module Match exposing (..)

{-| A match describes a game's history. It shows what took place.
-}

import Api
import Duration exposing (Duration)
import Element exposing (Element)
import Element.Background
import Http
import Json.Decode as D
import Layout
import Pixels exposing (Pixels)
import Quantity exposing (Quantity)
import Theme
import Time
import Zipper exposing (Zipper)



-- MODEL


type Match gameState
    = Match
        { autoScroll : Maybe Duration
        , baseUrl : String
        , decoder : D.Decoder gameState
        , empty : gameState
        , matchId : String
        , turns : Zipper gameState
        , winner : Maybe Int
        }


type Msg gameState
    = AskUpdate
    | Autoscroll
    | OnUpdate (Result Http.Error (Api.GameDetails gameState))
    | PageEnd
    | PageNext
    | PagePrev
    | PageStart


init :
    { autoScroll : Maybe Duration
    , baseUrl : String
    , decoder : D.Decoder gameState
    , empty : gameState
    , matchId : String
    }
    -> ( Match gameState, Cmd (Msg gameState) )
init data =
    ( Match
        { autoScroll = data.autoScroll
        , baseUrl = data.baseUrl
        , decoder = data.decoder
        , empty = data.empty
        , matchId = data.matchId
        , turns = Zipper.init data.empty
        , winner = Nothing
        }
    , Cmd.none
    )



-- UPDATE


update : Msg gameState -> Match gameState -> ( Match gameState, Cmd (Msg gameState) )
update msg (Match data) =
    case msg of
        AskUpdate ->
            ( Match data
            , Api.gameDetails
                { baseUrl = data.baseUrl
                , decoder = data.decoder
                , gameId = data.matchId
                , toMsg = OnUpdate
                }
            )

        Autoscroll ->
            ( Match { data | turns = Zipper.next data.turns }
            , Cmd.none
            )

        OnUpdate (Err _) ->
            -- For now, do nothing with failed API requests
            ( Match data, Cmd.none )

        OnUpdate (Ok details) ->
            ( Match
                { data
                    | turns =
                        details.turns
                            |> List.map .state
                            |> Zipper.fromList data.empty
                            |> Zipper.samePageAs data.turns
                    , winner = details.winner
                }
            , Cmd.none
            )

        PageEnd ->
            ( Match
                { data
                    | autoScroll = Nothing
                    , turns = Zipper.toEnd data.turns
                }
            , Cmd.none
            )

        PageNext ->
            ( Match
                { data
                    | autoScroll = Nothing
                    , turns = Zipper.next data.turns
                }
            , Cmd.none
            )

        PagePrev ->
            ( Match
                { data
                    | autoScroll = Nothing
                    , turns = Zipper.prev data.turns
                }
            , Cmd.none
            )

        PageStart ->
            ( Match
                { data
                    | autoScroll = Nothing
                    , turns = Zipper.toStart data.turns
                }
            , Cmd.none
            )



-- SUBSCRIPTIONS


subscriptions : Match gameState -> Sub (Msg gameState)
subscriptions (Match data) =
    Sub.batch
        [ case data.autoScroll of
            Just duration ->
                Time.every (Duration.inMilliseconds duration) (always Autoscroll)

            Nothing ->
                Sub.none
        , case data.winner of
            Just _ ->
                Sub.none

            Nothing ->
                Time.every 550 (always AskUpdate)
        ]



-- VIEW


view :
    { flavor : Theme.Flavor
    , height : Quantity Int Pixels
    , match : Match gameState
    , toMsg : Msg gameState -> msg
    , width : Quantity Int Pixels
    , viewGame :
        { flavor : Theme.Flavor
        , game : gameState
        , height : Quantity Int Pixels
        , width : Quantity Int Pixels
        }
        -> Element msg
    }
    -> Element msg
view data =
    let
        menuHeight =
            data.height
                |> Quantity.toFloatQuantity
                |> Quantity.multiplyBy (1 / 8)
                |> Quantity.floor

        tinyScreen =
            data.height |> Quantity.lessThan (Pixels.pixels 300)

        gameHeight =
            if tinyScreen then
                data.height
                    |> Quantity.minus menuHeight

            else
                data.height
    in
    Element.column
        [ Element.height (Element.px (Pixels.inPixels data.height))
        , Element.width (Element.px (Pixels.inPixels data.width))
        ]
        [ case data.match of
            Match { turns } ->
                data.viewGame
                    { flavor = data.flavor
                    , game = Zipper.current turns
                    , height = gameHeight
                    , width = data.width
                    }
        , if tinyScreen then
            viewMenu
                { height = menuHeight
                , width = data.width
                }
                |> Element.map data.toMsg

          else
            Element.none
        ]


viewListItem :
    { flavor : Theme.Flavor
    , height : Quantity Int Pixels
    , match : Match gameState
    , onPress : Maybe msg
    , width : Quantity Int Pixels
    }
    -> Element msg
viewListItem data =
    case data.match of
        Match match ->
            Layout.itemWithSubtext
                { color = Theme.mantle data.flavor
                , leftIcon = always Element.none
                , onPress = data.onPress
                , rightIcon = always Element.none
                , text = "Subtext"
                , title = match.matchId
                }
                []


viewMenu :
    { height : Quantity Int Pixels
    , width : Quantity Int Pixels
    }
    -> Element (Msg gameState)
viewMenu data =
    Element.none