponent.name
    ] ++
    if opponent.ready then [Html.text " ✅"] else []

view : Model -> List (Html Msg)
view model = case model of
    Error str ->
        [ Html.h1 [] [Html.text "Error"]
        , Html.p [] [Html.text str]
        ]
    Connecting state ->
        [ Html.h1 []
            [Html.text <| "Connecting to room " ++ state.roomId ++ "..."]
        ]
    Game game ->
        [ Html.h1 [] [Html.text "Opponents"]
        , Html.ul [] <| List.map
            (\o -> Html.li [] [viewOpponent o])
            game.view.opponents
        , Html.h1 [] [Html.text "You"]
        , Html.form
            [ Html.Attributes.action ""
            , Html.Events.onSubmit SubmitMyName
            ]
            [ Html.input
                [ Html.Attributes.value game.changeMyName
                , Html.Events.onInput ChangeMyName
                ]
                []
            , Html.button
                [ Html.Attributes.type_ "submit"
                , Html.Attributes.disabled <|
                    game.view.myName == game.changeMyName
                ]
                [Html.text "Update name"]
            ]
        ] ++
        [viewTable game] ++
        (List.map
            (\c -> whiteCard game.cards c (cardIsSelected game c))
            game.view.hand)

selectedWhiteCard : GameState -> Maybe WhiteCard
selectedWhiteCard game = case game.view.table of
    Messages.Proposing _ (Just my) -> Just my
    _ -> game.selectedWhiteCard

cardIsSelected : GameState -> WhiteCard -> Bool
cardIsSelected game card = selectedWhiteCard game == Just card

viewTable : GameState -> Html Msg
viewTable game = case game.view.table of
    Messages.Proposing c my -> Html.div [] <|
        [ blackCard game.cards c <| case selectedWhiteCard game of
            Nothing -> []
            Just wc -> [wc]
        , Html.button
            [ Html.Attributes.disabled <| case my of
                Just _ -> True
                _ -> case selectedWhiteCard game of
                    Nothing -> True
                    Just _ -> False
            , Html.Events.onClick ProposeWhiteCards
            ]
            [Html.text "Propose"]
        ]

intersperseWith : List a -> a -> List a -> List a
intersperseWith values def list = case list of
    [] -> []
    x :: [] -> x :: []
    x :: y :: t -> case values of
        [] -> x :: def :: intersperseWith values def (y :: t)
        v :: vs -> x :: v :: intersperseWith vs def (y :: t)

blackCard : Cards -> BlackCard -> List WhiteCard -> Html a
blackCard cards (Messages.BlackCard idx) whites =
    let blank mbWhite = Html.span
            [Html.Attributes.class "blank"] <|
            case mbWhite of
                Nothing -> []
                Just w -> [Html.text <| whiteCardContent cards w] in
    Html.div [Html.Attributes.class "card", Html.Attributes.class "black"] <|
    intersperseWith (List.map (\c -> blank (Just c)) whites) (blank Nothing) <|
    List.map Html.text <|
    String.split "\\BLANK" <| Maybe.withDefault "" <|
    Array.get idx cards.black

whiteCardContent : Cards -> WhiteCard -> String
whiteCardContent cards (Messages.WhiteCard idx) =
    Maybe.withDefault "" <| Array.get idx cards.white

whiteCard : Cards -> WhiteCard -> Bool -> Html Msg
whiteCard cards c selected = Html.div
    [ Html.Attributes.class "card"
    , Html.Attributes.class "white"
    , Html.Attributes.class <| if selected then "selected" else ""
    , Html.Events.onClick <| SelectWhiteCard c
    ]
    [ Html.text <| whiteCardContent cards c
    ]

subscriptions : Model -> Sub Msg
subscriptions model = webSocketIn WebSocketIn

send : Messages.ClientMessage -> Cmd Msg
send = webSocketOut << Json.Encode.encode 0 << Messages.jsonEncClientMessage

update : Msg -> Model -> (Model, Cmd Msg)
update msg model = case msg of
    Ignore -> (model, Cmd.none)
    Send -> (model, webSocketOut "Hi")
    WebSocketIn json ->
        case Json.Decode.decodeString Messages.jsonDecServerMessage json of
            Err str -> (Error <| Json.Decode.errorToString str, Cmd.none)
            Ok (Messages.Welcome playerId) ->
                Debug.log ("Welcome " ++ String.fromInt playerId) (model, Cmd.none)
            Ok Messages.Bye -> Debug.log "Bye" (model, Cmd.none)
            Ok (Messages.SyncGameView gameView) ->
                case model of
                    Game game -> (Game {game | view = gameView}, Cmd.none)
                    _ ->
                        ( Game
                            { cards = {black = Array.empty, white = Array.empty}
                            , view = gameView
                            , changeMyName = gameView.myName
                            , selectedWhiteCard = Nothing
                            }
                        , Cmd.none
                        )
            Ok (Messages.SyncCards cards) ->
                let arr =
                        { black = Array.fromList cards.black
                        , white = Array.fromList cards.white
                        } in
                case model of
                    Game game -> (Game {game | cards = arr}, Cmd.none)
                    _ -> (model, Cmd.none)

    ChangeMyName name -> case model of
        Game game -> (Game {game | changeMyName = name}, Cmd.none)
        _ -> (model, Cmd.none)
    SubmitMyName -> case model of
        Game game -> (model, send <| Messages.ChangeMyName game.changeMyName)
        _ -> (model, Cmd.none)

    SelectWhiteCard card -> case model of
        Game game -> (Game {game | selectedWhiteCard = Just card}, Cmd.none)
        _ -> (model, Cmd.none)

    ProposeWhiteCards -> case model of
        Game game ->
            ( Game {game | selectedWhiteCard = Nothing}
            , case game.selectedWhiteCard of
                Nothing -> Cmd.none
                Just c -> send <| Messages.ProposeWhiteCards c
            )
        _ -> (model, Cmd.none)

main : Program () Model Msg
main = Browser.application
    { init = \() url key -> case parseRoomId url of
        Err str -> (Error <| "Could not parse room ID: " ++ str, Cmd.none)
        Ok roomId -> (Connecting {roomId = roomId}, Cmd.none)
    , update = update
    , subscriptions = subscriptions
    , view = \model -> {title = "Client", body = view model}
    , onUrlChange = \url -> Ignore
    , onUrlRequest = \urlRequest -> Ignore
    }